PQconnectPoll(PGconn *conn)
{
	bool		reset_connection_state_machine = false;
	bool		need_new_connection = false;
	PGresult   *res;
	char		sebuf[PG_STRERROR_R_BUFLEN];
	int			optval;

	if (conn == NULL)
		return PGRES_POLLING_FAILED;

	/* Get the new data */
	switch (conn->status)
	{
			/*
			 * We really shouldn't have been polled in these two cases, but we
			 * can handle it.
			 */
		case CONNECTION_BAD:
			return PGRES_POLLING_FAILED;
		case CONNECTION_OK:
			return PGRES_POLLING_OK;

			/* These are reading states */
		case CONNECTION_AWAITING_RESPONSE:
		case CONNECTION_AUTH_OK:
		case CONNECTION_CHECK_WRITABLE:
		case CONNECTION_CONSUME:
		case CONNECTION_CHECK_STANDBY:
			{
				/* Load waiting data */
				int			n = pqReadData(conn);

				if (n < 0)
					goto error_return;
				if (n == 0)
					return PGRES_POLLING_READING;

				break;
			}

			/* These are writing states, so we just proceed. */
		case CONNECTION_STARTED:
		case CONNECTION_MADE:
			break;

			/* Special cases: proceed without waiting. */
		case CONNECTION_SSL_STARTUP:
		case CONNECTION_NEEDED:
		case CONNECTION_GSS_STARTUP:
		case CONNECTION_CHECK_TARGET:
			break;

		default:
			appendPQExpBufferStr(&conn->errorMessage,
								 libpq_gettext("invalid connection state, probably indicative of memory corruption\n"));
			goto error_return;
	}

keep_going:						/* We will come back to here until there is
								 * nothing left to do. */

	/* Time to advance to next address, or next host if no more addresses? */
	if (conn->try_next_addr)
	{
		if (conn->addr_cur && conn->addr_cur->ai_next)
		{
			conn->addr_cur = conn->addr_cur->ai_next;
			reset_connection_state_machine = true;
		}
		else
			conn->try_next_host = true;
		conn->try_next_addr = false;
	}

	/* Time to advance to next connhost[] entry? */
	if (conn->try_next_host)
	{
		pg_conn_host *ch;
		struct addrinfo hint;
		int			thisport;
		int			ret;
		char		portstr[MAXPGPATH];

		if (conn->whichhost + 1 < conn->nconnhost)
			conn->whichhost++;
		else
		{
			/*
			 * Oops, no more hosts.
			 *
			 * If we are trying to connect in "prefer-standby" mode, then drop
			 * the standby requirement and start over.
			 *
			 * Otherwise, an appropriate error message is already set up, so
			 * we just need to set the right status.
			 */
			if (conn->target_server_type == SERVER_TYPE_PREFER_STANDBY &&
				conn->nconnhost > 0)
			{
				conn->target_server_type = SERVER_TYPE_PREFER_STANDBY_PASS2;
				conn->whichhost = 0;
			}
			else
				goto error_return;
		}

		/* Drop any address info for previous host */
		release_conn_addrinfo(conn);

		/*
		 * Look up info for the new host.  On failure, log the problem in
		 * conn->errorMessage, then loop around to try the next host.  (Note
		 * we don't clear try_next_host until we've succeeded.)
		 */
		ch = &conn->connhost[conn->whichhost];

		/* Initialize hint structure */
		MemSet(&hint, 0, sizeof(hint));
		hint.ai_socktype = SOCK_STREAM;
		conn->addrlist_family = hint.ai_family = AF_UNSPEC;

		/* Figure out the port number we're going to use. */
		if (ch->port == NULL || ch->port[0] == '\0')
			thisport = DEF_PGPORT;
		else
		{
			if (!parse_int_param(ch->port, &thisport, conn, "port"))
				goto error_return;

			if (thisport < 1 || thisport > 65535)
			{
				appendPQExpBuffer(&conn->errorMessage,
								  libpq_gettext("invalid port number: \"%s\"\n"),
								  ch->port);
				goto keep_going;
			}
		}
		snprintf(portstr, sizeof(portstr), "%d", thisport);

		/* Use pg_getaddrinfo_all() to resolve the address */
		switch (ch->type)
		{
			case CHT_HOST_NAME:
				ret = pg_getaddrinfo_all(ch->host, portstr, &hint,
										 &conn->addrlist);
				if (ret || !conn->addrlist)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("could not translate host name \"%s\" to address: %s\n"),
									  ch->host, gai_strerror(ret));
					goto keep_going;
				}
				break;

			case CHT_HOST_ADDRESS:
				hint.ai_flags = AI_NUMERICHOST;
				ret = pg_getaddrinfo_all(ch->hostaddr, portstr, &hint,
										 &conn->addrlist);
				if (ret || !conn->addrlist)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("could not parse network address \"%s\": %s\n"),
									  ch->hostaddr, gai_strerror(ret));
					goto keep_going;
				}
				break;

			case CHT_UNIX_SOCKET:
#ifdef HAVE_UNIX_SOCKETS
				conn->addrlist_family = hint.ai_family = AF_UNIX;
				UNIXSOCK_PATH(portstr, thisport, ch->host);
				if (strlen(portstr) >= UNIXSOCK_PATH_BUFLEN)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("Unix-domain socket path \"%s\" is too long (maximum %d bytes)\n"),
									  portstr,
									  (int) (UNIXSOCK_PATH_BUFLEN - 1));
					goto keep_going;
				}

				/*
				 * NULL hostname tells pg_getaddrinfo_all to parse the service
				 * name as a Unix-domain socket path.
				 */
				ret = pg_getaddrinfo_all(NULL, portstr, &hint,
										 &conn->addrlist);
				if (ret || !conn->addrlist)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("could not translate Unix-domain socket path \"%s\" to address: %s\n"),
									  portstr, gai_strerror(ret));
					goto keep_going;
				}
#else
				Assert(false);
#endif
				break;
		}

		/* OK, scan this addrlist for a working server address */
		conn->addr_cur = conn->addrlist;
		reset_connection_state_machine = true;
		conn->try_next_host = false;
	}

	/* Reset connection state machine? */
	if (reset_connection_state_machine)
	{
		/*
		 * (Re) initialize our connection control variables for a set of
		 * connection attempts to a single server address.  These variables
		 * must persist across individual connection attempts, but we must
		 * reset them when we start to consider a new server.
		 */
		conn->pversion = PG_PROTOCOL(3, 0);
		conn->send_appname = true;
#ifdef USE_SSL
		/* initialize these values based on SSL mode */
		conn->allow_ssl_try = (conn->sslmode[0] != 'd');	/* "disable" */
		conn->wait_ssl_try = (conn->sslmode[0] == 'a'); /* "allow" */
#endif
#ifdef ENABLE_GSS
		conn->try_gss = (conn->gssencmode[0] != 'd');	/* "disable" */
#endif

		reset_connection_state_machine = false;
		need_new_connection = true;
	}

	/* Force a new connection (perhaps to the same server as before)? */
	if (need_new_connection)
	{
		/* Drop any existing connection */
		pqDropConnection(conn, true);

		/* Reset all state obtained from old server */
		pqDropServerData(conn);

		/* Drop any PGresult we might have, too */
		conn->asyncStatus = PGASYNC_IDLE;
		conn->xactStatus = PQTRANS_IDLE;
		conn->pipelineStatus = PQ_PIPELINE_OFF;
		pqClearAsyncResult(conn);

		/* Reset conn->status to put the state machine in the right state */
		conn->status = CONNECTION_NEEDED;

		need_new_connection = false;
	}

	/* Now try to advance the state machine for this connection */
	switch (conn->status)
	{
		case CONNECTION_NEEDED:
			{
				/*
				 * Try to initiate a connection to one of the addresses
				 * returned by pg_getaddrinfo_all().  conn->addr_cur is the
				 * next one to try.
				 *
				 * The extra level of braces here is historical.  It's not
				 * worth reindenting this whole switch case to remove 'em.
				 */
				{
					struct addrinfo *addr_cur = conn->addr_cur;
					char		host_addr[NI_MAXHOST];

					/*
					 * Advance to next possible host, if we've tried all of
					 * the addresses for the current host.
					 */
					if (addr_cur == NULL)
					{
						conn->try_next_host = true;
						goto keep_going;
					}

					/* Remember current address for possible use later */
					memcpy(&conn->raddr.addr, addr_cur->ai_addr,
						   addr_cur->ai_addrlen);
					conn->raddr.salen = addr_cur->ai_addrlen;

					/*
					 * Set connip, too.  Note we purposely ignore strdup
					 * failure; not a big problem if it fails.
					 */
					if (conn->connip != NULL)
					{
						free(conn->connip);
						conn->connip = NULL;
					}
					getHostaddr(conn, host_addr, NI_MAXHOST);
					if (host_addr[0])
						conn->connip = strdup(host_addr);

					/* Try to create the socket */
					conn->sock = socket(addr_cur->ai_family, SOCK_STREAM, 0);
					if (conn->sock == PGINVALID_SOCKET)
					{
						int			errorno = SOCK_ERRNO;

						/*
						 * Silently ignore socket() failure if we have more
						 * addresses to try; this reduces useless chatter in
						 * cases where the address list includes both IPv4 and
						 * IPv6 but kernel only accepts one family.
						 */
						if (addr_cur->ai_next != NULL ||
							conn->whichhost + 1 < conn->nconnhost)
						{
							conn->try_next_addr = true;
							goto keep_going;
						}
						emitHostIdentityInfo(conn, host_addr);
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("could not create socket: %s\n"),
										  SOCK_STRERROR(errorno, sebuf, sizeof(sebuf)));
						goto error_return;
					}

					/*
					 * Once we've identified a target address, all errors
					 * except the preceding socket()-failure case should be
					 * prefixed with host-identity information.  (If the
					 * connection succeeds, the contents of conn->errorMessage
					 * won't matter, so this is harmless.)
					 */
					emitHostIdentityInfo(conn, host_addr);

					/*
					 * Select socket options: no delay of outgoing data for
					 * TCP sockets, nonblock mode, close-on-exec.  Try the
					 * next address if any of this fails.
					 */
					if (!IS_AF_UNIX(addr_cur->ai_family))
					{
						if (!connectNoDelay(conn))
						{
							/* error message already created */
							conn->try_next_addr = true;
							goto keep_going;
						}
					}
					if (!pg_set_noblock(conn->sock))
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("could not set socket to nonblocking mode: %s\n"),
										  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
						conn->try_next_addr = true;
						goto keep_going;
					}

#ifdef F_SETFD
					if (fcntl(conn->sock, F_SETFD, FD_CLOEXEC) == -1)
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("could not set socket to close-on-exec mode: %s\n"),
										  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
						conn->try_next_addr = true;
						goto keep_going;
					}
#endif							/* F_SETFD */

					if (!IS_AF_UNIX(addr_cur->ai_family))
					{
#ifndef WIN32
						int			on = 1;
#endif
						int			usekeepalives = useKeepalives(conn);
						int			err = 0;

						if (usekeepalives < 0)
						{
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("keepalives parameter must be an integer\n"));
							err = 1;
						}
						else if (usekeepalives == 0)
						{
							/* Do nothing */
						}
#ifndef WIN32
						else if (setsockopt(conn->sock,
											SOL_SOCKET, SO_KEEPALIVE,
											(char *) &on, sizeof(on)) < 0)
						{
							appendPQExpBuffer(&conn->errorMessage,
											  libpq_gettext("%s(%s) failed: %s\n"),
											  "setsockopt",
											  "SO_KEEPALIVE",
											  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
							err = 1;
						}
						else if (!setKeepalivesIdle(conn)
								 || !setKeepalivesInterval(conn)
								 || !setKeepalivesCount(conn))
							err = 1;
#else							/* WIN32 */
#ifdef SIO_KEEPALIVE_VALS
						else if (!setKeepalivesWin32(conn))
							err = 1;
#endif							/* SIO_KEEPALIVE_VALS */
#endif							/* WIN32 */
						else if (!setTCPUserTimeout(conn))
							err = 1;

						if (err)
						{
							conn->try_next_addr = true;
							goto keep_going;
						}
					}

