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
65LWS_VISIBLE LWS_EXTERN struct lws_dsh *
66lws_dsh_create(lws_dll2_owner_t *owner, size_t buffer_size, int count_kinds);
67
82LWS_VISIBLE LWS_EXTERN void
83lws_dsh_destroy(struct lws_dsh **pdsh);
84
103LWS_VISIBLE LWS_EXTERN int
104lws_dsh_alloc_tail(struct lws_dsh *dsh, int kind, const void *src1,
105 size_t size1, const void *src2, size_t size2);
106
115LWS_VISIBLE LWS_EXTERN void
116lws_dsh_free(void **obj);
117
118LWS_VISIBLE LWS_EXTERN size_t
119lws_dsh_get_size(struct lws_dsh *dsh, int kind);
120
136LWS_VISIBLE LWS_EXTERN int
137lws_dsh_get_head(struct lws_dsh *dsh, int kind, void **obj, size_t *size);
138
147LWS_VISIBLE LWS_EXTERN void
148lws_dsh_describe(struct lws_dsh *dsh, const char *desc);
Definition: lws-dll2.h:203