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Diffstat (limited to 'include')
| -rw-r--r-- | include/curl/multi.h | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/include/curl/multi.h b/include/curl/multi.h new file mode 100644 index 000000000..42fa1dd4c --- /dev/null +++ b/include/curl/multi.h @@ -0,0 +1,189 @@ +#ifndef __CURL_MULTI_H +#define __CURL_MULTI_H +/***************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2002, Daniel Stenberg, <daniel@haxx.se>, et al. + * + * In order to be useful for every potential user, curl and libcurl are + * dual-licensed under the MPL and the MIT/X-derivate licenses. + * + * 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 MPL or the MIT/X-derivate + * licenses. You may pick one of these licenses. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + * $Id$ + *****************************************************************************/ +/* + This is meant to be the "external" header file. Don't give away any + internals here! + + This document presents a mixture of ideas from at least: + - Daniel Stenberg + - Steve Dekorte + - Sterling Hughes + - Ben Greear + + ------------------------------------------- + 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. + + Example sources using this interface is here: ../multi/ + +*/ +#ifdef HAVE_SYS_SOCKET_H +#include <sys/socket.h> +#endif +#if defined(WIN32) && !defined(__GNUC__) || defined(__MINGW32__) +#include <winsock.h> +#endif + +#include <curl/curl.h> + +typedef void CURLM; + +typedef enum { + CURLM_CALL_MULTI_PERFORM=-1, /* please call curl_multi_perform() 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_LAST +} CURLMcode; + +typedef enum { + CURLMSG_NONE, /* first, not used */ + CURLMSG_DONE, /* This easy handle has completed. 'whatever' points to + 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. + */ +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. + */ +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. + */ +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. + */ +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. + */ +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. + */ +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. + */ +CURLMsg *curl_multi_info_read(CURLM *multi_handle, + int *msgs_in_queue); + +#endif |