					/*----------
					 * We have three methods of blocking SIGPIPE during
					 * send() calls to this socket:
					 *
					 *	- setsockopt(sock, SO_NOSIGPIPE)
					 *	- send(sock, ..., MSG_NOSIGNAL)
					 *	- setting the signal mask to SIG_IGN during send()
					 *
					 * The third method requires three syscalls per send,
					 * so we prefer either of the first two, but they are
					 * less portable.  The state is tracked in the following
					 * members of PGconn:
					 *
					 * conn->sigpipe_so		- we have set up SO_NOSIGPIPE
					 * conn->sigpipe_flag	- we're specifying MSG_NOSIGNAL
					 *
					 * If we can use SO_NOSIGPIPE, then set sigpipe_so here
					 * and we're done.  Otherwise, set sigpipe_flag so that
					 * we will try MSG_NOSIGNAL on sends.  If we get an error
					 * with MSG_NOSIGNAL, we'll clear that flag and revert to
					 * signal masking.
					 *----------
					 */
					conn->sigpipe_so = false;
#ifdef MSG_NOSIGNAL
					conn->sigpipe_flag = true;
#else
					conn->sigpipe_flag = false;
#endif							/* MSG_NOSIGNAL */

#ifdef SO_NOSIGPIPE
					optval = 1;
					if (setsockopt(conn->sock, SOL_SOCKET, SO_NOSIGPIPE,
								   (char *) &optval, sizeof(optval)) == 0)
					{
						conn->sigpipe_so = true;
						conn->sigpipe_flag = false;
					}
#endif							/* SO_NOSIGPIPE */

					/*
					 * Start/make connection.  This should not block, since we
					 * are in nonblock mode.  If it does, well, too bad.
					 */
					if (connect(conn->sock, addr_cur->ai_addr,
								addr_cur->ai_addrlen) < 0)
					{
						if (SOCK_ERRNO == EINPROGRESS ||
#ifdef WIN32
							SOCK_ERRNO == EWOULDBLOCK ||
#endif
							SOCK_ERRNO == EINTR)
						{
							/*
							 * This is fine - we're in non-blocking mode, and
							 * the connection is in progress.  Tell caller to
							 * wait for write-ready on socket.
							 */
							conn->status = CONNECTION_STARTED;
							return PGRES_POLLING_WRITING;
						}
						/* otherwise, trouble */
					}
					else
					{
						/*
						 * Hm, we're connected already --- seems the "nonblock
						 * connection" wasn't.  Advance the state machine and
						 * go do the next stuff.
						 */
						conn->status = CONNECTION_STARTED;
						goto keep_going;
					}

					/*
					 * This connection failed.  Add the error report to
					 * conn->errorMessage, then try the next address if any.
					 */
					connectFailureMessage(conn, SOCK_ERRNO);
					conn->try_next_addr = true;
					goto keep_going;
				}
			}

		case CONNECTION_STARTED:
			{
				ACCEPT_TYPE_ARG3 optlen = sizeof(optval);

				/*
				 * Write ready, since we've made it here, so the connection
				 * has been made ... or has failed.
				 */

				/*
				 * Now check (using getsockopt) that there is not an error
				 * state waiting for us on the socket.
				 */

				if (getsockopt(conn->sock, SOL_SOCKET, SO_ERROR,
							   (char *) &optval, &optlen) == -1)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("could not get socket error status: %s\n"),
									  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
					goto error_return;
				}
				else if (optval != 0)
				{
					/*
					 * When using a nonblocking connect, we will typically see
					 * connect failures at this point, so provide a friendly
					 * error message.
					 */
					connectFailureMessage(conn, optval);

					/*
					 * Try the next address if any, just as in the case where
					 * connect() returned failure immediately.
					 */
					conn->try_next_addr = true;
					goto keep_going;
				}

				/* Fill in the client address */
				conn->laddr.salen = sizeof(conn->laddr.addr);
				if (getsockname(conn->sock,
								(struct sockaddr *) &conn->laddr.addr,
								&conn->laddr.salen) < 0)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("could not get client address from socket: %s\n"),
									  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
					goto error_return;
				}

				/*
				 * Make sure we can write before advancing to next step.
				 */
				conn->status = CONNECTION_MADE;
				return PGRES_POLLING_WRITING;
			}

		case CONNECTION_MADE:
			{
				char	   *startpacket;
				int			packetlen;

				/*
				 * Implement requirepeer check, if requested and it's a
				 * Unix-domain socket.
				 */
				if (conn->requirepeer && conn->requirepeer[0] &&
					IS_AF_UNIX(conn->raddr.addr.ss_family))
				{
#ifndef WIN32
					char		pwdbuf[BUFSIZ];
					struct passwd pass_buf;
					struct passwd *pass;
					int			passerr;
#endif
					uid_t		uid;
					gid_t		gid;

					errno = 0;
					if (getpeereid(conn->sock, &uid, &gid) != 0)
					{
						/*
						 * Provide special error message if getpeereid is a
						 * stub
						 */
						if (errno == ENOSYS)
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("requirepeer parameter is not supported on this platform\n"));
						else
							appendPQExpBuffer(&conn->errorMessage,
											  libpq_gettext("could not get peer credentials: %s\n"),
											  strerror_r(errno, sebuf, sizeof(sebuf)));
						goto error_return;
					}

#ifndef WIN32
					passerr = pqGetpwuid(uid, &pass_buf, pwdbuf, sizeof(pwdbuf), &pass);
					if (pass == NULL)
					{
						if (passerr != 0)
							appendPQExpBuffer(&conn->errorMessage,
											  libpq_gettext("could not look up local user ID %d: %s\n"),
											  (int) uid,
											  strerror_r(passerr, sebuf, sizeof(sebuf)));
						else
							appendPQExpBuffer(&conn->errorMessage,
											  libpq_gettext("local user with ID %d does not exist\n"),
											  (int) uid);
						goto error_return;
					}

					if (strcmp(pass->pw_name, conn->requirepeer) != 0)
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("requirepeer specifies \"%s\", but actual peer user name is \"%s\"\n"),
										  conn->requirepeer, pass->pw_name);
						goto error_return;
					}
#else							/* WIN32 */
					/* should have failed with ENOSYS above */
					Assert(false);
#endif							/* WIN32 */
				}

				if (IS_AF_UNIX(conn->raddr.addr.ss_family))
				{
					/* Don't request SSL or GSSAPI over Unix sockets */
#ifdef USE_SSL
					conn->allow_ssl_try = false;
#endif
#ifdef ENABLE_GSS
					conn->try_gss = false;
#endif
				}

#ifdef ENABLE_GSS

				/*
				 * If GSSAPI encryption is enabled, then call
				 * pg_GSS_have_cred_cache() which will return true if we can
				 * acquire credentials (and give us a handle to use in
				 * conn->gcred), and then send a packet to the server asking
				 * for GSSAPI Encryption (and skip past SSL negotiation and
				 * regular startup below).
				 */
				if (conn->try_gss && !conn->gctx)
					conn->try_gss = pg_GSS_have_cred_cache(&conn->gcred);
				if (conn->try_gss && !conn->gctx)
				{
					ProtocolVersion pv = pg_hton32(NEGOTIATE_GSS_CODE);

					if (pqPacketSend(conn, 0, &pv, sizeof(pv)) != STATUS_OK)
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("could not send GSSAPI negotiation packet: %s\n"),
										  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
						goto error_return;
					}

					/* Ok, wait for response */
					conn->status = CONNECTION_GSS_STARTUP;
					return PGRES_POLLING_READING;
				}
				else if (!conn->gctx && conn->gssencmode[0] == 'r')
				{
					appendPQExpBufferStr(&conn->errorMessage,
										 libpq_gettext("GSSAPI encryption required but was impossible (possibly no credential cache, no server support, or using a local socket)\n"));
					goto error_return;
				}
#endif

#ifdef USE_SSL

				/*
				 * Enable the libcrypto callbacks before checking if SSL needs
				 * to be done.  This is done before sending the startup packet
				 * as depending on the type of authentication done, like MD5
				 * or SCRAM that use cryptohashes, the callbacks would be
				 * required even without a SSL connection
				 */
				if (pqsecure_initialize(conn, false, true) < 0)
					goto error_return;

				/*
				 * If SSL is enabled and we haven't already got encryption of
				 * some sort running, request SSL instead of sending the
				 * startup message.
				 */
				if (conn->allow_ssl_try && !conn->wait_ssl_try &&
					!conn->ssl_in_use
#ifdef ENABLE_GSS
					&& !conn->gssenc
#endif
					)
				{
					ProtocolVersion pv;

					/*
					 * Send the SSL request packet.
					 *
					 * Theoretically, this could block, but it really
					 * shouldn't since we only got here if the socket is
					 * write-ready.
					 */
					pv = pg_hton32(NEGOTIATE_SSL_CODE);
					if (pqPacketSend(conn, 0, &pv, sizeof(pv)) != STATUS_OK)
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("could not send SSL negotiation packet: %s\n"),
										  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
						goto error_return;
					}
					/* Ok, wait for response */
					conn->status = CONNECTION_SSL_STARTUP;
					return PGRES_POLLING_READING;
				}
#endif							/* USE_SSL */

				/*
				 * Build the startup packet.
				 */
				startpacket = pqBuildStartupPacket3(conn, &packetlen,
													EnvironmentOptions);
				if (!startpacket)
				{
					appendPQExpBufferStr(&conn->errorMessage,
										 libpq_gettext("out of memory\n"));
					goto error_return;
				}

				/*
				 * Send the startup packet.
				 *
				 * Theoretically, this could block, but it really shouldn't
				 * since we only got here if the socket is write-ready.
				 */
				if (pqPacketSend(conn, 0, startpacket, packetlen) != STATUS_OK)
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("could not send startup packet: %s\n"),
									  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
					free(startpacket);
					goto error_return;
				}

				free(startpacket);

				conn->status = CONNECTION_AWAITING_RESPONSE;
				return PGRES_POLLING_READING;
			}

			/*
			 * Handle SSL negotiation: wait for postmaster messages and
			 * respond as necessary.
			 */
		case CONNECTION_SSL_STARTUP:
			{
#ifdef USE_SSL
				PostgresPollingStatusType pollres;

				/*
				 * On first time through, get the postmaster's response to our
				 * SSL negotiation packet.
				 */
				if (!conn->ssl_in_use)
				{
					/*
					 * We use pqReadData here since it has the logic to
					 * distinguish no-data-yet from connection closure. Since
					 * conn->ssl isn't set, a plain recv() will occur.
					 */
					char		SSLok;
					int			rdresult;

					rdresult = pqReadData(conn);
					if (rdresult < 0)
					{
						/* errorMessage is already filled in */
						goto error_return;
					}
					if (rdresult == 0)
					{
						/* caller failed to wait for data */
						return PGRES_POLLING_READING;
					}
					if (pqGetc(&SSLok, conn) < 0)
					{
						/* should not happen really */
						return PGRES_POLLING_READING;
					}
					if (SSLok == 'S')
					{
						/* mark byte consumed */
						conn->inStart = conn->inCursor;

						/*
						 * Set up global SSL state if required.  The crypto
						 * state has already been set if libpq took care of
						 * doing that, so there is no need to make that happen
						 * again.
						 */
						if (pqsecure_initialize(conn, true, false) != 0)
							goto error_return;
					}
					else if (SSLok == 'N')
					{
						/* mark byte consumed */
						conn->inStart = conn->inCursor;
						/* OK to do without SSL? */
						if (conn->sslmode[0] == 'r' ||	/* "require" */
							conn->sslmode[0] == 'v')	/* "verify-ca" or
														 * "verify-full" */
						{
							/* Require SSL, but server does not want it */
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("server does not support SSL, but SSL was required\n"));
							goto error_return;
						}
						/* Otherwise, proceed with normal startup */
						conn->allow_ssl_try = false;
						/* We can proceed using this connection */
						conn->status = CONNECTION_MADE;
						return PGRES_POLLING_WRITING;
					}
					else if (SSLok == 'E')
					{
						/*
						 * Server failure of some sort, such as failure to
						 * fork a backend process.  We need to process and
						 * report the error message, which might be formatted
						 * according to either protocol 2 or protocol 3.
						 * Rather than duplicate the code for that, we flip
						 * into AWAITING_RESPONSE state and let the code there
						 * deal with it.  Note we have *not* consumed the "E"
						 * byte here.
						 */
						conn->status = CONNECTION_AWAITING_RESPONSE;
						goto keep_going;
					}
					else
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("received invalid response to SSL negotiation: %c\n"),
										  SSLok);
						goto error_return;
					}
				}

