Tristan Matthews | 0a329cc | 2013-07-17 13:20:14 -0400 | [diff] [blame] | 1 | /* $Id: fifobuf.c 4537 2013-06-19 06:47:43Z riza $ */ |
| 2 | /* |
| 3 | * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) |
| 4 | * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; if not, write to the Free Software |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | */ |
| 20 | #include <pj/fifobuf.h> |
| 21 | #include <pj/log.h> |
| 22 | #include <pj/assert.h> |
| 23 | #include <pj/os.h> |
| 24 | |
| 25 | #define THIS_FILE "fifobuf" |
| 26 | |
| 27 | #define SZ sizeof(unsigned) |
| 28 | |
| 29 | PJ_DEF(void) pj_fifobuf_init (pj_fifobuf_t *fifobuf, void *buffer, unsigned size) |
| 30 | { |
| 31 | PJ_CHECK_STACK(); |
| 32 | |
| 33 | PJ_LOG(6, (THIS_FILE, |
| 34 | "fifobuf_init fifobuf=%p buffer=%p, size=%d", |
| 35 | fifobuf, buffer, size)); |
| 36 | |
| 37 | fifobuf->first = (char*)buffer; |
| 38 | fifobuf->last = fifobuf->first + size; |
| 39 | fifobuf->ubegin = fifobuf->uend = fifobuf->first; |
| 40 | fifobuf->full = 0; |
| 41 | } |
| 42 | |
| 43 | PJ_DEF(unsigned) pj_fifobuf_max_size (pj_fifobuf_t *fifobuf) |
| 44 | { |
| 45 | unsigned s1, s2; |
| 46 | |
| 47 | PJ_CHECK_STACK(); |
| 48 | |
| 49 | if (fifobuf->uend >= fifobuf->ubegin) { |
| 50 | s1 = (unsigned)(fifobuf->last - fifobuf->uend); |
| 51 | s2 = (unsigned)(fifobuf->ubegin - fifobuf->first); |
| 52 | } else { |
| 53 | s1 = s2 = (unsigned)(fifobuf->ubegin - fifobuf->uend); |
| 54 | } |
| 55 | |
| 56 | return s1<s2 ? s2 : s1; |
| 57 | } |
| 58 | |
| 59 | PJ_DEF(void*) pj_fifobuf_alloc (pj_fifobuf_t *fifobuf, unsigned size) |
| 60 | { |
| 61 | unsigned available; |
| 62 | char *start; |
| 63 | |
| 64 | PJ_CHECK_STACK(); |
| 65 | |
| 66 | if (fifobuf->full) { |
| 67 | PJ_LOG(6, (THIS_FILE, |
| 68 | "fifobuf_alloc fifobuf=%p, size=%d: full!", |
| 69 | fifobuf, size)); |
| 70 | return NULL; |
| 71 | } |
| 72 | |
| 73 | /* try to allocate from the end part of the fifo */ |
| 74 | if (fifobuf->uend >= fifobuf->ubegin) { |
| 75 | available = (unsigned)(fifobuf->last - fifobuf->uend); |
| 76 | if (available >= size+SZ) { |
| 77 | char *ptr = fifobuf->uend; |
| 78 | fifobuf->uend += (size+SZ); |
| 79 | if (fifobuf->uend == fifobuf->last) |
| 80 | fifobuf->uend = fifobuf->first; |
| 81 | if (fifobuf->uend == fifobuf->ubegin) |
| 82 | fifobuf->full = 1; |
| 83 | *(unsigned*)ptr = size+SZ; |
| 84 | ptr += SZ; |
| 85 | |
| 86 | PJ_LOG(6, (THIS_FILE, |
| 87 | "fifobuf_alloc fifobuf=%p, size=%d: returning %p, p1=%p, p2=%p", |
| 88 | fifobuf, size, ptr, fifobuf->ubegin, fifobuf->uend)); |
| 89 | return ptr; |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /* try to allocate from the start part of the fifo */ |
| 94 | start = (fifobuf->uend <= fifobuf->ubegin) ? fifobuf->uend : fifobuf->first; |
| 95 | available = (unsigned)(fifobuf->ubegin - start); |
