Andrew's git / gitweb.git / xdiff-interface.c
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xdiff-interface.con commit submodule: try harder to fetch needed sha1 by direct fetching sha1 (fb43e31)
   1#include "cache.h"
   2#include "xdiff-interface.h"
   3#include "xdiff/xtypes.h"
   4#include "xdiff/xdiffi.h"
   5#include "xdiff/xemit.h"
   6#include "xdiff/xmacros.h"
   7
   8struct xdiff_emit_state {
   9        xdiff_emit_consume_fn consume;
  10        void *consume_callback_data;
  11        struct strbuf remainder;
  12};
  13
  14static int parse_num(char **cp_p, int *num_p)
  15{
  16        char *cp = *cp_p;
  17        int num = 0;
  18
  19        while ('0' <= *cp && *cp <= '9')
  20                num = num * 10 + *cp++ - '0';
  21        if (!(cp - *cp_p))
  22                return -1;
  23        *cp_p = cp;
  24        *num_p = num;
  25        return 0;
  26}
  27
  28int parse_hunk_header(char *line, int len,
  29                      int *ob, int *on,
  30                      int *nb, int *nn)
  31{
  32        char *cp;
  33        cp = line + 4;
  34        if (parse_num(&cp, ob)) {
  35        bad_line:
  36                return error("malformed diff output: %s", line);
  37        }
  38        if (*cp == ',') {
  39                cp++;
  40                if (parse_num(&cp, on))
  41                        goto bad_line;
  42        }
  43        else
  44                *on = 1;
  45        if (*cp++ != ' ' || *cp++ != '+')
  46                goto bad_line;
  47        if (parse_num(&cp, nb))
  48                goto bad_line;
  49        if (*cp == ',') {
  50                cp++;
  51                if (parse_num(&cp, nn))
  52                        goto bad_line;
  53        }
  54        else
  55                *nn = 1;
  56        return -!!memcmp(cp, " @@", 3);
  57}
  58
  59static void consume_one(void *priv_, char *s, unsigned long size)
  60{
  61        struct xdiff_emit_state *priv = priv_;
  62        char *ep;
  63        while (size) {
  64                unsigned long this_size;
  65                ep = memchr(s, '\n', size);
  66                this_size = (ep == NULL) ? size : (ep - s + 1);
  67                priv->consume(priv->consume_callback_data, s, this_size);
  68                size -= this_size;
  69                s += this_size;
  70        }
  71}
  72
  73static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  74{
  75        struct xdiff_emit_state *priv = priv_;
  76        int i;
  77
  78        for (i = 0; i < nbuf; i++) {
  79                if (mb[i].ptr[mb[i].size-1] != '\n') {
  80                        /* Incomplete line */
  81                        strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  82                        continue;
  83                }
  84
  85                /* we have a complete line */
  86                if (!priv->remainder.len) {
  87                        consume_one(priv, mb[i].ptr, mb[i].size);
  88                        continue;
  89                }
  90                strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  91                consume_one(priv, priv->remainder.buf, priv->remainder.len);
  92                strbuf_reset(&priv->remainder);
  93        }
  94        if (priv->remainder.len) {
  95                consume_one(priv, priv->remainder.buf, priv->remainder.len);
  96                strbuf_reset(&priv->remainder);
  97        }
  98        return 0;
  99}
 100
 101/*
 102 * Trim down common substring at the end of the buffers,
 103 * but leave at least ctx lines at the end.
 104 */
 105static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
 106{
 107        const int blk = 1024;
 108        long trimmed = 0, recovered = 0;
 109        char *ap = a->ptr + a->size;
 110        char *bp = b->ptr + b->size;
 111        long smaller = (a->size < b->size) ? a->size : b->size;
 112
 113        if (ctx)
 114                return;
 115
 116        while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 117                trimmed += blk;
 118                ap -= blk;
 119                bp -= blk;
 120        }
 121
 122        while (recovered < trimmed)
 123                if (ap[recovered++] == '\n')
 124                        break;
 125        a->size -= trimmed - recovered;
 126        b->size -= trimmed - recovered;
 127}
 128
 129int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 130{
 131        mmfile_t a = *mf1;
 132        mmfile_t b = *mf2;
 133
 134        if (mf1->size > MAX_XDIFF_SIZE || mf2->size > MAX_XDIFF_SIZE)
 135                return -1;
 136
 137        trim_common_tail(&a, &b, xecfg->ctxlen);
 138
 139        return xdl_diff(&a, &b, xpp, xecfg, xecb);
 140}
 141
 142int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 143                  xdiff_emit_consume_fn fn, void *consume_callback_data,
 144                  xpparam_t const *xpp, xdemitconf_t const *xecfg)
 145{
 146        int ret;
 147        struct xdiff_emit_state state;
 148        xdemitcb_t ecb;
 149
 150        memset(&state, 0, sizeof(state));
 151        state.consume = fn;
 152        state.consume_callback_data = consume_callback_data;
 153        memset(&ecb, 0, sizeof(ecb));
 154        ecb.outf = xdiff_outf;
 155        ecb.priv = &state;
 156        strbuf_init(&state.remainder, 0);
 157        ret = xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 158        strbuf_release(&state.remainder);
 159        return ret;
 160}
 161
 162int read_mmfile(mmfile_t *ptr, const char *filename)
 163{
 164        struct stat st;