				/*
				 * Begin or continue the SSL negotiation process.
				 */
				pollres = pqsecure_open_client(conn);
				if (pollres == PGRES_POLLING_OK)
				{
					/*
					 * At this point we should have no data already buffered.
					 * If we do, it was received before we performed the SSL
					 * handshake, so it wasn't encrypted and indeed may have
					 * been injected by a man-in-the-middle.
					 */
					if (conn->inCursor != conn->inEnd)
					{
						appendPQExpBufferStr(&conn->errorMessage,
											 libpq_gettext("received unencrypted data after SSL response\n"));
						goto error_return;
					}

					/* SSL handshake done, ready to send startup packet */
					conn->status = CONNECTION_MADE;
					return PGRES_POLLING_WRITING;
				}
				if (pollres == PGRES_POLLING_FAILED)
				{
					/*
					 * Failed ... if sslmode is "prefer" then do a non-SSL
					 * retry
					 */
					if (conn->sslmode[0] == 'p' /* "prefer" */
						&& conn->allow_ssl_try	/* redundant? */
						&& !conn->wait_ssl_try) /* redundant? */
					{
						/* only retry once */
						conn->allow_ssl_try = false;
						need_new_connection = true;
						goto keep_going;
					}
					/* Else it's a hard failure */
					goto error_return;
				}
				/* Else, return POLLING_READING or POLLING_WRITING status */
				return pollres;
#else							/* !USE_SSL */
				/* can't get here */
				goto error_return;
#endif							/* USE_SSL */
			}

		case CONNECTION_GSS_STARTUP:
			{
#ifdef ENABLE_GSS
				PostgresPollingStatusType pollres;

				/*
				 * If we haven't yet, get the postmaster's response to our
				 * negotiation packet
				 */
				if (conn->try_gss && !conn->gctx)
				{
					char		gss_ok;
					int			rdresult = pqReadData(conn);

					if (rdresult < 0)
						/* pqReadData fills in error message */
						goto error_return;
					else if (rdresult == 0)
						/* caller failed to wait for data */
						return PGRES_POLLING_READING;
					if (pqGetc(&gss_ok, conn) < 0)
						/* shouldn't happen... */
						return PGRES_POLLING_READING;

					if (gss_ok == 'E')
					{
						/*
						 * Server failure of some sort.  Assume it's a
						 * protocol version support failure, and let's see if
						 * we can't recover (if it's not, we'll get a better
						 * error message on retry).  Server gets fussy if we
						 * don't hang up the socket, though.
						 */
						conn->try_gss = false;
						need_new_connection = true;
						goto keep_going;
					}

					/* mark byte consumed */
					conn->inStart = conn->inCursor;

					if (gss_ok == 'N')
					{
						/* Server doesn't want GSSAPI; fall back if we can */
						if (conn->gssencmode[0] == 'r')
						{
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("server doesn't support GSSAPI encryption, but it was required\n"));
							goto error_return;
						}

						conn->try_gss = false;
						/* We can proceed using this connection */
						conn->status = CONNECTION_MADE;
						return PGRES_POLLING_WRITING;
					}
					else if (gss_ok != 'G')
					{
						appendPQExpBuffer(&conn->errorMessage,
										  libpq_gettext("received invalid response to GSSAPI negotiation: %c\n"),
										  gss_ok);
						goto error_return;
					}
				}

				/* Begin or continue GSSAPI negotiation */
				pollres = pqsecure_open_gss(conn);
				if (pollres == PGRES_POLLING_OK)
				{
					/*
					 * At this point we should have no data already buffered.
					 * If we do, it was received before we performed the GSS
					 * handshake, so it wasn't encrypted and indeed may have
					 * been injected by a man-in-the-middle.
					 */
					if (conn->inCursor != conn->inEnd)
					{
						appendPQExpBufferStr(&conn->errorMessage,
											 libpq_gettext("received unencrypted data after GSSAPI encryption response\n"));
						goto error_return;
					}

					/* All set for startup packet */
					conn->status = CONNECTION_MADE;
					return PGRES_POLLING_WRITING;
				}
				else if (pollres == PGRES_POLLING_FAILED &&
						 conn->gssencmode[0] == 'p')
				{
					/*
					 * We failed, but we can retry on "prefer".  Have to drop
					 * the current connection to do so, though.
					 */
					conn->try_gss = false;
					need_new_connection = true;
					goto keep_going;
				}
				return pollres;
#else							/* !ENABLE_GSS */
				/* unreachable */
				goto error_return;
#endif							/* ENABLE_GSS */
			}

			/*
			 * Handle authentication exchange: wait for postmaster messages
			 * and respond as necessary.
			 */
		case CONNECTION_AWAITING_RESPONSE:
			{
				char		beresp;
				int			msgLength;
				int			avail;
				AuthRequest areq;
				int			res;

				/*
				 * Scan the message from current point (note that if we find
				 * the message is incomplete, we will return without advancing
				 * inStart, and resume here next time).
				 */
				conn->inCursor = conn->inStart;

				/* Read type byte */
				if (pqGetc(&beresp, conn))
				{
					/* We'll come back when there is more data */
					return PGRES_POLLING_READING;
				}

				/*
				 * Validate message type: we expect only an authentication
				 * request or an error here.  Anything else probably means
				 * it's not Postgres on the other end at all.
				 */
				if (!(beresp == 'R' || beresp == 'E'))
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("expected authentication request from server, but received %c\n"),
									  beresp);
					goto error_return;
				}

				/* Read message length word */
				if (pqGetInt(&msgLength, 4, conn))
				{
					/* We'll come back when there is more data */
					return PGRES_POLLING_READING;
				}

				/*
				 * Try to validate message length before using it.
				 * Authentication requests can't be very large, although GSS
				 * auth requests may not be that small.  Errors can be a
				 * little larger, but not huge.  If we see a large apparent
				 * length in an error, it means we're really talking to a
				 * pre-3.0-protocol server; cope.  (Before version 14, the
				 * server also used the old protocol for errors that happened
				 * before processing the startup packet.)
				 */
				if (beresp == 'R' && (msgLength < 8 || msgLength > 2000))
				{
					appendPQExpBuffer(&conn->errorMessage,
									  libpq_gettext("expected authentication request from server, but received %c\n"),
									  beresp);
					goto error_return;
				}

				if (beresp == 'E' && (msgLength < 8 || msgLength > 30000))
				{
					/* Handle error from a pre-3.0 server */
					conn->inCursor = conn->inStart + 1; /* reread data */
					if (pqGets_append(&conn->errorMessage, conn))
					{
						/* We'll come back when there is more data */
						return PGRES_POLLING_READING;
					}
					/* OK, we read the message; mark data consumed */
					conn->inStart = conn->inCursor;

					/*
					 * Before 7.2, the postmaster didn't always end its
					 * messages with a newline, so add one if needed to
					 * conform to libpq conventions.
					 */
					if (conn->errorMessage.len == 0 ||
						conn->errorMessage.data[conn->errorMessage.len - 1] != '\n')
					{
						appendPQExpBufferChar(&conn->errorMessage, '\n');
					}

					goto error_return;
				}

				/*
				 * Can't process if message body isn't all here yet.
				 */
				msgLength -= 4;
				avail = conn->inEnd - conn->inCursor;
				if (avail < msgLength)
				{
					/*
					 * Before returning, try to enlarge the input buffer if
					 * needed to hold the whole message; see notes in
					 * pqParseInput3.
					 */
					if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength,
											 conn))
						goto error_return;
					/* We'll come back when there is more data */
					return PGRES_POLLING_READING;
				}

				/* Handle errors. */
				if (beresp == 'E')
				{
					if (pqGetErrorNotice3(conn, true))
					{
						/* We'll come back when there is more data */
						return PGRES_POLLING_READING;
					}
					/* OK, we read the message; mark data consumed */
					conn->inStart = conn->inCursor;

					/*
					 * If error is "cannot connect now", try the next host if
					 * any (but we don't want to consider additional addresses
					 * for this host, nor is there much point in changing SSL
					 * or GSS mode).  This is helpful when dealing with
					 * standby servers that might not be in hot-standby state.
					 */
					if (strcmp(conn->last_sqlstate,
							   ERRCODE_CANNOT_CONNECT_NOW) == 0)
					{
						conn->try_next_host = true;
						goto keep_going;
					}

					/* Check to see if we should mention pgpassfile */
					pgpassfileWarning(conn);

#ifdef ENABLE_GSS

					/*
					 * If gssencmode is "prefer" and we're using GSSAPI, retry
					 * without it.
					 */
					if (conn->gssenc && conn->gssencmode[0] == 'p')
					{
						/* only retry once */
						conn->try_gss = false;
						need_new_connection = true;
						goto keep_going;
					}
#endif

#ifdef USE_SSL

					/*
					 * if sslmode is "allow" and we haven't tried an SSL
					 * connection already, then retry with an SSL connection
					 */
					if (conn->sslmode[0] == 'a' /* "allow" */
						&& !conn->ssl_in_use
						&& conn->allow_ssl_try
						&& conn->wait_ssl_try)
					{
						/* only retry once */
						conn->wait_ssl_try = false;
						need_new_connection = true;
						goto keep_going;
					}

					/*
					 * if sslmode is "prefer" and we're in an SSL connection,
					 * then do a non-SSL retry
					 */
					if (conn->sslmode[0] == 'p' /* "prefer" */
						&& conn->ssl_in_use
						&& conn->allow_ssl_try	/* redundant? */
						&& !conn->wait_ssl_try) /* redundant? */
					{
						/* only retry once */
						conn->allow_ssl_try = false;
						need_new_connection = true;
						goto keep_going;
					}
#endif

					goto error_return;
				}

				/* It is an authentication request. */
				conn->auth_req_received = true;

				/* Get the type of request. */
				if (pqGetInt((int *) &areq, 4, conn))
				{
					/* We'll come back when there are more data */
					return PGRES_POLLING_READING;
				}
				msgLength -= 4;

				/*
				 * Process the rest of the authentication request message, and
				 * respond to it if necessary.
				 *
				 * Note that conn->pghost must be non-NULL if we are going to
				 * avoid the Kerberos code doing a hostname look-up.
				 */
				res = pg_fe_sendauth(areq, msgLength, conn);

				/* OK, we have processed the message; mark data consumed */
				conn->inStart = conn->inCursor;

				if (res != STATUS_OK)
					goto error_return;

				/*
				 * Just make sure that any data sent by pg_fe_sendauth is
				 * flushed out.  Although this theoretically could block, it
				 * really shouldn't since we don't send large auth responses.
				 */
				if (pqFlush(conn))
					goto error_return;

				if (areq == AUTH_REQ_OK)
				{
					/* We are done with authentication exchange */
					conn->status = CONNECTION_AUTH_OK;

					/*
					 * Set asyncStatus so that PQgetResult will think that
					 * what comes back next is the result of a query.  See
					 * below.
					 */
					conn->asyncStatus = PGASYNC_BUSY;
				}

				/* Look to see if we have more data yet. */
				goto keep_going;
			}

		case CONNECTION_AUTH_OK:
			{
				/*
				 * Now we expect to hear from the backend. A ReadyForQuery
				 * message indicates that startup is successful, but we might
				 * also get an Error message indicating failure. (Notice
				 * messages indicating nonfatal warnings are also allowed by
				 * the protocol, as are ParameterStatus and BackendKeyData
				 * messages.) Easiest way to handle this is to let
				 * PQgetResult() read the messages. We just have to fake it
				 * out about the state of the connection, by setting
				 * asyncStatus = PGASYNC_BUSY (done above).
				 */

				if (PQisBusy(conn))
					return PGRES_POLLING_READING;

				res = PQgetResult(conn);

				/*
				 * NULL return indicating we have gone to IDLE state is
				 * expected
				 */
				if (res)
				{
					if (res->resultStatus != PGRES_FATAL_ERROR)
						appendPQExpBufferStr(&conn->errorMessage,
											 libpq_gettext("unexpected message from server during startup\n"));
					else if (conn->send_appname &&
							 (conn->appname || conn->fbappname))
					{
						/*
						 * If we tried to send application_name, check to see
						 * if the error is about that --- pre-9.0 servers will
						 * reject it at this stage of the process.  If so,
						 * close the connection and retry without sending
						 * application_name.  We could possibly get a false
						 * SQLSTATE match here and retry uselessly, but there
						 * seems no great harm in that; we'll just get the
						 * same error again if it's unrelated.
						 */
						const char *sqlstate;

						sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
						if (sqlstate &&
							strcmp(sqlstate, ERRCODE_APPNAME_UNKNOWN) == 0)
						{
							PQclear(res);
							conn->send_appname = false;
							need_new_connection = true;
							goto keep_going;
						}
					}

