/* * 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 <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); } 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; } #ifdef XDL_FAST_HASH #define REPEAT_BYTE(x) ((~0ul / 0xff) * (x)) #define ONEBYTES REPEAT_BYTE(0x01) #define NEWLINEBYTES REPEAT_BYTE(0x0a) #define HIGHBITS REPEAT_BYTE(0x80) /* Return the high bit set in the first byte that is a zero */ static inline unsigned long has_zero(unsigned long a) { return ((a - ONEBYTES) & ~a) & HIGHBITS; } static inline long count_masked_bytes(unsigned long mask) { if (sizeof(long) == 8) { /* * Jan Achrenius on G+: microoptimized version of * the simpler "(mask & ONEBYTES) * ONEBYTES >> 56" * that works for the bytemasks without having to * mask them first. */ /* * return mask * 0x0001020304050608 >> 56; * * Doing it like this avoids warnings on 32-bit machines. */ long a = (REPEAT_BYTE(0x01) / 0xff + 1); return mask * a >> (sizeof(long) * 7); } else { /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */ /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */ long a = (0x0ff0001 + mask) >> 23; /* Fix the 1 for 00 case */ return a & mask; } } unsigned long xdl_hash_record(char const **data, char const *top, long flags) { unsigned long hash = 5381; unsigned long a = 0, mask = 0; char const *ptr = *data; char const *end = top - sizeof(unsigned long) + 1; if (flags & XDF_WHITESPACE_FLAGS) return xdl_hash_record_with_whitespace(data, top, flags); ptr -= sizeof(unsigned long); do { hash += hash << 5; hash ^= a; ptr += sizeof(unsigned long); if (ptr >= end) break; a = *(unsigned long *)ptr; /* Do we have any '\n' bytes in this word? */ mask = has_zero(a ^ NEWLINEBYTES); } while (!mask); if (ptr >= end) { /* * There is only a partial word left at the end of the * buffer. Because we may work with a memory mapping, * we have to grab the rest byte by byte instead of * blindly reading it. * * To avoid problems with masking in a signed value, * we use an unsigned char here. */ const char *p; for (p = top - 1; p >= ptr; p--) a = (a << 8) + *((const unsigned char *)p); mask = has_zero(a ^ NEWLINEBYTES); if (!mask) /* * No '\n' found in the partial word. Make a * mask that matches what we read. */ mask = 1UL << (8 * (top - ptr) + 7); } /* The mask *below* the first high bit set */ mask = (mask - 1) & ~mask; mask >>= 7; hash += hash << 5; hash ^= a & mask; /* Advance past the last (possibly partial) word */ ptr += count_masked_bytes(mask); if (ptr < top) { assert(*ptr == '\n'); ptr++; } *data = ptr; return hash; } #else /* XDL_FAST_HASH */ 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; } #endif /* XDL_FAST_HASH */ 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; }