multi.h (18235B)
1 #ifndef CURLINC_MULTI_H 2 #define CURLINC_MULTI_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 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 https://curl.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 * SPDX-License-Identifier: curl 24 * 25 ***************************************************************************/ 26 /* 27 This is an "external" header file. Do not give away any internals here! 28 29 GOALS 30 31 o Enable a "pull" interface. The application that uses libcurl decides where 32 and when to ask libcurl to get/send data. 33 34 o Enable multiple simultaneous transfers in the same thread without making it 35 complicated for the application. 36 37 o Enable the application to select() on its own file descriptors and curl's 38 file descriptors simultaneous easily. 39 40 */ 41 42 /* 43 * This header file should not really need to include "curl.h" since curl.h 44 * itself includes this file and we expect user applications to do #include 45 * <curl/curl.h> without the need for especially including multi.h. 46 * 47 * For some reason we added this include here at one point, and rather than to 48 * break existing (wrongly written) libcurl applications, we leave it as-is 49 * but with this warning attached. 50 */ 51 #include "curl.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 are 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_RECURSIVE_API_CALL, /* an api function was called from inside a 72 callback */ 73 CURLM_WAKEUP_FAILURE, /* wakeup is unavailable or failed */ 74 CURLM_BAD_FUNCTION_ARGUMENT, /* function called with a bad parameter */ 75 CURLM_ABORTED_BY_CALLBACK, 76 CURLM_UNRECOVERABLE_POLL, 77 CURLM_LAST 78 } CURLMcode; 79 80 /* just to make code nicer when using curl_multi_socket() you can now check 81 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 82 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 83 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 84 85 /* bitmask bits for CURLMOPT_PIPELINING */ 86 #define CURLPIPE_NOTHING 0L 87 #define CURLPIPE_HTTP1 1L 88 #define CURLPIPE_MULTIPLEX 2L 89 90 typedef enum { 91 CURLMSG_NONE, /* first, not used */ 92 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 93 the CURLcode of the transfer */ 94 CURLMSG_LAST /* last, not used */ 95 } CURLMSG; 96 97 struct CURLMsg { 98 CURLMSG msg; /* what this message means */ 99 CURL *easy_handle; /* the handle it concerns */ 100 union { 101 void *whatever; /* message-specific data */ 102 CURLcode result; /* return code for transfer */ 103 } data; 104 }; 105 typedef struct CURLMsg CURLMsg; 106 107 /* Based on poll(2) structure and values. 108 * We do not use pollfd and POLL* constants explicitly 109 * to cover platforms without poll(). */ 110 #define CURL_WAIT_POLLIN 0x0001 111 #define CURL_WAIT_POLLPRI 0x0002 112 #define CURL_WAIT_POLLOUT 0x0004 113 114 struct curl_waitfd { 115 curl_socket_t fd; 116 short events; 117 short revents; 118 }; 119 120 /* 121 * Name: curl_multi_init() 122 * 123 * Desc: initialize multi-style curl usage 124 * 125 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 126 */ 127 CURL_EXTERN CURLM *curl_multi_init(void); 128 129 /* 130 * Name: curl_multi_add_handle() 131 * 132 * Desc: add a standard curl handle to the multi stack 133 * 134 * Returns: CURLMcode type, general multi error code. 135 */ 136 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 137 CURL *curl_handle); 138 139 /* 140 * Name: curl_multi_remove_handle() 141 * 142 * Desc: removes a curl handle from the multi stack again 143 * 144 * Returns: CURLMcode type, general multi error code. 145 */ 146 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 147 CURL *curl_handle); 148 149 /* 150 * Name: curl_multi_fdset() 151 * 152 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 153 * poll() on. We want curl_multi_perform() called as soon as one of 154 * them are ready. 