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 - 2007, 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  * $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