xref: /third_party/curl/lib/conncache.h (revision 13498266) 
1#ifndef HEADER_CURL_CONNCACHE_H
2#define HEADER_CURL_CONNCACHE_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
11 * Copyright (C) Linus Nielsen Feltzing, <linus@haxx.se>
12 *
13 * This software is licensed as described in the file COPYING, which
14 * you should have received as part of this distribution. The terms
15 * are also available at https://curl.se/docs/copyright.html.
16 *
17 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
18 * copies of the Software, and permit persons to whom the Software is
19 * furnished to do so, under the terms of the COPYING file.
20 *
21 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
22 * KIND, either express or implied.
23 *
24 * SPDX-License-Identifier: curl
25 *
26 ***************************************************************************/
27
28/*
29 * All accesses to struct fields and changing of data in the connection cache
30 * and connectbundles must be done with the conncache LOCKED. The cache might
31 * be shared.
32 */
33
34#include <curl/curl.h>
35#include "timeval.h"
36
37struct connectdata;
38
39struct conncache {
40  struct Curl_hash hash;
41  size_t num_conn;
42  curl_off_t next_connection_id;
43  curl_off_t next_easy_id;
44  struct curltime last_cleanup;
45  /* handle used for closing cached connections */
46  struct Curl_easy *closure_handle;
47};
48
49#define BUNDLE_NO_MULTIUSE -1
50#define BUNDLE_UNKNOWN     0  /* initial value */
51#define BUNDLE_MULTIPLEX   2
52
53#ifdef CURLDEBUG
54/* the debug versions of these macros make extra certain that the lock is
55   never doubly locked or unlocked */
56#define CONNCACHE_LOCK(x)                                               \
57  do {                                                                  \
58    if((x)->share) {                                                    \
59      Curl_share_lock((x), CURL_LOCK_DATA_CONNECT,                      \
60                      CURL_LOCK_ACCESS_SINGLE);                         \
61      DEBUGASSERT(!(x)->state.conncache_lock);                          \
62      (x)->state.conncache_lock = TRUE;                                 \
63    }                                                                   \
64  } while(0)
65
66#define CONNCACHE_UNLOCK(x)                                             \
67  do {                                                                  \
68    if((x)->share) {                                                    \
69      DEBUGASSERT((x)->state.conncache_lock);                           \
70      (x)->state.conncache_lock = FALSE;                                \
71      Curl_share_unlock((x), CURL_LOCK_DATA_CONNECT);                   \
72    }                                                                   \
73  } while(0)
74#else
75#define CONNCACHE_LOCK(x) if((x)->share)                                \
76    Curl_share_lock((x), CURL_LOCK_DATA_CONNECT, CURL_LOCK_ACCESS_SINGLE)
77#define CONNCACHE_UNLOCK(x) if((x)->share)              \
78    Curl_share_unlock((x), CURL_LOCK_DATA_CONNECT)
79#endif
80
81struct connectbundle {
82  int multiuse;                 /* supports multi-use */
83  size_t num_connections;       /* Number of connections in the bundle */
84  struct Curl_llist conn_list;  /* The connectdata members of the bundle */
85};
86
87/* returns 1 on error, 0 is fine */
88int Curl_conncache_init(struct conncache *, int size);
89void Curl_conncache_destroy(struct conncache *connc);
90
91/* return the correct bundle, to a host or a proxy */
92struct connectbundle *Curl_conncache_find_bundle(struct Curl_easy *data,
93                                                 struct connectdata *conn,
94                                                 struct conncache *connc);
95/* returns number of connections currently held in the connection cache */
96size_t Curl_conncache_size(struct Curl_easy *data);
97
98bool Curl_conncache_return_conn(struct Curl_easy *data,
99                                struct connectdata *conn);
100CURLcode Curl_conncache_add_conn(struct Curl_easy *data) WARN_UNUSED_RESULT;
101void Curl_conncache_remove_conn(struct Curl_easy *data,
102                                struct connectdata *conn,
103                                bool lock);
104bool Curl_conncache_foreach(struct Curl_easy *data,
105                            struct conncache *connc,
106                            void *param,
107                            int (*func)(struct Curl_easy *data,
108                                        struct connectdata *conn,
109                                        void *param));
110
111struct connectdata *
112Curl_conncache_find_first_connection(struct conncache *connc);
113
114struct connectdata *
115Curl_conncache_extract_bundle(struct Curl_easy *data,
116                              struct connectbundle *bundle);
117struct connectdata *
118Curl_conncache_extract_oldest(struct Curl_easy *data);
119void Curl_conncache_close_all_connections(struct conncache *connc);
120void Curl_conncache_print(struct conncache *connc);
121
122#endif /* HEADER_CURL_CONNCACHE_H */
123