libwebsockets
Lightweight C library for HTML5 websockets
lws-dsh.h
1 /*
2  * libwebsockets - small server side websockets and web server implementation
3  *
4  * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22  * IN THE SOFTWARE.
23  */
24 
25 /*
26  * lws_dsh (Disordered Shared Heap) is an opaque abstraction supporting a single
27  * linear buffer (overallocated at end of the lws_dsh_t) which may contain
28  * multiple kinds of packets that are retired out of order, and tracked by kind.
29  *
30  * Each kind of packet has an lws_dll2 list of its kind of packets and acts as
31  * a FIFO; packets of a particular type are always retired in order. But there
32  * is no requirement about the order types are retired matching the original
33  * order they arrived.
34  *
35  * Gaps are tracked as just another kind of "packet" list.
36  *
37  * "allocations" (including gaps) are prepended by an lws_dsh_object_t.
38  *
39  * dsh may themselves be on an lws_dll2_owner list, and under memory pressure
40  * allocate into other buffers on the list.
41  *
42  * All management structures exist inside the allocated buffer.
43  */
44 
65 LWS_VISIBLE LWS_EXTERN struct lws_dsh *
66 lws_dsh_create(lws_dll2_owner_t *owner, size_t buffer_size, int count_kinds);
67 
82 LWS_VISIBLE LWS_EXTERN void
83 lws_dsh_destroy(struct lws_dsh **pdsh);
84 
103 LWS_VISIBLE LWS_EXTERN int
104 lws_dsh_alloc_tail(struct lws_dsh *dsh, int kind, const void *src1,
105  size_t size1, const void *src2, size_t size2);
106 
115 LWS_VISIBLE LWS_EXTERN void
116 lws_dsh_free(void **obj);
117 
118 LWS_VISIBLE LWS_EXTERN size_t
119 lws_dsh_get_size(struct lws_dsh *dsh, int kind);
120 
136 LWS_VISIBLE LWS_EXTERN int
137 lws_dsh_get_head(struct lws_dsh *dsh, int kind, void **obj, size_t *size);
138 
147 LWS_VISIBLE LWS_EXTERN void
148 lws_dsh_describe(struct lws_dsh *dsh, const char *desc);
Definition: lws-dll2.h:203