diff options
Diffstat (limited to 'src/xdiff/xutils.c')
-rw-r--r-- | src/xdiff/xutils.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/src/xdiff/xutils.c b/src/xdiff/xutils.c new file mode 100644 index 000000000..bb7bdee49 --- /dev/null +++ b/src/xdiff/xutils.c @@ -0,0 +1,419 @@ +/* + * LibXDiff by Davide Libenzi ( File Differential Library ) + * Copyright (C) 2003 Davide Libenzi + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Davide Libenzi <davidel@xmailserver.org> + * + */ + +#include "xinclude.h" + + + + +long xdl_bogosqrt(long n) { + long i; + + /* + * Classical integer square root approximation using shifts. + */ + for (i = 1; n > 0; n >>= 2) + i <<= 1; + + return i; +} + + +int xdl_emit_diffrec(char const *rec, long size, char const *pre, long psize, + xdemitcb_t *ecb) { + int i = 2; + mmbuffer_t mb[3]; + + mb[0].ptr = (char *) pre; + mb[0].size = psize; + mb[1].ptr = (char *) rec; + mb[1].size = size; + if (size > 0 && rec[size - 1] != '\n') { + mb[2].ptr = (char *) "\n\\ No newline at end of file\n"; + mb[2].size = strlen(mb[2].ptr); + i++; + } + if (ecb->outf(ecb->priv, mb, i) < 0) { + + return -1; + } + + return 0; +} + +void *xdl_mmfile_first(mmfile_t *mmf, long *size) +{ + *size = (long)mmf->size; + return mmf->ptr; +} + + +long xdl_mmfile_size(mmfile_t *mmf) +{ + return (long)mmf->size; +} + + +int xdl_cha_init(chastore_t *cha, long isize, long icount) { + + cha->head = cha->tail = NULL; + cha->isize = isize; + cha->nsize = icount * isize; + cha->ancur = cha->sncur = NULL; + cha->scurr = 0; + + return 0; +} + + +void xdl_cha_free(chastore_t *cha) { + chanode_t *cur, *tmp; + + for (cur = cha->head; (tmp = cur) != NULL;) { + cur = cur->next; + xdl_free(tmp); + } +} + + +void *xdl_cha_alloc(chastore_t *cha) { + chanode_t *ancur; + void *data; + + if (!(ancur = cha->ancur) || ancur->icurr == cha->nsize) { + if (!(ancur = (chanode_t *) xdl_malloc(sizeof(chanode_t) + cha->nsize))) { + + return NULL; + } + ancur->icurr = 0; + ancur->next = NULL; + if (cha->tail) + cha->tail->next = ancur; + if (!cha->head) + cha->head = ancur; + cha->tail = ancur; + cha->ancur = ancur; + } + + data = (char *) ancur + sizeof(chanode_t) + ancur->icurr; + ancur->icurr += cha->isize; + + return data; +} + + +void *xdl_cha_first(chastore_t *cha) { + chanode_t *sncur; + + if (!(cha->sncur = sncur = cha->head)) + return NULL; + + cha->scurr = 0; + + return (char *) sncur + sizeof(chanode_t) + cha->scurr; +} + + +void *xdl_cha_next(chastore_t *cha) { + chanode_t *sncur; + + if (!(sncur = cha->sncur)) + return NULL; + cha->scurr += cha->isize; + if (cha->scurr == sncur->icurr) { + if (!(sncur = cha->sncur = sncur->next)) + return NULL; + cha->scurr = 0; + } + + return (char *) sncur + sizeof(chanode_t) + cha->scurr; +} + + +long xdl_guess_lines(mmfile_t *mf, long sample) { + long nl = 0, size, tsize = 0; + char const *data, *cur, *top; + + if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) { + for (top = data + size; nl < sample && cur < top; ) { + nl++; + if (!(cur = memchr(cur, '\n', top - cur))) + cur = top; + else + cur++; + } + tsize += (long) (cur - data); + } + + if (nl && tsize) + nl = xdl_mmfile_size(mf) / (tsize / nl); + + return nl + 1; +} + +int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) +{ + int i1, i2; + + if (s1 == s2 && !memcmp(l1, l2, s1)) + return 1; + if (!(flags & XDF_WHITESPACE_FLAGS)) + return 0; + + i1 = 0; + i2 = 0; + + /* + * -w matches everything that matches with -b, and -b in turn + * matches everything that matches with --ignore-space-at-eol. + * + * Each flavor of ignoring needs different logic to skip whitespaces + * while we have both sides to compare. + */ + if (flags & XDF_IGNORE_WHITESPACE) { + goto skip_ws; + while (i1 < s1 && i2 < s2) { + if (l1[i1++] != l2[i2++]) + return 0; + skip_ws: + while (i1 < s1 && XDL_ISSPACE(l1[i1])) + i1++; + while (i2 < s2 && XDL_ISSPACE(l2[i2])) + i2++; + } + } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) { + while (i1 < s1 && i2 < s2) { + if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) { + /* Skip matching spaces and try again */ + while (i1 < s1 && XDL_ISSPACE(l1[i1])) + i1++; + while (i2 < s2 && XDL_ISSPACE(l2[i2])) + i2++; + continue; + } + if (l1[i1++] != l2[i2++]) + return 0; + } + } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) { + while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++]) + ; /* keep going */ + } + + /* + * After running out of one side, the remaining side must have + * nothing