changeset 36761:09f320067591

xdiff: remove whitespace related feature In Mercurial, whitespace related handling are done at a higher level than the low-level diff algorithm so "ignore spaces". So it's not used by mdiff. Some of the upcoming optimizations would be more difficult with whitespace related features kept. So let's remove them. Differential Revision: https://phab.mercurial-scm.org/D2683
author Jun Wu <quark@fb.com>
date Sun, 04 Mar 2018 00:07:04 -0800
parents 7bf80d9d9543
children b5bb0f99064d
files mercurial/thirdparty/xdiff/xdiff.h mercurial/thirdparty/xdiff/xdiffi.c mercurial/thirdparty/xdiff/xutils.c mercurial/thirdparty/xdiff/xutils.h
diffstat 4 files changed, 1 insertions(+), 187 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/thirdparty/xdiff/xdiff.h	Tue Mar 06 14:32:14 2018 -0800
+++ b/mercurial/thirdparty/xdiff/xdiff.h	Sun Mar 04 00:07:04 2018 -0800
@@ -32,17 +32,6 @@
 /* xpparm_t.flags */
 #define XDF_NEED_MINIMAL (1 << 0)
 
-#define XDF_IGNORE_WHITESPACE (1 << 1)
-#define XDF_IGNORE_WHITESPACE_CHANGE (1 << 2)
-#define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 3)
-#define XDF_IGNORE_CR_AT_EOL (1 << 4)
-#define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | \
-			      XDF_IGNORE_WHITESPACE_CHANGE | \
-			      XDF_IGNORE_WHITESPACE_AT_EOL | \
-			      XDF_IGNORE_CR_AT_EOL)
-
-#define XDF_IGNORE_BLANK_LINES (1 << 7)
-
 #define XDF_INDENT_HEURISTIC (1 << 23)
 
 /* xdemitconf_t.flags */
--- a/mercurial/thirdparty/xdiff/xdiffi.c	Tue Mar 06 14:32:14 2018 -0800
+++ b/mercurial/thirdparty/xdiff/xdiffi.c	Sun Mar 04 00:07:04 2018 -0800
@@ -1041,27 +1041,6 @@
 	return 0;
 }
 
-static void xdl_mark_ignorable(xdchange_t *xscr, xdfenv_t *xe, long flags)
-{
-	xdchange_t *xch;
-
-	for (xch = xscr; xch; xch = xch->next) {
-		int ignore = 1;
-		xrecord_t **rec;
-		long i;
-
-		rec = &xe->xdf1.recs[xch->i1];
-		for (i = 0; i < xch->chg1 && ignore; i++)
-			ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
-
-		rec = &xe->xdf2.recs[xch->i2];
-		for (i = 0; i < xch->chg2 && ignore; i++)
-			ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
-
-		xch->ignore = ignore;
-	}
-}
-
 int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 	     xdemitconf_t const *xecfg, xdemitcb_t *ecb) {
 	xdchange_t *xscr;
@@ -1080,8 +1059,6 @@
 		return -1;
 	}
 
-	if (xpp->flags & XDF_IGNORE_BLANK_LINES)
-		xdl_mark_ignorable(xscr, &xe, xpp->flags);
 	if (ef(&xe, xscr, ecb, xecfg) < 0) {
 		xdl_free_script(xscr);
 		xdl_free_env(&xe);
--- a/mercurial/thirdparty/xdiff/xutils.c	Tue Mar 06 14:32:14 2018 -0800
+++ b/mercurial/thirdparty/xdiff/xutils.c	Sun Mar 04 00:07:04 2018 -0800
@@ -143,168 +143,17 @@
 	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;
+	return 0;
 }
 
 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;
--- a/mercurial/thirdparty/xdiff/xutils.h	Tue Mar 06 14:32:14 2018 -0800
+++ b/mercurial/thirdparty/xdiff/xutils.h	Sun Mar 04 00:07:04 2018 -0800
@@ -32,7 +32,6 @@
 void xdl_cha_free(chastore_t *cha);
 void *xdl_cha_alloc(chastore_t *cha);
 long xdl_guess_lines(mmfile_t *mf, long sample);
-int xdl_blankline(const char *line, long size, long flags);
 int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags);
 unsigned long xdl_hash_record(char const **data, char const *top, long flags);
 unsigned int xdl_hashbits(unsigned int size);