1 #ifndef __CURL_MULTI_H 2 #define __CURL_MULTI_H 3 /*************************************************************************** 4 * _ _ ____ _ 5 * Project ___| | | | _ \| | 6 * / __| | | | |_) | | 7 * | (__| |_| | _ <| |___ 8 * \___|\___/|_| \_\_____| 9 * 10 * Copyright (C) 1998 - 2015, 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.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 52 extern "C" { 53 #endif 54 55 typedef void CURLM; 56 57 typedef 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_ADDED_ALREADY, /* an easy handle already added to a multi handle was 68 attempted to get added - again */ 69 CURLM_LAST 70 } CURLMcode; 71 72 /* just to make code nicer when using curl_multi_socket() you can now check 73 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 74 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 75 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 76 77 /* bitmask bits for CURLMOPT_PIPELINING */ 78 #define CURLPIPE_NOTHING 0L 79 #define CURLPIPE_HTTP1 1L 80 #define CURLPIPE_MULTIPLEX 2L 81 82 typedef enum { 83 CURLMSG_NONE, /* first, not used */ 84 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 85 the CURLcode of the transfer */ 86 CURLMSG_LAST /* last, not used */ 87 } CURLMSG; 88 89 struct CURLMsg { 90 CURLMSG msg; /* what this message means */ 91 CURL *easy_handle; /* the handle it concerns */ 92 union { 93 void *whatever; /* message-specific data */ 94 CURLcode result; /* return code for transfer */ 95 } data; 96 }; 97 typedef struct CURLMsg CURLMsg; 98 99 /* Based on poll(2) structure and values. 100 * We don't use pollfd and POLL* constants explicitly 101 * to cover platforms without poll(). */ 102 #define CURL_WAIT_POLLIN 0x0001 103 #define CURL_WAIT_POLLPRI 0x0002 104 #define CURL_WAIT_POLLOUT 0x0004 105 106 struct curl_waitfd { 107 curl_socket_t fd; 108 short events; 109 short revents; /* not supported yet */ 110 }; 111 112 /* 113 * Name: curl_multi_init() 114 * 115 * Desc: inititalize multi-style curl usage 116 * 117 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 118 */ 119 CURL_EXTERN CURLM *curl_multi_init(void); 120 121 /* 122 * Name: curl_multi_add_handle() 123 * 124 * Desc: add a standard curl handle to the multi stack 125 * 126 * Returns: CURLMcode type, general multi error code. 127 */ 128 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 129 CURL *curl_handle); 130 131 /* 132 * Name: curl_multi_remove_handle() 133 * 134 * Desc: removes a curl handle from the multi stack again 135 * 136 * Returns: CURLMcode type, general multi error code. 137 */ 138 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 139 CURL *curl_handle); 140 141 /* 142 * Name: curl_multi_fdset() 143 * 144 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 145 * poll() on. We want curl_multi_perform() called as soon as one of 146 * them are ready. 147 * 148 * Returns: CURLMcode type, general multi error code. 149 */ 150 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 151 fd_set *read_fd_set, 152 fd_set *write_fd_set, 153 fd_set *exc_fd_set, 154 int *max_fd); 155 156 /* 157 * Name: curl_multi_wait() 158 * 159 * Desc: Poll on all fds within a CURLM set as well as any 160 * additional fds passed to the function. 161 * 162 * Returns: CURLMcode type, general multi error code. 163 */ 164 CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle, 165 struct curl_waitfd extra_fds[], 166 unsigned int extra_nfds, 167 int timeout_ms, 168 int *ret); 169 170 /* 171 * Name: curl_multi_perform() 172 * 173 * Desc: When the app thinks there's data available for curl it calls this 174 * function to read/write whatever there is right now. This returns 175 * as soon as the reads and writes are done. This function does not 176 * require that there actually is data available for reading or that 177 * data can be written, it can be called just in case. It returns 178 * the number of handles that still transfer data in the second 179 * argument's integer-pointer. 