Andrew's git - gitweb.git/blob

   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        int read_some;
  19
  20        while ('0' <= *cp && *cp <= '9')
  21                num = num * 10 + *cp++ - '0';
  22        if (!(read_some = cp - *cp_p))
  23                return -1;
  24        *cp_p = cp;
  25        *num_p = num;
  26        return 0;
  27}
  28
  29int parse_hunk_header(char *line, int len,
  30                      int *ob, int *on,
  31                      int *nb, int *nn)
  32{
  33        char *cp;
  34        cp = line + 4;
  35        if (parse_num(&cp, ob)) {
  36        bad_line:
  37                return error("malformed diff output: %s", line);
  38        }
  39        if (*cp == ',') {
  40                cp++;
  41                if (parse_num(&cp, on))
  42                        goto bad_line;
  43        }
  44        else
  45                *on = 1;
  46        if (*cp++ != ' ' || *cp++ != '+')
  47                goto bad_line;
  48        if (parse_num(&cp, nb))
  49                goto bad_line;
  50        if (*cp == ',') {
  51                cp++;
  52                if (parse_num(&cp, nn))
  53                        goto bad_line;
  54        }
  55        else
  56                *nn = 1;
  57        return -!!memcmp(cp, " @@", 3);
  58}
  59
  60static void consume_one(void *priv_, char *s, unsigned long size)
  61{
  62        struct xdiff_emit_state *priv = priv_;
  63        char *ep;
  64        while (size) {
  65                unsigned long this_size;
  66                ep = memchr(s, '\n', size);
  67                this_size = (ep == NULL) ? size : (ep - s + 1);
  68                priv->consume(priv->consume_callback_data, s, this_size);
  69                size -= this_size;
  70                s += this_size;
  71        }
  72}
  73
  74static int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
  75{
  76        struct xdiff_emit_state *priv = priv_;
  77        int i;
  78
  79        for (i = 0; i < nbuf; i++) {
  80                if (mb[i].ptr[mb[i].size-1] != '\n') {
  81                        /* Incomplete line */
  82                        strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  83                        continue;
  84                }
  85
  86                /* we have a complete line */
  87                if (!priv->remainder.len) {
  88                        consume_one(priv, mb[i].ptr, mb[i].size);
  89                        continue;
  90                }
  91                strbuf_add(&priv->remainder, mb[i].ptr, mb[i].size);
  92                consume_one(priv, priv->remainder.buf, priv->remainder.len);
  93                strbuf_reset(&priv->remainder);
  94        }
  95        if (priv->remainder.len) {
  96                consume_one(priv, priv->remainder.buf, priv->remainder.len);
  97                strbuf_reset(&priv->remainder);
  98        }
  99        return 0;
 100}
 101
 102/*
 103 * Trim down common substring at the end of the buffers,
 104 * but leave at least ctx lines at the end.
 105 */
 106static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx)
 107{
 108        const int blk = 1024;
 109        long trimmed = 0, recovered = 0;
 110        char *ap = a->ptr + a->size;
 111        char *bp = b->ptr + b->size;
 112        long smaller = (a->size < b->size) ? a->size : b->size;
 113
 114        if (ctx)
 115                return;
 116
 117        while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) {
 118                trimmed += blk;
 119                ap -= blk;
 120                bp -= blk;
 121        }
 122
 123        while (recovered < trimmed)
 124                if (ap[recovered++] == '\n')
 125                        break;
 126        a->size -= trimmed - recovered;
 127        b->size -= trimmed - recovered;
 128}
 129
 130int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 131{
 132        mmfile_t a = *mf1;
 133        mmfile_t b = *mf2;
 134
 135        trim_common_tail(&a, &b, xecfg->ctxlen);
 136
 137        return xdl_diff(&a, &b, xpp, xecfg, xecb);
 138}
 139
 140int xdi_diff_outf(mmfile_t *mf1, mmfile_t *mf2,
 141                  xdiff_emit_consume_fn fn, void *consume_callback_data,
 142                  xpparam_t const *xpp,
 143                  xdemitconf_t const *xecfg, xdemitcb_t *xecb)
 144{
 145        int ret;
 146        struct xdiff_emit_state state;
 147
 148        memset(&state, 0, sizeof(state));
 149        state.consume = fn;
 150        state.consume_callback_data = consume_callback_data;
 151        xecb->outf = xdiff_outf;
 152        xecb->priv = &state;
 153        strbuf_init(&state.remainder, 0);
 154        ret = xdi_diff(mf1, mf2, xpp, xecfg, xecb);
 155        strbuf_release(&state.remainder);
 156        return ret;
 157}
 158
 159struct xdiff_emit_hunk_state {
 160        xdiff_emit_hunk_consume_fn consume;
 161        void *consume_callback_data;
 162};
 163
 164static int process_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 165                        xdemitconf_t const *xecfg)
 166{
 167        long s1, s2, same, p_next, t_next;
 168        xdchange_t *xch, *xche;
 169        struct xdiff_emit_hunk_state *state = ecb->priv;
 170        xdiff_emit_hunk_consume_fn fn = state->consume;
 171        void *consume_callback_data = state->consume_callback_data;
 172
 173        for (xch = xscr; xch; xch = xche->next) {
 174                xche = xdl_get_hunk(xch, xecfg);
 175
 176                s1 = XDL_MAX(xch->i1 - xecfg->ctxlen, 0);
 177                s2 = XDL_MAX(xch->i2 - xecfg->ctxlen, 0);
