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 (at) 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 * $Id: multi.h,v 1.45 2008-05-20 10:21:50 patrickm Exp $ 24 ***************************************************************************/ 25 /* 26 This is an "external" header file. Don't give away any internals here! 27 28 GOALS 29 30 o Enable a "pull" interface. The application that uses libcurl decides where 31 and when to ask libcurl to get/send data. 32 33 o Enable multiple simultaneous transfers in the same thread without making it 34 complicated for the application. 35 36 o Enable the application to select() on its own file descriptors and curl's 37 file descriptors simultaneous easily. 38 39 */ 40 41 /* 42 * This header file should not really need to include "curl.h" since curl.h 43 * itself includes this file and we expect user applications to do #include 44 * <curl/curl.h> without the need for especially including multi.h. 45 * 46 * For some reason we added this include here at one point, and rather than to 47 * break existing (wrongly written) libcurl applications, we leave it as-is 48 * but with this warning attached. 49 */ 50 #include "curl.h" 51 52 #ifdef __cplusplus 53 extern "C" { 54 #endif 55 56 typedef void CURLM; 57 58 typedef enum { 59 CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or 60 curl_multi_socket*() soon */ 61 CURLM_OK, 62 CURLM_BAD_HANDLE, /* the passed-in handle is not a valid CURLM handle */ 63 CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */ 64 CURLM_OUT_OF_MEMORY, /* if you ever get this, you're in deep sh*t */ 65 CURLM_INTERNAL_ERROR, /* this is a libcurl bug */ 66 CURLM_BAD_SOCKET, /* the passed in socket argument did not match */ 67 CURLM_UNKNOWN_OPTION, /* curl_multi_setopt() with unsupported option */ 68 CURLM_LAST 69 } CURLMcode; 70 71 /* just to make code nicer when using curl_multi_socket() you can now check 72 for CURLM_CALL_MULTI_SOCKET too in the same style it works for 73 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */ 74 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM 75 76 typedef enum { 77 CURLMSG_NONE, /* first, not used */ 78 CURLMSG_DONE, /* This easy handle has completed. 'result' contains 79 the CURLcode of the transfer */ 80 CURLMSG_LAST /* last, not used */ 81 } CURLMSG; 82 83 struct CURLMsg { 84 CURLMSG msg; /* what this message means */ 85 CURL *easy_handle; /* the handle it concerns */ 86 union { 87 void *whatever; /* message-specific data */ 88 CURLcode result; /* return code for transfer */ 89 } data; 90 }; 91 typedef struct CURLMsg CURLMsg; 92 93 /* 94 * Name: curl_multi_init() 95 * 96 * Desc: inititalize multi-style curl usage 97 * 98 * Returns: a new CURLM handle to use in all 'curl_multi' functions. 99 */ 100 CURL_EXTERN CURLM *curl_multi_init(void); 101 102 /* 103 * Name: curl_multi_add_handle() 104 * 105 * Desc: add a standard curl handle to the multi stack 106 * 107 * Returns: CURLMcode type, general multi error code. 108 */ 109 CURL_EXTERN CURLMcode curl_multi_add_handle(CURLM *multi_handle, 110 CURL *curl_handle); 111 112 /* 113 * Name: curl_multi_remove_handle() 114 * 115 * Desc: removes a curl handle from the multi stack again 116 * 117 * Returns: CURLMcode type, general multi error code. 118 */ 119 CURL_EXTERN CURLMcode curl_multi_remove_handle(CURLM *multi_handle, 120 CURL *curl_handle); 121 122 /* 123 * Name: curl_multi_fdset() 124 * 125 * Desc: Ask curl for its fd_set sets. The app can use these to select() or 126 * poll() on. We want curl_multi_perform() called as soon as one of 127 * them are ready. 128 * 129 * Returns: CURLMcode type, general multi error code. 130 */ 131 CURL_EXTERN CURLMcode curl_multi_fdset(CURLM *multi_handle, 132 fd_set *read_fd_set, 133 fd_set *write_fd_set, 134 fd_set *exc_fd_set, 135 int *max_fd); 136 137 /* 138 * Name: curl_multi_perform() 139 * 140 * Desc: When the app thinks there's data available for curl it calls this 141 * function to read/write whatever there is right now. This returns 142 * as soon as the reads and writes are done. This function does not 143 * require that there actually is data available for reading or that 144 * data can be written, it can be called just in case. It returns 145 * the number of handles that still transfer data in the second 146 * argument's integer-pointer. 147 * 148 * Returns: CURLMcode type, general multi error code. *NOTE* that this only 149 * returns errors etc regarding the whole multi stack. There might 150 * still have occurred problems on invidual transfers even when this 151 * returns OK. 152 */ 153 CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle, 154 int *running_handles); 155 156 /* 157 * Name: curl_multi_cleanup() 158 * 159 * Desc: Cleans up and removes a whole multi stack. It does not free or 160 * touch any individual easy handles in any way. We need to define 161 * in what state those handles will be if this function is called 162 * in the middle of a transfer. 163 * 164 * Returns: CURLMcode type, general multi error code. 165 */ 166 CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle); 167 168 /* 169 * Name: curl_multi_info_read() 170 * 171 * Desc: Ask the multi handle if there's any messages/informationals from 172 * the individual transfers. Messages include informationals such as 173 * error code from the transfer or just the fact that a transfer is 174 * completed. More details on these should be written down as well. 175 * 176 * Repeated calls to this function will return a new struct each 177 * time, until a special "end of msgs" struct is returned as a signal 178 * that there is no more to get at this point. 