but whitespace for the lines to match. Note that + * ignore-whitespace-at-eol case may break out of the loop + * while there still are characters remaining on both lines. + */ + if (i1 < s1) { + while (i1 < s1 && XDL_ISSPACE(l1[i1])) + i1++; + if (s1 != i1) + return 0; + } + if (i2 < s2) { + while (i2 < s2 && XDL_ISSPACE(l2[i2])) + i2++; + return (s2 == i2); + } + return 1; +} + +static unsigned long xdl_hash_record_with_whitespace(char const **data, + char const *top, long flags) { + unsigned long ha = 5381; + char const *ptr = *data; + + for (; ptr < top && *ptr != '\n'; ptr++) { + if (XDL_ISSPACE(*ptr)) { + const char *ptr2 = ptr; + int at_eol; + while (ptr + 1 < top && XDL_ISSPACE(ptr[1]) + && ptr[1] != '\n') + ptr++; + at_eol = (top <= ptr + 1 || ptr[1] == '\n'); + if (flags & XDF_IGNORE_WHITESPACE) + ; /* already handled */ + else if (flags & XDF_IGNORE_WHITESPACE_CHANGE + && !at_eol) { + ha += (ha << 5); + ha ^= (unsigned long) ' '; + } + else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL + && !at_eol) { + while (ptr2 != ptr + 1) { + ha += (ha << 5); + ha ^= (unsigned long) *ptr2; + ptr2++; + } + } + continue; + } + ha += (ha << 5); + ha ^= (unsigned long) *ptr; + } + *data = ptr < top ? ptr + 1: ptr; + + return ha; +} + + +unsigned long xdl_hash_record(char const **data, char const *top, long flags) { + unsigned long ha = 5381; + char const *ptr = *data; + + if (flags & XDF_WHITESPACE_FLAGS) + return xdl_hash_record_with_whitespace(data, top, flags); + + for (; ptr < top && *ptr != '\n'; ptr++) { + ha += (ha << 5); + ha ^= (unsigned long) *ptr; + } + *data = ptr < top ? ptr + 1: ptr; + + return ha; +} + + +unsigned int xdl_hashbits(unsigned int size) { + unsigned int val = 1, bits = 0; + + for (; val < size && bits < CHAR_BIT * sizeof(unsigned int); val <<= 1, bits++); + return bits ? bits: 1; +} + + +int xdl_num_out(char *out, long val) { + char *ptr, *str = out; + char buf[32]; + + ptr = buf + sizeof(buf) - 1; + *ptr = '\0'; + if (val < 0) { + *--ptr = '-'; + val = -val; + } + for (; val && ptr > buf; val /= 10) + *--ptr = "0123456789"[val % 10]; + if (*ptr) + for (; *ptr; ptr++, str++) + *str = *ptr; + else + *str++ = '0'; + *str = '\0'; + + return (int)(str - out); +} + + +long xdl_atol(char const *str, char const **next) { + long val, base; + char const *top; + + for (top = str; XDL_ISDIGIT(*top); top++); + if (next) + *next = top; + for (val = 0, base = 1, top--; top >= str; top--, base *= 10) + val += base * (long)(*top - '0'); + return val; +} + + +int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2, + const char *func, long funclen, xdemitcb_t *ecb) { + int nb = 0; + mmbuffer_t mb; + char buf[128]; + + memcpy(buf, "@@ -", 4); + nb += 4; + + nb += xdl_num_out(buf + nb, c1 ? s1: s1 - 1); + + if (c1 != 1) { + memcpy(buf + nb, ",", 1); + nb += 1; + + nb += xdl_num_out(buf + nb, c1); + } + + memcpy(buf + nb, " +", 2); + nb += 2; + + nb += xdl_num_out(buf + nb, c2 ? s2: s2 - 1); + + if (c2 != 1) { + memcpy(buf + nb, ",", 1); + nb += 1; + + nb += xdl_num_out(buf + nb, c2); + } + + memcpy(buf + nb, " @@", 3); + nb += 3; + if (func && funclen) { + buf[nb++] = ' '; + if (funclen > (long)sizeof(buf) - nb - 1) + funclen = (long)sizeof(buf) - nb - 1; + memcpy(buf + nb, func, funclen); + nb += funclen; + } + buf[nb++] = '\n'; + + mb.ptr = buf; + mb.size = nb; + if (ecb->outf(ecb->priv, &mb, 1) < 0) + return -1; + + return 0; +} + +int xdl_fall_back_diff(xdfenv_t *diff_env, xpparam_t const *xpp, + int line1, int count1, int line2, int count2) +{ + /* + * This probably does not work outside Git, since + * we have a very simple mmfile structure. + * + * Note: ideally, we would reuse the prepared environment, but + * the libxdiff interface does not (yet) allow for diffing only + * ranges of lines instead of the whole files. + */ + mmfile_t subfile1, subfile2; + xdfenv_t env; + + subfile1.ptr = (char *)diff_env->xdf1.recs[line1 - 1]->ptr; + subfile1.size = diff_env->xdf1.recs[line1 + count1 - 2]->ptr + + diff_env->xdf1.recs[line1 + count1 - 2]->size - subfile1.ptr; + subfile2.ptr = (char *)diff_env->xdf2.recs[line2 - 1]->ptr; + subfile2.size = diff_env->xdf2.recs[line2 + count2 - 2]->ptr + + diff_env->xdf2.recs[line2 + count2 - 2]->size - subfile2.ptr; + if (xdl_do_diff(&subfile1, &subfile2, xpp, &env) < 0) + return -1; + + memcpy(diff_env->xdf1.rchg + line1 - 1, env.xdf1.rchg, count1); + memcpy(diff_env->xdf2.rchg + line2 - 1, env.xdf2.rchg, count2); + + xdl_free_env(&env); + + return 0; +} |