180 * 181 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 182 * returns errors etc regarding the whole multi stack. There might 183 * still have occurred problems on invidual transfers even when this 184 * returns OK. 185 */ 186 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 187 int *running_handles); 188 189 /* 190 * Name: curl_multi_cleanup() 191 * 192 * Desc: Cleans up and removes a whole multi stack. It does not free or 193 * touch any individual easy handles in any way. We need to define 194 * in what state those handles will be if this function is called 195 * in the middle of a transfer. 196 * 197 * Returns: CURLMcode type, general multi error code. 198 */ 199 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 200 201 /* 202 * Name: curl_multi_info_read() 203 * 204 * Desc: Ask the multi handle if there's any messages/informationals from 205 * the individual transfers. Messages include informationals such as 206 * error code from the transfer or just the fact that a transfer is 207 * completed. More details on these should be written down as well. 208 * 209 * Repeated calls to this function will return a new struct each 210 * time, until a special "end of msgs" struct is returned as a signal 211 * that there is no more to get at this point. 212 * 213 * The data the returned pointer points to will not survive calling 214 * curl_multi_cleanup(). 215 * 216 * The 'CURLMsg' struct is meant to be very simple and only contain 217 * very basic informations. If more involved information is wanted, 218 * we will provide the particular "transfer handle" in that struct 219 * and that should/could/would be used in subsequent 220 * curl_easy_getinfo() calls (or similar). The point being that we 221 * must never expose complex structs to applications, as then we'll 222 * undoubtably get backwards compatibility problems in the future. 223 * 224 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 225 * of structs. It also writes the number of messages left in the 226 * queue (after this read) in the integer the second argument points 227 * to. 228 */ 229 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 230 int *msgs_in_queue); 231 232 /* 233 * Name: curl_multi_strerror() 234 * 235 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 236 * value into the equivalent human readable error string. This is 237 * useful for printing meaningful error messages. 238 * 239 * Returns: A pointer to a zero-terminated error message. 240 */ 241 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 242 243 /* 244 * Name: curl_multi_socket() and 245 * curl_multi_socket_all() 246 * 247 * Desc: An alternative version of curl_multi_perform() that allows the 248 * application to pass in one of the file descriptors that have been 249 * detected to have "action" on them and let libcurl perform. 250 * See man page for details. 251 */ 252 #define CURL_POLL_NONE 0 253 #define CURL_POLL_IN 1 254 #define CURL_POLL_OUT 2 255 #define CURL_POLL_INOUT 3 256 #define CURL_POLL_REMOVE 4 257 258 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 259 260 #define CURL_CSELECT_IN 0x01 261 #define CURL_CSELECT_OUT 0x02 262 #define CURL_CSELECT_ERR 0x04 263 264 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 265 curl_socket_t s, /* socket */ 266 int what, /* see above */ 267 void *userp, /* private callback 268 pointer */ 269 void *socketp); /* private socket 270 pointer */ 271 /* 272 * Name: curl_multi_timer_callback 273 * 274 * Desc: Called by libcurl whenever the library detects a change in the 275 * maximum number of milliseconds the app is allowed to wait before 276 * curl_multi_socket() or curl_multi_perform() must be called 277 * (to allow libcurl's timed events to take place). 278 * 279 * Returns: The callback should return zero. 280 */ 281 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 282 long timeout_ms, /* see above */ 283 void *userp); /* private callback 284 pointer */ 285 286 CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, 287 int *running_handles); 288 289 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 290 curl_socket_t s, 291 int ev_bitmask, 292 int *running_handles); 293 294 CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, 295 int *running_handles); 296 297 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 298 /* This macro below was added in 7.16.3 to push users who recompile to use 299 the new curl_multi_socket_action() instead of the old curl_multi_socket() 300 */ 301 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 302 #endif 303 304 /* 305 * Name: curl_multi_timeout() 306 * 307 * Desc: Returns the maximum number of milliseconds the app is allowed to 308 * wait before curl_multi_socket() or curl_multi_perform() must be 309 * called (to allow libcurl's timed events to take place). 