3 /***************************************************************************
5 * Project ___| | | | _ \| |
7 * | (__| |_| | _ <| |___
8 * \___|\___/|_| \_\_____|
10 * Copyright (C) 1998 - 2007, Daniel Stenberg, <daniel@haxx.se>, et al.
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.
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.
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
23 ***************************************************************************/
25 This is an "external" header file. Don't give away any internals here!
29 o Enable a "pull" interface. The application that uses libcurl decides where
30 and when to ask libcurl to get/send data.
32 o Enable multiple simultaneous transfers in the same thread without making it
33 complicated for the application.
35 o Enable the application to select() on its own file descriptors and curl's
36 file descriptors simultaneous easily.
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.
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.
58 CURLM_CALL_MULTI_PERFORM
= -1, /* please call curl_multi_perform() or
59 curl_multi_socket*() soon */
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 */
70 /* just to make code nicer when using curl_multi_socket() you can now check
71 for CURLM_CALL_MULTI_SOCKET too in the same style it works for
72 curl_multi_perform() and CURLM_CALL_MULTI_PERFORM */
73 #define CURLM_CALL_MULTI_SOCKET CURLM_CALL_MULTI_PERFORM
76 CURLMSG_NONE
, /* first, not used */
77 CURLMSG_DONE
, /* This easy handle has completed. 'result' contains
78 the CURLcode of the transfer */
79 CURLMSG_LAST
/* last, not used */
83 CURLMSG msg
; /* what this message means */
84 CURL
*easy_handle
; /* the handle it concerns */
86 void *whatever
; /* message-specific data */
87 CURLcode result
; /* return code for transfer */
90 typedef struct CURLMsg CURLMsg
;
93 * Name: curl_multi_init()
95 * Desc: inititalize multi-style curl usage
97 * Returns: a new CURLM handle to use in all 'curl_multi' functions.
99 CURL_EXTERN CURLM
*curl_multi_init(void);
102 * Name: curl_multi_add_handle()
104 * Desc: add a standard curl handle to the multi stack
106 * Returns: CURLMcode type, general multi error code.
108 CURL_EXTERN CURLMcode
curl_multi_add_handle(CURLM
*multi_handle
,
112 * Name: curl_multi_remove_handle()
114 * Desc: removes a curl handle from the multi stack again
116 * Returns: CURLMcode type, general multi error code.
118 CURL_EXTERN CURLMcode
curl_multi_remove_handle(CURLM
*multi_handle
,
122 * Name: curl_multi_fdset()
124 * Desc: Ask curl for its fd_set sets. The app can use these to select() or
125 * poll() on. We want curl_multi_perform() called as soon as one of
128 * Returns: CURLMcode type, general multi error code.
130 CURL_EXTERN CURLMcode
curl_multi_fdset(CURLM
*multi_handle
,
132 fd_set
*write_fd_set
,
137 * Name: curl_multi_perform()
139 * Desc: When the app thinks there's data available for curl it calls this
140 * function to read/write whatever there is right now. This returns
141 * as soon as the reads and writes are done. This function does not
142 * require that there actually is data available for reading or that
143 * data can be written, it can be called just in case. It returns
144 * the number of handles that still transfer data in the second
145 * argument's integer-pointer.
147 * Returns: CURLMcode type, general multi error code. *NOTE* that this only
148 * returns errors etc regarding the whole multi stack. There might
149 * still have occurred problems on invidual transfers even when this
152 CURL_EXTERN CURLMcode
curl_multi_perform(CURLM
*multi_handle
,
153 int *running_handles
);
156 * Name: curl_multi_cleanup()
158 * Desc: Cleans up and removes a whole multi stack. It does not free or
159 * touch any individual easy handles in any way. We need to define
160 * in what state those handles will be if this function is called
161 * in the middle of a transfer.
163 * Returns: CURLMcode type, general multi error code.
165 CURL_EXTERN CURLMcode
curl_multi_cleanup(CURLM
*multi_handle
);
168 * Name: curl_multi_info_read()
170 * Desc: Ask the multi handle if there's any messages/informationals from
171 * the individual transfers. Messages include informationals such as
172 * error code from the transfer or just the fact that a transfer is
173 * completed. More details on these should be written down as well.
175 * Repeated calls to this function will return a new struct each
176 * time, until a special "end of msgs" struct is returned as a signal
177 * that there is no more to get at this point.
179 * The data the returned pointer points to will not survive calling
180 * curl_multi_cleanup().
182 * The 'CURLMsg' struct is meant to be very simple and only contain
183 * very basic informations. If more involved information is wanted,
184 * we will provide the particular "transfer handle" in that struct
185 * and that should/could/would be used in subsequent
186 * curl_easy_getinfo() calls (or similar). The point being that we
187 * must never expose complex structs to applications, as then we'll
188 * undoubtably get backwards compatibility problems in the future.
