text: /**
   *  Copyright 2009-2014 MongoDB, Inc.
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   */
  #include <string.h>
  #include <errno.h>
  #include <sys/types.h>
  #ifdef WIN32
  #include <winsock2.h>
  #include <ws2tcpip.h>
  #endif
  #ifndef WIN32
  #include <sys/socket.h>
  #include <sys/time.h>
  #include <unistd.h>
  #endif
  #include <stdlib.h>
  #include <stdio.h>
  #include "types.h"
  
  #ifndef WIN32
  #include <poll.h>
  
  /* Wait on socket availability with a timeout
   *
   * Returns:
   * 0 on success
   * -1 on failure, but not critical enough to throw an exception
   * 1.. on failure, and throw an exception. The return value is the error code */
  int mongo_io_wait_with_timeout(int sock, int timeout, char **error_message)
  {
  	/* Socket timeout behavior varies based on the following:
  	 * - Negative => no timeout (i.e. block indefinitely)
  	 * - Zero => not specified (use default)
  	 * - Positive => used specified timeout
  	 *
  	 * Note: MONGO_CONNECTION_DEFAULT_CONNECT_TIMEOUT is used as the default
  	 * because it is consistent with default_socket_value (used by streams). We
  	 * don't actually reference the INI option here, since mcon has no PHP
  	 * dependencies. */
  	if (timeout < 0) {
  		timeout = -1;
  	}
  
  	if (timeout == 0) {
  		timeout = MONGO_CONNECTION_DEFAULT_CONNECT_TIMEOUT;
  	}
  
  	while (1) {
  		struct pollfd fds[1];
  		int status;
  
  		fds[0].fd = sock;
  		fds[0].events = POLLIN | POLLHUP | POLLERR;
  		status = poll(fds, 1, timeout);
  
  		if (status == -1) {
  			/* on EINTR, retry - this resets the timeout however to its full length */
  			if (errno == EINTR) {
  				continue;
  			}
  
  			*error_message = strdup(strerror(errno));
  			return 13;
  		}
  
  		if (status == 0) {
  			*error_message = malloc(256);
  			snprintf(
  				*error_message, 256,
  				"cursor timed out (timeout: %d, status: %d)",
  				timeout, status
  			);
  			return 80;
  		}
  
  		if (status > 0 && !(fds[0].revents & POLLIN)) {
  			*error_message = strdup("Exceptional condition on socket");
  			return 17;
  		}
  		break;
  	}
  
  	return 0;
  }
  #else
  
  /* Win32 doesn't have a working poll(), so we use the old select() branch. */
  int mongo_io_wait_with_timeout(int sock, int timeout, char **error_message)
  {
  	/* Socket timeout behavior varies based on the following:
  	 * - Negative => no timeout (i.e. block indefinitely)
  	 * - Zero => not specified (use default)
  	 * - Positive => used specified timeout
  	 *
  	 * Note: MONGO_CONNECTION_DEFAULT_CONNECT_TIMEOUT is used as the default
  	 * because it is consistent with default_socket_value (used by streams). We
  	 * don't actually reference the INI option here, since mcon has no PHP
  	 * dependencies. */
  	if (timeout == 0) {
  		timeout = MONGO_CONNECTION_DEFAULT_CONNECT_TIMEOUT;
  	}
  
  
  	while (1) {
  		int status;
  		struct timeval tval;
  		fd_set readfds, exceptfds;
  
  		FD_ZERO(&readfds);
  		FD_SET(sock, &readfds);
  		FD_ZERO(&exceptfds);
  		FD_SET(sock, &exceptfds);
  
  		if (timeout >= 0) {
  			tval.tv_sec = timeout / 1000;
  			tval.tv_usec = (timeout % 1000) * 1000;
  		}
  
  		status = select(sock+1, &readfds, NULL, &exceptfds, timeout >= 0 ? &tval : NULL);
  
  		if (status == -1) {
  			/* on EINTR, retry - this resets the timeout however to its full length */
  			if (errno == EINTR) {
  				continue;
  			}
  
