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@@ -1,369 +1,373 b'' | |||
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1 | 1 | /* |
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2 | 2 | bdiff.c - efficient binary diff extension for Mercurial |
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3 | 3 | |
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4 | 4 | Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> |
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5 | 5 | |
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6 | 6 | This software may be used and distributed according to the terms of |
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7 | 7 | the GNU General Public License, incorporated herein by reference. |
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8 | 8 | |
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9 | 9 | Based roughly on Python difflib |
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10 | 10 | */ |
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11 | 11 | |
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12 | 12 | #include <Python.h> |
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13 | 13 | #include <stdlib.h> |
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14 | 14 | #include <string.h> |
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15 | 15 | |
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16 | 16 | #if defined __hpux || defined __SUNPRO_C || defined _AIX |
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17 | 17 | # define inline |
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18 | 18 | #endif |
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19 | 19 | |
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20 | 20 | #ifdef _WIN32 |
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21 | 21 | #ifdef _MSC_VER |
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22 | 22 | #define inline __inline |
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23 | 23 | typedef unsigned long uint32_t; |
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24 | 24 | #else |
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25 | 25 | #include <stdint.h> |
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26 | 26 | #endif |
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27 | 27 | static uint32_t htonl(uint32_t x) |
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28 | 28 | { |
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29 | 29 | return ((x & 0x000000ffUL) << 24) | |
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30 | 30 | ((x & 0x0000ff00UL) << 8) | |
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31 | 31 | ((x & 0x00ff0000UL) >> 8) | |
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32 | 32 | ((x & 0xff000000UL) >> 24); |
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33 | 33 | } |
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34 | 34 | #else |
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35 | 35 | #include <sys/types.h> |
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36 | #ifdef __BEOS__ | |
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37 | #include <ByteOrder.h> | |
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38 | #else | |
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36 | 39 | #include <arpa/inet.h> |
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40 | #endif | |
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37 | 41 | #include <inttypes.h> |
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38 | 42 | #endif |
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39 | 43 | |
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40 | 44 | struct line { |
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41 | 45 | int h, len, n, e; |
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42 | 46 | const char *l; |
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43 | 47 | }; |
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44 | 48 | |
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45 | 49 | struct pos { |
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46 | 50 | int pos, len; |
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47 | 51 | }; |
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48 | 52 | |
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49 | 53 | struct hunk { |
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50 | 54 | int a1, a2, b1, b2; |
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51 | 55 | }; |
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52 | 56 | |
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53 | 57 | struct hunklist { |
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54 | 58 | struct hunk *base, *head; |
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55 | 59 | }; |
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56 | 60 | |
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57 | 61 | static inline uint32_t rol32(uint32_t word, unsigned int shift) |
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58 | 62 | { |
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59 | 63 | return (word << shift) | (word >> (32 - shift)); |
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60 | 64 | } |
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61 | 65 | |
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62 | 66 | int splitlines(const char *a, int len, struct line **lr) |
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63 | 67 | { |
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64 | 68 | int g, h, i; |
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65 | 69 | const char *p, *b = a; |
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66 | 70 | struct line *l; |
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67 | 71 | |
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68 | 72 | /* count the lines */ |
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69 | 73 | i = 1; /* extra line for sentinel */ |
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70 | 74 | for (p = a; p < a + len; p++) |
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71 | 75 | if (*p == '\n' || p == a + len - 1) |
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72 | 76 | i++; |
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73 | 77 | |
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74 | 78 | *lr = l = (struct line *)malloc(sizeof(struct line) * i); |
