Merge in xdiff cleanup pieces
[git/git.git] / xdiff / xutils.c
CommitLineData
3443546f
LT
1/*
2 * LibXDiff by Davide Libenzi ( File Differential Library )
3 * Copyright (C) 2003 Davide Libenzi
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 * Davide Libenzi <davidel@xmailserver.org>
20 *
21 */
22
23#include "xinclude.h"
24
25
26
27#define XDL_GUESS_NLINES 256
28
29
30
31
ca557aff
DL
32long xdl_bogosqrt(long n) {
33 long i;
34
35 /*
36 * Classical integer square root approximation using shifts.
37 */
38 for (i = 1; n > 0; n >>= 2)
39 i <<= 1;
40
41 return i;
42}
43
44
3443546f
LT
45int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize,
46 xdemitcb_t *ecb) {
621c53cc
LT
47 mmbuffer_t mb[3];
48 int i;
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LT
49
50 mb[0].ptr = (char *) pre;
51 mb[0].size = psize;
52 mb[1].ptr = (char *) rec;
53 mb[1].size = size;
621c53cc 54 i = 2;
3443546f 55
621c53cc
LT
56 if (!size || rec[size-1] != '\n') {
57 mb[2].ptr = "\n\\ No newline at end of file\n";
58 mb[2].size = strlen(mb[2].ptr);
59 i = 3;
60 }
61
62 if (ecb->outf(ecb->priv, mb, i) < 0) {
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LT
63
64 return -1;
65 }
66
67 return 0;
68}
69
70void *xdl_mmfile_first(mmfile_t *mmf, long *size)
71{
72 *size = mmf->size;
73 return mmf->ptr;
74}
75
76
77void *xdl_mmfile_next(mmfile_t *mmf, long *size)
78{
79 return NULL;
80}
81
82
83long xdl_mmfile_size(mmfile_t *mmf)
84{
85 return mmf->size;
86}
87
88
89int xdl_cha_init(chastore_t *cha, long isize, long icount) {
90
91 cha->head = cha->tail = NULL;
92 cha->isize = isize;
93 cha->nsize = icount * isize;
94 cha->ancur = cha->sncur = NULL;
95 cha->scurr = 0;
96
97 return 0;
98}
99
100
101void xdl_cha_free(chastore_t *cha) {
102 chanode_t *cur, *tmp;
103
104 for (cur = cha->head; (tmp = cur) != NULL;) {
105 cur = cur->next;
106 xdl_free(tmp);
107 }
108}
109
110
111void *xdl_cha_alloc(chastore_t *cha) {
112 chanode_t *ancur;
113 void *data;
114
115 if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) {
116 if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) {
117
118 return NULL;
119 }
120 ancur->icurr = 0;
121 ancur->next = NULL;
122 if (cha->tail)
123 cha->tail->next = ancur;
124 if (!cha->head)
125 cha->head = ancur;
126 cha->tail = ancur;
127 cha->ancur = ancur;
128 }
129
130 data = (char *) ancur + sizeof(chanode_t) + ancur->icurr;
131 ancur->icurr += cha->isize;
132
133 return data;
134}
135
136
137void *xdl_cha_first(chastore_t *cha) {
138 chanode_t *sncur;
139
140 if (!(cha->sncur = sncur = cha->head))
141 return NULL;
142
143 cha->scurr = 0;
144
145 return (char *) sncur + sizeof(chanode_t) + cha->scurr;
146}
147
148
149void *xdl_cha_next(chastore_t *cha) {
150 chanode_t *sncur;
151
152 if (!(sncur = cha->sncur))
153 return NULL;
154 cha->scurr += cha->isize;
155 if (cha->scurr == sncur->icurr) {
156 if (!(sncur = cha->sncur = sncur->next))
157 return NULL;
158 cha->scurr = 0;
159 }
160
161 return (char *) sncur + sizeof(chanode_t) + cha->scurr;
162}
163
164
165long xdl_guess_lines(mmfile_t *mf) {
166 long nl = 0, size, tsize = 0;