  			*error_message = strdup(strerror(errno));
  			return 13;
  		}
  
  		if (FD_ISSET(sock, &exceptfds)) {
  			*error_message = strdup("Exceptional condition on socket");
  			return 17;
  		}
  
  		if (status == 0 && !FD_ISSET(sock, &readfds)) {
  			*error_message = malloc(256);
  			snprintf(
  				*error_message, 256,
  				"cursor timed out (timeout: %d, time left: %ld:%ld, status: %d)",
  				timeout, (long) tval.tv_sec, (long) tval.tv_usec, status
  			);
  			return 80;
  		}
  
  		/* if our descriptor is ready break out */
  		if (FD_ISSET(sock, &readfds)) {
  			break;
  		}
  	}
  
  	return 0;
  }
  #endif
  
  /* Low-level send function.
   *
   * Goes through the buffer sending 4K byte batches.
   * On failure, sets errmsg to errno string and returns -1.
   * On success, returns number of bytes sent.
   * Does not attempt to reconnect nor throw any exceptions.
   *
   * On failure, the calling function is responsible for disconnecting */
  int mongo_io_send(mongo_connection *con, mongo_server_options *options, void *data, int size, char **error_message)
  {
  	int sent = 0, status = 1;
  
  	while (sent < size && status > 0) {
  		int len = 4096 < (size - sent) ? 4096 : size - sent;
  
  		status = send((int) (long)con->socket, (const char*)data + sent, len, 0);
  
  		if (status == -1) {
  			*error_message = strdup(strerror(errno));
  			return -1;
  		}
  		sent += status;
  	}
  
  	return sent;
  }
  
  /* Low-level receive functions.
   *
   * On failure, sets errmsg to errno string and returns -1.
   * On success, returns number of bytes read.
   * Does not attempt to reconnect nor throw any exceptions.
   *
   * On failure, the calling function is responsible for disconnecting */
  int mongo_io_recv_header(mongo_connection *con, mongo_server_options *options, int timeout, void *data, int size, char **error_message)
  {
  	int status = mongo_io_wait_with_timeout((int) (long)con->socket, timeout ? timeout : options->socketTimeoutMS, error_message);
  
  	if (status != 0) {
  		/* We don't care which failure it was, it just failed and the error_message has been set */
  		*error_message = strdup("Timed out waiting for header data");
  		return -80;
  	}
  	status = recv((int) (long) con->socket, data, size, 0);
  
  	if (status == -1) {
  		*error_message = strdup(strerror(errno));
  #ifndef WIN32
  		if (errno == ECONNRESET) {
  			return -32;
  		} else {
  			return -31;
  		}
  #else
  		return -31;
  #endif
  	} else if (status == 0) {
  		*error_message = strdup("Remote server has closed the connection");
  		return -32;
  	}
  	return status;
  }
  
  int mongo_io_recv_data(mongo_connection *con, mongo_server_options *options, int timeout, void *data, int size, char **error_message)
  {
  	int num = 1, received = 0;
  
  	/* this can return FAILED if there is just no more data from db */
  	while (received < size && num > 0) {
  		int len = 4096 < (size - received) ? 4096 : size - received;
  
  		if (mongo_io_wait_with_timeout((int) (long) con->socket, timeout ? timeout : options->socketTimeoutMS, error_message) != 0) {
  			/* We don't care which failure it was, it just failed */
  			return -31;
  		}
  		// windows gives a WSAEFAULT if you try to get more bytes
  		num = recv((int) (long)con->socket, (char*)data, len, 0);
  
  		if (num < 0) {
  			return -31;
  		}
  
  		data = (char*)data + num;
  		received += num;
  	}
  	return received;
  }
  
  
  /*
   * Local variables:
   * tab-width: 4
   * c-basic-offset: 4
   * End:
   * vim600: fdm=marker
   * vim: noet sw=4 ts=4
   */
  