#ifndef __CURL_MULTI_H #define __CURL_MULTI_H /*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at http://curl.haxx.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ***************************************************************************/ /* This is an "external" header file. Don't give away any internals here! GOALS o Enable a "pull" interface. The application that uses libcurl decides where and when to ask libcurl to get/send data. o Enable multiple simultaneous transfers in the same thread without making it complicated for the application. o Enable the application to select() on its own file descriptors and curl's file descriptors simultaneous easily. */ /* * This header file should not really need to include "curl.h" since curl.h * itself includes this file and we expect user applications to do #include * <curl/curl.h> without the need for especially including multi.h. * * For some reason we added this include here at one point, and rather than to * break existing (wrongly written) libcurl applications, we leave it as-is * but with this warning attached. */ #include "curl.h" #ifdef __cplusplus extern "C" { #endif typedef void CURLM; typedef enum { CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or curl_multi_socket*() soon */ CURLM_OK, CURLM_BAD_HANDLE, /* the passed-in handle is not a valid CURLM handle */ CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */ CURLM_OUT_OF_MEMORY, /* if you ever get this, you're in deep sh*t */ CURLM_INTERNAL_ERROR, /* this is a libcurl bug */ CURLM_BAD_SOCKET, /* the passed in socket argument did not match */ CURLM_UNKNOWN_OPTION, /* curl_multi_setopt() with unsupported option */ CURLM_LAST } CURLMcode; /* just to make code nicer when using curl_multi_socket() you can now check for CURLM_CALL_MULTI_SOCKET too in the same style it works for curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM typedef enum { CURLMSG_NONE, /* first, not used */ CURLMSG_DONE, /* This easy handle has completed. 'result' contains the CURLcode of the transfer */ CURLMSG_LAST /* last, not used */ } CURLMSG; struct CURLMsg { CURLMSG msg; /* what this message means */ CURL *easy_handle; /* the handle it concerns */ union { void *whatever; /* message-specific data */ CURLcode result; /* return code for transfer */ } data; }; typedef struct CURLMsg CURLMsg; /* * Name: curl_multi_init() * * Desc: inititalize multi-style curl usage * * Returns: a new CURLM handle to use in all 'curl_multi' functions. */ CURL_EXTERN CURLM *curl_multi_init(void); /* * Name: curl_multi_add_handle() * * Desc: add a standard curl handle to the multi stack * * Returns: CURLMcode type, general multi error code. */ CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, CURL *curl_handle); /* * Name: curl_multi_remove_handle() * * Desc: removes a curl handle from the multi stack again * * Returns: CURLMcode type, general multi error code. */ CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, CURL *curl_handle); /* * Name: curl_multi_fdset() * * Desc: Ask curl for its fd_set sets. The app can use these to select() or * poll() on. We want curl_multi_perform() called as soon as one of * them are ready. * * Returns: CURLMcode type, general multi error code. */ CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, fd_set *read_fd_set, fd_set *write_fd_set, fd_set *exc_fd_set, int *max_fd); /* * Name: curl_multi_perform() * * Desc: When the app thinks there's data available for curl it calls this * function to read/write whatever there is right now. This returns * as soon as the reads and writes are done. This function does not * require that there actually is data available for reading or that * data can be written, it can be called just in case. It returns * the number of handles that still transfer data in the second * argument's integer-pointer. * * Returns: CURLMcode type, general multi error code. *NOTE* that this only * returns errors etc regarding the whole multi stack. There might * still have occurred problems on invidual transfers even when this * returns OK. */ CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles); /* * Name: curl_multi_cleanup() * * Desc: Cleans up and removes a whole multi stack. It does not free or * touch any individual easy handles in any way. We need to define * in what state those handles will be if this function is called * in the middle of a transfer. * * Returns: CURLMcode type, general multi error code. */ CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); /* * Name: curl_multi_info_read() * * Desc: Ask the multi handle if there's any messages/informationals from * the individual transfers. Messages include informationals such as * error code from the transfer or just the fact that a transfer is * completed. More details on these should be written down as well. * * Repeated calls to this function will return a new struct each * time, until a special "end of msgs" struct is returned