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75 | 79 | if (!l) |
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76 | 80 | return -1; |
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77 | 81 | |
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78 | 82 | /* build the line array and calculate hashes */ |
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79 | 83 | h = 0; |
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80 | 84 | for (p = a; p < a + len; p++) { |
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81 | 85 | /* |
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82 | 86 | * a simple hash from GNU diff, with better collision |
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83 | 87 | * resistance from hashpjw. this slows down common |
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84 | 88 | * case by 10%, but speeds up worst case by 100x. |
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85 | 89 | */ |
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86 | 90 | h = *p + rol32(h, 7); |
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87 | 91 | if ((g = h & 0xf0000000)) { |
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88 | 92 | h ^= g >> 24; |
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89 | 93 | h ^= g; |
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90 | 94 | } |
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91 | 95 | if (*p == '\n' || p == a + len - 1) { |
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92 | 96 | l->len = p - b + 1; |
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93 | 97 | l->h = h * l->len; |
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94 | 98 | l->l = b; |
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95 | 99 | l->n = -1; |
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96 | 100 | l++; |
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97 | 101 | b = p + 1; |
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98 | 102 | h = 0; |
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99 | 103 | } |
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100 | 104 | } |
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101 | 105 | |
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102 | 106 | /* set up a sentinel */ |
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103 | 107 | l->h = l->len = 0; |
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104 | 108 | l->l = a + len; |
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105 | 109 | return i - 1; |
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106 | 110 | } |
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107 | 111 | |
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108 | 112 | int inline cmp(struct line *a, struct line *b) |
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109 | 113 | { |
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110 | 114 | return a->h != b->h || a->len != b->len || memcmp(a->l, b->l, a->len); |
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111 | 115 | } |
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112 | 116 | |
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113 | 117 | static int equatelines(struct line *a, int an, struct line *b, int bn) |
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114 | 118 | { |
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115 | 119 | int i, j, buckets = 1, t; |
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116 | 120 | struct pos *h; |
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117 | 121 | |
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118 | 122 | /* build a hash table of the next highest power of 2 */ |
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119 | 123 | while (buckets < bn + 1) |
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120 | 124 | buckets *= 2; |
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121 | 125 | |
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122 | 126 | h = (struct pos *)malloc(buckets * sizeof(struct pos)); |
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123 | 127 | buckets = buckets - 1; |
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124 | 128 | if (!h) |
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125 | 129 | return 0; |
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126 | 130 | |
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127 | 131 | /* clear the hash table */ |
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128 | 132 | for (i = 0; i <= buckets; i++) { |
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129 | 133 | h[i].pos = -1; |
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130 | 134 | h[i].len = 0; |
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131 | 135 | } |
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132 | 136 | |
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133 | 137 | /* add lines to the hash table chains */ |
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134 | 138 | for (i = bn - 1; i >= 0; i--) { |
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135 | 139 | /* find the equivalence class */ |
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136 | 140 | for (j = b[i].h & buckets; h[j].pos != -1; |
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137 | 141 | j = (j + 1) & buckets) |
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138 | 142 | if (!cmp(b + i, b + h[j].pos)) |
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139 | 143 | break; |
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140 | 144 | |
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141 | 145 | /* add to the head of the equivalence class */ |
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142 | 146 | b[i].n = h[j].pos; |
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143 | 147 | b[i].e = j; |
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144 | 148 | h[j].pos = i; |
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145 | 149 | h[j].len++; /* keep track of popularity */ |
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146 | 150 | } |
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147 | 151 | |
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148 | 152 | /* compute popularity threshold */ |
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149 | 153 | t = (bn >= 200) ? bn / 100 : bn + 1; |