					/*
					 * if the resultStatus is FATAL, then conn->errorMessage
					 * already has a copy of the error; needn't copy it back.
					 * But add a newline if it's not there already, since
					 * postmaster error messages may not have one.
					 */
					if (conn->errorMessage.len <= 0 ||
						conn->errorMessage.data[conn->errorMessage.len - 1] != '\n')
						appendPQExpBufferChar(&conn->errorMessage, '\n');
					PQclear(res);
					goto error_return;
				}

				/* Almost there now ... */
				conn->status = CONNECTION_CHECK_TARGET;
				goto keep_going;
			}

		case CONNECTION_CHECK_TARGET:
			{
				/*
				 * If a read-write, read-only, primary, or standby connection
				 * is required, see if we have one.
				 */
				if (conn->target_server_type == SERVER_TYPE_READ_WRITE ||
					conn->target_server_type == SERVER_TYPE_READ_ONLY)
				{
					bool		read_only_server;

					/*
					 * If the server didn't report
					 * "default_transaction_read_only" or "in_hot_standby" at
					 * startup, we must determine its state by sending the
					 * query "SHOW transaction_read_only".  This GUC exists in
					 * all server versions that support 3.0 protocol.
					 */
					if (conn->default_transaction_read_only == PG_BOOL_UNKNOWN ||
						conn->in_hot_standby == PG_BOOL_UNKNOWN)
					{
						/*
						 * We use PQsendQueryContinue so that
						 * conn->errorMessage does not get cleared.  We need
						 * to preserve any error messages related to previous
						 * hosts we have tried and failed to connect to.
						 */
						conn->status = CONNECTION_OK;
						if (!PQsendQueryContinue(conn,
												 "SHOW transaction_read_only"))
							goto error_return;
						/* We'll return to this state when we have the answer */
						conn->status = CONNECTION_CHECK_WRITABLE;
						return PGRES_POLLING_READING;
					}

					/* OK, we can make the test */
					read_only_server =
						(conn->default_transaction_read_only == PG_BOOL_YES ||
						 conn->in_hot_standby == PG_BOOL_YES);

					if ((conn->target_server_type == SERVER_TYPE_READ_WRITE) ?
						read_only_server : !read_only_server)
					{
						/* Wrong server state, reject and try the next host */
						if (conn->target_server_type == SERVER_TYPE_READ_WRITE)
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("session is read-only\n"));
						else
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("session is not read-only\n"));

						/* Close connection politely. */
						conn->status = CONNECTION_OK;
						sendTerminateConn(conn);

						/*
						 * Try next host if any, but we don't want to consider
						 * additional addresses for this host.
						 */
						conn->try_next_host = true;
						goto keep_going;
					}
				}
				else if (conn->target_server_type == SERVER_TYPE_PRIMARY ||
						 conn->target_server_type == SERVER_TYPE_STANDBY ||
						 conn->target_server_type == SERVER_TYPE_PREFER_STANDBY)
				{
					/*
					 * If the server didn't report "in_hot_standby" at
					 * startup, we must determine its state by sending the
					 * query "SELECT pg_catalog.pg_is_in_recovery()".  Servers
					 * before 9.0 don't have that function, but by the same
					 * token they don't have any standby mode, so we may just
					 * assume the result.
					 */
					if (conn->sversion < 90000)
						conn->in_hot_standby = PG_BOOL_NO;

					if (conn->in_hot_standby == PG_BOOL_UNKNOWN)
					{
						/*
						 * We use PQsendQueryContinue so that
						 * conn->errorMessage does not get cleared.  We need
						 * to preserve any error messages related to previous
						 * hosts we have tried and failed to connect to.
						 */
						conn->status = CONNECTION_OK;
						if (!PQsendQueryContinue(conn,
												 "SELECT pg_catalog.pg_is_in_recovery()"))
							goto error_return;
						/* We'll return to this state when we have the answer */
						conn->status = CONNECTION_CHECK_STANDBY;
						return PGRES_POLLING_READING;
					}

					/* OK, we can make the test */
					if ((conn->target_server_type == SERVER_TYPE_PRIMARY) ?
						(conn->in_hot_standby == PG_BOOL_YES) :
						(conn->in_hot_standby == PG_BOOL_NO))
					{
						/* Wrong server state, reject and try the next host */
						if (conn->target_server_type == SERVER_TYPE_PRIMARY)
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("server is in hot standby mode\n"));
						else
							appendPQExpBufferStr(&conn->errorMessage,
												 libpq_gettext("server is not in hot standby mode\n"));

						/* Close connection politely. */
						conn->status = CONNECTION_OK;
						sendTerminateConn(conn);

						/*
						 * Try next host if any, but we don't want to consider
						 * additional addresses for this host.
						 */
						conn->try_next_host = true;
						goto keep_going;
					}
				}

				/* We can release the address list now. */
				release_conn_addrinfo(conn);

				/*
				 * Contents of conn->errorMessage are no longer interesting
				 * (and it seems some clients expect it to be empty after a
				 * successful connection).
				 */
				resetPQExpBuffer(&conn->errorMessage);

				/* We are open for business! */
				conn->status = CONNECTION_OK;
				return PGRES_POLLING_OK;
			}

		case CONNECTION_CONSUME:
			{
				/*
				 * This state just makes sure the connection is idle after
				 * we've obtained the result of a SHOW or SELECT query.  Once
				 * we're clear, return to CONNECTION_CHECK_TARGET state to
				 * decide what to do next.  We must transiently set status =
				 * CONNECTION_OK in order to use the result-consuming
				 * subroutines.
				 */
				conn->status = CONNECTION_OK;
				if (!PQconsumeInput(conn))
					goto error_return;

				if (PQisBusy(conn))
				{
					conn->status = CONNECTION_CONSUME;
					return PGRES_POLLING_READING;
				}

				/* Call PQgetResult() again until we get a NULL result */
				res = PQgetResult(conn);
				if (res != NULL)
				{
					PQclear(res);
					conn->status = CONNECTION_CONSUME;
					return PGRES_POLLING_READING;
				}

				conn->status = CONNECTION_CHECK_TARGET;
				goto keep_going;
			}

		case CONNECTION_CHECK_WRITABLE:
			{
				/*
				 * Waiting for result of "SHOW transaction_read_only".  We
				 * must transiently set status = CONNECTION_OK in order to use
				 * the result-consuming subroutines.
				 */
				conn->status = CONNECTION_OK;
				if (!PQconsumeInput(conn))
					goto error_return;

				if (PQisBusy(conn))
				{
					conn->status = CONNECTION_CHECK_WRITABLE;
					return PGRES_POLLING_READING;
				}

				res = PQgetResult(conn);
				if (res && PQresultStatus(res) == PGRES_TUPLES_OK &&
					PQntuples(res) == 1)
				{
					char	   *val = PQgetvalue(res, 0, 0);

					/*
					 * "transaction_read_only = on" proves that at least one
					 * of default_transaction_read_only and in_hot_standby is
					 * on, but we don't actually know which.  We don't care
					 * though for the purpose of identifying a read-only
					 * session, so satisfy the CONNECTION_CHECK_TARGET code by
					 * claiming they are both on.  On the other hand, if it's
					 * a read-write session, they are certainly both off.
					 */
					if (strncmp(val, "on", 2) == 0)
					{
						conn->default_transaction_read_only = PG_BOOL_YES;
						conn->in_hot_standby = PG_BOOL_YES;
					}
					else
					{
						conn->default_transaction_read_only = PG_BOOL_NO;
						conn->in_hot_standby = PG_BOOL_NO;
					}
					PQclear(res);

					/* Finish reading messages before continuing */
					conn->status = CONNECTION_CONSUME;
					goto keep_going;
				}

				/* Something went wrong with "SHOW transaction_read_only". */
				if (res)
					PQclear(res);

				/* Append error report to conn->errorMessage. */
				appendPQExpBuffer(&conn->errorMessage,
								  libpq_gettext("\"%s\" failed\n"),
								  "SHOW transaction_read_only");

				/* Close connection politely. */
				conn->status = CONNECTION_OK;
				sendTerminateConn(conn);

				/* Try next host. */
				conn->try_next_host = true;
				goto keep_going;
			}

		case CONNECTION_CHECK_STANDBY:
			{
				/*
				 * Waiting for result of "SELECT pg_is_in_recovery()".  We
				 * must transiently set status = CONNECTION_OK in order to use
				 * the result-consuming subroutines.
				 */
				conn->status = CONNECTION_OK;
				if (!PQconsumeInput(conn))
					goto error_return;

				if (PQisBusy(conn))
				{
					conn->status = CONNECTION_CHECK_STANDBY;
					return PGRES_POLLING_READING;
				}

				res = PQgetResult(conn);
				if (res && PQresultStatus(res) == PGRES_TUPLES_OK &&
					PQntuples(res) == 1)
				{
					char	   *val = PQgetvalue(res, 0, 0);

					if (strncmp(val, "t", 1) == 0)
						conn->in_hot_standby = PG_BOOL_YES;
					else
						conn->in_hot_standby = PG_BOOL_NO;
					PQclear(res);

					/* Finish reading messages before continuing */
					conn->status = CONNECTION_CONSUME;
					goto keep_going;
				}

				/* Something went wrong with "SELECT pg_is_in_recovery()". */
				if (res)
					PQclear(res);

				/* Append error report to conn->errorMessage. */
				appendPQExpBuffer(&conn->errorMessage,
								  libpq_gettext("\"%s\" failed\n"),
								  "SELECT pg_is_in_recovery()");

				/* Close connection politely. */
				conn->status = CONNECTION_OK;
				sendTerminateConn(conn);

				/* Try next host. */
				conn->try_next_host = true;
				goto keep_going;
			}

		default:
			appendPQExpBuffer(&conn->errorMessage,
							  libpq_gettext("invalid connection state %d, "
											"probably indicative of memory corruption\n"),
							  conn->status);
			goto error_return;
	}

	/* Unreachable */

error_return:

	/*
	 * We used to close the socket at this point, but that makes it awkward
	 * for those above us if they wish to remove this socket from their own
	 * records (an fd_set for example).  We'll just have this socket closed
	 * when PQfinish is called (which is compulsory even after an error, since
	 * the connection structure must be freed).
	 */
	conn->status = CONNECTION_BAD;
	return PGRES_POLLING_FAILED;
}


bool RepeatedAttrDefEqual(
    const protobuf::RepeatedPtrField<OpDef::AttrDef>& a1,
    const protobuf::RepeatedPtrField<OpDef::AttrDef>& a2) {
  std::unordered_map<string, const OpDef::AttrDef*> a1_set;
  for (const OpDef::AttrDef& def : a1) {
    DCHECK(a1_set.find(def.name()) == a1_set.end())
        << "AttrDef names must be unique, but '" << def.name()
        << "' appears more than once";
    a1_set[def.name()] = &def;
  }
  for (const OpDef::AttrDef& def : a2) {
    auto iter = a1_set.find(def.name());
    if (iter == a1_set.end()) return false;
    if (!AttrDefEqual(*iter->second, def)) return false;
    a1_set.erase(iter);
  }
  if (!a1_set.empty()) return false;
  return true;
}

Remove a `DCHECK`-fail, log an error instead.

`DCHECK` in debug mode results in crashes. TensorFlow has had multiple vulnerabilities due to this.

Outside of debug mode, `DCHECK` is a no-op.

A better alternative is to report an error to the log buffer and continue. This should happen both in debug mode and in prod mode.