| 96 | if (available >= size+SZ) { |
| 97 | char *ptr = start; |
| 98 | fifobuf->uend = start + size + SZ; |
| 99 | if (fifobuf->uend == fifobuf->ubegin) |
| 100 | fifobuf->full = 1; |
| 101 | *(unsigned*)ptr = size+SZ; |
| 102 | ptr += SZ; |
| 103 | |
| 104 | PJ_LOG(6, (THIS_FILE, |
| 105 | "fifobuf_alloc fifobuf=%p, size=%d: returning %p, p1=%p, p2=%p", |
| 106 | fifobuf, size, ptr, fifobuf->ubegin, fifobuf->uend)); |
| 107 | return ptr; |
| 108 | } |
| 109 | |
| 110 | PJ_LOG(6, (THIS_FILE, |
| 111 | "fifobuf_alloc fifobuf=%p, size=%d: no space left! p1=%p, p2=%p", |
| 112 | fifobuf, size, fifobuf->ubegin, fifobuf->uend)); |
| 113 | return NULL; |
| 114 | } |
| 115 | |
| 116 | PJ_DEF(pj_status_t) pj_fifobuf_unalloc (pj_fifobuf_t *fifobuf, void *buf) |
| 117 | { |
| 118 | char *ptr = (char*)buf; |
| 119 | char *endptr; |
| 120 | unsigned sz; |
| 121 | |
| 122 | PJ_CHECK_STACK(); |
| 123 | |
| 124 | ptr -= SZ; |
| 125 | sz = *(unsigned*)ptr; |
| 126 | |
| 127 | endptr = fifobuf->uend; |
| 128 | if (endptr == fifobuf->first) |
| 129 | endptr = fifobuf->last; |
| 130 | |
| 131 | if (ptr+sz != endptr) { |
| 132 | pj_assert(!"Invalid pointer to undo alloc"); |
| 133 | return -1; |
| 134 | } |
| 135 | |
| 136 | fifobuf->uend = ptr; |
| 137 | fifobuf->full = 0; |
| 138 | |
| 139 | PJ_LOG(6, (THIS_FILE, |
| 140 | "fifobuf_unalloc fifobuf=%p, ptr=%p, size=%d, p1=%p, p2=%p", |
| 141 | fifobuf, buf, sz, fifobuf->ubegin, fifobuf->uend)); |
| 142 | |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | PJ_DEF(pj_status_t) pj_fifobuf_free (pj_fifobuf_t *fifobuf, void *buf) |
| 147 | { |
| 148 | char *ptr = (char*)buf; |
| 149 | char *end; |
| 150 | unsigned sz; |
| 151 | |
| 152 | PJ_CHECK_STACK(); |
| 153 | |
| 154 | ptr -= SZ; |
| 155 | if (ptr < fifobuf->first || ptr >= fifobuf->last) { |
| 156 | pj_assert(!"Invalid pointer to free"); |
| 157 | return -1; |
| 158 | } |
| 159 | |
| 160 | if (ptr != fifobuf->ubegin && ptr != fifobuf->first) { |
| 161 | pj_assert(!"Invalid free() sequence!"); |
| 162 | return -1; |
| 163 | } |
| 164 | |
| 165 | end = (fifobuf->uend > fifobuf->ubegin) ? fifobuf->uend : fifobuf->last; |
| 166 | sz = *(unsigned*)ptr; |
| 167 | if (ptr+sz > end) { |
| 168 | pj_assert(!"Invalid size!"); |
| 169 | return -1; |
| 170 | } |
| 171 | |
| 172 | fifobuf->ubegin = ptr + sz; |
| 173 | |
| 174 | /* Rollover */ |
| 175 | if (fifobuf->ubegin == fifobuf->last) |
| 176 | fifobuf->ubegin = fifobuf->first; |
| 177 | |
| 178 | /* Reset if fifobuf is empty */ |
| 179 | if (fifobuf->ubegin == fifobuf->uend) |
| 180 | fifobuf->ubegin = fifobuf->uend = fifobuf->first; |
| 181 | |
| 182 | fifobuf->full = 0; |
| 183 | |
| 184 | PJ_LOG(6, (THIS_FILE, |
| 185 | "fifobuf_free fifobuf=%p, ptr=%p, size=%d, p1=%p, p2=%p", |
| 186 | fifobuf, buf, sz, fifobuf->ubegin, fifobuf->uend)); |
| 187 | |
| 188 | return 0; |
| 189 | } |