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150 | 154 | |
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151 | 155 | /* match items in a to their equivalence class in b */ |
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152 | 156 | for (i = 0; i < an; i++) { |
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153 | 157 | /* find the equivalence class */ |
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154 | 158 | for (j = a[i].h & buckets; h[j].pos != -1; |
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155 | 159 | j = (j + 1) & buckets) |
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156 | 160 | if (!cmp(a + i, b + h[j].pos)) |
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157 | 161 | break; |
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158 | 162 | |
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159 | 163 | a[i].e = j; /* use equivalence class for quick compare */ |
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160 | 164 | if (h[j].len <= t) |
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161 | 165 | a[i].n = h[j].pos; /* point to head of match list */ |
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162 | 166 | else |
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163 | 167 | a[i].n = -1; /* too popular */ |
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164 | 168 | } |
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165 | 169 | |
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166 | 170 | /* discard hash tables */ |
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167 | 171 | free(h); |
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168 | 172 | return 1; |
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169 | 173 | } |
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170 | 174 | |
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171 | 175 | static int longest_match(struct line *a, struct line *b, struct pos *pos, |
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172 | 176 | int a1, int a2, int b1, int b2, int *omi, int *omj) |
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173 | 177 | { |
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174 | 178 | int mi = a1, mj = b1, mk = 0, mb = 0, i, j, k; |
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175 | 179 | |
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176 | 180 | for (i = a1; i < a2; i++) { |
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177 | 181 | /* skip things before the current block */ |
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178 | 182 | for (j = a[i].n; j != -1 && j < b1; j = b[j].n) |
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179 | 183 | ; |
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180 | 184 | |
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181 | 185 | /* loop through all lines match a[i] in b */ |
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182 | 186 | for (; j != -1 && j < b2; j = b[j].n) { |
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183 | 187 | /* does this extend an earlier match? */ |
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184 | 188 | if (i > a1 && j > b1 && pos[j - 1].pos == i - 1) |
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185 | 189 | k = pos[j - 1].len + 1; |
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186 | 190 | else |
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187 | 191 | k = 1; |
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188 | 192 | pos[j].pos = i; |
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189 | 193 | pos[j].len = k; |
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190 | 194 | |
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191 | 195 | /* best match so far? */ |
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192 | 196 | if (k > mk) { |
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193 | 197 | mi = i; |
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194 | 198 | mj = j; |
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195 | 199 | mk = k; |
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196 | 200 | } |
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197 | 201 | } |
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198 | 202 | } |
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199 | 203 | |
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200 | 204 | if (mk) { |
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201 | 205 | mi = mi - mk + 1; |
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202 | 206 | mj = mj - mk + 1; |
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203 | 207 | } |
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204 | 208 | |
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205 | 209 | /* expand match to include neighboring popular lines */ |
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206 | 210 | while (mi - mb > a1 && mj - mb > b1 && |
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207 | 211 | a[mi - mb - 1].e == b[mj - mb - 1].e) |
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208 | 212 | mb++; |
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209 | 213 | while (mi + mk < a2 && mj + mk < b2 && |
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210 | 214 | a[mi + mk].e == b[mj + mk].e) |
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211 | 215 | mk++; |
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212 | 216 | |
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213 | 217 | *omi = mi - mb; |
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214 | 218 | *omj = mj - mb; |
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215 | 219 | return mk + mb; |
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216 | 220 | } |
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217 | 221 | |
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218 | 222 | static void recurse(struct line *a, struct line *b, struct pos *pos, |
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219 | 223 | int a1, int a2, int b1, int b2, struct hunklist *l) |
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220 | 224 | { |
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221 | 225 | int i, j, k; |
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222 | 226 | |
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223 | 227 | /* find the longest match in this chunk */ |
