1#ifndef __CURL_MULTI_H 2#define __CURL_MULTI_H 3/*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al. 11 * 12 * This software is licensed as described in the file COPYING, which 13 * you should have received as part of this distribution. The terms 14 * are also available at http://curl.haxx.se/docs/copyright.html. 15 * 16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 17 * copies of the Software, and permit persons to whom the Software is 18 * furnished to do so, under the terms of the COPYING file. 19 * 20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 21 * KIND, either express or implied. 22 * 23 ***************************************************************************/ 24/* 25 This is an "external" header file. Don't give away any internals here! 26 27 GOALS 28 29 o Enable a "pull" interface. The application that uses libcurl decides where 30 and when to ask libcurl to get/send data. 31 32 o Enable multiple simultaneous transfers in the same thread without making it 33 complicated for the application. 34 35 o Enable the application to select() on its own file descriptors and curl's 36 file descriptors simultaneous easily. 37 38*/ 39 40/* 41 * This header file should not really need to include "curl.h" since curl.h 42 * itself includes this file and we expect user applications to do #include 43 * <curl/curl.h> without the need for especially including multi.h. 44 * 45 * For some reason we added this include here at one point, and rather than to 46 * break existing (wrongly written) libcurl applications, we leave it as-is 47 * but with this warning attached. 48 */ 49#include "curl.h" 50 51#ifdef __cplusplus 52extern "C" { 53#endif 54 55typedef void CURLM; 56 57typedef enum { 58 CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or 59 curl_multi_socket*() soon */ 60 CURLM_OK, 61 CURLM_BAD_HANDLE, /* the passed-in handle is not a valid CURLM handle */ 62 CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */ 63 CURLM_OUT_OF_MEMORY, /* if you ever get this, you're in deep sh*t */ 64 CURLM_INTERNAL_ERROR, /* this is a libcurl bug */ 65 CURLM_BAD_SOCKET, /* the passed in socket argument did not match */ 66 CURLM_UNKNOWN_OPTION, /* curl_multi_setopt() with unsupported option */ 67 CURLM_LAST 68} CURLMcode; 69 70/* just to make code nicer when using curl_multi_socket() you can now check 71 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 72 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 73#define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 74 75typedef enum { 76 CURLMSG_NONE, /* first, not used */ 77 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 78 the CURLcode of the transfer */ 79 CURLMSG_LAST /* last, not used */ 80} CURLMSG; 81 82struct CURLMsg { 83 CURLMSG msg; /* what this message means */ 84 CURL *easy_handle; /* the handle it concerns */ 85 union { 86 void *whatever; /* message-specific data */ 87 CURLcode result; /* return code for transfer */ 88 } data; 89}; 90typedef struct CURLMsg CURLMsg; 91 92/* 93 * Name: curl_multi_init() 94 * 95 * Desc: inititalize multi-style curl usage 96 * 97 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 98 */ 99CURL_EXTERN CURLM *curl_multi_init(void); 100 101/* 102 * Name: curl_multi_add_handle() 103 * 104 * Desc: add a standard curl handle to the multi stack 105 * 106 * Returns: CURLMcode type, general multi error code. 107 */ 108CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 109 CURL *curl_handle); 110 111 /* 112 * Name: curl_multi_remove_handle() 113 * 114 * Desc: removes a curl handle from the multi stack again 115 * 116 * Returns: CURLMcode type, general multi error code. 117 */ 118CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 119 CURL *curl_handle); 120 121 /* 122 * Name: curl_multi_fdset() 123 * 124 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 125 * poll() on. We want curl_multi_perform() called as soon as one of 126 * them are ready. 127 * 128 * Returns: CURLMcode type, general multi error code. 129 */ 130CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 131 fd_set *read_fd_set, 132 fd_set *write_fd_set, 133 fd_set *exc_fd_set, 134 int *max_fd); 135 136 /* 137 * Name: curl_multi_perform() 138 * 139 * Desc: When the app thinks there's data available for curl it calls this 140 * function to read/write whatever there is right now. This returns 141 * as soon as the reads and writes are done. This function does not 142 * require that there actually is data available for reading or that 143 * data can be written, it can be called just in case. It returns 144 * the number of handles that still transfer data in the second 145 * argument's integer-pointer. 146 * 147 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 148 * returns errors etc regarding the whole multi stack. There might 149 * still have occurred problems on invidual transfers even when this 150 * returns OK. 151 */ 152CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 153 int *running_handles); 154 155 /* 156 * Name: curl_multi_cleanup() 157 * 158 * Desc: Cleans up and removes a whole multi stack. It does not free or 159 * touch any individual easy handles in any way. We need to define 160 * in what state those handles will be if this function is called 161 * in the middle of a transfer. 162 * 163 * Returns: CURLMcode type, general multi error code. 164 */ 165CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 166 167/* 168 * Name: curl_multi_info_read() 169 * 170 * Desc: Ask the multi handle if there's any messages/informationals from 171 * the individual transfers. Messages include informationals such as 172 * error code from the transfer or just the fact that a transfer is 173 * completed. More details on these should be written down as well. 174 * 175 * Repeated calls to this function will return a new struct each 176 * time, until a special "end of msgs" struct is returned as a signal 177 * that there is no more to get at this point. 