1 #ifndef __CURL_MULTI_H 2 #define __CURL_MULTI_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 1998 - 2013, 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 #include <Availability.h> 52 53 #ifdef __cplusplus 54 extern "C" { 55 #endif 56 57 typedef void CURLM; 58 59 typedef enum { 60 CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or 61 curl_multi_socket*() soon */ 62 CURLM_OK, 63 CURLM_BAD_HANDLE, /* the passed-in handle is not a valid CURLM handle */ 64 CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */ 65 CURLM_OUT_OF_MEMORY, /* if you ever get this, you're in deep sh*t */ 66 CURLM_INTERNAL_ERROR, /* this is a libcurl bug */ 67 CURLM_BAD_SOCKET, /* the passed in socket argument did not match */ 68 CURLM_UNKNOWN_OPTION, /* curl_multi_setopt() with unsupported option */ 69 CURLM_ADDED_ALREADY, /* an easy handle already added to a multi handle was 70 attempted to get added - again */ 71 CURLM_LAST 72 } CURLMcode; 73 74 /* just to make code nicer when using curl_multi_socket() you can now check 75 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 76 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 77 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 78 79 typedef enum { 80 CURLMSG_NONE, /* first, not used */ 81 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 82 the CURLcode of the transfer */ 83 CURLMSG_LAST /* last, not used */ 84 } CURLMSG; 85 86 struct CURLMsg { 87 CURLMSG msg; /* what this message means */ 88 CURL *easy_handle; /* the handle it concerns */ 89 union { 90 void *whatever; /* message-specific data */ 91 CURLcode result; /* return code for transfer */ 92 } data; 93 }; 94 typedef struct CURLMsg CURLMsg; 95 96 /* Based on poll(2) structure and values. 97 * We don't use pollfd and POLL* constants explicitly 98 * to cover platforms without poll(). */ 99 #define CURL_WAIT_POLLIN 0x0001 100 #define CURL_WAIT_POLLPRI 0x0002 101 #define CURL_WAIT_POLLOUT 0x0004 102 103 struct curl_waitfd { 104 curl_socket_t fd; 105 short events; 106 short revents; /* not supported yet */ 107 }; 108 109 /* 110 * Name: curl_multi_init() 111 * 112 * Desc: inititalize multi-style curl usage 113 * 114 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 115 */ 116 CURL_EXTERN CURLM *curl_multi_init(void); 117 118 /* 119 * Name: curl_multi_add_handle() 120 * 121 * Desc: add a standard curl handle to the multi stack 122 * 123 * Returns: CURLMcode type, general multi error code. 124 */ 125 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 126 CURL *curl_handle); 127 128 /* 129 * Name: curl_multi_remove_handle() 130 * 131 * Desc: removes a curl handle from the multi stack again 132 * 133 * Returns: CURLMcode type, general multi error code. 134 */ 135 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 136 CURL *curl_handle); 137 138 /* 139 * Name: curl_multi_fdset() 140 * 141 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 142 * poll() on. We want curl_multi_perform() called as soon as one of 143 * them are ready. 144 * 145 * Returns: CURLMcode type, general multi error code. 146 */ 147 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 148 fd_set *read_fd_set, 149 fd_set *write_fd_set, 150 fd_set *exc_fd_set, 151 int *max_fd); 152 153 /* 154 * Name: curl_multi_wait() 155 * 156 * Desc: Poll on all fds within a CURLM set as well as any 157 * additional fds passed to the function. 158 * 159 * Returns: CURLMcode type, general multi error code. 160 */ 161 __OSX_AVAILABLE_STARTING(__MAC_10_9, __IPHONE_7_0) 162 CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, 163 struct curl_waitfd extra_fds[], 164 unsigned int extra_nfds, 165 int timeout_ms, 166 int *ret); 167 168 /* 169 * Name: curl_multi_perform() 170 * 171 * Desc: When the app thinks there's data available for curl it calls this 172 * function to read/write whatever there is right now. This returns 173 * as soon as the reads and writes are done. This function does not 174 * require that there actually is data available for reading or that 175 * data can be written, it can be called just in case. It returns 176 * the number of handles that still transfer data in the second 177 * argument's integer-pointer. 178 * 179 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 180 * returns errors etc regarding the whole multi stack. There might 181 * still have occurred problems on invidual transfers even when this 182 * returns OK. 183 */ 184 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 185 int *running_handles); 186 187 /* 188 * Name: curl_multi_cleanup() 189 * 190 * Desc: Cleans up and removes a whole multi stack. It does not free or 191 * touch any individual easy handles in any way. We need to define 192 * in what state those handles will be if this function is called 193 * in the middle of a transfer. 194 * 195 * Returns: CURLMcode type, general multi error code. 196 */ 197 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 198 199 /* 200 * Name: curl_multi_info_read() 201 * 202 * Desc: Ask the multi handle if there's any messages/informationals from 203 * the individual transfers. Messages include informationals such as 204 * error code from the transfer or just the fact that a transfer is 205 * completed. More details on these should be written down as well. 206 * 207 * Repeated calls to this function will return a new struct each 208 * time, until a special "end of msgs" struct is returned as a signal 209 * that there is no more to get at this point. 210 * 211 * The data the returned pointer points to will not survive calling 212 * curl_multi_cleanup(). 213 * 214 * The 'CURLMsg' struct is meant to be very simple and only contain 215 * very basic informations. If more involved information is wanted, 216 * we will provide the particular "transfer handle" in that struct 217 * and that should/could/would be used in subsequent 218 * curl_easy_getinfo() calls (or similar). The point being that we 219 * must never expose complex structs to applications, as then we'll 220 * undoubtably get backwards compatibility problems in the future. 