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224 | 228 | k = longest_match(a, b, pos, a1, a2, b1, b2, &i, &j); |
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225 | 229 | if (!k) |
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226 | 230 | return; |
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227 | 231 | |
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228 | 232 | /* and recurse on the remaining chunks on either side */ |
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229 | 233 | recurse(a, b, pos, a1, i, b1, j, l); |
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230 | 234 | l->head->a1 = i; |
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231 | 235 | l->head->a2 = i + k; |
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232 | 236 | l->head->b1 = j; |
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233 | 237 | l->head->b2 = j + k; |
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234 | 238 | l->head++; |
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235 | 239 | recurse(a, b, pos, i + k, a2, j + k, b2, l); |
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236 | 240 | } |
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237 | 241 | |
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238 | 242 | static struct hunklist diff(struct line *a, int an, struct line *b, int bn) |
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239 | 243 | { |
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240 | 244 | struct hunklist l; |
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241 | 245 | struct pos *pos; |
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242 | 246 | int t; |
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243 | 247 | |
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244 | 248 | /* allocate and fill arrays */ |
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245 | 249 | t = equatelines(a, an, b, bn); |
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246 | 250 | pos = (struct pos *)calloc(bn, sizeof(struct pos)); |
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247 | 251 | /* we can't have more matches than lines in the shorter file */ |
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248 | 252 | l.head = l.base = (struct hunk *)malloc(sizeof(struct hunk) * |
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249 | 253 | ((an<bn ? an:bn) + 1)); |
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250 | 254 | |
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251 | 255 | if (pos && l.base && t) { |
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252 | 256 | /* generate the matching block list */ |
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253 | 257 | recurse(a, b, pos, 0, an, 0, bn, &l); |
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254 | 258 | l.head->a1 = an; |
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255 | 259 | l.head->b1 = bn; |
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256 | 260 | l.head++; |
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257 | 261 | } |
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258 | 262 | |
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259 | 263 | free(pos); |
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260 | 264 | return l; |
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261 | 265 | } |
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262 | 266 | |
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263 | 267 | static PyObject *blocks(PyObject *self, PyObject *args) |
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264 | 268 | { |
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265 | 269 | PyObject *sa, *sb, *rl = NULL, *m; |
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266 | 270 | struct line *a, *b; |
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267 | 271 | struct hunklist l = {NULL, NULL}; |
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268 | 272 | struct hunk *h; |
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269 | 273 | int an, bn, pos = 0; |
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270 | 274 | |
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271 | 275 | if (!PyArg_ParseTuple(args, "SS:bdiff", &sa, &sb)) |
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272 | 276 | return NULL; |
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273 | 277 | |
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274 | 278 | an = splitlines(PyString_AsString(sa), PyString_Size(sa), &a); |
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275 | 279 | bn = splitlines(PyString_AsString(sb), PyString_Size(sb), &b); |
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276 | 280 | if (!a || !b) |
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277 | 281 | goto nomem; |
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278 | 282 | |
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279 | 283 | l = diff(a, an, b, bn); |
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280 | 284 | rl = PyList_New(l.head - l.base); |
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281 | 285 | if (!l.head || !rl) |
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282 | 286 | goto nomem; |
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283 | 287 | |
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284 | 288 | for (h = l.base; h != l.head; h++) { |
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285 | 289 | m = Py_BuildValue("iiii", h->a1, h->a2, h->b1, h->b2); |
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286 | 290 | PyList_SetItem(rl, pos, m); |
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287 | 291 | pos++; |
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288 | 292 | } |
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289 | 293 | |
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290 | 294 | nomem: |
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291 | 295 | free(a); |
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292 | 296 | free(b); |
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293 | 297 | free(l.base); |
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294 | 298 | return rl ? rl : PyErr_NoMemory(); |
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295 | 299 | } |
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296 | 300 | |
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297 | 301 | static PyObject *bdiff(PyObject *self, PyObject *args) |