as a signal * that there is no more to get at this point. * * The data the returned pointer points to will not survive calling * curl_multi_cleanup(). * * The 'CURLMsg' struct is meant to be very simple and only contain * very basic informations. If more involved information is wanted, * we will provide the particular "transfer handle" in that struct * and that should/could/would be used in subsequent * curl_easy_getinfo() calls (or similar). The point being that we * must never expose complex structs to applications, as then we'll * undoubtably get backwards compatibility problems in the future. * * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out * of structs. It also writes the number of messages left in the * queue (after this read) in the integer the second argument points * to. */ CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, int *msgs_in_queue); /* * Name: curl_multi_strerror() * * Desc: The curl_multi_strerror function may be used to turn a CURLMcode * value into the equivalent human readable error string. This is * useful for printing meaningful error messages. * * Returns: A pointer to a zero-terminated error message. */ CURL_EXTERN const char *curl_multi_strerror(CURLMcode); /* * Name: curl_multi_socket() and * curl_multi_socket_all() * * Desc: An alternative version of curl_multi_perform() that allows the * application to pass in one of the file descriptors that have been * detected to have "action" on them and let libcurl perform. * See man page for details. */ #define CURL_POLL_NONE 0 #define CURL_POLL_IN 1 #define CURL_POLL_OUT 2 #define CURL_POLL_INOUT 3 #define CURL_POLL_REMOVE 4 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD #define CURL_CSELECT_IN 0x01 #define CURL_CSELECT_OUT 0x02 #define CURL_CSELECT_ERR 0x04 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ curl_socket_t s, /* socket */ int what, /* see above */ void *userp, /* private callback pointer */ void *socketp); /* private socket pointer */ /* * Name: curl_multi_timer_callback * * Desc: Called by libcurl whenever the library detects a change in the * maximum number of milliseconds the app is allowed to wait before * curl_multi_socket() or curl_multi_perform() must be called * (to allow libcurl's timed events to take place). * * Returns: The callback should return zero. */ typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ long timeout_ms, /* see above */ void *userp); /* private callback pointer */ CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, int *running_handles); CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, curl_socket_t s, int ev_bitmask, int *running_handles); CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, int *running_handles); #ifndef CURL_ALLOW_OLD_MULTI_SOCKET /* This macro below was added in 7.16.3 to push users who recompile to use the new curl_multi_socket_action() instead of the old curl_multi_socket() */ #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) #endif /* * Name: curl_multi_timeout() * * Desc: Returns the maximum number of milliseconds the app is allowed to * wait before curl_multi_socket() or curl_multi_perform() must be * called (to allow libcurl's timed events to take place). * * Returns: CURLM error code. */ CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, long *milliseconds); #undef CINIT /* re-using the same name as in curl.h */ #ifdef CURL_ISOCPP #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num #else /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ #define LONG CURLOPTTYPE_LONG #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT #define OFF_T CURLOPTTYPE_OFF_T #define CINIT(name,type,number) CURLMOPT_/**/name = type + number #endif typedef enum { /* This is the socket callback function pointer */ CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), /* This is the argument passed to the socket callback */ CINIT(SOCKETDATA, OBJECTPOINT, 2), /* set to 1 to enable pipelining for this multi handle */ CINIT(PIPELINING, LONG, 3), /* This is the timer callback function pointer */ CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), /* This is the argument passed to the timer callback */ CINIT(TIMERDATA, OBJECTPOINT, 5), /* maximum number of entries in the connection cache */ CINIT(MAXCONNECTS, LONG, 6), CURLMOPT_LASTENTRY /* the last unused */ } CURLMoption; /* * Name: curl_multi_setopt() * * Desc: Sets options for the multi handle. * * Returns: CURLM error code. */ CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, CURLMoption option, ...); /* * Name: curl_multi_assign() * * Desc: This function sets an association in the multi handle between the * given socket and a private pointer of the application. This is * (only) useful for curl_multi_socket uses. * * Returns: CURLM error code. */ CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, curl_socket_t sockfd, void *sockp); #ifdef __cplusplus } /* end of extern "C" */ #endif #endif