PiperOrigin-RevId: 408375925
Change-Id: Id5b3e19c73f3fbe0cc4bba26ca44ff9607bb6356


bool RepeatedAttrDefEqual(
    const protobuf::RepeatedPtrField<OpDef::AttrDef>& a1,
    const protobuf::RepeatedPtrField<OpDef::AttrDef>& a2) {
  std::unordered_map<string, const OpDef::AttrDef*> a1_set;
  for (const OpDef::AttrDef& def : a1) {
    if (a1_set.find(def.name()) != a1_set.end()) {
      LOG(ERROR) << "AttrDef names must be unique, but '" << def.name()
                 << "' appears more than once";
    }
    a1_set[def.name()] = &def;
  }
  for (const OpDef::AttrDef& def : a2) {
    auto iter = a1_set.find(def.name());
    if (iter == a1_set.end()) return false;
    if (!AttrDefEqual(*iter->second, def)) return false;
    a1_set.erase(iter);
  }
  if (!a1_set.empty()) return false;
  return true;
}


  void Compute(tensorflow::OpKernelContext* context) override {
    for (int ngram_width : ngram_widths_) {
      OP_REQUIRES(
          context, ngram_width > 0,
          errors::InvalidArgument("ngram_widths must contain positive values"));
    }

    const tensorflow::Tensor* data;
    OP_REQUIRES_OK(context, context->input("data", &data));
    const auto& input_data = data->flat<tstring>().data();

    const tensorflow::Tensor* splits;
    OP_REQUIRES_OK(context, context->input("data_splits", &splits));
    const auto& splits_vec = splits->flat<SPLITS_TYPE>();

    // Validate that the splits are valid indices into data, only if there are
    // splits specified.
    const int input_data_size = data->flat<tstring>().size();
    const int splits_vec_size = splits_vec.size();
    if (splits_vec_size > 0) {
      int prev_split = splits_vec(0);
      OP_REQUIRES(context, prev_split == 0,
                  errors::InvalidArgument("First split value must be 0, got ",
                                          prev_split));
      for (int i = 1; i < splits_vec_size; ++i) {
        bool valid_splits = splits_vec(i) >= prev_split;
        valid_splits = valid_splits && (splits_vec(i) <= input_data_size);
        OP_REQUIRES(context, valid_splits,
                    errors::InvalidArgument(
                        "Invalid split value ", splits_vec(i), ", must be in [",
                        prev_split, ", ", input_data_size, "]"));
        prev_split = splits_vec(i);
      }
      OP_REQUIRES(context, prev_split == input_data_size,
                  errors::InvalidArgument(
                      "Last split value must be data size. Expected ",
                      input_data_size, ", got ", prev_split));
    }

    int num_batch_items = splits_vec.size() - 1;
    tensorflow::Tensor* ngrams_splits;
    OP_REQUIRES_OK(
        context, context->allocate_output(1, splits->shape(), &ngrams_splits));
    auto ngrams_splits_data = ngrams_splits->flat<SPLITS_TYPE>().data();

    // If there is no data or size, return an empty RT.
    if (data->flat<tstring>().size() == 0 || splits_vec.size() == 0) {
      tensorflow::Tensor* empty;
      OP_REQUIRES_OK(context,
                     context->allocate_output(0, data->shape(), &empty));
      for (int i = 0; i <= num_batch_items; ++i) {
        ngrams_splits_data[i] = 0;
      }
      return;
    }

    ngrams_splits_data[0] = 0;
    for (int i = 1; i <= num_batch_items; ++i) {
      int length = splits_vec(i) - splits_vec(i - 1);
      int num_ngrams = 0;
      for (int ngram_width : ngram_widths_)
        num_ngrams += get_num_ngrams(length, ngram_width);
      if (preserve_short_ && length > 0 && num_ngrams == 0) {
        num_ngrams = 1;
      }
      ngrams_splits_data[i] = ngrams_splits_data[i - 1] + num_ngrams;
    }

    tensorflow::Tensor* ngrams;
    OP_REQUIRES_OK(
        context,
        context->allocate_output(
            0, TensorShape({ngrams_splits_data[num_batch_items]}), &ngrams));
    auto ngrams_data = ngrams->flat<tstring>().data();

    for (int i = 0; i < num_batch_items; ++i) {
      auto data_start = &input_data[splits_vec(i)];
      int output_start_idx = ngrams_splits_data[i];
      for (int ngram_width : ngram_widths_) {
        auto output_start = &ngrams_data[output_start_idx];
        int length = splits_vec(i + 1) - splits_vec(i);
        int num_ngrams = get_num_ngrams(length, ngram_width);
        CreateNgrams(data_start, output_start, num_ngrams, ngram_width);
        output_start_idx += num_ngrams;
      }
      // If we're preserving short sequences, check to see if no sequence was
      // generated by comparing the current output start idx to the original
      // one (ngram_splits_data). If no ngrams were generated, then they will
      // be equal (since we increment output_start_idx by num_ngrams every
      // time we create a set of ngrams.)
      if (preserve_short_ && output_start_idx == ngrams_splits_data[i]) {
        int data_length = splits_vec(i + 1) - splits_vec(i);
        // One legitimate reason to not have any ngrams when preserve_short_
        // is true is if the sequence itself is empty. In that case, move on.
        if (data_length == 0) {
          continue;
        }
        // We don't have to worry about dynamic padding sizes here: if padding
        // was dynamic, every sequence would have had sufficient padding to
        // generate at least one ngram.
        int ngram_width = data_length + 2 * pad_width_;
        auto output_start = &ngrams_data[output_start_idx];
        int num_ngrams = 1;
        CreateNgrams(data_start, output_start, num_ngrams, ngram_width);
      }
    }
  }

Add a check for pad width to be a positive value.

PiperOrigin-RevId: 413275853
Change-Id: I261a8db9dabf5ce48a806a9e58129080c9fac619


  void Compute(tensorflow::OpKernelContext* context) override {
    for (int ngram_width : ngram_widths_) {
      OP_REQUIRES(
          context, ngram_width > 0,
          errors::InvalidArgument("ngram_widths must contain positive values"));
    }

    const tensorflow::Tensor* data;
    OP_REQUIRES_OK(context, context->input("data", &data));
    const auto& input_data = data->flat<tstring>().data();

    const tensorflow::Tensor* splits;
    OP_REQUIRES_OK(context, context->input("data_splits", &splits));
    const auto& splits_vec = splits->flat<SPLITS_TYPE>();

    // Validate that the splits are valid indices into data, only if there are
    // splits specified.
    const int input_data_size = data->flat<tstring>().size();
    const int splits_vec_size = splits_vec.size();
    if (splits_vec_size > 0) {
      int prev_split = splits_vec(0);
      OP_REQUIRES(context, prev_split == 0,
                  errors::InvalidArgument("First split value must be 0, got ",
                                          prev_split));
      for (int i = 1; i < splits_vec_size; ++i) {
        bool valid_splits = splits_vec(i) >= prev_split;
        valid_splits = valid_splits && (splits_vec(i) <= input_data_size);
        OP_REQUIRES(context, valid_splits,
                    errors::InvalidArgument(
                        "Invalid split value ", splits_vec(i), ", must be in [",
                        prev_split, ", ", input_data_size, "]"));
        prev_split = splits_vec(i);
      }
      OP_REQUIRES(context, prev_split == input_data_size,
                  errors::InvalidArgument(
                      "Last split value must be data size. Expected ",
                      input_data_size, ", got ", prev_split));
    }

    int num_batch_items = splits_vec.size() - 1;
    tensorflow::Tensor* ngrams_splits;
    OP_REQUIRES_OK(
        context, context->allocate_output(1, splits->shape(), &ngrams_splits));
    auto ngrams_splits_data = ngrams_splits->flat<SPLITS_TYPE>().data();

    // If there is no data or size, return an empty RT.
    if (data->flat<tstring>().size() == 0 || splits_vec.size() == 0) {
      tensorflow::Tensor* empty;
      OP_REQUIRES_OK(context,
                     context->allocate_output(0, data->shape(), &empty));
      for (int i = 0; i <= num_batch_items; ++i) {
        ngrams_splits_data[i] = 0;
      }
      return;
    }

    ngrams_splits_data[0] = 0;
    for (int i = 1; i <= num_batch_items; ++i) {
      int length = splits_vec(i) - splits_vec(i - 1);
      int num_ngrams = 0;
      for (int ngram_width : ngram_widths_)
        num_ngrams += get_num_ngrams(length, ngram_width);
      if (preserve_short_ && length > 0 && num_ngrams == 0) {
        num_ngrams = 1;
      }
      ngrams_splits_data[i] = ngrams_splits_data[i - 1] + num_ngrams;
    }

    tensorflow::Tensor* ngrams;
    OP_REQUIRES_OK(
        context,
        context->allocate_output(
            0, TensorShape({ngrams_splits_data[num_batch_items]}), &ngrams));
    auto ngrams_data = ngrams->flat<tstring>().data();

    for (int i = 0; i < num_batch_items; ++i) {
      auto data_start = &input_data[splits_vec(i)];
      int output_start_idx = ngrams_splits_data[i];
      for (int ngram_width : ngram_widths_) {
        auto output_start = &ngrams_data[output_start_idx];
        int length = splits_vec(i + 1) - splits_vec(i);
        int num_ngrams = get_num_ngrams(length, ngram_width);
        CreateNgrams(data_start, output_start, num_ngrams, ngram_width);
        output_start_idx += num_ngrams;
      }
      // If we're preserving short sequences, check to see if no sequence was
      // generated by comparing the current output start idx to the original
      // one (ngram_splits_data). If no ngrams were generated, then they will
      // be equal (since we increment output_start_idx by num_ngrams every
      // time we create a set of ngrams.)
      if (preserve_short_ && output_start_idx == ngrams_splits_data[i]) {
        int data_length = splits_vec(i + 1) - splits_vec(i);
        // One legitimate reason to not have any ngrams when preserve_short_
        // is true is if the sequence itself is empty. In that case, move on.
        if (data_length == 0) {
          continue;
        }
        // We don't have to worry about dynamic padding sizes here: if padding
        // was dynamic, every sequence would have had sufficient padding to
        // generate at least one ngram.

        // If reached here, pad_width should be > 0, pad_width_ = -1,
        // which indicates max(ngram_widths) - 1 cannot be used here since
        // ngram_width is not known.
        OP_REQUIRES(
            context, pad_width_ >= 0,
            errors::InvalidArgument("Pad width should be >= 0 when "
                                    "preserve_short_sequences is True and "
                                    "ngram_widths are not provided, got ",
                                    pad_width_));
        int ngram_width = data_length + 2 * pad_width_;
        auto output_start = &ngrams_data[output_start_idx];
        int num_ngrams = 1;
        CreateNgrams(data_start, output_start, num_ngrams, ngram_width);
      }
    }
  }


static int vidioc_querycap(struct file *file, void *priv,
			   struct v4l2_capability *cap)
{
	struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file);
	int labellen = (sizeof(cap->card) < sizeof(dev->card_label)) ?
			       sizeof(cap->card) :
				     sizeof(dev->card_label);
	int device_nr =
		((struct v4l2loopback_private *)video_get_drvdata(dev->vdev))
			->device_nr;
	__u32 capabilities = V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;

	strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver));
	snprintf(cap->card, labellen, dev->card_label);
	snprintf(cap->bus_info, sizeof(cap->bus_info),
		 "platform:v4l2loopback-%03d", device_nr);

#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0)
	/* since 3.1.0, the v4l2-core system is supposed to set the version */
	cap->version = V4L2LOOPBACK_VERSION_CODE;
#endif

#ifdef V4L2_CAP_VIDEO_M2M
	capabilities |= V4L2_CAP_VIDEO_M2M;
#endif /* V4L2_CAP_VIDEO_M2M */

	if (dev->announce_all_caps) {
		capabilities |= V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT;
	} else {
		if (dev->ready_for_capture) {
			capabilities |= V4L2_CAP_VIDEO_CAPTURE;
		}
		if (dev->ready_for_output) {
			capabilities |= V4L2_CAP_VIDEO_OUTPUT;
		}
	}

#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
	dev->vdev->device_caps =
#endif /* >=linux-4.7.0 */
		cap->device_caps = cap->capabilities = capabilities;

#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 3, 0)
	cap->capabilities |= V4L2_CAP_DEVICE_CAPS;
#endif

	memset(cap->reserved, 0, sizeof(cap->reserved));
	return 0;
}

add explicit format specifier to printf() invocations

CWE-134


static int vidioc_querycap(struct file *file, void *priv,
			   struct v4l2_capability *cap)
{
	struct v4l2_loopback_device *dev = v4l2loopback_getdevice(file);
	int labellen = (sizeof(cap->card) < sizeof(dev->card_label)) ?
			       sizeof(cap->card) :
				     sizeof(dev->card_label);
	int device_nr =
		((struct v4l2loopback_private *)video_get_drvdata(dev->vdev))
			->device_nr;
	__u32 capabilities = V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;

	strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver));
	snprintf(cap->card, labellen, "%s", dev->card_label);
	snprintf(cap->bus_info, sizeof(cap->bus_info),
		 "platform:v4l2loopback-%03d", device_nr);

#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 1, 0)
	/* since 3.1.0, the v4l2-core system is supposed to set the version */
	cap->version = V4L2LOOPBACK_VERSION_CODE;
#endif

