mingw/include/curl/multi.h

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