 178                same = s2 + XDL_MAX(xch->i1 - s1, 0);
 179                p_next = xche->i1 + xche->chg1;
 180                t_next = xche->i2 + xche->chg2;
 181
 182                fn(consume_callback_data, same, p_next, t_next);
 183        }
 184        return 0;
 185}
 186
 187int xdi_diff_hunks(mmfile_t *mf1, mmfile_t *mf2,
 188                   xdiff_emit_hunk_consume_fn fn, void *consume_callback_data,
 189                   xpparam_t const *xpp, xdemitconf_t *xecfg)
 190{
 191        struct xdiff_emit_hunk_state state;
 192        xdemitcb_t ecb;
 193
 194        memset(&state, 0, sizeof(state));
 195        memset(&ecb, 0, sizeof(ecb));
 196        state.consume = fn;
 197        state.consume_callback_data = consume_callback_data;
 198        xecfg->emit_func = (void (*)())process_diff;
 199        ecb.priv = &state;
 200        return xdi_diff(mf1, mf2, xpp, xecfg, &ecb);
 201}
 202
 203int read_mmfile(mmfile_t *ptr, const char *filename)
 204{
 205        struct stat st;
 206        FILE *f;
 207        size_t sz;
 208
 209        if (stat(filename, &st))
 210                return error("Could not stat %s", filename);
 211        if ((f = fopen(filename, "rb")) == NULL)
 212                return error("Could not open %s", filename);
 213        sz = xsize_t(st.st_size);
 214        ptr->ptr = xmalloc(sz ? sz : 1);
 215        if (sz && fread(ptr->ptr, sz, 1, f) != 1)
 216                return error("Could not read %s", filename);
 217        fclose(f);
 218        ptr->size = sz;
 219        return 0;
 220}
 221
 222#define FIRST_FEW_BYTES 8000
 223int buffer_is_binary(const char *ptr, unsigned long size)
 224{
 225        if (FIRST_FEW_BYTES < size)
 226                size = FIRST_FEW_BYTES;
 227        return !!memchr(ptr, 0, size);
 228}
 229
 230struct ff_regs {
 231        int nr;
 232        struct ff_reg {
 233                regex_t re;
 234                int negate;
 235        } *array;
 236};
 237
 238static long ff_regexp(const char *line, long len,
 239                char *buffer, long buffer_size, void *priv)
 240{
 241        char *line_buffer;
 242        struct ff_regs *regs = priv;
 243        regmatch_t pmatch[2];
 244        int i;
 245        int result = -1;
 246
 247        /* Exclude terminating newline (and cr) from matching */
 248        if (len > 0 && line[len-1] == '\n') {
 249                if (len > 1 && line[len-2] == '\r')
 250                        len -= 2;
 251                else
 252                        len--;
 253        }
 254
 255        line_buffer = xstrndup(line, len); /* make NUL terminated */
 256
 257        for (i = 0; i < regs->nr; i++) {
 258                struct ff_reg *reg = regs->array + i;
 259                if (!regexec(&reg->re, line_buffer, 2, pmatch, 0)) {
 260                        if (reg->negate)
 261                                goto fail;
 262                        break;
 263                }
 264        }
 265        if (regs->nr <= i)
 266                goto fail;
 267        i = pmatch[1].rm_so >= 0 ? 1 : 0;
 268        line += pmatch[i].rm_so;
 269        result = pmatch[i].rm_eo - pmatch[i].rm_so;
 270        if (result > buffer_size)
 271                result = buffer_size;
 272        else
 273                while (result > 0 && (isspace(line[result - 1])))
 274                        result--;
 275        memcpy(buffer, line, result);
 276 fail:
 277        free(line_buffer);
 278        return result;
 279}
 280
 281void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value, int cflags)
 282{
 283        int i;
 284        struct ff_regs *regs;
 285
 286        xecfg->find_func = ff_regexp;
 287        regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs));
 288        for (i = 0, regs->nr = 1; value[i]; i++)
 289                if (value[i] == '\n')
 290                        regs->nr++;
 291        regs->array = xmalloc(regs->nr * sizeof(struct ff_reg));
 292        for (i = 0; i < regs->nr; i++) {
 293                struct ff_reg *reg = regs->array + i;
 294                const char *ep = strchr(value, '\n'), *expression;
 295                char *buffer = NULL;
 296
 297                reg->negate = (*value == '!');
 298                if (reg->negate && i == regs->nr - 1)
 299                        die("Last expression must not be negated: %s", value);
 300                if (*value == '!')
 301                        value++;
 302                if (ep)
 303                        expression = buffer = xstrndup(value, ep - value);
 304                else
 305                        expression = value;
 306                if (regcomp(&reg->re, expression, cflags))
 307                        die("Invalid regexp to look for hunk header: %s", expression);
 308                free(buffer);
 309                value = ep + 1;
 310        }
 311}
 312
 313int git_xmerge_style = -1;
 314
 315int git_xmerge_config(const char *var, const char *value, void *cb)
 316{
 317        if (!strcasecmp(var, "merge.conflictstyle")) {
 318                if (!value)
 319                        die("'%s' is not a boolean", var);
 320                if (!strcmp(value, "diff3"))
 321                        git_xmerge_style = XDL_MERGE_DIFF3;
 322                else if (!strcmp(value, "merge"))
 323                        git_xmerge_style = 0;
 324                else
 325                        die("unknown style '%s' given for '%s'",
 326                            value, var);
 327                return 0;
 328        }
 329        return git_default_config(var, value, cb);
 330}