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@@ -30,6 +30,10 b' struct line {' | |||||
30 | const char *l; |
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30 | const char *l; | |
31 | }; |
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31 | }; | |
32 |
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32 | |||
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33 | struct pos { | |||
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34 | int pos, len; | |||
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35 | }; | |||
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36 | ||||
33 | struct hunk { |
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37 | struct hunk { | |
34 | int a1, a2, b1, b2; |
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38 | int a1, a2, b1, b2; | |
35 | }; |
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39 | }; | |
@@ -87,36 +91,37 b' int inline cmp(struct line *a, struct li' | |||||
87 |
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91 | |||
88 | static int equatelines(struct line *a, int an, struct line *b, int bn) |
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92 | static int equatelines(struct line *a, int an, struct line *b, int bn) | |
89 | { |
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93 | { | |
90 |
int i, j, buckets = 1, t |
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94 | int i, j, buckets = 1, t; | |
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95 | struct pos *h; | |||
91 |
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96 | |||
92 | /* build a hash table of the next highest power of 2 */ |
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97 | /* build a hash table of the next highest power of 2 */ | |
93 | while (buckets < bn + 1) |
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98 | while (buckets < bn + 1) | |
94 | buckets *= 2; |
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99 | buckets *= 2; | |
95 |
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100 | |||
96 |
h = malloc(buckets * sizeof( |
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101 | h = malloc(buckets * sizeof(struct pos)); | |
97 | l = calloc(buckets, sizeof(int)); |
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98 | buckets = buckets - 1; |
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102 | buckets = buckets - 1; | |
99 |
if (!h |
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103 | if (!h) | |
100 | free(h); |
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101 | return 0; |
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104 | return 0; | |
102 | } |
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103 |
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105 | |||
104 | /* clear the hash table */ |
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106 | /* clear the hash table */ | |
105 | for (i = 0; i <= buckets; i++) |
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107 | for (i = 0; i <= buckets; i++) { | |
106 | h[i] = -1; |
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108 | h[i].pos = -1; | |
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109 | h[i].len = 0; | |||
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110 | } | |||
107 |
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111 | |||
108 | /* add lines to the hash table chains */ |
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112 | /* add lines to the hash table chains */ | |
109 | for (i = bn - 1; i >= 0; i--) { |
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113 | for (i = bn - 1; i >= 0; i--) { | |
110 | /* find the equivalence class */ |
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114 | /* find the equivalence class */ | |
111 |
for (j = b[i].h & buckets; h[j] != -1; |
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115 | for (j = b[i].h & buckets; h[j].pos != -1; | |
112 | if (!cmp(b + i, b + h[j])) |
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116 | j = (j + 1) & buckets) | |
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117 | if (!cmp(b + i, b + h[j].pos)) | |||
113 | break; |
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118 | break; | |
114 |
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119 | |||
115 | /* add to the head of the equivalence class */ |
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120 | /* add to the head of the equivalence class */ | |
116 | b[i].n = h[j]; |
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121 | b[i].n = h[j].pos; | |
117 | b[i].e = j; |
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122 | b[i].e = j; | |
118 | h[j] = i; |
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123 | h[j].pos = i; | |
119 |
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124 | h[j].len++; /* keep track of popularity */ | |
120 | } |
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125 | } | |
121 |
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126 | |||
122 | /* compute popularity threshold */ |
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127 | /* compute popularity threshold */ | |
@@ -125,24 +130,24 b' static int equatelines(struct line *a, i' | |||||
125 | /* match items in a to their equivalence class in b */ |
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130 | /* match items in a to their equivalence class in b */ | |
126 | for (i = 0; i < an; i++) { |
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131 | for (i = 0; i < an; i++) { | |
127 | /* find the equivalence class */ |
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132 | /* find the equivalence class */ | |
128 |
for (j = a[i].h & buckets; h[j] != -1; |
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133 | for (j = a[i].h & buckets; h[j].pos != -1; | |
129 | if (!cmp(a + i, b + h[j])) |
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134 | j = (j + 1) & buckets) | |
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135 | if (!cmp(a + i, b + h[j].pos)) | |||
130 | break; |
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136 | break; | |
131 |
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137 | |||
132 | a[i].e = j; /* use equivalence class for quick compare */ |
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138 | a[i].e = j; /* use equivalence class for quick compare */ | |
133 |
if( |
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139 | if(h[j].len <= t) | |
134 | a[i].n = h[j]; /* point to head of match list */ |
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140 | a[i].n = h[j].pos; /* point to head of match list */ | |
135 | else |
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141 | else | |
136 | a[i].n = -1; /* too popular */ |
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142 | a[i].n = -1; /* too popular */ | |
137 | } |
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143 | } | |
138 |
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144 | |||
139 | /* discard hash tables */ |
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145 | /* discard hash tables */ | |
140 | free(h); |
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146 | free(h); | |
141 | free(l); |
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142 | return 1; |
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147 | return 1; | |
143 | } |