155 * 156 * Returns: CURLMcode type, general multi error code. 157 */ 158 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 159 fd_set *read_fd_set, 160 fd_set *write_fd_set, 161 fd_set *exc_fd_set, 162 int *max_fd); 163 164 /* 165 * Name: curl_multi_wait() 166 * 167 * Desc: Poll on all fds within a CURLM set as well as any 168 * additional fds passed to the function. 169 * 170 * Returns: CURLMcode type, general multi error code. 171 */ 172 CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, 173 struct curl_waitfd extra_fds[], 174 unsigned int extra_nfds, 175 int timeout_ms, 176 int *ret); 177 178 /* 179 * Name: curl_multi_poll() 180 * 181 * Desc: Poll on all fds within a CURLM set as well as any 182 * additional fds passed to the function. 183 * 184 * Returns: CURLMcode type, general multi error code. 185 */ 186 CURL_EXTERN CURLMcode curl_multi_poll(CURLM *multi_handle, 187 struct curl_waitfd extra_fds[], 188 unsigned int extra_nfds, 189 int timeout_ms, 190 int *ret); 191 192 /* 193 * Name: curl_multi_wakeup() 194 * 195 * Desc: wakes up a sleeping curl_multi_poll call. 196 * 197 * Returns: CURLMcode type, general multi error code. 198 */ 199 CURL_EXTERN CURLMcode curl_multi_wakeup(CURLM *multi_handle); 200 201 /* 202 * Name: curl_multi_perform() 203 * 204 * Desc: When the app thinks there is data available for curl it calls this 205 * function to read/write whatever there is right now. This returns 206 * as soon as the reads and writes are done. This function does not 207 * require that there actually is data available for reading or that 208 * data can be written, it can be called just in case. It returns 209 * the number of handles that still transfer data in the second 210 * argument's integer-pointer. 211 * 212 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 213 * returns errors etc regarding the whole multi stack. There might 214 * still have occurred problems on individual transfers even when 215 * this returns OK. 216 */ 217 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 218 int *running_handles); 219 220 /* 221 * Name: curl_multi_cleanup() 222 * 223 * Desc: Cleans up and removes a whole multi stack. It does not free or 224 * touch any individual easy handles in any way. We need to define 225 * in what state those handles will be if this function is called 226 * in the middle of a transfer. 227 * 228 * Returns: CURLMcode type, general multi error code. 229 */ 230 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 231 232 /* 233 * Name: curl_multi_info_read() 234 * 235 * Desc: Ask the multi handle if there is any messages/informationals from 236 * the individual transfers. Messages include informationals such as 237 * error code from the transfer or just the fact that a transfer is 238 * completed. More details on these should be written down as well. 239 * 240 * Repeated calls to this function will return a new struct each 241 * time, until a special "end of msgs" struct is returned as a signal 242 * that there is no more to get at this point. 243 * 244 * The data the returned pointer points to will not survive calling 245 * curl_multi_cleanup(). 246 * 247 * The 'CURLMsg' struct is meant to be simple and only contain basic 248 * information. If more involved information is wanted, we will 249 * provide the particular "transfer handle" in that struct and that 250 * should/could/would be used in subsequent curl_easy_getinfo() calls 251 * (or similar). The point being that we must never expose complex 252 * structs to applications, as then we will undoubtably get backwards 253 * compatibility problems in the future. 