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298 | 302 | { |
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299 | 303 | char *sa, *sb; |
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300 | 304 | PyObject *result = NULL; |
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301 | 305 | struct line *al, *bl; |
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302 | 306 | struct hunklist l = {NULL, NULL}; |
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303 | 307 | struct hunk *h; |
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304 | 308 | char encode[12], *rb; |
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305 | 309 | int an, bn, len = 0, la, lb; |
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306 | 310 | |
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307 | 311 | if (!PyArg_ParseTuple(args, "s#s#:bdiff", &sa, &la, &sb, &lb)) |
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308 | 312 | return NULL; |
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309 | 313 | |
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310 | 314 | an = splitlines(sa, la, &al); |
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311 | 315 | bn = splitlines(sb, lb, &bl); |
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312 | 316 | if (!al || !bl) |
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313 | 317 | goto nomem; |
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314 | 318 | |
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315 | 319 | l = diff(al, an, bl, bn); |
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316 | 320 | if (!l.head) |
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317 | 321 | goto nomem; |
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318 | 322 | |
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319 | 323 | /* calculate length of output */ |
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320 | 324 | la = lb = 0; |
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321 | 325 | for (h = l.base; h != l.head; h++) { |
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322 | 326 | if (h->a1 != la || h->b1 != lb) |
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323 | 327 | len += 12 + bl[h->b1].l - bl[lb].l; |
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324 | 328 | la = h->a2; |
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325 | 329 | lb = h->b2; |
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326 | 330 | } |
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327 | 331 | |
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328 | 332 | result = PyString_FromStringAndSize(NULL, len); |
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329 | 333 | if (!result) |
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330 | 334 | goto nomem; |
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331 | 335 | |
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332 | 336 | /* build binary patch */ |
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333 | 337 | rb = PyString_AsString(result); |
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334 | 338 | la = lb = 0; |
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335 | 339 | |
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336 | 340 | for (h = l.base; h != l.head; h++) { |
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337 | 341 | if (h->a1 != la || h->b1 != lb) { |
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338 | 342 | len = bl[h->b1].l - bl[lb].l; |
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339 | 343 | *(uint32_t *)(encode) = htonl(al[la].l - al->l); |
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340 | 344 | *(uint32_t *)(encode + 4) = htonl(al[h->a1].l - al->l); |
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341 | 345 | *(uint32_t *)(encode + 8) = htonl(len); |
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342 | 346 | memcpy(rb, encode, 12); |
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343 | 347 | memcpy(rb + 12, bl[lb].l, len); |
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344 | 348 | rb += 12 + len; |
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345 | 349 | } |
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346 | 350 | la = h->a2; |
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347 | 351 | lb = h->b2; |
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348 | 352 | } |
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349 | 353 | |
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350 | 354 | nomem: |
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351 | 355 | free(al); |
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352 | 356 | free(bl); |
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353 | 357 | free(l.base); |
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354 | 358 | return result ? result : PyErr_NoMemory(); |
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355 | 359 | } |
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356 | 360 | |
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357 | 361 | static char mdiff_doc[] = "Efficient binary diff."; |
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358 | 362 | |
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359 | 363 | static PyMethodDef methods[] = { |
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360 | 364 | {"bdiff", bdiff, METH_VARARGS, "calculate a binary diff\n"}, |
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361 | 365 | {"blocks", blocks, METH_VARARGS, "find a list of matching lines\n"}, |
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362 | 366 | {NULL, NULL} |
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363 | 367 | }; |
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364 | 368 | |
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365 | 369 | PyMODINIT_FUNC initbdiff(void) |
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366 | 370 | { |
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367 | 371 | Py_InitModule3("bdiff", methods, mdiff_doc); |
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368 | 372 | } |
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369 | 373 |
@@ -1,411 +1,415 b'' | |||
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1 | 1 | /* |
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2 | 2 | mpatch.c - efficient binary patching for Mercurial |