179 * 180 * The data the returned pointer points to will not survive calling 181 * curl_multi_cleanup(). 182 * 183 * The 'CURLMsg' struct is meant to be very simple and only contain 184 * very basic informations. If more involved information is wanted, 185 * we will provide the particular "transfer handle" in that struct 186 * and that should/could/would be used in subsequent 187 * curl_easy_getinfo() calls (or similar). The point being that we 188 * must never expose complex structs to applications, as then we'll 189 * undoubtably get backwards compatibility problems in the future. 190 * 191 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out 192 * of structs. It also writes the number of messages left in the 193 * queue (after this read) in the integer the second argument points 194 * to. 195 */ 196 CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle, 197 int *msgs_in_queue); 198 199 /* 200 * Name: curl_multi_strerror() 201 * 202 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode 203 * value into the equivalent human readable error string. This is 204 * useful for printing meaningful error messages. 205 * 206 * Returns: A pointer to a zero-terminated error message. 207 */ 208 CURL_EXTERN const char *curl_multi_strerror(CURLMcode); 209 210 /* 211 * Name: curl_multi_socket() and 212 * curl_multi_socket_all() 213 * 214 * Desc: An alternative version of curl_multi_perform() that allows the 215 * application to pass in one of the file descriptors that have been 216 * detected to have "action" on them and let libcurl perform. 217 * See man page for details. 218 */ 219 #define CURL_POLL_NONE 0 220 #define CURL_POLL_IN 1 221 #define CURL_POLL_OUT 2 222 #define CURL_POLL_INOUT 3 223 #define CURL_POLL_REMOVE 4 224 225 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD 226 227 #define CURL_CSELECT_IN 0x01 228 #define CURL_CSELECT_OUT 0x02 229 #define CURL_CSELECT_ERR 0x04 230 231 typedef int (*curl_socket_callback)(CURL *easy, /* easy handle */ 232 curl_socket_t s, /* socket */ 233 int what, /* see above */ 234 void *userp, /* private callback 235 pointer */ 236 void *socketp); /* private socket 237 pointer */ 238 /* 239 * Name: curl_multi_timer_callback 240 * 241 * Desc: Called by libcurl whenever the library detects a change in the 242 * maximum number of milliseconds the app is allowed to wait before 243 * curl_multi_socket() or curl_multi_perform() must be called 244 * (to allow libcurl's timed events to take place). 245 * 246 * Returns: The callback should return zero. 247 */ 248 typedef int (*curl_multi_timer_callback)(CURLM *multi, /* multi handle */ 249 long timeout_ms, /* see above */ 250 void *userp); /* private callback 251 pointer */ 252 253 CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s, 254 int *running_handles); 255 256 CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle, 257 curl_socket_t s, 258 int ev_bitmask, 259 int *running_handles); 260 261 CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle, 262 int *running_handles); 263 264 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET 265 /* This macro below was added in 7.16.3 to push users who recompile to use 266 the new curl_multi_socket_action() instead of the old curl_multi_socket() 267 */ 268 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z) 269 #endif 270 271 /* 272 * Name: curl_multi_timeout() 273 * 274 * Desc: Returns the maximum number of milliseconds the app is allowed to 275 * wait before curl_multi_socket() or curl_multi_perform() must be 276 * called (to allow libcurl's timed events to take place). 277 * 278 * Returns: CURLM error code. 279 */ 280 CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle, 281 long *milliseconds); 282 283 #undef CINIT /* re-using the same name as in curl.h */ 284 285 #ifdef CURL_ISOCPP 286 #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num 287 #else 288 /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */ 289 #define LONG CURLOPTTYPE_LONG 290 #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT 291 #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT 292 #define OFF_T CURLOPTTYPE_OFF_T 293 #define CINIT(name,type,number) CURLMOPT_/**/name = type + number 294 #endif 295 296 typedef enum { 297 /* This is the socket callback function pointer */ 298 CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1), 299 300 /* This is the argument passed to the socket callback */ 301 CINIT(SOCKETDATA, OBJECTPOINT, 2), 302 303 /* set to 1 to enable pipelining for this multi handle */ 304 CINIT(PIPELINING, LONG, 3), 305 306 /* This is the timer callback function pointer */ 307 CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4), 308 309 /* This is the argument passed to the timer callback */ 310 CINIT(TIMERDATA, OBJECTPOINT, 5), 311 312 /* maximum number of entries in the connection cache */ 313 CINIT(MAXCONNECTS, LONG, 6), 314 315 CURLMOPT_LASTENTRY /* the last unused */ 316 } CURLMoption; 317 318 319 /* 320 * Name: curl_multi_setopt() 321 * 322 * Desc: Sets options for the multi handle. 323 * 324 * Returns: CURLM error code. 325 */ 326 CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle, 327 CURLMoption option, ...); 328 329 330 /* 331 * Name: curl_multi_assign() 332 * 333 * Desc: This function sets an association in the multi handle between the 334 * given socket and a private pointer of the application. This is 335 * (only) useful for curl_multi_socket uses. 336 * 337 * Returns: CURLM error code. 338 */ 339 CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle, 340 curl_socket_t sockfd, void *sockp); 341 342 #ifdef __cplusplus 343 } /* end of extern "C" */ 344 #endif 345 346 #endif 347
