comparison: src/circbuffer.c
src/circbuffer.c
- changeset 14253
- b63ebf84c42b
- parent 14252
- d10dda2777a9
- child 14254
- 77edc7a6191a
equal
deleted
inserted
replaced
| 14252:d10dda2777a9 | 14253:b63ebf84c42b |
|---|---|
| 1 /* | |
| 2 * @file circbuffer.h Buffer Utility Functions | |
| 3 * @ingroup core | |
| 4 * | |
| 5 * Gaim is the legal property of its developers, whose names are too numerous | |
| 6 * to list here. Please refer to the COPYRIGHT file distributed with this | |
| 7 * source distribution. | |
| 8 * | |
| 9 * This program is free software; you can redistribute it and/or modify | |
| 10 * it under the terms of the GNU General Public License as published by | |
| 11 * the Free Software Foundation; either version 2 of the License, or | |
| 12 * (at your option) any later version. | |
| 13 * | |
| 14 * This program is distributed in the hope that it will be useful, | |
| 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 17 * GNU General Public License for more details. | |
| 18 * | |
| 19 * You should have received a copy of the GNU General Public License | |
| 20 * along with this program; if not, write to the Free Software | |
| 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 22 */ | |
| 23 #include "internal.h" | |
| 24 | |
| 25 #include "circbuffer.h" | |
| 26 | |
| 27 #define DEFAULT_BUF_SIZE 256 | |
| 28 | |
| 29 GaimCircBuffer * | |
| 30 gaim_circ_buffer_new(gsize growsize) { | |
| 31 GaimCircBuffer *buf = g_new0(GaimCircBuffer, 1); | |
| 32 buf->growsize = growsize ? growsize : DEFAULT_BUF_SIZE; | |
| 33 return buf; | |
| 34 } | |
| 35 | |
| 36 void gaim_circ_buffer_destroy(GaimCircBuffer *buf) { | |
| 37 g_return_if_fail(buf); | |
| 38 g_free(buf->buffer); | |
| 39 g_free(buf); | |
| 40 } | |
| 41 | |
| 42 static void grow_circ_buffer(GaimCircBuffer *buf, gsize len) { | |
| 43 int in_offset = 0, out_offset = 0; | |
| 44 int start_buflen = buf->buflen; | |
| 45 | |
| 46 while ((buf->buflen - buf->bufused) < len) | |
| 47 buf->buflen += buf->growsize; | |
| 48 | |
| 49 if (buf->inptr != NULL) { | |
| 50 in_offset = buf->inptr - buf->buffer; | |
| 51 out_offset = buf->outptr - buf->buffer; | |
| 52 } | |
| 53 buf->buffer = g_realloc(buf->buffer, buf->buflen); | |
| 54 | |
| 55 /* adjust the fill and remove pointer locations */ | |
| 56 if (buf->inptr == NULL) { | |
| 57 buf->inptr = buf->outptr = buf->buffer; | |
| 58 } else { | |
| 59 buf->inptr = buf->buffer + in_offset; | |
| 60 buf->outptr = buf->buffer + out_offset; | |
| 61 } | |
| 62 | |
| 63 /* If the fill pointer is wrapped to before the remove | |
| 64 * pointer, we need to shift the data */ | |
| 65 if (in_offset < out_offset) { | |
| 66 int shift_n = MIN(buf->buflen - start_buflen, | |
| 67 in_offset); | |
| 68 memcpy(buf->buffer + start_buflen, buf->buffer, | |
| 69 shift_n); | |
| 70 | |
| 71 /* If we couldn't fit the wrapped read buffer | |
| 72 * at the end */ | |
| 73 if (shift_n < in_offset) { | |
| 74 memmove(buf->buffer, | |
| 75 buf->buffer + shift_n, | |
| 76 in_offset - shift_n); | |
| 77 buf->inptr = buf->buffer + | |
| 78 (in_offset - shift_n); | |
| 79 } else { | |
| 80 buf->inptr = buf->buffer + | |
| 81 start_buflen + in_offset; | |
| 82 } | |
| 83 } | |
| 84 } | |
| 85 | |
| 86 void gaim_circ_buffer_append(GaimCircBuffer *buf, gconstpointer src, gsize len) { | |
| 87 | |
| 88 int len_stored; | |
| 89 | |
| 90 /* Grow the buffer, if necessary */ | |
| 91 if ((buf->buflen - buf->bufused) < len) | |
| 92 grow_circ_buffer(buf, len); | |
| 93 | |
| 94 /* If there is not enough room to copy all of src before hitting | |
| 95 * the end of the buffer then we will need to do two copies. | |
| 96 * One copy from inptr to the end of the buffer, and the | |
| 97 * second copy from the start of the buffer to the end of src. */ | |
| 98 if (buf->inptr >= buf->outptr) | |
| 99 len_stored = MIN(len, buf->buflen | |
| 100 - (buf->inptr - buf->buffer)); | |
| 101 else | |
| 102 len_stored = len; | |
| 103 | |
| 104 memcpy(buf->inptr, src, len_stored); | |
| 105 | |
| 106 if (len_stored < len) { | |
| 107 memcpy(buf->buffer, src + len_stored, len - len_stored); | |
| 108 buf->inptr = buf->buffer + (len - len_stored); | |
| 109 } else if ((buf->buffer - buf->inptr) == len_stored) { | |
| 110 buf->inptr = buf->buffer; | |
| 111 } else { | |
| 112 buf->inptr += len_stored; | |
| 113 } | |
| 114 | |
| 115 buf->bufused += len; | |
| 116 } | |
| 117 | |
| 118 gsize gaim_circ_buffer_get_max_read(GaimCircBuffer *buf) { | |
| 119 int max_read; | |
| 120 | |
| 121 if (buf->bufused == 0) | |
| 122 max_read = 0; | |
| 123 else if ((buf->outptr - buf->inptr) >= 0) | |
| 124 max_read = buf->buflen - (buf->outptr - buf->buffer); | |
| 125 else | |
| 126 max_read = buf->inptr - buf->outptr; | |
| 127 | |
| 128 return max_read; | |
| 129 } | |
| 130 | |
| 131 gboolean gaim_circ_buffer_mark_read(GaimCircBuffer *buf, gsize len) { | |
| 132 g_return_val_if_fail(gaim_circ_buffer_get_max_read(buf) >= len, FALSE); | |
| 133 | |
| 134 buf->outptr += len; | |
| 135 buf->bufused -= len; | |
| 136 /* wrap to the start if we're at the end */ | |
| 137 if ((buf->outptr - buf->buffer) == buf->buflen) | |
| 138 buf->outptr = buf->buffer; | |
| 139 | |
| 140 return TRUE; | |
| 141 } | |
| 142 |