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3 | 3 | |
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4 | 4 | This implements a patch algorithm that's O(m + nlog n) where m is the |
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5 | 5 | size of the output and n is the number of patches. |
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6 | 6 | |
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7 | 7 | Given a list of binary patches, it unpacks each into a hunk list, |
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8 | 8 | then combines the hunk lists with a treewise recursion to form a |
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9 | 9 | single hunk list. This hunk list is then applied to the original |
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10 | 10 | text. |
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11 | 11 | |
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12 | 12 | The text (or binary) fragments are copied directly from their source |
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13 | 13 | Python objects into a preallocated output string to avoid the |
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14 | 14 | allocation of intermediate Python objects. Working memory is about 2x |
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15 | 15 | the total number of hunks. |
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16 | 16 | |
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17 | 17 | Copyright 2005, 2006 Matt Mackall <mpm@selenic.com> |
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18 | 18 | |
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19 | 19 | This software may be used and distributed according to the terms |
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20 | 20 | of the GNU General Public License, incorporated herein by reference. |
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21 | 21 | */ |
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22 | 22 | |
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23 | 23 | #include <Python.h> |
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24 | 24 | #include <stdlib.h> |
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25 | 25 | #include <string.h> |
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26 | 26 | |
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27 | 27 | #ifdef _WIN32 |
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28 | 28 | # ifdef _MSC_VER |
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29 | 29 | /* msvc 6.0 has problems */ |
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30 | 30 | # define inline __inline |
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31 | 31 | typedef unsigned long uint32_t; |
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32 | 32 | # else |
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33 | 33 | # include <stdint.h> |
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34 | 34 | # endif |
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35 | 35 | static uint32_t ntohl(uint32_t x) |
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36 | 36 | { |
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37 | 37 | return ((x & 0x000000ffUL) << 24) | |
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38 | 38 | ((x & 0x0000ff00UL) << 8) | |
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39 | 39 | ((x & 0x00ff0000UL) >> 8) | |
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40 | 40 | ((x & 0xff000000UL) >> 24); |
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41 | 41 | } |
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42 | 42 | #else |
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43 | 43 | /* not windows */ |
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44 | 44 | # include <sys/types.h> |
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45 | # include <arpa/inet.h> | |
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45 | # ifdef __BEOS__ | |
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46 | # include <ByteOrder.h> | |
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47 | # else | |
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48 | # include <arpa/inet.h> | |
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49 | # endif | |
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46 | 50 | # include <inttypes.h> |
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47 | 51 | #endif |
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48 | 52 | |
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49 | 53 | static char mpatch_doc[] = "Efficient binary patching."; |
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50 | 54 | static PyObject *mpatch_Error; |
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51 | 55 | |
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52 | 56 | struct frag { |
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53 | 57 | int start, end, len; |
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54 | 58 | char *data; |
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55 | 59 | }; |
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56 | 60 | |
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57 | 61 | struct flist { |
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58 | 62 | struct frag *base, *head, *tail; |
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59 | 63 | }; |
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60 | 64 | |
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61 | 65 | static struct flist *lalloc(int size) |
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62 | 66 | { |
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63 | 67 | struct flist *a = NULL; |
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64 | 68 | |
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65 | 69 | if (size < 1) |
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66 | 70 | size = 1; |
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67 | 71 | |
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68 | 72 | a = (struct flist *)malloc(sizeof(struct flist)); |
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69 | 73 | if (a) { |
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70 | 74 | a->base = (struct frag *)malloc(sizeof(struct frag) * size); |
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71 | 75 | if (a->base) { |