#ifdef V4L2_CAP_VIDEO_M2M
	capabilities |= V4L2_CAP_VIDEO_M2M;
#endif /* V4L2_CAP_VIDEO_M2M */

	if (dev->announce_all_caps) {
		capabilities |= V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT;
	} else {
		if (dev->ready_for_capture) {
			capabilities |= V4L2_CAP_VIDEO_CAPTURE;
		}
		if (dev->ready_for_output) {
			capabilities |= V4L2_CAP_VIDEO_OUTPUT;
		}
	}

#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 7, 0)
	dev->vdev->device_caps =
#endif /* >=linux-4.7.0 */
		cap->device_caps = cap->capabilities = capabilities;

#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 3, 0)
	cap->capabilities |= V4L2_CAP_DEVICE_CAPS;
#endif

	memset(cap->reserved, 0, sizeof(cap->reserved));
	return 0;
}


bool IsIdentityConsumingSwitch(const MutableGraphView& graph,
                               const NodeDef& node) {
  if ((IsIdentity(node) || IsIdentityNSingleInput(node)) &&
      node.input_size() > 0) {
    TensorId tensor_id = ParseTensorName(node.input(0));
    if (IsTensorIdControlling(tensor_id)) {
      return false;
    }

    NodeDef* input_node = graph.GetNode(tensor_id.node());
    return IsSwitch(*input_node);
  }
  return false;
}

Prevent null pointer dereference in `mutable_graph_view`

PiperOrigin-RevId: 409684472
Change-Id: I577eb9d9ac470fcec0501423171e739a4ec0cb5c


bool IsIdentityConsumingSwitch(const MutableGraphView& graph,
                               const NodeDef& node) {
  if ((IsIdentity(node) || IsIdentityNSingleInput(node)) &&
      node.input_size() > 0) {
    TensorId tensor_id = ParseTensorName(node.input(0));
    if (IsTensorIdControlling(tensor_id)) {
      return false;
    }

    NodeDef* input_node = graph.GetNode(tensor_id.node());
    if (input_node == nullptr) {
      return false;
    }
    return IsSwitch(*input_node);
  }
  return false;
}


int TfLiteIntArrayGetSizeInBytes(int size) {
  static TfLiteIntArray dummy;

  int computed_size = sizeof(dummy) + sizeof(dummy.data[0]) * size;
#if defined(_MSC_VER)
  // Context for why this is needed is in http://b/189926408#comment21
  computed_size -= sizeof(dummy.data[0]);
#endif
  return computed_size;
}

[lite] Update TfLiteIntArrayCreate to return size_t

PiperOrigin-RevId: 416439896
Change-Id: I847f69b68d1ddaff4b1e925a09b8b69c1756653b


size_t TfLiteIntArrayGetSizeInBytes(int size) {
  static TfLiteIntArray dummy;

  size_t computed_size = sizeof(dummy) + sizeof(dummy.data[0]) * size;
#if defined(_MSC_VER)
  // Context for why this is needed is in http://b/189926408#comment21
  computed_size -= sizeof(dummy.data[0]);
#endif
  return computed_size;
}


TfLiteIntArray* TfLiteIntArrayCreate(int size) {
  int alloc_size = TfLiteIntArrayGetSizeInBytes(size);
  if (alloc_size <= 0) return NULL;
  TfLiteIntArray* ret = (TfLiteIntArray*)malloc(alloc_size);
  if (!ret) return ret;
  ret->size = size;
  return ret;
}


TfLiteIntArray* TfLiteIntArrayCreate(int size) {
  size_t alloc_size = TfLiteIntArrayGetSizeInBytes(size);
  if (alloc_size <= 0) return NULL;
  TfLiteIntArray* ret = (TfLiteIntArray*)malloc(alloc_size);
  if (!ret) return ret;
  ret->size = size;
  return ret;
}


  void Compute(OpKernelContext* context) override {
    typedef Eigen::Map<const Eigen::Matrix<T, Eigen::Dynamic, Eigen::Dynamic>>
        ConstEigenMatrixMap;
    typedef Eigen::Map<Eigen::Matrix<T, Eigen::Dynamic, Eigen::Dynamic>>
        EigenMatrixMap;

    constexpr int tensor_in_and_out_dims = 4;

    const Tensor& tensor_in = context->input(0);
    OP_REQUIRES(context, tensor_in.dims() == tensor_in_and_out_dims,
                errors::InvalidArgument("tensor_in must be 4-dimensional"));

    std::vector<int> input_size(tensor_in_and_out_dims);
    std::vector<int> output_size(tensor_in_and_out_dims);
    for (int i = 0; i < tensor_in_and_out_dims; ++i) {
      input_size[i] = tensor_in.dim_size(i);
    }
    // Output size.
    for (int i = 0; i < tensor_in_and_out_dims; ++i) {
      // This must match the same logic in the shape function in
      // core/ops/nn_ops.cc.
      output_size[i] =
          static_cast<int>(std::floor(input_size[i] / pooling_ratio_[i]));
      DCHECK_GT(output_size[i], 0);
    }

    // Generate pooling sequence.
    std::vector<int64_t> height_cum_seq;
    std::vector<int64_t> width_cum_seq;
    GuardedPhiloxRandom generator;
    generator.Init(seed_, seed2_);
    height_cum_seq = GeneratePoolingSequence(input_size[1], output_size[1],
                                             &generator, pseudo_random_);
    width_cum_seq = GeneratePoolingSequence(input_size[2], output_size[2],
                                            &generator, pseudo_random_);

    // Prepare output.
    Tensor* output_tensor = nullptr;
    OP_REQUIRES_OK(context, context->allocate_output(
                                0,
                                TensorShape({output_size[0], output_size[1],
                                             output_size[2], output_size[3]}),
                                &output_tensor));
    Tensor* output_height_seq_tensor = nullptr;
    OP_REQUIRES_OK(
        context,
        context->allocate_output(
            1, TensorShape({static_cast<int64_t>(height_cum_seq.size())}),
            &output_height_seq_tensor));
    Tensor* output_width_seq_tensor = nullptr;
    OP_REQUIRES_OK(
        context,
        context->allocate_output(
            2, TensorShape({static_cast<int64_t>(width_cum_seq.size())}),
            &output_width_seq_tensor));

    ConstEigenMatrixMap in_mat(tensor_in.flat<T>().data(), input_size[3],
                               input_size[2] * input_size[1] * input_size[0]);

    EigenMatrixMap out_mat(output_tensor->flat<T>().data(), output_size[3],
                           output_size[2] * output_size[1] * output_size[0]);

    // Initializes the output tensor with MIN<T>.
    output_tensor->flat<T>().setConstant(Eigen::NumTraits<T>::lowest());

    auto output_height_seq_flat = output_height_seq_tensor->flat<int64_t>();
    auto output_width_seq_flat = output_width_seq_tensor->flat<int64_t>();

    // Set output tensors.
    for (int i = 0; i < height_cum_seq.size(); ++i) {
      output_height_seq_flat(i) = height_cum_seq[i];
    }

    for (int i = 0; i < width_cum_seq.size(); ++i) {
      output_width_seq_flat(i) = width_cum_seq[i];
    }

    // For both input and output,
    // 0: batch
    // 1: height / row
    // 2: width / col
    // 3: depth / channel
    const int64_t height_max = input_size[1] - 1;
    const int64_t width_max = input_size[2] - 1;
    for (int64_t b = 0; b < input_size[0]; ++b) {
      // height sequence.
      for (int64_t hs = 0; hs < height_cum_seq.size() - 1; ++hs) {
        // height start and end.
        const int64_t height_start = height_cum_seq[hs];
        int64_t height_end =
            overlapping_ ? height_cum_seq[hs + 1] : height_cum_seq[hs + 1] - 1;
        height_end = std::min(height_end, height_max);

        // width sequence.
        for (int64_t ws = 0; ws < width_cum_seq.size() - 1; ++ws) {
          const int64_t out_offset =
              (b * output_size[1] + hs) * output_size[2] + ws;
          // width start and end.
          const int64_t width_start = width_cum_seq[ws];
          int64_t width_end =
              overlapping_ ? width_cum_seq[ws + 1] : width_cum_seq[ws + 1] - 1;
          width_end = std::min(width_end, width_max);
          for (int64_t h = height_start; h <= height_end; ++h) {
            for (int64_t w = width_start; w <= width_end; ++w) {
              const int64_t in_offset =
                  (b * input_size[1] + h) * input_size[2] + w;
              out_mat.col(out_offset) =
                  out_mat.col(out_offset).cwiseMax(in_mat.col(in_offset));
            }
          }
        }
      }
    }
  }

Fix potential divide by zero error when executing FractionalMaxPool, when pooling ratio is higher than input size for a particular dimension.

PiperOrigin-RevId: 412151722
Change-Id: I06e57cbb8eca43816eff79eac264fa7aae8f7163


  void Compute(OpKernelContext* context) override {
    typedef Eigen::Map<const Eigen::Matrix<T, Eigen::Dynamic, Eigen::Dynamic>>
        ConstEigenMatrixMap;
    typedef Eigen::Map<Eigen::Matrix<T, Eigen::Dynamic, Eigen::Dynamic>>
        EigenMatrixMap;

    constexpr int tensor_in_and_out_dims = 4;

    const Tensor& tensor_in = context->input(0);
    OP_REQUIRES(context, tensor_in.dims() == tensor_in_and_out_dims,
                errors::InvalidArgument("tensor_in must be 4-dimensional"));

    std::vector<int> input_size(tensor_in_and_out_dims);
    std::vector<int> output_size(tensor_in_and_out_dims);
    for (int i = 0; i < tensor_in_and_out_dims; ++i) {
      input_size[i] = tensor_in.dim_size(i);

      OP_REQUIRES(
          context, input_size[i] >= pooling_ratio_[i],
          errors::InvalidArgument("Pooling ratio is higher than input "
                                  "dimension size for dimension ",
                                  i, ". Input dim size: ", input_size[i],
                                  " pooling ratio: ", pooling_ratio_[i]));
    }
    // Output size.
    for (int i = 0; i < tensor_in_and_out_dims; ++i) {
      // This must match the same logic in the shape function in
      // core/ops/nn_ops.cc.
      output_size[i] =
          static_cast<int>(std::floor(input_size[i] / pooling_ratio_[i]));
      DCHECK_GT(output_size[i], 0);
    }

    // Generate pooling sequence.
    std::vector<int64_t> height_cum_seq;
    std::vector<int64_t> width_cum_seq;
    GuardedPhiloxRandom generator;
    generator.Init(seed_, seed2_);
    height_cum_seq = GeneratePoolingSequence(input_size[1], output_size[1],
                                             &generator, pseudo_random_);
    width_cum_seq = GeneratePoolingSequence(input_size[2], output_size[2],
                                            &generator, pseudo_random_);

    // Prepare output.
    Tensor* output_tensor = nullptr;
    OP_REQUIRES_OK(context, context->allocate_output(
                                0,
                                TensorShape({output_size[0], output_size[1],
                                             output_size[2], output_size[3]}),
                                &output_tensor));
    Tensor* output_height_seq_tensor = nullptr;
    OP_REQUIRES_OK(
        context,
        context->allocate_output(
            1, TensorShape({static_cast<int64_t>(height_cum_seq.size())}),
            &output_height_seq_tensor));
    Tensor* output_width_seq_tensor = nullptr;
    OP_REQUIRES_OK(
        context,
        context->allocate_output(
            2, TensorShape({static_cast<int64_t>(width_cum_seq.size())}),
            &output_width_seq_tensor));

    ConstEigenMatrixMap in_mat(tensor_in.flat<T>().data(), input_size[3],
                               input_size[2] * input_size[1] * input_size[0]);

    EigenMatrixMap out_mat(output_tensor->flat<T>().data(), output_size[3],
                           output_size[2] * output_size[1] * output_size[0]);

    // Initializes the output tensor with MIN<T>.
    output_tensor->flat<T>().setConstant(Eigen::NumTraits<T>::lowest());

    auto output_height_seq_flat = output_height_seq_tensor->flat<int64_t>();
    auto output_width_seq_flat = output_width_seq_tensor->flat<int64_t>();

    // Set output tensors.
    for (int i = 0; i < height_cum_seq.size(); ++i) {
      output_height_seq_flat(i) = height_cum_seq[i];
    }

    for (int i = 0; i < width_cum_seq.size(); ++i) {
      output_width_seq_flat(i) = width_cum_seq[i];
    }