254 * 255 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 256 * of structs. It also writes the number of messages left in the 257 * queue (after this read) in the integer the second argument points 258 * to. 259 */ 260 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 261 int *msgs_in_queue); 262 263 /* 264 * Name: curl_multi_strerror() 265 * 266 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 267 * value into the equivalent human readable error string. This is 268 * useful for printing meaningful error messages. 269 * 270 * Returns: A pointer to a null-terminated error message. 271 */ 272 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 273 274 /* 275 * Name: curl_multi_socket() and 276 * curl_multi_socket_all() 277 * 278 * Desc: An alternative version of curl_multi_perform() that allows the 279 * application to pass in one of the file descriptors that have been 280 * detected to have "action" on them and let libcurl perform. 281 * See manpage for details. 282 */ 283 #define CURL_POLL_NONE 0 284 #define CURL_POLL_IN 1 285 #define CURL_POLL_OUT 2 286 #define CURL_POLL_INOUT 3 287 #define CURL_POLL_REMOVE 4 288 289 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 290 291 #define CURL_CSELECT_IN 0x01 292 #define CURL_CSELECT_OUT 0x02 293 #define CURL_CSELECT_ERR 0x04 294 295 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 296 curl_socket_t s, /* socket */ 297 int what, /* see above */ 298 void *userp, /* private callback 299 pointer */ 300 void *socketp); /* private socket 301 pointer */ 302 /* 303 * Name: curl_multi_timer_callback 304 * 305 * Desc: Called by libcurl whenever the library detects a change in the 306 * maximum number of milliseconds the app is allowed to wait before 307 * curl_multi_socket() or curl_multi_perform() must be called 308 * (to allow libcurl's timed events to take place). 309 * 310 * Returns: The callback should return zero. 311 */ 312 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 313 long timeout_ms, /* see above */ 314 void *userp); /* private callback 315 pointer */ 316 317 CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()") 318 curl_multi_socket(CURLM *multi_handle, curl_socket_t s, int *running_handles); 319 320 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 321 curl_socket_t s, 322 int ev_bitmask, 323 int *running_handles); 324 325 CURL_EXTERN CURLMcode CURL_DEPRECATED(7.19.5, "Use curl_multi_socket_action()") 326 curl_multi_socket_all(CURLM *multi_handle, int *running_handles); 327 328 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 329 /* This macro below was added in 7.16.3 to push users who recompile to use 330 the new curl_multi_socket_action() instead of the old curl_multi_socket() 331 */ 332 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 333 #endif 334 335 /* 336 * Name: curl_multi_timeout() 337 * 338 * Desc: Returns the maximum number of milliseconds the app is allowed to 339 * wait before curl_multi_socket() or curl_multi_perform() must be 340 * called (to allow libcurl's timed events to take place). 341 * 342 * Returns: CURLM error code. 343 */ 344 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 345 long *milliseconds); 346 347 typedef enum { 348 /* This is the socket callback function pointer */ 349 CURLOPT(CURLMOPT_SOCKETFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 1), 350 351 /* This is the argument passed to the socket callback */ 352 CURLOPT(CURLMOPT_SOCKETDATA, CURLOPTTYPE_OBJECTPOINT, 2), 353 354 /* set to 1 to enable pipelining for this multi handle */ 355 CURLOPT(CURLMOPT_PIPELINING, CURLOPTTYPE_LONG, 3), 356 357 /* This is the timer callback function pointer */ 358 CURLOPT(CURLMOPT_TIMERFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 4), 359 360 /* This is the argument passed to the timer callback */ 361 CURLOPT(CURLMOPT_TIMERDATA, CURLOPTTYPE_OBJECTPOINT, 5), 362 363 /* maximum number of entries in the connection cache */ 364 CURLOPT(CURLMOPT_MAXCONNECTS, CURLOPTTYPE_LONG, 6), 365 366 /* maximum number of (pipelining) connections to one host */ 367 CURLOPT(CURLMOPT_MAX_HOST_CONNECTIONS, CURLOPTTYPE_LONG, 