221 * 222 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 223 * of structs. It also writes the number of messages left in the 224 * queue (after this read) in the integer the second argument points 225 * to. 226 */ 227 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 228 int *msgs_in_queue); 229 230 /* 231 * Name: curl_multi_strerror() 232 * 233 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 234 * value into the equivalent human readable error string. This is 235 * useful for printing meaningful error messages. 236 * 237 * Returns: A pointer to a zero-terminated error message. 238 */ 239 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 240 241 /* 242 * Name: curl_multi_socket() and 243 * curl_multi_socket_all() 244 * 245 * Desc: An alternative version of curl_multi_perform() that allows the 246 * application to pass in one of the file descriptors that have been 247 * detected to have "action" on them and let libcurl perform. 248 * See man page for details. 249 */ 250 #define CURL_POLL_NONE 0 251 #define CURL_POLL_IN 1 252 #define CURL_POLL_OUT 2 253 #define CURL_POLL_INOUT 3 254 #define CURL_POLL_REMOVE 4 255 256 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 257 258 #define CURL_CSELECT_IN 0x01 259 #define CURL_CSELECT_OUT 0x02 260 #define CURL_CSELECT_ERR 0x04 261 262 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 263 curl_socket_t s, /* socket */ 264 int what, /* see above */ 265 void *userp, /* private callback 266 pointer */ 267 void *socketp); /* private socket 268 pointer */ 269 /* 270 * Name: curl_multi_timer_callback 271 * 272 * Desc: Called by libcurl whenever the library detects a change in the 273 * maximum number of milliseconds the app is allowed to wait before 274 * curl_multi_socket() or curl_multi_perform() must be called 275 * (to allow libcurl's timed events to take place). 276 * 277 * Returns: The callback should return zero. 278 */ 279 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 280 long timeout_ms, /* see above */ 281 void *userp); /* private callback 282 pointer */ 283 284 CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, 285 int *running_handles); 286 287 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 288 curl_socket_t s, 289 int ev_bitmask, 290 int *running_handles); 291 292 CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, 293 int *running_handles); 294 295 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 296 /* This macro below was added in 7.16.3 to push users who recompile to use 297 the new curl_multi_socket_action() instead of the old curl_multi_socket() 298 */ 299 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 300 #endif 301 302 /* 303 * Name: curl_multi_timeout() 304 * 305 * Desc: Returns the maximum number of milliseconds the app is allowed to 306 * wait before curl_multi_socket() or curl_multi_perform() must be 307 * called (to allow libcurl's timed events to take place). 308 * 309 * Returns: CURLM error code. 310 */ 311 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 312 long *milliseconds); 313 314 #undef CINIT /* re-using the same name as in curl.h */ 315 316 #ifdef CURL_ISOCPP 317 #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num 318 #else 319 /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ 320 #define LONG CURLOPTTYPE_LONG 321 #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT 322 #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT 323 #define OFF_T CURLOPTTYPE_OFF_T 324 #define CINIT(name,type,number) CURLMOPT_/**/name = type + number 325 #endif 326 327 typedef enum { 328 /* This is the socket callback function pointer */ 329 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), 330 331 /* This is the argument passed to the socket callback */ 332 CINIT(SOCKETDATA, OBJECTPOINT, 2), 333 334 /* set to 1 to enable pipelining for this multi handle */ 335 CINIT(PIPELINING, LONG, 3), 336 337 /* This is the timer callback function pointer */ 338 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), 339 340 /* This is the argument passed to the timer callback */ 341 CINIT(TIMERDATA, OBJECTPOINT, 5), 342 343 /* maximum number of entries in the connection cache */ 344 CINIT(MAXCONNECTS, LONG, 6), 345 346 /* maximum number of (pipelining) connections to one host */ 347 CINIT(MAX_HOST_CONNECTIONS, LONG, 7), 348 349 /* maximum number of requests in a pipeline */ 350 CINIT(MAX_PIPELINE_LENGTH, LONG, 8), 351 352 /* a connection with a content-length longer than this 353 will not be considered for pipelining */ 354 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9), 355 356 /* a connection with a chunk length longer than this 357 will not be considered for pipelining */ 358 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10), 359 360 /* a list of site names(+port) that are blacklisted from 361 pipelining */ 362 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11), 363 364 /* a list of server types that are blacklisted from 365 pipelining */ 366 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12), 367 368 /* maximum number of open connections in total */ 369 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13), 370 371 CURLMOPT_LASTENTRY /* the last unused */ 372 } CURLMoption; 373 374 375 /* 376 * Name: curl_multi_setopt() 377 * 378 * Desc: Sets options for the multi handle. 379 * 380 * Returns: CURLM error code. 381 */ 382 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 383 CURLMoption option, ...); 384 385 386 /* 387 * Name: curl_multi_assign() 388 * 389 * Desc: This function sets an association in the multi handle between the 390 * given socket and a private pointer of the application. This is 391 * (only) useful for curl_multi_socket uses. 392 * 393 * Returns: CURLM error code. 394 */ 395 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 396 curl_socket_t sockfd, void *sockp); 397 398 #ifdef __cplusplus 399 } /* end of extern "C" */ 400 #endif 401 402 #endif 403