190 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
191 * of structs. It also writes the number of messages left in the
192 * queue (after this read) in the integer the second argument points
195 CURL_EXTERN CURLMsg
*curl_multi_info_read(CURLM
*multi_handle
,
199 * Name: curl_multi_strerror()
201 * Desc: The curl_multi_strerror function may be used to turn a CURLMcode
202 * value into the equivalent human readable error string. This is
203 * useful for printing meaningful error messages.
205 * Returns: A pointer to a zero-terminated error message.
207 CURL_EXTERN
const char *curl_multi_strerror(CURLMcode
);
210 * Name: curl_multi_socket() and
211 * curl_multi_socket_all()
213 * Desc: An alternative version of curl_multi_perform() that allows the
214 * application to pass in one of the file descriptors that have been
215 * detected to have "action" on them and let libcurl perform.
216 * See man page for details.
218 #define CURL_POLL_NONE 0
219 #define CURL_POLL_IN 1
220 #define CURL_POLL_OUT 2
221 #define CURL_POLL_INOUT 3
222 #define CURL_POLL_REMOVE 4
224 #define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
226 #define CURL_CSELECT_IN 0x01
227 #define CURL_CSELECT_OUT 0x02
228 #define CURL_CSELECT_ERR 0x04
230 typedef int (*curl_socket_callback
)(CURL
*easy
, /* easy handle */
231 curl_socket_t s
, /* socket */
232 int what
, /* see above */
233 void *userp
, /* private callback
235 void *socketp
); /* private socket
238 * Name: curl_multi_timer_callback
240 * Desc: Called by libcurl whenever the library detects a change in the
241 * maximum number of milliseconds the app is allowed to wait before
242 * curl_multi_socket() or curl_multi_perform() must be called
243 * (to allow libcurl's timed events to take place).
245 * Returns: The callback should return zero.
247 typedef int (*curl_multi_timer_callback
)(CURLM
*multi
, /* multi handle */
248 long timeout_ms
, /* see above */
249 void *userp
); /* private callback
252 CURL_EXTERN CURLMcode
curl_multi_socket(CURLM
*multi_handle
, curl_socket_t s
,
253 int *running_handles
);
255 CURL_EXTERN CURLMcode
curl_multi_socket_action(CURLM
*multi_handle
,
258 int *running_handles
);
260 CURL_EXTERN CURLMcode
curl_multi_socket_all(CURLM
*multi_handle
,
261 int *running_handles
);
263 #ifndef CURL_ALLOW_OLD_MULTI_SOCKET
264 /* This macro below was added in 7.16.3 to push users who recompile to use
265 the new curl_multi_socket_action() instead of the old curl_multi_socket()
267 #define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
271 * Name: curl_multi_timeout()
273 * Desc: Returns the maximum number of milliseconds the app is allowed to
274 * wait before curl_multi_socket() or curl_multi_perform() must be
275 * called (to allow libcurl's timed events to take place).
277 * Returns: CURLM error code.
279 CURL_EXTERN CURLMcode
curl_multi_timeout(CURLM
*multi_handle
,
282 #undef CINIT /* re-using the same name as in curl.h */
285 #define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num
287 /* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
288 #define LONG CURLOPTTYPE_LONG
289 #define OBJECTPOINT CURLOPTTYPE_OBJECTPOINT
290 #define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT
291 #define OFF_T CURLOPTTYPE_OFF_T
292 #define CINIT(name,type,number) CURLMOPT_/**/name = type + number
296 /* This is the socket callback function pointer */
297 CINIT(SOCKETFUNCTION
, FUNCTIONPOINT
, 1),
299 /* This is the argument passed to the socket callback */
300 CINIT(SOCKETDATA
, OBJECTPOINT
, 2),
302 /* set to 1 to enable pipelining for this multi handle */
303 CINIT(PIPELINING
, LONG
, 3),
305 /* This is the timer callback function pointer */
306 CINIT(TIMERFUNCTION
, FUNCTIONPOINT
, 4),
308 /* This is the argument passed to the timer callback */
309 CINIT(TIMERDATA
, OBJECTPOINT
, 5),
311 /* maximum number of entries in the connection cache */
312 CINIT(MAXCONNECTS
, LONG
, 6),
314 CURLMOPT_LASTENTRY
/* the last unused */
319 * Name: curl_multi_setopt()
321 * Desc: Sets options for the multi handle.
323 * Returns: CURLM error code.
325 CURL_EXTERN CURLMcode
curl_multi_setopt(CURLM
*multi_handle
,
326 CURLMoption option
, ...);
330 * Name: curl_multi_assign()
332 * Desc: This function sets an association in the multi handle between the
333 * given socket and a private pointer of the application. This is
334 * (only) useful for curl_multi_socket uses.
336 * Returns: CURLM error code.
338 CURL_EXTERN CURLMcode
curl_multi_assign(CURLM
*multi_handle
,
339 curl_socket_t sockfd
, void *sockp
);
342 } /* end of extern "C" */