7), 368 369 /* maximum number of requests in a pipeline */ 370 CURLOPT(CURLMOPT_MAX_PIPELINE_LENGTH, CURLOPTTYPE_LONG, 8), 371 372 /* a connection with a content-length longer than this 373 will not be considered for pipelining */ 374 CURLOPT(CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 9), 375 376 /* a connection with a chunk length longer than this 377 will not be considered for pipelining */ 378 CURLOPT(CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE, CURLOPTTYPE_OFF_T, 10), 379 380 /* a list of site names(+port) that are blocked from pipelining */ 381 CURLOPT(CURLMOPT_PIPELINING_SITE_BL, CURLOPTTYPE_OBJECTPOINT, 11), 382 383 /* a list of server types that are blocked from pipelining */ 384 CURLOPT(CURLMOPT_PIPELINING_SERVER_BL, CURLOPTTYPE_OBJECTPOINT, 12), 385 386 /* maximum number of open connections in total */ 387 CURLOPT(CURLMOPT_MAX_TOTAL_CONNECTIONS, CURLOPTTYPE_LONG, 13), 388 389 /* This is the server push callback function pointer */ 390 CURLOPT(CURLMOPT_PUSHFUNCTION, CURLOPTTYPE_FUNCTIONPOINT, 14), 391 392 /* This is the argument passed to the server push callback */ 393 CURLOPT(CURLMOPT_PUSHDATA, CURLOPTTYPE_OBJECTPOINT, 15), 394 395 /* maximum number of concurrent streams to support on a connection */ 396 CURLOPT(CURLMOPT_MAX_CONCURRENT_STREAMS, CURLOPTTYPE_LONG, 16), 397 398 CURLMOPT_LASTENTRY /* the last unused */ 399 } CURLMoption; 400 401 402 /* 403 * Name: curl_multi_setopt() 404 * 405 * Desc: Sets options for the multi handle. 406 * 407 * Returns: CURLM error code. 408 */ 409 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 410 CURLMoption option, ...); 411 412 413 /* 414 * Name: curl_multi_assign() 415 * 416 * Desc: This function sets an association in the multi handle between the 417 * given socket and a private pointer of the application. This is 418 * (only) useful for curl_multi_socket uses. 419 * 420 * Returns: CURLM error code. 421 */ 422 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 423 curl_socket_t sockfd, void *sockp); 424 425 /* 426 * Name: curl_multi_get_handles() 427 * 428 * Desc: Returns an allocated array holding all handles currently added to 429 * the multi handle. Marks the final entry with a NULL pointer. If 430 * there is no easy handle added to the multi handle, this function 431 * returns an array with the first entry as a NULL pointer. 432 * 433 * Returns: NULL on failure, otherwise a CURL **array pointer 434 */ 435 CURL_EXTERN CURL **curl_multi_get_handles(CURLM *multi_handle); 436 437 /* 438 * Name: curl_push_callback 439 * 440 * Desc: This callback gets called when a new stream is being pushed by the 441 * server. It approves or denies the new stream. It can also decide 442 * to completely fail the connection. 443 * 444 * Returns: CURL_PUSH_OK, CURL_PUSH_DENY or CURL_PUSH_ERROROUT 445 */ 446 #define CURL_PUSH_OK 0 447 #define CURL_PUSH_DENY 1 448 #define CURL_PUSH_ERROROUT 2 /* added in 7.72.0 */ 449 450 struct curl_pushheaders; /* forward declaration only */ 451 452 CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h, 453 size_t num); 454 CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h, 455 const char *name); 456 457 typedef int (*curl_push_callback)(CURL *parent, 458 CURL *easy, 459 size_t num_headers, 460 struct curl_pushheaders *headers, 461 void *userp); 462 463 /* 464 * Name: curl_multi_waitfds() 465 * 466 * Desc: Ask curl for fds for polling. The app can use these to poll on. 467 * We want curl_multi_perform() called as soon as one of them are 468 * ready. Passing zero size allows to get just a number of fds. 469 * 470 * Returns: CURLMcode type, general multi error code. 471 */ 472 CURL_EXTERN CURLMcode curl_multi_waitfds(CURLM *multi, 473 struct curl_waitfd *ufds, 474 unsigned int size, 475 unsigned int *fd_count); 476 477 #ifdef __cplusplus 478 } /* end of extern "C" */ 479 #endif 480 481 #endif