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72 | 76 | a->head = a->tail = a->base; |
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73 | 77 | return a; |
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74 | 78 | } |
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75 | 79 | free(a); |
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76 | 80 | a = NULL; |
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77 | 81 | } |
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78 | 82 | if (!PyErr_Occurred()) |
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79 | 83 | PyErr_NoMemory(); |
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80 | 84 | return NULL; |
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81 | 85 | } |
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82 | 86 | |
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83 | 87 | static void lfree(struct flist *a) |
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84 | 88 | { |
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85 | 89 | if (a) { |
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86 | 90 | free(a->base); |
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87 | 91 | free(a); |
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88 | 92 | } |
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89 | 93 | } |
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90 | 94 | |
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91 | 95 | static int lsize(struct flist *a) |
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92 | 96 | { |
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93 | 97 | return a->tail - a->head; |
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94 | 98 | } |
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95 | 99 | |
|
96 | 100 | /* move hunks in source that are less cut to dest, compensating |
|
97 | 101 | for changes in offset. the last hunk may be split if necessary. |
|
98 | 102 | */ |
|
99 | 103 | static int gather(struct flist *dest, struct flist *src, int cut, int offset) |
|
100 | 104 | { |
|
101 | 105 | struct frag *d = dest->tail, *s = src->head; |
|
102 | 106 | int postend, c, l; |
|
103 | 107 | |
|
104 | 108 | while (s != src->tail) { |
|
105 | 109 | if (s->start + offset >= cut) |
|
106 | 110 | break; /* we've gone far enough */ |
|
107 | 111 | |
|
108 | 112 | postend = offset + s->start + s->len; |
|
109 | 113 | if (postend <= cut) { |
|
110 | 114 | /* save this hunk */ |
|
111 | 115 | offset += s->start + s->len - s->end; |
|
112 | 116 | *d++ = *s++; |
|
113 | 117 | } |
|
114 | 118 | else { |
|
115 | 119 | /* break up this hunk */ |
|
116 | 120 | c = cut - offset; |
|
117 | 121 | if (s->end < c) |
|
118 | 122 | c = s->end; |
|
119 | 123 | l = cut - offset - s->start; |
|
120 | 124 | if (s->len < l) |
|
121 | 125 | l = s->len; |
|
122 | 126 | |
|
123 | 127 | offset += s->start + l - c; |
|
124 | 128 | |
|
125 | 129 | d->start = s->start; |
|
126 | 130 | d->end = c; |
|
127 | 131 | d->len = l; |
|
128 | 132 | d->data = s->data; |
|
129 | 133 | d++; |
|
130 | 134 | s->start = c; |
|
131 | 135 | s->len = s->len - l; |
|
132 | 136 | s->data = s->data + l; |
|
133 | 137 | |
|
134 | 138 | break; |
|
135 | 139 | } |
|
136 | 140 | } |
|
137 | 141 | |
|
138 | 142 | dest->tail = d; |
|
139 | 143 | src->head = s; |
|
140 | 144 | return offset; |
|
141 | 145 | } |
|
142 | 146 | |
|
143 | 147 | /* like gather, but with no output list */ |
|
144 | 148 | static int discard(struct flist *src, int cut, int offset) |
|
145 | 149 | { |
|
146 | 150 | struct frag *s = src->head; |
|
147 | 151 | int postend, c, l; |
|
148 | 152 | |
|
149 | 153 | while (s != src->tail) { |
|
150 | 154 | if (s->start + offset >= cut) |
|
151 | 155 | break; |
|
152 | 156 | |
|
153 | 157 | postend = offset + s->start + s->len; |
|
154 | 158 | if (postend <= cut) { |
|
155 | 159 | offset += s->start + s->len - s->end; |
|
156 | 160 | s++; |
|
157 | 161 | } |
|
158 | 162 | else { |
|
159 | 163 | c = cut - offset; |
|
160 | 164 | if (s->end < c) |
|
161 | 165 | c = s->end; |
|
162 | 166 | l = cut - offset - s->start; |
|
163 | 167 | if (s->len < l) |
|
164 | 168 | l = s->len; |
|
165 | 169 | |
|
166 | 170 | offset += s->start + l - c; |
|
167 | 171 | s->start = c; |
|
168 | 172 | s->len = s->len - l; |
|
169 | 173 | s->data = s->data + l; |
|
170 | 174 | |
|
171 | 175 | break; |
|
172 | 176 | } |
|
173 | 177 | } |
|
174 | 178 | |
|
175 | 179 | src->head = s; |
|
176 | 180 | return offset; |
|
177 | 181 | } |
|
178 | 182 | |
|
179 | 183 | /* combine hunk lists a and b, while adjusting b for offset changes in a/ |
|
180 | 184 | this deletes a and b and returns the resultant list. */ |
|
181 | 185 | static struct flist *combine(struct flist *a, struct flist *b) |
|
182 | 186 | { |
|
183 | 187 | struct flist *c = NULL; |
|
184 | 188 | struct frag *bh, *ct; |
|
185 | 189 | int offset = 0, post; |
|
186 | 190 | |
|
187 | 191 | if (a && b) |
|
188 | 192 | c = lalloc((lsize(a) + lsize(b)) * 2); |
|
189 | 193 | |
|
190 | 194 | if (c) { |
|
191 | 195 | |
|
192 | 196 | for (bh = b->head; bh != b->tail; bh++) { |
|
193 | 197 | /* save old hunks */ |
|
194 | 198 | offset = gather(c, a, bh->start, offset); |
|
195 | 199 | |
|
196 | 200 | /* discard replaced hunks */ |
|
197 | 201 | post = discard(a, bh->end, offset); |
|
198 | 202 | |
|
199 | 203 | /* insert new hunk */ |
|
200 | 204 | ct = c->tail; |
|
201 | 205 | ct->start = bh->start - offset; |
|
202 | 206 | ct->end = bh->end - post; |
|
203 | 207 | ct->len = bh->len; |
|
204 | 208 | ct->data = bh->data; |
|
205 | 209 | c->tail++; |
|
206 | 210 | offset = post; |
|
207 | 211 | } |
|
208 | 212 | |
|
209 | 213 | /* hold on to tail from a */ |
|
210 | 214 | memcpy(c->tail, a->head, sizeof(struct frag) * lsize(a)); |
|
211 | 215 | c->tail += lsize(a); |
|
212 | 216 | } |
|
213 | 217 | |
|
214 | 218 | lfree(a); |
|
215 | 219 | lfree(b); |
|
216 | 220 | return c; |
|
217 | 221 | } |
|
218 | 222 | |
|
219 | 223 | /* decode a binary patch into a hunk list */ |
|
220 | 224 | static struct flist *decode(char *bin, int len) |
|
221 | 225 | { |
|
222 | 226 | struct flist *l; |
|
223 | 227 | struct frag *lt; |
|
224 | 228 | char *end = bin + len; |
|
225 | 229 | char decode[12]; /* for dealing with alignment issues */ |
|
226 | 230 | |
|
227 | 231 | /* assume worst case size, we won't have many of these lists */ |
|
228 | 232 | l = lalloc(len / 12); |
|
229 | 233 | if (!l) |
|
230 | 234 | return NULL; |
|
231 | 235 | |
