[PATCH 4/5] xdiff: introduce XDF_IGNORE_CASE
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Feb 20, 2012, 02:16 UTC
- Message-ID
- <1329704188-9955-5-git-send-email-gitster@pobox.com>
- In-Reply-To
- <1329704188-9955-1-git-send-email-gitster@pobox.com>
Teach the hash function and per-line comparison logic to compare lines while ignoring the differences in case. It is not an ignore-whitespace option but still needs to trigger the inexact match logic, and that is why the previous step introduced XDF_INEXACT_MATCH mask.
Assign the 7th bit for this option, and move the bits to select diff algorithms out of the way in order to leave room for a few bits to add more variants of ignore-whitespace, such as --ignore-tab-expansion, if somebody else is inclined to do so later.
We would still need to teach the front-end to flip this bit, for this change to be any useful.
Signed-off-by: Junio C Hamano <gitster@pobox.com> --- xdiff/xdiff.h | 7 ++++--- xdiff/xutils.c | 50 ++++++++++++++++++++++++++++++++++++++++++-------- 2 files changed, 46 insertions(+), 11 deletions(-)
diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h index 48793f9..5a01a0e 100644 --- a/xdiff/xdiff.h +++ b/xdiff/xdiff.h @@ -36,10 +36,11 @@ extern "C" { (XDF_IGNORE_WHITESPACE | \ XDF_IGNORE_WHITESPACE_CHANGE | \ XDF_IGNORE_WHITESPACE_AT_EOL) -#define XDF_INEXACT_MATCH XDF_WHITESPACE_FLAGS +#define XDF_IGNORE_CASE (1 << 7) +#define XDF_INEXACT_MATCH (XDF_WHITESPACE_FLAGS | XDF_IGNORE_CASE) -#define XDF_PATIENCE_DIFF (1 << 5) -#define XDF_HISTOGRAM_DIFF (1 << 6) +#define XDF_PATIENCE_DIFF (1 << 8) +#define XDF_HISTOGRAM_DIFF (1 << 9) #define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF) #define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK) diff --git a/xdiff/xutils.c b/xdiff/xutils.c index aa6de74..925f1d0 100644 --- a/xdiff/xutils.c +++ b/xdiff/xutils.c @@ -170,6 +170,19 @@ long xdl_guess_lines(mmfile_t *mf, long sample) { return nl + 1; } +static inline int match_a_byte(char ch1, char ch2, long flags) +{ + if (ch1 == ch2) + return 1; + if (!(flags & XDF_IGNORE_CASE) || ((ch1 | ch2) & 0x80)) + return 0; + if (isupper(ch1)) + ch1 = tolower(ch1); + if (isupper(ch2)) + ch2 = tolower(ch2); + return (ch1 == ch2); +} + int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) { int i1, i2; @@ -192,7 +205,7 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) if (flags & XDF_IGNORE_WHITESPACE) { goto skip_ws; while (i1 < s1 && i2 < s2) { - if (l1[i1++] != l2[i2++]) + if (!match_a_byte(l1[i1++], l2[i2++], flags)) return 0; skip_ws: while (i1 < s1 && XDL_ISSPACE(l1[i1])) @@ -210,15 +223,28 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) i2++; continue; } - if (l1[i1++] != l2[i2++]) + if (!match_a_byte(l1[i1++], l2[i2++], flags)) return 0; } - } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL) { - while (i1 < s1 && i2 < s2 && l1[i1++] == l2[i2++]) + } else { + /* + * Either XDF_IGNORE_WHITESPACE_AT_EOL is set, or + * no whitespace is ignored, but INEXACT_MATCH is + * in effect for other reasons. + */ + while (i1 < s1 && i2 < s2 && + match_a_byte(l1[i1++], l2[i2++], flags)) ; /* keep going */ } /* + * If we are not ignoring any whitespace, we must have consumed + * everything for the lines to match. + */ + if (!(flags & XDF_WHITESPACE_FLAGS)) + return i1 == s1 && i2 == s2; + + /* * 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 @@ -238,6 +264,14 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags) return 1; } +static inline unsigned long hash_a_byte(const char ch_, long flags) +{ + unsigned long ch = ch_ & 0xFF; + if ((flags & XDF_IGNORE_CASE) && !(ch & 0x80) && isupper(ch)) + ch = tolower(ch); + return ch; +} + static unsigned long xdl_hash_record_with_whitespace(char const **data, char const *top, long flags) { unsigned long ha = 5381; @@ -256,20 +290,20 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data, else if (flags & XDF_IGNORE_WHITESPACE_CHANGE && !at_eol) { ha += (ha << 5); - ha ^= (unsigned long) ' '; + ha ^= hash_a_byte(' ', flags); } else if (flags & XDF_IGNORE_WHITESPACE_AT_EOL && !at_eol) { while (ptr2 != ptr + 1) { ha += (ha << 5); - ha ^= (unsigned long) *ptr2; + ha ^= hash_a_byte(*ptr2, flags); ptr2++; } } continue; } ha += (ha << 5); - ha ^= (unsigned long) *ptr; + ha ^= hash_a_byte(*ptr, flags); } *data = ptr < top ? ptr + 1: ptr; @@ -286,7 +320,7 @@ unsigned long xdl_hash_record(char const **data, char const *top, long flags) { for (; ptr < top && *ptr != '\n'; ptr++) { ha += (ha << 5); - ha ^= (unsigned long) *ptr; + ha ^= hash_a_byte(*ptr, flags); } *data = ptr < top ? ptr + 1: ptr;
-- 1.7.9.1.265.g25f75