    // For both input and output,
    // 0: batch
    // 1: height / row
    // 2: width / col
    // 3: depth / channel
    const int64_t height_max = input_size[1] - 1;
    const int64_t width_max = input_size[2] - 1;
    for (int64_t b = 0; b < input_size[0]; ++b) {
      // height sequence.
      for (int64_t hs = 0; hs < height_cum_seq.size() - 1; ++hs) {
        // height start and end.
        const int64_t height_start = height_cum_seq[hs];
        int64_t height_end =
            overlapping_ ? height_cum_seq[hs + 1] : height_cum_seq[hs + 1] - 1;
        height_end = std::min(height_end, height_max);

        // width sequence.
        for (int64_t ws = 0; ws < width_cum_seq.size() - 1; ++ws) {
          const int64_t out_offset =
              (b * output_size[1] + hs) * output_size[2] + ws;
          // width start and end.
          const int64_t width_start = width_cum_seq[ws];
          int64_t width_end =
              overlapping_ ? width_cum_seq[ws + 1] : width_cum_seq[ws + 1] - 1;
          width_end = std::min(width_end, width_max);
          for (int64_t h = height_start; h <= height_end; ++h) {
            for (int64_t w = width_start; w <= width_end; ++w) {
              const int64_t in_offset =
                  (b * input_size[1] + h) * input_size[2] + w;
              out_mat.col(out_offset) =
                  out_mat.col(out_offset).cwiseMax(in_mat.col(in_offset));
            }
          }
        }
      }
    }
  }


static Image *ReadPCLImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
#define CropBox  "CropBox"
#define DeviceCMYK  "DeviceCMYK"
#define MediaBox  "MediaBox"
#define RenderPCLText  "  Rendering PCL...  "

  char
    command[MaxTextExtent],
    *density,
    filename[MaxTextExtent],
    geometry[MaxTextExtent],
    *options,
    input_filename[MaxTextExtent];

  const DelegateInfo
    *delegate_info;

  Image
    *image,
    *next_image;

  ImageInfo
    *read_info;

  int
    c;

  MagickBooleanType
    cmyk,
    status;

  PointInfo
    delta;

  RectangleInfo
    bounding_box,
    page;

  char
    *p;

  SegmentInfo
    bounds;

  size_t
    height,
    width;

  ssize_t
    count;

  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  /*
    Open image file.
  */
  image=AcquireImage(image_info);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  status=AcquireUniqueSymbolicLink(image_info->filename,input_filename);
  if (status == MagickFalse)
    {
      ThrowFileException(exception,FileOpenError,"UnableToCreateTemporaryFile",
        image_info->filename);
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  /*
    Set the page density.
  */
  delta.x=DefaultResolution;
  delta.y=DefaultResolution;
  if ((image->x_resolution == 0.0) || (image->y_resolution == 0.0))
    {
      GeometryInfo
        geometry_info;

      MagickStatusType
        flags;

      flags=ParseGeometry(PSDensityGeometry,&geometry_info);
      if ((flags & RhoValue) != 0)
        image->x_resolution=geometry_info.rho;
      image->y_resolution=image->x_resolution;
      if ((flags & SigmaValue) != 0)
        image->y_resolution=geometry_info.sigma;
    }
  /*
    Determine page geometry from the PCL media box.
  */
  cmyk=image->colorspace == CMYKColorspace ? MagickTrue : MagickFalse;
  count=0;
  (void) memset(&bounding_box,0,sizeof(bounding_box));
  (void) memset(&bounds,0,sizeof(bounds));
  (void) memset(&page,0,sizeof(page));
  (void) memset(command,0,sizeof(command));
  p=command;
  for (c=ReadBlobByte(image); c != EOF; c=ReadBlobByte(image))
  {
    if (image_info->page != (char *) NULL)
      continue;
    /*
      Note PCL elements.
    */
    *p++=(char) c;
    if ((c != (int) '/') && (c != '\n') &&
        ((size_t) (p-command) < (MaxTextExtent-1)))
      continue;
    *p='\0';
    p=command;
    /*
      Is this a CMYK document?
    */
    if (LocaleNCompare(DeviceCMYK,command,strlen(DeviceCMYK)) == 0)
      cmyk=MagickTrue;
    if (LocaleNCompare(CropBox,command,strlen(CropBox)) == 0)
      {
        /*
          Note region defined by crop box.
        */
        count=(ssize_t) sscanf(command,"CropBox [%lf %lf %lf %lf",
          &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
        if (count != 4)
          count=(ssize_t) sscanf(command,"CropBox[%lf %lf %lf %lf",
            &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
      }
    if (LocaleNCompare(MediaBox,command,strlen(MediaBox)) == 0)
      {
        /*
          Note region defined by media box.
        */
        count=(ssize_t) sscanf(command,"MediaBox [%lf %lf %lf %lf",
          &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
        if (count != 4)
          count=(ssize_t) sscanf(command,"MediaBox[%lf %lf %lf %lf",
            &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
      }
    if (count != 4)
      continue;
    /*
      Set PCL render geometry.
    */
    width=(size_t) floor(bounds.x2-bounds.x1+0.5);
    height=(size_t) floor(bounds.y2-bounds.y1+0.5);
    if (width > page.width)
      page.width=width;
    if (height > page.height)
      page.height=height;
  }
  (void) CloseBlob(image);
  /*
    Render PCL with the GhostPCL delegate.
  */
  if ((page.width == 0) || (page.height == 0))
    (void) ParseAbsoluteGeometry(PSPageGeometry,&page);
  if (image_info->page != (char *) NULL)
    (void) ParseAbsoluteGeometry(image_info->page,&page);
  (void) FormatLocaleString(geometry,MaxTextExtent,"%.20gx%.20g",(double)
    page.width,(double) page.height);
  if (image_info->monochrome != MagickFalse)
    delegate_info=GetDelegateInfo("pcl:mono",(char *) NULL,exception);
  else
     if (cmyk != MagickFalse)
       delegate_info=GetDelegateInfo("pcl:cmyk",(char *) NULL,exception);
     else
       delegate_info=GetDelegateInfo("pcl:color",(char *) NULL,exception);
  if (delegate_info == (const DelegateInfo *) NULL)
    {
      image=DestroyImage(image);
      return((Image *) NULL);
    }
  if ((page.width == 0) || (page.height == 0))
    (void) ParseAbsoluteGeometry(PSPageGeometry,&page);
  if (image_info->page != (char *) NULL)
    (void) ParseAbsoluteGeometry(image_info->page,&page);
  density=AcquireString("");
  options=AcquireString("");
  (void) FormatLocaleString(density,MaxTextExtent,"%gx%g",
    image->x_resolution,image->y_resolution);
  if (image_info->ping != MagickFalse)
    (void) FormatLocaleString(density,MagickPathExtent,"2.0x2.0");
  page.width=(size_t) floor((double) page.width*image->x_resolution/delta.x+
    0.5);
  page.height=(size_t) floor((double) page.height*image->y_resolution/delta.y+
    0.5);
  (void) FormatLocaleString(options,MaxTextExtent,"-g%.20gx%.20g ",(double)
     page.width,(double) page.height);
  image=DestroyImage(image);
  read_info=CloneImageInfo(image_info);
  *read_info->magick='\0';
  if (read_info->number_scenes != 0)
    {
      if (read_info->number_scenes != 1)
        (void) FormatLocaleString(options,MaxTextExtent,"-dLastPage=%.20g",
          (double) (read_info->scene+read_info->number_scenes));
      else
        (void) FormatLocaleString(options,MaxTextExtent,
          "-dFirstPage=%.20g -dLastPage=%.20g",(double) read_info->scene+1,
          (double) (read_info->scene+read_info->number_scenes));
      read_info->number_scenes=0;
      if (read_info->scenes != (char *) NULL)
        *read_info->scenes='\0';
    }
  (void) CopyMagickString(filename,read_info->filename,MaxTextExtent);
  (void) AcquireUniqueFilename(read_info->filename);
  (void) FormatLocaleString(command,MaxTextExtent,
    GetDelegateCommands(delegate_info),
    read_info->antialias != MagickFalse ? 4 : 1,
    read_info->antialias != MagickFalse ? 4 : 1,density,options,
    read_info->filename,input_filename);
  options=DestroyString(options);
  density=DestroyString(density);
  status=ExternalDelegateCommand(MagickFalse,read_info->verbose,command,
    (char *) NULL,exception) != 0 ? MagickTrue : MagickFalse;
  image=ReadImage(read_info,exception);
  (void) RelinquishUniqueFileResource(read_info->filename);
  (void) RelinquishUniqueFileResource(input_filename);
  read_info=DestroyImageInfo(read_info);
  if (image == (Image *) NULL)
    ThrowReaderException(DelegateError,"PCLDelegateFailed");
  if (LocaleCompare(image->magick,"BMP") == 0)
    {
      Image
        *cmyk_image;

      cmyk_image=ConsolidateCMYKImages(image,&image->exception);
      if (cmyk_image != (Image *) NULL)
        {
          image=DestroyImageList(image);
          image=cmyk_image;
        }
    }
  do
  {
    (void) CopyMagickString(image->filename,filename,MaxTextExtent);
    image->page=page;
    if (image_info->ping != MagickFalse)
      {
        image->magick_columns*=image->x_resolution/2.0;
        image->magick_rows*=image->y_resolution/2.0;
        image->columns*=image->x_resolution/2.0;
        image->rows*=image->y_resolution/2.0;
      }
    next_image=SyncNextImageInList(image);
    if (next_image != (Image *) NULL)
      image=next_image;
  } while (next_image != (Image *) NULL);
  return(GetFirstImageInList(image));
}


static Image *ReadPCLImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
#define CropBox  "CropBox"
#define DeviceCMYK  "DeviceCMYK"
#define MediaBox  "MediaBox"
#define RenderPCLText  "  Rendering PCL...  "

  char
    command[MaxTextExtent],
    *density,
    filename[MaxTextExtent],
    geometry[MaxTextExtent],
    *options,
    input_filename[MaxTextExtent];

  const DelegateInfo
    *delegate_info;

  Image
    *image,
    *next_image;

  ImageInfo
    *read_info;

  int
    c;

  MagickBooleanType
    cmyk,
    status;

  PointInfo
    delta;

  RectangleInfo
    bounding_box,
    page;

  char
    *p;

  SegmentInfo
    bounds;

  size_t
    height,
    width;

  ssize_t
    count;

  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickCoreSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickCoreSignature);
  /*
    Open image file.
  */
  image=AcquireImage(image_info);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  status=AcquireUniqueSymbolicLink(image_info->filename,input_filename);
  if (status == MagickFalse)
    {
      ThrowFileException(exception,FileOpenError,"UnableToCreateTemporaryFile",
        image_info->filename);
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  /*
    Set the page density.
  */
  delta.x=DefaultResolution;
  delta.y=DefaultResolution;
  if ((image->x_resolution == 0.0) || (image->y_resolution == 0.0))
    {
      GeometryInfo
        geometry_info;