|
232 | 236 | lt = l->tail; |
|
233 | 237 | |
|
234 | 238 | while (bin < end) { |
|
235 | 239 | memcpy(decode, bin, 12); |
|
236 | 240 | lt->start = ntohl(*(uint32_t *)decode); |
|
237 | 241 | lt->end = ntohl(*(uint32_t *)(decode + 4)); |
|
238 | 242 | lt->len = ntohl(*(uint32_t *)(decode + 8)); |
|
239 | 243 | lt->data = bin + 12; |
|
240 | 244 | bin += 12 + lt->len; |
|
241 | 245 | lt++; |
|
242 | 246 | } |
|
243 | 247 | |
|
244 | 248 | if (bin != end) { |
|
245 | 249 | if (!PyErr_Occurred()) |
|
246 | 250 | PyErr_SetString(mpatch_Error, "patch cannot be decoded"); |
|
247 | 251 | lfree(l); |
|
248 | 252 | return NULL; |
|
249 | 253 | } |
|
250 | 254 | |
|
251 | 255 | l->tail = lt; |
|
252 | 256 | return l; |
|
253 | 257 | } |
|
254 | 258 | |
|
255 | 259 | /* calculate the size of resultant text */ |
|
256 | 260 | static int calcsize(int len, struct flist *l) |
|
257 | 261 | { |
|
258 | 262 | int outlen = 0, last = 0; |
|
259 | 263 | struct frag *f = l->head; |
|
260 | 264 | |
|
261 | 265 | while (f != l->tail) { |
|
262 | 266 | if (f->start < last || f->end > len) { |
|
263 | 267 | if (!PyErr_Occurred()) |
|
264 | 268 | PyErr_SetString(mpatch_Error, |
|
265 | 269 | "invalid patch"); |
|
266 | 270 | return -1; |
|
267 | 271 | } |
|
268 | 272 | outlen += f->start - last; |
|
269 | 273 | last = f->end; |
|
270 | 274 | outlen += f->len; |
|
271 | 275 | f++; |
|
272 | 276 | } |
|
273 | 277 | |
|
274 | 278 | outlen += len - last; |
|
275 | 279 | return outlen; |
|
276 | 280 | } |
|
277 | 281 | |
|
278 | 282 | static int apply(char *buf, char *orig, int len, struct flist *l) |
|
279 | 283 | { |
|
280 | 284 | struct frag *f = l->head; |
|
281 | 285 | int last = 0; |
|
282 | 286 | char *p = buf; |
|
283 | 287 | |
|
284 | 288 | while (f != l->tail) { |
|
285 | 289 | if (f->start < last || f->end > len) { |
|
286 | 290 | if (!PyErr_Occurred()) |
|
287 | 291 | PyErr_SetString(mpatch_Error, |
|
288 | 292 | "invalid patch"); |
|
289 | 293 | return 0; |
|
290 | 294 | } |
|
291 | 295 | memcpy(p, orig + last, f->start - last); |
|
292 | 296 | p += f->start - last; |
|
293 | 297 | memcpy(p, f->data, f->len); |
|
294 | 298 | last = f->end; |
|
295 | 299 | p += f->len; |
|
296 | 300 | f++; |
|
297 | 301 | } |
|
298 | 302 | memcpy(p, orig + last, len - last); |
|
299 | 303 | return 1; |
|
300 | 304 | } |
|
301 | 305 | |
|
302 | 306 | /* recursively generate a patch of all bins between start and end */ |
|
303 | 307 | static struct flist *fold(PyObject *bins, int start, int end) |
|
304 | 308 | { |
|
305 | 309 | int len; |
|
306 | 310 | |
|
307 | 311 | if (start + 1 == end) { |
|
308 | 312 | /* trivial case, output a decoded list */ |
|
309 | 313 | PyObject *tmp = PyList_GetItem(bins, start); |
|
310 | 314 | if (!tmp) |
|
311 | 315 | return NULL; |
|
312 | 316 | return decode(PyString_AsString(tmp), PyString_Size(tmp)); |
|
313 | 317 | } |
|
314 | 318 | |
|
315 | 319 | /* divide and conquer, memory management is elsewhere */ |
|
316 | 320 | len = (end - start) / 2; |
|
317 | 321 | return combine(fold(bins, start, start + len), |
|
318 | 322 | fold(bins, start + len, end)); |
|
319 | 323 | } |
|
320 | 324 | |
|
321 | 325 | static PyObject * |
|
322 | 326 | patches(PyObject *self, PyObject *args) |
|
323 | 327 | { |
|
324 | 328 | PyObject *text, *bins, *result; |
|
325 | 329 | struct flist *patch; |
|
326 | 330 | char *in, *out; |
|
327 | 331 | int len, outlen; |
|
328 | 332 | |
|
329 | 333 | if (!PyArg_ParseTuple(args, "SO:mpatch", &text, &bins)) |
|
330 | 334 | return NULL; |
|
331 | 335 | |
|
332 | 336 | len = PyList_Size(bins); |
|
333 | 337 | if (!len) { |
|
334 | 338 | /* nothing to do */ |
|
335 | 339 | Py_INCREF(text); |
|
336 | 340 | return text; |
|
337 | 341 | } |
|
338 | 342 | |
|
339 | 343 | patch = fold(bins, 0, len); |
|
340 | 344 | if (!patch) |
|
341 | 345 | return NULL; |
|
342 | 346 | |
|
343 | 347 | outlen = calcsize(PyString_Size(text), patch); |
|
344 | 348 | if (outlen < 0) { |
|
345 | 349 | result = NULL; |
|
346 | 350 | goto cleanup; |
|
347 | 351 | } |
|
348 | 352 | result = PyString_FromStringAndSize(NULL, outlen); |
|
349 | 353 | if (!result) { |
|
350 | 354 | result = NULL; |
|
351 | 355 | goto cleanup; |
|
352 | 356 | } |
|
353 | 357 | in = PyString_AsString(text); |
|
354 | 358 | out = PyString_AsString(result); |
|
355 | 359 | if (!apply(out, in, PyString_Size(text), patch)) { |
|
356 | 360 | Py_DECREF(result); |
|
357 | 361 | result = NULL; |
|
358 | 362 | } |
|
359 | 363 | cleanup: |
|
360 | 364 | lfree(patch); |
|
361 | 365 | return result; |
|
362 | 366 | } |
|
363 | 367 | |
|
364 | 368 | /* calculate size of a patched file directly */ |
|
365 | 369 | static PyObject * |
|
366 | 370 | patchedsize(PyObject *self, PyObject *args) |
|
367 | 371 | { |
|
368 | 372 | long orig, start, end, len, outlen = 0, last = 0; |
|
369 | 373 | int patchlen; |
|
370 | 374 | char *bin, *binend; |
|
371 | 375 | char decode[12]; /* for dealing with alignment issues */ |
|
372 | 376 | |
|
373 | 377 | if (!PyArg_ParseTuple(args, "ls#", &orig, &bin, &patchlen)) |
|
374 | 378 | return NULL; |
|
375 | 379 | |
|
376 | 380 | binend = bin + patchlen; |
|
377 | 381 | |
|
378 | 382 | while (bin < binend) { |
|
379 | 383 | memcpy(decode, bin, 12); |
|
380 | 384 | start = ntohl(*(uint32_t *)decode); |
|
381 | 385 | end = ntohl(*(uint32_t *)(decode + 4)); |
|
382 | 386 | len = ntohl(*(uint32_t *)(decode + 8)); |
|
383 | 387 | bin += 12 + len; |
|
384 | 388 | outlen += start - last; |
|
385 | 389 | last = end; |
|
386 | 390 | outlen += len; |
|
387 | 391 | } |
|
388 | 392 | |
|
389 | 393 | if (bin != binend) { |
|
390 | 394 | if (!PyErr_Occurred()) |
|
391 | 395 | PyErr_SetString(mpatch_Error, "patch cannot be decoded"); |
|
392 | 396 | return NULL; |
|
393 | 397 | } |
|
394 | 398 | |
|
395 | 399 | outlen += orig - last; |
|
396 | 400 | return Py_BuildValue("l", outlen); |
|
397 | 401 | } |
|
398 | 402 | |
|
399 | 403 | static PyMethodDef methods[] = { |
|
400 | 404 | {"patches", patches, METH_VARARGS, "apply a series of patches\n"}, |
|
401 | 405 | {"patchedsize", patchedsize, METH_VARARGS, "calculed patched size\n"}, |
|
402 | 406 | {NULL, NULL} |
|
403 | 407 | }; |
|
404 | 408 | |
|
405 | 409 | PyMODINIT_FUNC |
|
406 | 410 | initmpatch(void) |
|
407 | 411 | { |
|
408 | 412 | Py_InitModule3("mpatch", methods, mpatch_doc); |
|
409 | 413 | mpatch_Error = PyErr_NewException("mpatch.mpatchError", NULL, NULL); |
|
410 | 414 | } |
|
411 | 415 |
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