diff options
Diffstat (limited to 'xdiff/xutils.c')
| -rw-r--r-- | xdiff/xutils.c | 154 |
1 files changed, 42 insertions, 112 deletions
diff --git a/xdiff/xutils.c b/xdiff/xutils.c index 62cb23dfd3..88e5995535 100644 --- a/xdiff/xutils.c +++ b/xdiff/xutils.c @@ -13,8 +13,8 @@ * 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 + * License along with this library; if not, see + * <http://www.gnu.org/licenses/>. * * Davide Libenzi <davidel@xmailserver.org> * @@ -156,6 +156,24 @@ int xdl_blankline(const char *line, long size, long flags) 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; @@ -170,7 +188,8 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) /* * -w matches everything that matches with -b, and -b in turn - * matches everything that matches with --ignore-space-at-eol. + * 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. @@ -200,8 +219,18 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) return 0; } } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) { - while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++]) - ; /* keep going */ + 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)); } /* @@ -228,9 +257,16 @@ 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 (XDL_ISSPACE(*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]) @@ -262,110 +298,6 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data, 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; @@ -382,8 +314,6 @@ unsigned long xdl_hash_record(char const **data, char const *top, long flags) { return ha; } -#endif /* XDL_FAST_HASH */ - unsigned int xdl_hashbits(unsigned int size) { unsigned int val = 1, bits = 0; |