178 * 179 * The data the returned pointer points to will not survive calling 180 * curl_multi_cleanup(). 181 * 182 * The 'CURLMsg' struct is meant to be very simple and only contain 183 * very basic informations. If more involved information is wanted, 184 * we will provide the particular "transfer handle" in that struct 185 * and that should/could/would be used in subsequent 186 * curl_easy_getinfo() calls (or similar). The point being that we 187 * must never expose complex structs to applications, as then we'll 188 * undoubtably get backwards compatibility problems in the future. 189 * 190 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 191 * of structs. It also writes the number of messages left in the 192 * queue (after this read) in the integer the second argument points 193 * to. 194 */ 195CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 196 int *msgs_in_queue); 197 198/* 199 * Name: curl_multi_strerror() 200 * 201 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 202 * value into the equivalent human readable error string. This is 203 * useful for printing meaningful error messages. 204 * 205 * Returns: A pointer to a zero-terminated error message. 206 */ 207CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 208 209/* 210 * Name: curl_multi_socket() and 211 * curl_multi_socket_all() 212 * 213 * Desc: An alternative version of curl_multi_perform() that allows the 214 * application to pass in one of the file descriptors that have been 215 * detected to have "action" on them and let libcurl perform. 216 * See man page for details. 217 */ 218#define CURL_POLL_NONE 0 219#define CURL_POLL_IN 1 220#define CURL_POLL_OUT 2 221#define CURL_POLL_INOUT 3 222#define CURL_POLL_REMOVE 4 223 224#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 225 226#define CURL_CSELECT_IN 0x01 227#define CURL_CSELECT_OUT 0x02 228#define CURL_CSELECT_ERR 0x04 229 230typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 231 curl_socket_t s, /* socket */ 232 int what, /* see above */ 233 void *userp, /* private callback 234 pointer */ 235 void *socketp); /* private socket 236 pointer */ 237/* 238 * Name: curl_multi_timer_callback 239 * 240 * Desc: Called by libcurl whenever the library detects a change in the 241 * maximum number of milliseconds the app is allowed to wait before 242 * curl_multi_socket() or curl_multi_perform() must be called 243 * (to allow libcurl's timed events to take place). 244 * 245 * Returns: The callback should return zero. 246 */ 247typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 248 long timeout_ms, /* see above */ 249 void *userp); /* private callback 250 pointer */ 251 252CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, 253 int *running_handles); 254 255CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 256 curl_socket_t s, 257 int ev_bitmask, 258 int *running_handles); 259 260CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, 261 int *running_handles); 262 263#ifndef CURL_ALLOW_OLD_MULTI_SOCKET 264/* This macro below was added in 7.16.3 to push users who recompile to use 265 the new curl_multi_socket_action() instead of the old curl_multi_socket() 266*/ 267#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 268#endif 269 270/* 271 * Name: curl_multi_timeout() 272 * 273 * Desc: Returns the maximum number of milliseconds the app is allowed to 274 * wait before curl_multi_socket() or curl_multi_perform() must be 275 * called (to allow libcurl's timed events to take place). 276 * 277 * Returns: CURLM error code. 278 */ 279CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 280 long *milliseconds); 281 282#undef CINIT /* re-using the same name as in curl.h */ 283 284#ifdef CURL_ISOCPP 285#define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num 286#else 287/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ 288#define LONG CURLOPTTYPE_LONG 289#define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT 290#define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT 291#define OFF_T CURLOPTTYPE_OFF_T 292#define CINIT(name,type,number) CURLMOPT_/**/name = type + number 293#endif 294 295typedef enum { 296 /* This is the socket callback function pointer */ 297 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), 298 299 /* This is the argument passed to the socket callback */ 300 CINIT(SOCKETDATA, OBJECTPOINT, 2), 301 302 /* set to 1 to enable pipelining for this multi handle */ 303 CINIT(PIPELINING, LONG, 3), 304 305 /* This is the timer callback function pointer */ 306 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), 307 308 /* This is the argument passed to the timer callback */ 309 CINIT(TIMERDATA, OBJECTPOINT, 5), 310 311 /* maximum number of entries in the connection cache */ 312 CINIT(MAXCONNECTS, LONG, 6), 313 314 CURLMOPT_LASTENTRY /* the last unused */ 315} CURLMoption; 316 317 318/* 319 * Name: curl_multi_setopt() 320 * 321 * Desc: Sets options for the multi handle. 322 * 323 * Returns: CURLM error code. 324 */ 325CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 326 CURLMoption option, ...); 327 328 329/* 330 * Name: curl_multi_assign() 331 * 332 * Desc: This function sets an association in the multi handle between the 333 * given socket and a private pointer of the application. This is 334 * (only) useful for curl_multi_socket uses. 335 * 336 * Returns: CURLM error code. 337 */ 338CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 339 curl_socket_t sockfd, void *sockp); 340 341#ifdef __cplusplus 342} /* end of extern "C" */ 343#endif 344 345#endif 346