nexmon – Blame information for rev 1
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1 | office | 1 | /* buffer.c |
2 | * |
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3 | * Wiretap Library |
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4 | * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu> |
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5 | * |
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6 | * This program is free software; you can redistribute it and/or |
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7 | * modify it under the terms of the GNU General Public License |
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8 | * as published by the Free Software Foundation; either version 2 |
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9 | * of the License, or (at your option) any later version. |
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10 | * |
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11 | * This program is distributed in the hope that it will be useful, |
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12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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14 | * GNU General Public License for more details. |
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15 | * |
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16 | * You should have received a copy of the GNU General Public License |
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17 | * along with this program; if not, write to the Free Software |
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18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
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19 | * |
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20 | */ |
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21 | #include "config.h" |
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22 | |||
23 | #include <stdlib.h> |
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24 | #include <string.h> |
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25 | |||
26 | #include "buffer.h" |
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27 | |||
28 | /* Initializes a buffer with a certain amount of allocated space */ |
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29 | void |
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30 | ws_buffer_init(Buffer* buffer, gsize space) |
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31 | { |
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32 | buffer->data = (guint8*)g_malloc(space); |
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33 | buffer->allocated = space; |
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34 | buffer->start = 0; |
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35 | buffer->first_free = 0; |
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36 | } |
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37 | |||
38 | /* Frees the memory used by a buffer */ |
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39 | void |
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40 | ws_buffer_free(Buffer* buffer) |
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41 | { |
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42 | g_free(buffer->data); |
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43 | buffer->data = NULL; |
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44 | } |
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45 | |||
46 | /* Assures that there are 'space' bytes at the end of the used space |
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47 | so that another routine can copy directly into the buffer space. After |
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48 | doing that, the routine will also want to run |
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49 | ws_buffer_increase_length(). */ |
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50 | void |
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51 | ws_buffer_assure_space(Buffer* buffer, gsize space) |
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52 | { |
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53 | gsize available_at_end = buffer->allocated - buffer->first_free; |
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54 | gsize space_used; |
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55 | gboolean space_at_beginning; |
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56 | |||
57 | /* If we've got the space already, good! */ |
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58 | if (space <= available_at_end) { |
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59 | return; |
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60 | } |
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61 | |||
62 | /* Maybe we don't have the space available at the end, but we would |
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63 | if we moved the used space back to the beginning of the |
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64 | allocation. The buffer could have become fragmented through lots |
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65 | of calls to ws_buffer_remove_start(). I'm using buffer->start as the |
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66 | same as 'available_at_start' in this comparison. */ |
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67 | |||
68 | /* or maybe there's just no more room. */ |
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69 | |||
70 | space_at_beginning = buffer->start >= space; |
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71 | if (space_at_beginning || buffer->start > 0) { |
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72 | space_used = buffer->first_free - buffer->start; |
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73 | /* this memory copy better be safe for overlapping memory regions! */ |
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74 | memmove(buffer->data, buffer->data + buffer->start, space_used); |
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75 | buffer->start = 0; |
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76 | buffer->first_free = space_used; |
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77 | } |
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78 | /*if (buffer->start >= space) {*/ |
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79 | if (space_at_beginning) { |
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80 | return; |
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81 | } |
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82 | |||
83 | /* We'll allocate more space */ |
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84 | buffer->allocated += space + 1024; |
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85 | buffer->data = (guint8*)g_realloc(buffer->data, buffer->allocated); |
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86 | } |
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87 | |||
88 | void |
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89 | ws_buffer_append(Buffer* buffer, guint8 *from, gsize bytes) |
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90 | { |
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91 | ws_buffer_assure_space(buffer, bytes); |
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92 | memcpy(buffer->data + buffer->first_free, from, bytes); |
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93 | buffer->first_free += bytes; |
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94 | } |
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95 | |||
96 | void |
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97 | ws_buffer_remove_start(Buffer* buffer, gsize bytes) |
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98 | { |
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99 | if (buffer->start + bytes > buffer->first_free) { |
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100 | g_error("ws_buffer_remove_start trying to remove %" G_GINT64_MODIFIER "u bytes. s=%" G_GINT64_MODIFIER "u ff=%" G_GINT64_MODIFIER "u!\n", |
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101 | (guint64)bytes, (guint64)buffer->start, |
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102 | (guint64)buffer->first_free); |
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103 | /** g_error() does an abort() and thus never returns **/ |
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104 | } |
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105 | buffer->start += bytes; |
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106 | |||
107 | if (buffer->start == buffer->first_free) { |
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108 | buffer->start = 0; |
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109 | buffer->first_free = 0; |
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110 | } |
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111 | } |
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112 | |||
113 | |||
114 | #ifndef SOME_FUNCTIONS_ARE_DEFINES |
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115 | void |
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116 | ws_buffer_clean(Buffer* buffer) |
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117 | { |
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118 | ws_buffer_remove_start(buffer, ws_buffer_length(buffer)); |
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119 | } |
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120 | #endif |
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121 | |||
122 | #ifndef SOME_FUNCTIONS_ARE_DEFINES |
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123 | void |
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124 | ws_buffer_increase_length(Buffer* buffer, gsize bytes) |
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125 | { |
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126 | buffer->first_free += bytes; |
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127 | } |
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128 | #endif |
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129 | |||
130 | #ifndef SOME_FUNCTIONS_ARE_DEFINES |
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131 | gsize |
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132 | ws_buffer_length(Buffer* buffer) |
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133 | { |
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134 | return buffer->first_free - buffer->start; |
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135 | } |
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136 | #endif |
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137 | |||
138 | #ifndef SOME_FUNCTIONS_ARE_DEFINES |
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139 | guint8 * |
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140 | ws_buffer_start_ptr(Buffer* buffer) |
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141 | { |
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142 | return buffer->data + buffer->start; |
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143 | } |
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144 | #endif |
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145 | |||
146 | #ifndef SOME_FUNCTIONS_ARE_DEFINES |
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147 | guint8 * |
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148 | ws_buffer_end_ptr(Buffer* buffer) |
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149 | { |
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150 | return buffer->data + buffer->first_free; |
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151 | } |
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152 | #endif |
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153 | |||
154 | #ifndef SOME_FUNCTIONS_ARE_DEFINES |
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155 | void |
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156 | ws_buffer_append_buffer(Buffer* buffer, Buffer* src_buffer) |
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157 | { |
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158 | ws_buffer_append(buffer, ws_buffer_start_ptr(src_buffer), ws_buffer_length(src_buffer)); |
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159 | } |
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160 | #endif |
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161 | |||
162 | /* |
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163 | * Editor modelines - http://www.wireshark.org/tools/modelines.html |
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164 | * |
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165 | * Local variables: |
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166 | * c-basic-offset: 8 |
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167 | * tab-width: 8 |
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168 | * indent-tabs-mode: t |
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169 | * End: |
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170 | * |
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171 | * vi: set shiftwidth=8 tabstop=8 noexpandtab: |
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172 | * :indentSize=8:tabSize=8:noTabs=false: |
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173 | */ |