      MagickStatusType
        flags;

      flags=ParseGeometry(PSDensityGeometry,&geometry_info);
      if ((flags & RhoValue) != 0)
        image->x_resolution=geometry_info.rho;
      image->y_resolution=image->x_resolution;
      if ((flags & SigmaValue) != 0)
        image->y_resolution=geometry_info.sigma;
    }
  /*
    Determine page geometry from the PCL media box.
  */
  cmyk=image->colorspace == CMYKColorspace ? MagickTrue : MagickFalse;
  count=0;
  (void) memset(&bounding_box,0,sizeof(bounding_box));
  (void) memset(&bounds,0,sizeof(bounds));
  (void) memset(&page,0,sizeof(page));
  (void) memset(command,0,sizeof(command));
  p=command;
  for (c=ReadBlobByte(image); c != EOF; c=ReadBlobByte(image))
  {
    if (image_info->page != (char *) NULL)
      continue;
    /*
      Note PCL elements.
    */
    *p++=(char) c;
    if ((c != (int) '/') && (c != '\n') &&
        ((size_t) (p-command) < (MaxTextExtent-1)))
      continue;
    *p='\0';
    p=command;
    /*
      Is this a CMYK document?
    */
    if (LocaleNCompare(DeviceCMYK,command,strlen(DeviceCMYK)) == 0)
      cmyk=MagickTrue;
    if (LocaleNCompare(CropBox,command,strlen(CropBox)) == 0)
      {
        /*
          Note region defined by crop box.
        */
        count=(ssize_t) sscanf(command,"CropBox [%lf %lf %lf %lf",
          &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
        if (count != 4)
          count=(ssize_t) sscanf(command,"CropBox[%lf %lf %lf %lf",
            &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
      }
    if (LocaleNCompare(MediaBox,command,strlen(MediaBox)) == 0)
      {
        /*
          Note region defined by media box.
        */
        count=(ssize_t) sscanf(command,"MediaBox [%lf %lf %lf %lf",
          &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
        if (count != 4)
          count=(ssize_t) sscanf(command,"MediaBox[%lf %lf %lf %lf",
            &bounds.x1,&bounds.y1,&bounds.x2,&bounds.y2);
      }
    if (count != 4)
      continue;
    /*
      Set PCL render geometry.
    */
    width=(size_t) CastDoubleToLong(floor(bounds.x2-bounds.x1+0.5));
    height=(size_t) CastDoubleToLong(floor(bounds.y2-bounds.y1+0.5));
    if (width > page.width)
      page.width=width;
    if (height > page.height)
      page.height=height;
  }
  (void) CloseBlob(image);
  /*
    Render PCL with the GhostPCL delegate.
  */
  if ((page.width == 0) || (page.height == 0))
    (void) ParseAbsoluteGeometry(PSPageGeometry,&page);
  if (image_info->page != (char *) NULL)
    (void) ParseAbsoluteGeometry(image_info->page,&page);
  (void) FormatLocaleString(geometry,MaxTextExtent,"%.20gx%.20g",(double)
    page.width,(double) page.height);
  if (image_info->monochrome != MagickFalse)
    delegate_info=GetDelegateInfo("pcl:mono",(char *) NULL,exception);
  else
     if (cmyk != MagickFalse)
       delegate_info=GetDelegateInfo("pcl:cmyk",(char *) NULL,exception);
     else
       delegate_info=GetDelegateInfo("pcl:color",(char *) NULL,exception);
  if (delegate_info == (const DelegateInfo *) NULL)
    {
      image=DestroyImage(image);
      return((Image *) NULL);
    }
  if ((page.width == 0) || (page.height == 0))
    (void) ParseAbsoluteGeometry(PSPageGeometry,&page);
  if (image_info->page != (char *) NULL)
    (void) ParseAbsoluteGeometry(image_info->page,&page);
  density=AcquireString("");
  options=AcquireString("");
  (void) FormatLocaleString(density,MaxTextExtent,"%gx%g",
    image->x_resolution,image->y_resolution);
  if (image_info->ping != MagickFalse)
    (void) FormatLocaleString(density,MagickPathExtent,"2.0x2.0");
  page.width=(size_t) floor((double) page.width*image->x_resolution/delta.x+
    0.5);
  page.height=(size_t) floor((double) page.height*image->y_resolution/delta.y+
    0.5);
  (void) FormatLocaleString(options,MaxTextExtent,"-g%.20gx%.20g ",(double)
     page.width,(double) page.height);
  image=DestroyImage(image);
  read_info=CloneImageInfo(image_info);
  *read_info->magick='\0';
  if (read_info->number_scenes != 0)
    {
      if (read_info->number_scenes != 1)
        (void) FormatLocaleString(options,MaxTextExtent,"-dLastPage=%.20g",
          (double) (read_info->scene+read_info->number_scenes));
      else
        (void) FormatLocaleString(options,MaxTextExtent,
          "-dFirstPage=%.20g -dLastPage=%.20g",(double) read_info->scene+1,
          (double) (read_info->scene+read_info->number_scenes));
      read_info->number_scenes=0;
      if (read_info->scenes != (char *) NULL)
        *read_info->scenes='\0';
    }
  (void) CopyMagickString(filename,read_info->filename,MaxTextExtent);
  (void) AcquireUniqueFilename(read_info->filename);
  (void) FormatLocaleString(command,MaxTextExtent,
    GetDelegateCommands(delegate_info),
    read_info->antialias != MagickFalse ? 4 : 1,
    read_info->antialias != MagickFalse ? 4 : 1,density,options,
    read_info->filename,input_filename);
  options=DestroyString(options);
  density=DestroyString(density);
  status=ExternalDelegateCommand(MagickFalse,read_info->verbose,command,
    (char *) NULL,exception) != 0 ? MagickTrue : MagickFalse;
  image=ReadImage(read_info,exception);
  (void) RelinquishUniqueFileResource(read_info->filename);
  (void) RelinquishUniqueFileResource(input_filename);
  read_info=DestroyImageInfo(read_info);
  if (image == (Image *) NULL)
    ThrowReaderException(DelegateError,"PCLDelegateFailed");
  if (LocaleCompare(image->magick,"BMP") == 0)
    {
      Image
        *cmyk_image;

      cmyk_image=ConsolidateCMYKImages(image,&image->exception);
      if (cmyk_image != (Image *) NULL)
        {
          image=DestroyImageList(image);
          image=cmyk_image;
        }
    }
  do
  {
    (void) CopyMagickString(image->filename,filename,MaxTextExtent);
    image->page=page;
    if (image_info->ping != MagickFalse)
      {
        image->magick_columns*=image->x_resolution/2.0;
        image->magick_rows*=image->y_resolution/2.0;
        image->columns*=image->x_resolution/2.0;
        image->rows*=image->y_resolution/2.0;
      }
    next_image=SyncNextImageInList(image);
    if (next_image != (Image *) NULL)
      image=next_image;
  } while (next_image != (Image *) NULL);
  return(GetFirstImageInList(image));
}


void gitn_box_del(GF_Box *s)
{
	u32 i;
	GroupIdToNameBox *ptr = (GroupIdToNameBox *)s;
	if (ptr == NULL) return;
	for (i=0; i<ptr->nb_entries; i++) {
		if (ptr->entries[i].name) gf_free(ptr->entries[i].name);
	}
	if (ptr->entries) gf_free(ptr->entries);
	gf_free(ptr);

fixed #2092


void gitn_box_del(GF_Box *s)
{
	u32 i;
	GroupIdToNameBox *ptr = (GroupIdToNameBox *)s;
	if (ptr == NULL) return;
	if (ptr->entries) {
		for (i=0; i<ptr->nb_entries; i++) {
			if (ptr->entries[i].name) gf_free(ptr->entries[i].name);
		}
		gf_free(ptr->entries);
	}
	gf_free(ptr);

fixed #2092


  void MakeDataset(OpKernelContext* ctx, DatasetBase** output) override {
    // Create a new SparseTensorSliceDatasetOp::Dataset, insert it in
    // the step container, and return it as the output.
    const Tensor* indices;
    OP_REQUIRES_OK(ctx, ctx->input("indices", &indices));
    const Tensor* values;
    OP_REQUIRES_OK(ctx, ctx->input("values", &values));
    const Tensor* dense_shape;
    OP_REQUIRES_OK(ctx, ctx->input("dense_shape", &dense_shape));

    OP_REQUIRES(ctx, TensorShapeUtils::IsMatrix(indices->shape()),
                errors::InvalidArgument(
                    "Input indices should be a matrix but received shape ",
                    indices->shape().DebugString()));

    const auto num_indices = indices->NumElements();
    const auto num_values = values->NumElements();
    if (num_indices == 0 || num_values == 0) {
      OP_REQUIRES(ctx, num_indices == num_values,
                  errors::InvalidArgument(
                      "If indices or values are empty, the other one must also "
                      "be. Got indices of shape ",
                      indices->shape().DebugString(), " and values of shape ",
                      values->shape().DebugString()));
    }
    OP_REQUIRES(ctx, TensorShapeUtils::IsVector(values->shape()),
                errors::InvalidArgument(
                    "Input values should be a vector but received shape ",
                    indices->shape().DebugString()));
    OP_REQUIRES(ctx, TensorShapeUtils::IsVector(dense_shape->shape()),
                errors::InvalidArgument(
                    "Input shape should be a vector but received shape ",
                    dense_shape->shape().DebugString()));

    // We currently ensure that `sparse_tensor` is ordered in the
    // batch dimension.
    // TODO(mrry): Investigate ways to avoid this unconditional check
    // if we can be sure that the sparse tensor was produced in an
    // appropriate order (e.g. by `tf.parse_example()` or a Dataset
    // that batches elements into rows of a SparseTensor).
    int64_t previous_batch_index = -1;
    for (int64_t i = 0; i < indices->dim_size(0); ++i) {
      int64_t next_batch_index = indices->matrix<int64_t>()(i, 0);
      OP_REQUIRES(
          ctx, next_batch_index >= previous_batch_index,
          errors::Unimplemented("The SparseTensor must be ordered in the batch "
                                "dimension; handling arbitrarily ordered input "
                                "is not currently supported."));
      previous_batch_index = next_batch_index;
    }
    gtl::InlinedVector<int64_t, 8> std_order(dense_shape->NumElements(), 0);
    sparse::SparseTensor tensor;
    OP_REQUIRES_OK(
        ctx, sparse::SparseTensor::Create(
                 *indices, *values, TensorShape(dense_shape->vec<int64_t>()),
                 std_order, &tensor));
    *output = new Dataset<T>(ctx, std::move(tensor));
  }

Properly validate sparse tensor in `SparseTensorSliceDataset`

Existing validation was incomplete.

PiperOrigin-RevId: 415375048
Change-Id: I14cd18f29ede73286f3ffac35171bd15828997e9


  void MakeDataset(OpKernelContext* ctx, DatasetBase** output) override {
    // Create a new SparseTensorSliceDatasetOp::Dataset, insert it in
    // the step container, and return it as the output.
    const Tensor* indices;
    OP_REQUIRES_OK(ctx, ctx->input("indices", &indices));
    const Tensor* values;
    OP_REQUIRES_OK(ctx, ctx->input("values", &values));
    const Tensor* dense_shape;
    OP_REQUIRES_OK(ctx, ctx->input("dense_shape", &dense_shape));

    OP_REQUIRES(ctx, TensorShapeUtils::IsMatrix(indices->shape()),
                errors::InvalidArgument("Input indices must be a matrix. Got: ",
                                        indices->shape().DebugString()));
    OP_REQUIRES(ctx, TensorShapeUtils::IsVector(values->shape()),
                errors::InvalidArgument("Input values must be a vector. Got: ",
                                        values->shape().DebugString()));
    OP_REQUIRES(ctx, TensorShapeUtils::IsVector(dense_shape->shape()),
                errors::InvalidArgument("Input shape must be a vector. Got: ",
                                        dense_shape->shape().DebugString()));
    OP_REQUIRES(
        ctx, values->shape().dim_size(0) == indices->shape().dim_size(0),
        errors::InvalidArgument(
            "Number of values must match first dimension of indices. ", "Got ",
            values->shape().dim_size(0),
            " values, indices shape: ", indices->shape().DebugString()));
    OP_REQUIRES(
        ctx, dense_shape->shape().dim_size(0) == indices->shape().dim_size(1),
        errors::InvalidArgument(
            "Number of dimensions must match second dimension of indices. ",
            "Got ", dense_shape->shape().dim_size(0),
            " dimensions, indices shape: ", indices->shape().DebugString()));
    OP_REQUIRES(ctx, dense_shape->NumElements() > 0,
                errors::InvalidArgument(
                    "The shape argument requires at least one element."));

    // We currently ensure that `sparse_tensor` is ordered in the
    // batch dimension.
    // TODO(mrry): Investigate ways to avoid this unconditional check
    // if we can be sure that the sparse tensor was produced in an
    // appropriate order (e.g. by `tf.parse_example()` or a Dataset
    // that batches elements into rows of a SparseTensor).
    int64_t previous_batch_index = -1;
    for (int64_t i = 0; i < indices->dim_size(0); ++i) {
      int64_t next_batch_index = indices->matrix<int64_t>()(i, 0);
      OP_REQUIRES(
          ctx, next_batch_index >= previous_batch_index,
          errors::Unimplemented("The SparseTensor must be ordered in the batch "
                                "dimension; handling arbitrarily ordered input "
                                "is not currently supported."));
      previous_batch_index = next_batch_index;
    }
    gtl::InlinedVector<int64_t, 8> std_order(dense_shape->NumElements(), 0);
    sparse::SparseTensor tensor;
    OP_REQUIRES_OK(
        ctx, sparse::SparseTensor::Create(
                 *indices, *values, TensorShape(dense_shape->vec<int64_t>()),
                 std_order, &tensor));
    *output = new Dataset<T>(ctx, std::move(tensor));
  }