1#ifndef __CURL_MULTI_H
2#define __CURL_MULTI_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2012, 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#include <Availability.h>
52
53#ifdef  __cplusplus
54extern "C" {
55#endif
56
57typedef void CURLM;
58
59typedef enum {
60  CURLM_CALL_MULTI_PERFORM = -1, /* please call curl_multi_perform() or
61                                    curl_multi_socket*() soon */
62  CURLM_OK,
63  CURLM_BAD_HANDLE,      /* the passed-in handle is not a valid CURLM handle */
64  CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */
65  CURLM_OUT_OF_MEMORY,   /* if you ever get this, you're in deep sh*t */
66  CURLM_INTERNAL_ERROR,  /* this is a libcurl bug */
67  CURLM_BAD_SOCKET,      /* the passed in socket argument did not match */
68  CURLM_UNKNOWN_OPTION,  /* curl_multi_setopt() with unsupported option */
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
77typedef 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
84struct 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};
92typedef 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
101struct 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 */
114CURL_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 */
123CURL_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  */
133CURL_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  */
145CURL_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__OSX_AVAILABLE_STARTING(__MAC_10_9, __IPHONE_7_0)
160CURL_EXTERN CURLMcode curl_multi_wait(CURLM *multi_handle,
161                                      struct curl_waitfd extra_fds[],
162                                      unsigned int extra_nfds,
163                                      int timeout_ms,
164                                      int *ret);
165
166 /*
167  * Name:    curl_multi_perform()
168  *
169  * Desc:    When the app thinks there's data available for curl it calls this
170  *          function to read/write whatever there is right now. This returns
171  *          as soon as the reads and writes are done. This function does not
172  *          require that there actually is data available for reading or that
173  *          data can be written, it can be called just in case. It returns
174  *          the number of handles that still transfer data in the second
175  *          argument's integer-pointer.
176  *
177  * Returns: CURLMcode type, general multi error code. *NOTE* that this only
178  *          returns errors etc regarding the whole multi stack. There might
179  *          still have occurred problems on invidual transfers even when this
180  *          returns OK.
181  */
182CURL_EXTERN CURLMcode curl_multi_perform(CURLM *multi_handle,
183                                         int *running_handles);
184
185 /*
186  * Name:    curl_multi_cleanup()
187  *
188  * Desc:    Cleans up and removes a whole multi stack. It does not free or
189  *          touch any individual easy handles in any way. We need to define
190  *          in what state those handles will be if this function is called
191  *          in the middle of a transfer.
192  *
193  * Returns: CURLMcode type, general multi error code.
194  */
195CURL_EXTERN CURLMcode curl_multi_cleanup(CURLM *multi_handle);
196
197/*
198 * Name:    curl_multi_info_read()
199 *
200 * Desc:    Ask the multi handle if there's any messages/informationals from
201 *          the individual transfers. Messages include informationals such as
202 *          error code from the transfer or just the fact that a transfer is
203 *          completed. More details on these should be written down as well.
204 *
205 *          Repeated calls to this function will return a new struct each
206 *          time, until a special "end of msgs" struct is returned as a signal
207 *          that there is no more to get at this point.
208 *
209 *          The data the returned pointer points to will not survive calling
210 *          curl_multi_cleanup().
211 *
212 *          The 'CURLMsg' struct is meant to be very simple and only contain
213 *          very basic informations. If more involved information is wanted,
214 *          we will provide the particular "transfer handle" in that struct
215 *          and that should/could/would be used in subsequent
216 *          curl_easy_getinfo() calls (or similar). The point being that we
217 *          must never expose complex structs to applications, as then we'll
218 *          undoubtably get backwards compatibility problems in the future.
219 *
220 * Returns: A pointer to a filled-in struct, or NULL if it failed or ran out
221 *          of structs. It also writes the number of messages left in the
222 *          queue (after this read) in the integer the second argument points
223 *          to.
224 */
225CURL_EXTERN CURLMsg *curl_multi_info_read(CURLM *multi_handle,
226                                          int *msgs_in_queue);
227
228/*
229 * Name:    curl_multi_strerror()
230 *
231 * Desc:    The curl_multi_strerror function may be used to turn a CURLMcode
232 *          value into the equivalent human readable error string.  This is
233 *          useful for printing meaningful error messages.
234 *
235 * Returns: A pointer to a zero-terminated error message.
236 */
237CURL_EXTERN const char *curl_multi_strerror(CURLMcode);
238
239/*
240 * Name:    curl_multi_socket() and
241 *          curl_multi_socket_all()
242 *
243 * Desc:    An alternative version of curl_multi_perform() that allows the
244 *          application to pass in one of the file descriptors that have been
245 *          detected to have "action" on them and let libcurl perform.
246 *          See man page for details.
247 */
248#define CURL_POLL_NONE   0
249#define CURL_POLL_IN     1
250#define CURL_POLL_OUT    2
251#define CURL_POLL_INOUT  3
252#define CURL_POLL_REMOVE 4
253
254#define CURL_SOCKET_TIMEOUT CURL_SOCKET_BAD
255
256#define CURL_CSELECT_IN   0x01
257#define CURL_CSELECT_OUT  0x02
258#define CURL_CSELECT_ERR  0x04
259
260typedef int (*curl_socket_callback)(CURL *easy,      /* easy handle */
261                                    curl_socket_t s, /* socket */
262                                    int what,        /* see above */
263                                    void *userp,     /* private callback
264                                                        pointer */
265                                    void *socketp);  /* private socket
266                                                        pointer */
267/*
268 * Name:    curl_multi_timer_callback
269 *
270 * Desc:    Called by libcurl whenever the library detects a change in the
271 *          maximum number of milliseconds the app is allowed to wait before
272 *          curl_multi_socket() or curl_multi_perform() must be called
273 *          (to allow libcurl's timed events to take place).
