/* * 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, see * <http://www.gnu.org/licenses/>. * * Davide Libenzi <davidel@xmailserver.org> * */ #include <limits.h> #include <assert.h> #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 = mmf->size; return mmf->ptr; } long xdl_mmfile_size(mmfile_t *mmf) { return 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; } 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_blankline(const char *line, long size, long flags) { long i; if (!(flags & XDF_WHITESPACE_FLAGS)) return (size <= 1); for (i = 0; i < size && XDL_ISSPACE(line[i]); i++) ; return (i == size); } /* * Have we eaten everything on the line, except for an optional * CR at the very end? */ static int ends_with_optional_cr(const char *l, long s, long i) { int complete = s && l[s-1] == '\n'; if (complete) s--; if (s == i) return 1; /* do not ignore CR at the end of an incomplete line */ if (complete && s == i + 1 && l[i] == '\r') return 1; return 0; } 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, * which in turn matches everything that matches with --ignore-cr-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]) { i1++; i2++; } } else if (flags & XDF_IGNORE_CR_AT_EOL) { /* Find the first difference and see how the line ends */ while (i1 < s1 && i2 < s2 && l1[i1] == l2[i2]) { i1++; i2++; } return (ends_with_optional_cr(l1, s1, i1) && ends_with_optional_cr(l2, s2, i2)); } /* * 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; int cr_at_eol_only = (flags & XDF_WHITESPACE_FLAGS) == XDF_IGNORE_CR_AT_EOL; for (; ptr < top && *ptr != '\n'; ptr++) { if (cr_at_eol_only) { /* do not ignore CR at the end of an incomplete line */ if (*ptr == '\r' && (ptr + 1 < top && ptr[1] == '\n')) continue; } else 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 str - out; } 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 > sizeof(buf) - nb - 1) funclen = 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; }