310 * 311 * Returns: CURLM error code. 312 */ 313 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 314 long *milliseconds); 315 316 #undef CINIT /* re-using the same name as in curl.h */ 317 318 #ifdef CURL_ISOCPP 319 #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num 320 #else 321 /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ 322 #define LONG CURLOPTTYPE_LONG 323 #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT 324 #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT 325 #define OFF_T CURLOPTTYPE_OFF_T 326 #define CINIT(name,type,number) CURLMOPT_/**/name = type + number 327 #endif 328 329 typedef enum { 330 /* This is the socket callback function pointer */ 331 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), 332 333 /* This is the argument passed to the socket callback */ 334 CINIT(SOCKETDATA, OBJECTPOINT, 2), 335 336 /* set to 1 to enable pipelining for this multi handle */ 337 CINIT(PIPELINING, LONG, 3), 338 339 /* This is the timer callback function pointer */ 340 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), 341 342 /* This is the argument passed to the timer callback */ 343 CINIT(TIMERDATA, OBJECTPOINT, 5), 344 345 /* maximum number of entries in the connection cache */ 346 CINIT(MAXCONNECTS, LONG, 6), 347 348 /* maximum number of (pipelining) connections to one host */ 349 CINIT(MAX_HOST_CONNECTIONS, LONG, 7), 350 351 /* maximum number of requests in a pipeline */ 352 CINIT(MAX_PIPELINE_LENGTH, LONG, 8), 353 354 /* a connection with a content-length longer than this 355 will not be considered for pipelining */ 356 CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9), 357 358 /* a connection with a chunk length longer than this 359 will not be considered for pipelining */ 360 CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10), 361 362 /* a list of site names(+port) that are blacklisted from 363 pipelining */ 364 CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11), 365 366 /* a list of server types that are blacklisted from 367 pipelining */ 368 CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12), 369 370 /* maximum number of open connections in total */ 371 CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13), 372 373 /* This is the server push callback function pointer */ 374 CINIT(PUSHFUNCTION, FUNCTIONPOINT, 14), 375 376 /* This is the argument passed to the server push callback */ 377 CINIT(PUSHDATA, OBJECTPOINT, 15), 378 379 CURLMOPT_LASTENTRY /* the last unused */ 380 } CURLMoption; 381 382 383 /* 384 * Name: curl_multi_setopt() 385 * 386 * Desc: Sets options for the multi handle. 387 * 388 * Returns: CURLM error code. 389 */ 390 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 391 CURLMoption option, ...); 392 393 394 /* 395 * Name: curl_multi_assign() 396 * 397 * Desc: This function sets an association in the multi handle between the 398 * given socket and a private pointer of the application. This is 399 * (only) useful for curl_multi_socket uses. 400 * 401 * Returns: CURLM error code. 402 */ 403 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 404 curl_socket_t sockfd, void *sockp); 405 406 407 /* 408 * Name: curl_push_callback 409 * 410 * Desc: This callback gets called when a new stream is being pushed by the 411 * server. It approves or denies the new stream. 412 * 413 * Returns: CURL_PUSH_OK or CURL_PUSH_DENY. 414 */ 415 #define CURL_PUSH_OK 0 416 #define CURL_PUSH_DENY 1 417 418 struct curl_pushheaders; /* forward declaration only */ 419 420 CURL_EXTERN char *curl_pushheader_bynum(struct curl_pushheaders *h, 421 size_t num); 422 CURL_EXTERN char *curl_pushheader_byname(struct curl_pushheaders *h, 423 const char *name); 424 425 typedef int (*curl_push_callback)(CURL *parent, 426 CURL *easy, 427 size_t num_headers, 428 struct curl_pushheaders *headers, 429 void *userp); 430 431 #ifdef __cplusplus 432 } /* end of extern "C" */ 433 #endif 434 435 #endif 436