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148 | } | |
144 |
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149 | |||
145 |
static int longest_match(struct line *a, struct line *b, |
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150 | static int longest_match(struct line *a, struct line *b, struct pos *pos, | |
146 | int a1, int a2, int b1, int b2, int *omi, int *omj) |
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151 | int a1, int a2, int b1, int b2, int *omi, int *omj) | |
147 | { |
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152 | { | |
148 | int mi = a1, mj = b1, mk = 0, mb = 0, i, j, k; |
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153 | int mi = a1, mj = b1, mk = 0, mb = 0, i, j, k; | |
@@ -155,12 +160,12 b' static int longest_match(struct line *a,' | |||||
155 | /* loop through all lines match a[i] in b */ |
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160 | /* loop through all lines match a[i] in b */ | |
156 | for (; j != -1 && j < b2; j = b[j].n) { |
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161 | for (; j != -1 && j < b2; j = b[j].n) { | |
157 | /* does this extend an earlier match? */ |
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162 | /* does this extend an earlier match? */ | |
158 |
if (i > a1 && j > b1 && |
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163 | if (i > a1 && j > b1 && pos[j - 1].pos == i - 1) | |
159 |
k = |
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164 | k = pos[j - 1].len + 1; | |
160 | else |
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165 | else | |
161 | k = 1; |
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166 | k = 1; | |
162 |
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167 | pos[j].pos = i; | |
163 |
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168 | pos[j].len = k; | |
164 |
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169 | |||
165 | /* best match so far? */ |
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170 | /* best match so far? */ | |
166 | if (k > mk) { |
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171 | if (k > mk) { | |
@@ -189,47 +194,46 b' static int longest_match(struct line *a,' | |||||
189 | return mk + mb; |
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194 | return mk + mb; | |
190 | } |
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195 | } | |
191 |
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196 | |||
192 |
static void recurse(struct line *a, struct line *b, |
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197 | static void recurse(struct line *a, struct line *b, struct pos *pos, | |
193 | int a1, int a2, int b1, int b2, struct hunklist *l) |
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198 | int a1, int a2, int b1, int b2, struct hunklist *l) | |
194 | { |
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199 | { | |
195 | int i, j, k; |
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200 | int i, j, k; | |
196 |
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201 | |||
197 | /* find the longest match in this chunk */ |
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202 | /* find the longest match in this chunk */ | |
198 |
k = longest_match(a, b, |
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203 | k = longest_match(a, b, pos, a1, a2, b1, b2, &i, &j); | |
199 | if (!k) |
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204 | if (!k) | |
200 | return; |
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205 | return; | |
201 |
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206 | |||
202 | /* and recurse on the remaining chunks on either side */ |
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207 | /* and recurse on the remaining chunks on either side */ | |
203 |
recurse(a, b, |
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208 | recurse(a, b, pos, a1, i, b1, j, l); | |
204 | l->head->a1 = i; |
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209 | l->head->a1 = i; | |
205 | l->head->a2 = i + k; |
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210 | l->head->a2 = i + k; | |
206 | l->head->b1 = j; |
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211 | l->head->b1 = j; | |
207 | l->head->b2 = j + k; |
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212 | l->head->b2 = j + k; | |
208 | l->head++; |
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213 | l->head++; | |
209 |
recurse(a, b, |
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214 | recurse(a, b, pos, i + k, a2, j + k, b2, l); | |
210 | } |
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215 | } | |
211 |
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216 | |||
212 | static struct hunklist diff(struct line *a, int an, struct line *b, int bn) |
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217 | static struct hunklist diff(struct line *a, int an, struct line *b, int bn) | |
213 | { |
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218 | { | |
214 | struct hunklist l; |
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219 | struct hunklist l; | |
215 | int *jpos, *jlen, t; |
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220 | struct pos *pos; | |
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221 | int t; | |||
216 |
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222 | |||
217 | /* allocate and fill arrays */ |
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223 | /* allocate and fill arrays */ | |
218 | t = equatelines(a, an, b, bn); |
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224 | t = equatelines(a, an, b, bn); | |
219 |
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225 | pos = calloc(bn, sizeof(struct pos)); | |
220 | jlen = calloc(bn, sizeof(int)); |
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221 | l.head = l.base = malloc(sizeof(struct hunk) * ((an + bn) / 4 + 2)); |
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226 | l.head = l.base = malloc(sizeof(struct hunk) * ((an + bn) / 4 + 2)); | |
222 |
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227 | |||
223 |
if ( |
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228 | if (pos && l.base && t) { | |
224 | /* generate the matching block list */ |
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229 | /* generate the matching block list */ | |
225 |
recurse(a, b, |
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230 | recurse(a, b, pos, 0, an, 0, bn, &l); | |
226 | l.head->a1 = an; |
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231 | l.head->a1 = an; | |
227 | l.head->b1 = bn; |
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232 | l.head->b1 = bn; | |
228 | l.head++; |
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233 | l.head++; | |
229 | } |
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234 | } | |
230 |
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235 | |||
231 |
free( |
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236 | free(pos); | |
232 | free(jlen); |
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233 | return l; |
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237 | return l; | |
234 | } |
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238 | } | |
235 |
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239 |
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