167 char const *data, *cur, *top;
168
169 if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
170 for (top = data + size; nl < XDL_GUESS_NLINES;) {
171 if (cur >= top) {
172 tsize += (long) (cur - data);
173 if (!(cur = data = xdl_mmfile_next(mf, &size)))
174 break;
175 top = data + size;
176 }
177 nl++;
178 if (!(cur = memchr(cur, '\n', top - cur)))
179 cur = top;
180 else
181 cur++;
182 }
183 tsize += (long) (cur - data);
184 }
185
186 if (nl && tsize)
187 nl = xdl_mmfile_size(mf) / (tsize / nl);
188
189 return nl + 1;
190}
191
192
193unsigned long xdl_hash_record(char const **data, char const *top) {
194 unsigned long ha = 5381;
195 char const *ptr = *data;
196
197 for (; ptr < top && *ptr != '\n'; ptr++) {
198 ha += (ha << 5);
199 ha ^= (unsigned long) *ptr;
200 }
201 *data = ptr < top ? ptr + 1: ptr;
202
203 return ha;
204}
205
206
207unsigned int xdl_hashbits(unsigned int size) {
208 unsigned int val = 1, bits = 0;
209
210 for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++);
211 return bits ? bits: 1;
212}
213
214
215int xdl_num_out(char *out, long val) {
216 char *ptr, *str = out;
217 char buf[32];
218
219 ptr = buf + sizeof(buf) - 1;
220 *ptr = '\0';
221 if (val < 0) {
222 *--ptr = '-';
223 val = -val;
224 }
225 for (; val && ptr > buf; val /= 10)
226 *--ptr = "0123456789"[val % 10];
227 if (*ptr)
228 for (; *ptr; ptr++, str++)
229 *str = *ptr;
230 else
231 *str++ = '0';
232 *str = '\0';
233
234 return str - out;
235}
236
237
238long xdl_atol(char const *str, char const **next) {
239 long val, base;
240 char const *top;
241
242 for (top = str; XDL_ISDIGIT(*top); top++);
243 if (next)
244 *next = top;
245 for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
246 val += base * (long)(*top - '0');
247 return val;
248}
249
250
acb72577
MW
251int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
252 const char *func, long funclen, xdemitcb_t *ecb) {
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LT
253 int nb = 0;
254 mmbuffer_t mb;
255 char buf[128];
256
257 memcpy(buf, "@@ -", 4);
258 nb += 4;
259
ca557aff 260 nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1);
3443546f 261
3ce8f089
JH
262 if (c1 != 1) {
263 memcpy(buf + nb, ",", 1);
264 nb += 1;
3443546f 265
3ce8f089
JH
266 nb += xdl_num_out(buf + nb, c1);
267 }
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LT
268
269 memcpy(buf + nb, " +", 2);
270 nb += 2;
271
ca557aff 272 nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1);
3443546f 273
3ce8f089
JH
274 if (c2 != 1) {
275 memcpy(buf + nb, ",", 1);
276 nb += 1;
3443546f 277
3ce8f089
JH
278 nb += xdl_num_out(buf + nb, c2);
279 }
3443546f 280
acb72577
MW
281 memcpy(buf + nb, " @@", 3);
282 nb += 3;
283 if (func && funclen) {
284 buf[nb++] = ' ';
285 if (funclen > sizeof(buf) - nb - 1)
286 funclen = sizeof(buf) - nb - 1;
287 memcpy(buf + nb, func, funclen);
288 nb += funclen;
289 }
290 buf[nb++] = '\n';
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LT
291
292 mb.ptr = buf;
293 mb.size = nb;
294 if (ecb->outf(ecb->priv, &mb, 1) < 0)
295 return -1;
296
297 return 0;
298}
299