274 *
275 * Returns: The callback should return zero.
276 */
277typedef int (*curl_multi_timer_callback)(CURLM *multi,    /* multi handle */
278                                         long timeout_ms, /* see above */
279                                         void *userp);    /* private callback
280                                                             pointer */
281
282CURL_EXTERN CURLMcode curl_multi_socket(CURLM *multi_handle, curl_socket_t s,
283                                        int *running_handles);
284
285CURL_EXTERN CURLMcode curl_multi_socket_action(CURLM *multi_handle,
286                                               curl_socket_t s,
287                                               int ev_bitmask,
288                                               int *running_handles);
289
290CURL_EXTERN CURLMcode curl_multi_socket_all(CURLM *multi_handle,
291                                            int *running_handles);
292
293#ifndef CURL_ALLOW_OLD_MULTI_SOCKET
294/* This macro below was added in 7.16.3 to push users who recompile to use
295   the new curl_multi_socket_action() instead of the old curl_multi_socket()
296*/
297#define curl_multi_socket(x,y,z) curl_multi_socket_action(x,y,0,z)
298#endif
299
300/*
301 * Name:    curl_multi_timeout()
302 *
303 * Desc:    Returns the maximum number of milliseconds the app is allowed to
304 *          wait before curl_multi_socket() or curl_multi_perform() must be
305 *          called (to allow libcurl's timed events to take place).
306 *
307 * Returns: CURLM error code.
308 */
309CURL_EXTERN CURLMcode curl_multi_timeout(CURLM *multi_handle,
310                                         long *milliseconds);
311
312#undef CINIT /* re-using the same name as in curl.h */
313
314#ifdef CURL_ISOCPP
315#define CINIT(name,type,num) CURLMOPT_ ## name = CURLOPTTYPE_ ## type + num
316#else
317/* The macro "##" is ISO C, we assume pre-ISO C doesn't support it. */
318#define LONG          CURLOPTTYPE_LONG
319#define OBJECTPOINT   CURLOPTTYPE_OBJECTPOINT
320#define FUNCTIONPOINT CURLOPTTYPE_FUNCTIONPOINT
321#define OFF_T         CURLOPTTYPE_OFF_T
322#define CINIT(name,type,number) CURLMOPT_/**/name = type + number
323#endif
324
325typedef enum {
326  /* This is the socket callback function pointer */
327  CINIT(SOCKETFUNCTION, FUNCTIONPOINT, 1),
328
329  /* This is the argument passed to the socket callback */
330  CINIT(SOCKETDATA, OBJECTPOINT, 2),
331
332    /* set to 1 to enable pipelining for this multi handle */
333  CINIT(PIPELINING, LONG, 3),
334
335   /* This is the timer callback function pointer */
336  CINIT(TIMERFUNCTION, FUNCTIONPOINT, 4),
337
338  /* This is the argument passed to the timer callback */
339  CINIT(TIMERDATA, OBJECTPOINT, 5),
340
341  /* maximum number of entries in the connection cache */
342  CINIT(MAXCONNECTS, LONG, 6),
343
344  /* maximum number of (pipelining) connections to one host */
345  CINIT(MAX_HOST_CONNECTIONS, LONG, 7),
346
347  /* maximum number of requests in a pipeline */
348  CINIT(MAX_PIPELINE_LENGTH, LONG, 8),
349
350  /* a connection with a content-length longer than this
351     will not be considered for pipelining */
352  CINIT(CONTENT_LENGTH_PENALTY_SIZE, OFF_T, 9),
353
354  /* a connection with a chunk length longer than this
355     will not be considered for pipelining */
356  CINIT(CHUNK_LENGTH_PENALTY_SIZE, OFF_T, 10),
357
358  /* a list of site names(+port) that are blacklisted from
359     pipelining */
360  CINIT(PIPELINING_SITE_BL, OBJECTPOINT, 11),
361
362  /* a list of server types that are blacklisted from
363     pipelining */
364  CINIT(PIPELINING_SERVER_BL, OBJECTPOINT, 12),
365
366  /* maximum number of open connections in total */
367  CINIT(MAX_TOTAL_CONNECTIONS, LONG, 13),
368
369  CURLMOPT_LASTENTRY /* the last unused */
370} CURLMoption;
371
372
373/*
374 * Name:    curl_multi_setopt()
375 *
376 * Desc:    Sets options for the multi handle.
377 *
378 * Returns: CURLM error code.
379 */
380CURL_EXTERN CURLMcode curl_multi_setopt(CURLM *multi_handle,
381                                        CURLMoption option, ...);
382
383
384/*
385 * Name:    curl_multi_assign()
386 *
387 * Desc:    This function sets an association in the multi handle between the
388 *          given socket and a private pointer of the application. This is
389 *          (only) useful for curl_multi_socket uses.
390 *
391 * Returns: CURLM error code.
392 */
393CURL_EXTERN CURLMcode curl_multi_assign(CURLM *multi_handle,
394                                        curl_socket_t sockfd, void *sockp);
395
396#ifdef __cplusplus
397} /* end of extern "C" */
398#endif
399
400#endif
401