 165        FILE *f;
 166        size_t sz;
 167
 168        if (stat(filename, &st))
 169                return error("Could not stat %s", filename);
 170        if ((f = fopen(filename, "rb")) == NULL)
 171                return error("Could not open %s", filename);
 172        sz = xsize_t(st.st_size);
 173        ptr->ptr = xmalloc(sz ? sz : 1);
 174        if (sz && fread(ptr->ptr, sz, 1, f) != 1) {
 175                fclose(f);
 176                return error("Could not read %s", filename);
 177        }
 178        fclose(f);
 179        ptr->size = sz;
 180        return 0;
 181}
 182
 183void read_mmblob(mmfile_t *ptr, const unsigned char *sha1)
 184{
 185        unsigned long size;
 186        enum object_type type;
 187
 188        if (!hashcmp(sha1, null_sha1)) {
 189                ptr->ptr = xstrdup("");
 190                ptr->size = 0;
 191                return;
 192        }
 193
 194        ptr->ptr = read_sha1_file(sha1, &type, &size);
 195        if (!ptr->ptr || type != OBJ_BLOB)
 196                die("unable to read blob object %s", sha1_to_hex(sha1));
 197        ptr->size = size;
 198}
 199
 200#define FIRST_FEW_BYTES 8000
 201int buffer_is_binary(const char *ptr, unsigned long size)
 202{
 203        if (FIRST_FEW_BYTES < size)
 204                size = FIRST_FEW_BYTES;
 205        return !!memchr(ptr, 0, size);
 206}
 207
 208struct ff_regs {
 209        int nr;
 210        struct ff_reg {
 211                regex_t re;
 212                int negate;
 213        } *array;
 214};
 215
 216static long ff_regexp(const char *line, long len,
 217                char *buffer, long buffer_size, void *priv)
 218{
 219        char *line_buffer;
 220        struct ff_regs *regs = priv;
 221        regmatch_t pmatch[2];
 222        int i;
 223        int result = -1;
 224
 225        /* Exclude terminating newline (and cr) from matching */
 226        if (len > 0 && line[len-1] == '\n') {
 227                if (len > 1 && line[len-2] == '\r')
 228                        len -= 2;
 229                else
 230                        len--;
 231        }
 232
 233        line_buffer = xstrndup(line, len); /* make NUL terminated */
 234
 235        for (i = 0; i < regs->nr; i++) {
 236                struct ff_reg *reg = regs->array + i;
 237                if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
 238                        if (reg->negate)
 239                                goto fail;
 240                        break;
 241                }
 242        }
 243        if (regs->nr <= i)
 244                goto fail;
 245        i = pmatch[1].rm_so >= 0 ? 1 : 0;
 246        line += pmatch[i].rm_so;
 247        result = pmatch[i].rm_eo - pmatch[i].rm_so;
 248        if (result > buffer_size)
 249                result = buffer_size;
 250        while (result > 0 && (isspace(line[result - 1])))
 251                result--;
 252        memcpy(buffer, line, result);
 253 fail:
 254        free(line_buffer);
 255        return result;
 256}
 257
 258void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 259{
 260        int i;
 261        struct ff_regs *regs;
 262
 263        xecfg->find_func = ff_regexp;
 264        regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 265        for (i = 0, regs->nr = 1; value[i]; i++)
 266                if (value[i] == '\n')
 267                        regs->nr++;
 268        regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
 269        for (i = 0; i < regs->nr; i++) {
 270                struct ff_reg *reg = regs->array + i;
 271                const char *ep = strchr(value, '\n'), *expression;
 272                char *buffer = NULL;
 273
 274                reg->negate = (*value == '!');
 275                if (reg->negate && i == regs->nr - 1)
 276                        die("Last expression must not be negated: %s", value);
 277                if (*value == '!')
 278                        value++;
 279                if (ep)
 280                        expression = buffer = xstrndup(value, ep - value);
 281                else
 282                        expression = value;
 283                if (regcomp(&reg->re, expression, cflags))
 284                        die("Invalid regexp to look for hunk header: %s", expression);
 285                free(buffer);
 286                value = ep + 1;
 287        }
 288}
 289
 290void xdiff_clear_find_func(xdemitconf_t *xecfg)
 291{
 292        if (xecfg->find_func) {
 293                int i;
 294                struct ff_regs *regs = xecfg->find_func_priv;
 295
 296                for (i = 0; i < regs->nr; i++)
 297                        regfree(&regs->array[i].re);
 298                free(regs->array);
 299                free(regs);
 300                xecfg->find_func = NULL;
 301                xecfg->find_func_priv = NULL;
 302        }
 303}
 304
 305int git_xmerge_style = -1;
 306
 307int git_xmerge_config(const char *var, const char *value, void *cb)
 308{
 309        if (!strcmp(var, "merge.conflictstyle")) {
 310                if (!value)
 311                        die("'%s' is not a boolean", var);
 312                if (!strcmp(value, "diff3"))
 313                        git_xmerge_style = XDL_MERGE_DIFF3;
 314                else if (!strcmp(value, "merge"))
 315                        git_xmerge_style = 0;
 316                else
 317                        die("unknown style '%s' given for '%s'",
 318                            value, var);
 319                return 0;
 320        }
 321        return git_default_config(var, value, cb);
 322}