1 #ifndef HEADER_CURL_CONNCACHE_H
2 #define HEADER_CURL_CONNCACHE_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 2015 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
11  * Copyright (C) 2012 - 2014, 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.haxx.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  ***************************************************************************/
25 
26 /*
27  * All accesses to struct fields and changing of data in the connection cache
28  * and connectbundles must be done with the conncache LOCKED. The cache might
29  * be shared.
30  */
31 
32 struct conncache {
33   struct Curl_hash hash;
34   size_t num_conn;
35   long next_connection_id;
36   struct curltime last_cleanup;
37   /* handle used for closing cached connections */
38   struct Curl_easy *closure_handle;
39 };
40 
41 #define BUNDLE_NO_MULTIUSE -1
42 #define BUNDLE_UNKNOWN     0  /* initial value */
43 #define BUNDLE_MULTIPLEX   2
44 
45 #ifdef CURLDEBUG
46 /* the debug versions of these macros make extra certain that the lock is
47    never doubly locked or unlocked */
48 #define CONNCACHE_LOCK(x) if((x)->share) {                              \
49     Curl_share_lock((x), CURL_LOCK_DATA_CONNECT, CURL_LOCK_ACCESS_SINGLE); \
50     DEBUGASSERT(!(x)->state.conncache_lock);                            \
51     (x)->state.conncache_lock = TRUE;                                   \
52   }
53 
54 #define CONNCACHE_UNLOCK(x) if((x)->share) {                            \
55     DEBUGASSERT((x)->state.conncache_lock);                             \
56     (x)->state.conncache_lock = FALSE;                                  \
57     Curl_share_unlock((x), CURL_LOCK_DATA_CONNECT);                     \
58   }
59 #else
60 #define CONNCACHE_LOCK(x) if((x)->share)                                \
61     Curl_share_lock((x), CURL_LOCK_DATA_CONNECT, CURL_LOCK_ACCESS_SINGLE)
62 #define CONNCACHE_UNLOCK(x) if((x)->share)              \
63     Curl_share_unlock((x), CURL_LOCK_DATA_CONNECT)
64 #endif
65 
66 struct connectbundle {
67   int multiuse;                 /* supports multi-use */
68   size_t num_connections;       /* Number of connections in the bundle */
69   struct Curl_llist conn_list;  /* The connectdata members of the bundle */
70 };
71 
72 /* returns 1 on error, 0 is fine */
73 int Curl_conncache_init(struct conncache *, int size);
74 void Curl_conncache_destroy(struct conncache *connc);
75 
76 /* return the correct bundle, to a host or a proxy */
77 struct connectbundle *Curl_conncache_find_bundle(struct connectdata *conn,
78                                                  struct conncache *connc,
79                                                  const char **hostp);
80 /* returns number of connections currently held in the connection cache */
81 size_t Curl_conncache_size(struct Curl_easy *data);
82 
83 bool Curl_conncache_return_conn(struct Curl_easy *data,
84                                 struct connectdata *conn);
85 CURLcode Curl_conncache_add_conn(struct conncache *connc,
86                                  struct connectdata *conn) WARN_UNUSED_RESULT;
87 void Curl_conncache_remove_conn(struct Curl_easy *data,
88                                 struct connectdata *conn,
89                                 bool lock);
90 bool Curl_conncache_foreach(struct Curl_easy *data,
91                             struct conncache *connc,
92                             void *param,
93                             int (*func)(struct connectdata *conn,
94                                         void *param));
95 
96 struct connectdata *
97 Curl_conncache_find_first_connection(struct conncache *connc);
98 
99 struct connectdata *
100 Curl_conncache_extract_bundle(struct Curl_easy *data,
101                               struct connectbundle *bundle);
102 struct connectdata *
103 Curl_conncache_extract_oldest(struct Curl_easy *data);
104 void Curl_conncache_close_all_connections(struct conncache *connc);
105 void Curl_conncache_print(struct conncache *connc);
106 
107 #endif /* HEADER_CURL_CONNCACHE_H */
108