gitweb: use new Git::Repo API, and add optional caching
[git/gitweb-caching.git] / xdiff-interface.c
blob944ad9887f5c94ca0e63f9a6c901447634f871ce
1 #include "cache.h"
2 #include "xdiff-interface.h"
3 #include "strbuf.h"
5 struct xdiff_emit_state {
6 xdiff_emit_consume_fn consume;
7 void *consume_callback_data;
8 struct strbuf remainder;
9 };
11 static int parse_num(char **cp_p, int *num_p)
13 char *cp = *cp_p;
14 int num = 0;
15 int read_some;
17 while ('0' <= *cp && *cp <= '9')
18 num = num * 10 + *cp++ - '0';
19 if (!(read_some = cp - *cp_p))
20 return -1;
21 *cp_p = cp;
22 *num_p = num;
23 return 0;
26 int parse_hunk_header(char *line, int len,
27 int *ob, int *on,
28 int *nb, int *nn)
30 char *cp;
31 cp = line + 4;
32 if (parse_num(&cp, ob)) {
33 bad_line:
34 return error("malformed diff output: %s", line);
36 if (*cp == ',') {
37 cp++;
38 if (parse_num(&cp, on))
39 goto bad_line;
41 else
42 *on = 1;
43 if (*cp++ != ' ' || *cp++ != '+')
44 goto bad_line;
45 if (parse_num(&cp, nb))
46 goto bad_line;
47 if (*cp == ',') {
48 cp++;
49 if (parse_num(&cp, nn))
50 goto bad_line;
52 else
53 *nn = 1;
54 return -!!memcmp(cp, " @@", 3);
57 static void consume_one(void *priv_, char *s, unsigned long size)
59 struct xdiff_emit_state *priv = priv_;
60 char *ep;
61 while (size) {
62 unsigned long this_size;
63 ep = memchr(s, '\n', size);
64 this_size = (ep == NULL) ? size : (ep - s + 1);
65 priv->consume(priv->consume_callback_data, s, this_size);
66 size -= this_size;
67 s += this_size;
71 static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
73 struct xdiff_emit_state *priv = priv_;
74 int i;
76 for (i = 0; i < nbuf; i++) {
77 if (mb[i].ptr[mb[i].size-1] != '\n') {
78 /* Incomplete line */
79 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
80 continue;
83 /* we have a complete line */
84 if (!priv->remainder.len) {
85 consume_one(priv, mb[i].ptr, mb[i].size);
86 continue;
88 strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
89 consume_one(priv, priv->remainder.buf, priv->remainder.len);
90 strbuf_reset(&priv->remainder);
92 if (priv->remainder.len) {
93 consume_one(priv, priv->remainder.buf, priv->remainder.len);
94 strbuf_reset(&priv->remainder);
96 return 0;
100 * Trim down common substring at the end of the buffers,
101 * but leave at least ctx lines at the end.
103 static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
105 const int blk = 1024;
106 long trimmed = 0, recovered = 0;
107 char *ap = a->ptr + a->size;
108 char *bp = b->ptr + b->size;
109 long smaller = (a->size < b->size) ? a->size : b->size;
111 if (ctx)
112 return;
114 while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
115 trimmed += blk;
116 ap -= blk;
117 bp -= blk;
120 while (recovered < trimmed)
121 if (ap[recovered++] == '\n')
122 break;
123 a->size -= trimmed - recovered;
124 b->size -= trimmed - recovered;
127 int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
129 mmfile_t a = *mf1;
130 mmfile_t b = *mf2;
132 trim_common_tail(&a, &b, xecfg->ctxlen);
134 return xdl_diff(&a, &b, xpp, xecfg, xecb);
137 int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
138 xdiff_emit_consume_fn fn, void *consume_callback_data,
139 xpparam_t const *xpp,
140 xdemitconf_t const *xecfg, xdemitcb_t *xecb)
142 int ret;
143 struct xdiff_emit_state state;
145 memset(&state, 0, sizeof(state));
146 state.consume = fn;
147 state.consume_callback_data = consume_callback_data;
148 xecb->outf = xdiff_outf;
149 xecb->priv = &state;
150 strbuf_init(&state.remainder, 0);
151 ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
152 strbuf_release(&state.remainder);
153 return ret;
156 int read_mmfile(mmfile_t *ptr, const char *filename)
158 struct stat st;
159 FILE *f;
160 size_t sz;
162 if (stat(filename, &st))
163 return error("Could not stat %s", filename);
164 if ((f = fopen(filename, "rb")) == NULL)
165 return error("Could not open %s", filename);
166 sz = xsize_t(st.st_size);
167 ptr->ptr = xmalloc(sz ? sz : 1);
168 if (sz && fread(ptr->ptr, sz, 1, f) != 1)
169 return error("Could not read %s", filename);
170 fclose(f);
171 ptr->size = sz;
172 return 0;
175 #define FIRST_FEW_BYTES 8000
176 int buffer_is_binary(const char *ptr, unsigned long size)
178 if (FIRST_FEW_BYTES < size)
179 size = FIRST_FEW_BYTES;
180 return !!memchr(ptr, 0, size);
183 struct ff_regs {
184 int nr;
185 struct ff_reg {
186 regex_t re;
187 int negate;
188 } *array;
191 static long ff_regexp(const char *line, long len,
192 char *buffer, long buffer_size, void *priv)
194 char *line_buffer = xstrndup(line, len); /* make NUL terminated */
195 struct ff_regs *regs = priv;
196 regmatch_t pmatch[2];
197 int result = 0, i;
199 for (i = 0; i < regs->nr; i++) {
200 struct ff_reg *reg = regs->array + i;
201 if (reg->negate ^ !!regexec(&reg->re,
202 line_buffer, 2, pmatch, 0)) {
203 free(line_buffer);
204 return -1;
207 i = pmatch[1].rm_so >= 0 ? 1 : 0;
208 line += pmatch[i].rm_so;
209 result = pmatch[i].rm_eo - pmatch[i].rm_so;
210 if (result > buffer_size)
211 result = buffer_size;
212 else
213 while (result > 0 && (isspace(line[result - 1]) ||
214 line[result - 1] == '\n'))
215 result--;
216 memcpy(buffer, line, result);
217 free(line_buffer);
218 return result;
221 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value)
223 int i;
224 struct ff_regs *regs;
226 xecfg->find_func = ff_regexp;
227 regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
228 for (i = 0, regs->nr = 1; value[i]; i++)
229 if (value[i] == '\n')
230 regs->nr++;
231 regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
232 for (i = 0; i < regs->nr; i++) {
233 struct ff_reg *reg = regs->array + i;
234 const char *ep = strchr(value, '\n'), *expression;
235 char *buffer = NULL;
237 reg->negate = (*value == '!');
238 if (reg->negate && i == regs->nr - 1)
239 die("Last expression must not be negated: %s", value);
240 if (*value == '!')
241 value++;
242 if (ep)
243 expression = buffer = xstrndup(value, ep - value);
244 else
245 expression = value;
246 if (regcomp(&reg->re, expression, 0))
247 die("Invalid regexp to look for hunk header: %s", expression);
248 free(buffer);
249 value = ep + 1;