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-rw-r--r--xdiff/xdiff.h10
-rw-r--r--xdiff/xdiffi.c4
-rw-r--r--xdiff/xhistogram.c2
-rw-r--r--xdiff/xpatience.c2
-rw-r--r--xdiff/xprepare.c21
-rw-r--r--xdiff/xutils.c106
6 files changed, 124 insertions, 21 deletions
diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h
index 00d36c3..09215af 100644
--- a/xdiff/xdiff.h
+++ b/xdiff/xdiff.h
@@ -32,14 +32,12 @@ extern "C" {
#define XDF_IGNORE_WHITESPACE (1 << 2)
#define XDF_IGNORE_WHITESPACE_CHANGE (1 << 3)
#define XDF_IGNORE_WHITESPACE_AT_EOL (1 << 4)
-#define XDF_PATIENCE_DIFF (1 << 5)
-#define XDF_HISTOGRAM_DIFF (1 << 6)
#define XDF_WHITESPACE_FLAGS (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE | XDF_IGNORE_WHITESPACE_AT_EOL)
-#define XDL_PATCH_NORMAL '-'
-#define XDL_PATCH_REVERSE '+'
-#define XDL_PATCH_MODEMASK ((1 << 8) - 1)
-#define XDL_PATCH_IGNOREBSPACE (1 << 8)
+#define XDF_PATIENCE_DIFF (1 << 5)
+#define XDF_HISTOGRAM_DIFF (1 << 6)
+#define XDF_DIFF_ALGORITHM_MASK (XDF_PATIENCE_DIFF | XDF_HISTOGRAM_DIFF)
+#define XDF_DIFF_ALG(x) ((x) & XDF_DIFF_ALGORITHM_MASK)
#define XDL_EMIT_FUNCNAMES (1 << 0)
#define XDL_EMIT_COMMON (1 << 1)
diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c
index 75a3922..bc889e8 100644
--- a/xdiff/xdiffi.c
+++ b/xdiff/xdiffi.c
@@ -328,10 +328,10 @@ int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
xdalgoenv_t xenv;
diffdata_t dd1, dd2;
- if (xpp->flags & XDF_PATIENCE_DIFF)
+ if (XDF_DIFF_ALG(xpp->flags) == XDF_PATIENCE_DIFF)
return xdl_do_patience_diff(mf1, mf2, xpp, xe);
- if (xpp->flags & XDF_HISTOGRAM_DIFF)
+ if (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF)
return xdl_do_histogram_diff(mf1, mf2, xpp, xe);
if (xdl_prepare_env(mf1, mf2, xpp, xe) < 0) {
diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
index 18f6f99..bf99787 100644
--- a/xdiff/xhistogram.c
+++ b/xdiff/xhistogram.c
@@ -252,7 +252,7 @@ static int fall_back_to_classic_diff(struct histindex *index,
int line1, int count1, int line2, int count2)
{
xpparam_t xpp;
- xpp.flags = index->xpp->flags & ~XDF_HISTOGRAM_DIFF;
+ xpp.flags = index->xpp->flags & ~XDF_DIFF_ALGORITHM_MASK;
return xdl_fall_back_diff(index->env, &xpp,
line1, count1, line2, count2);
diff --git a/xdiff/xpatience.c b/xdiff/xpatience.c
index fdd7d02..04e1a1a 100644
--- a/xdiff/xpatience.c
+++ b/xdiff/xpatience.c
@@ -288,7 +288,7 @@ static int fall_back_to_classic_diff(struct hashmap *map,
int line1, int count1, int line2, int count2)
{
xpparam_t xpp;
- xpp.flags = map->xpp->flags & ~XDF_PATIENCE_DIFF;
+ xpp.flags = map->xpp->flags & ~XDF_DIFF_ALGORITHM_MASK;
return xdl_fall_back_diff(map->env, &xpp,
line1, count1, line2, count2);
diff --git a/xdiff/xprepare.c b/xdiff/xprepare.c
index e419f4f..63a22c6 100644
--- a/xdiff/xprepare.c
+++ b/xdiff/xprepare.c
@@ -181,7 +181,7 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_
if (!(recs = (xrecord_t **) xdl_malloc(narec * sizeof(xrecord_t *))))
goto abort;
- if (xpp->flags & XDF_HISTOGRAM_DIFF)
+ if (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF)
hbits = hsize = 0;
else {
hbits = xdl_hashbits((unsigned int) narec);
@@ -209,8 +209,8 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_
crec->ha = hav;
recs[nrec++] = crec;
- if (!(xpp->flags & XDF_HISTOGRAM_DIFF) &&
- xdl_classify_record(pass, cf, rhash, hbits, crec) < 0)
+ if ((XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
+ xdl_classify_record(pass, cf, rhash, hbits, crec) < 0)
goto abort;
}
}
@@ -273,16 +273,15 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
* (nrecs) will be updated correctly anyway by
* xdl_prepare_ctx().
*/
- sample = xpp->flags & XDF_HISTOGRAM_DIFF ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1;
+ sample = (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF
+ ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1);
enl1 = xdl_guess_lines(mf1, sample) + 1;
enl2 = xdl_guess_lines(mf2, sample) + 1;
- if (!(xpp->flags & XDF_HISTOGRAM_DIFF) &&
- xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0) {
-
+ if (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF &&
+ xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0)
return -1;
- }
if (xdl_prepare_ctx(1, mf1, enl1, xpp, &cf, &xe->xdf1) < 0) {
@@ -296,9 +295,9 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
return -1;
}
- if (!(xpp->flags & XDF_PATIENCE_DIFF) &&
- !(xpp->flags & XDF_HISTOGRAM_DIFF) &&
- xdl_optimize_ctxs(&cf, &xe->xdf1, &xe->xdf2) < 0) {
+ if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) &&
+ (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) &&
+ xdl_optimize_ctxs(&cf, &xe->xdf1, &xe->xdf2) < 0) {
xdl_free_ctx(&xe->xdf2);
xdl_free_ctx(&xe->xdf1);
diff --git a/xdiff/xutils.c b/xdiff/xutils.c
index 0de084e..1b3b471 100644
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@ -20,6 +20,8 @@
*
*/
+#include <limits.h>
+#include <assert.h>
#include "xinclude.h"
@@ -276,6 +278,109 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data,
return ha;
}
+#ifdef XDL_FAST_HASH
+
+#define ONEBYTES 0x0101010101010101ul
+#define NEWLINEBYTES 0x0a0a0a0a0a0a0a0aul
+#define HIGHBITS 0x8080808080808080ul
+
+/* 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;
+ } else {
+ /*
+ * Modified Carl Chatfield G+ version for 32-bit *
+ *
+ * (a) gives us
+ * -1 (0, ff), 0 (ffff) or 1 (ffffff)
+ * (b) gives us
+ * 0 for 0, 1 for (ff ffff ffffff)
+ * (a+b+1) gives us
+ * correct 0-3 bytemask count result
+ */
+ long a = (mask - 256) >> 23;
+ long b = mask & 1;
+ return a + b + 1;
+ }
+}
+
+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;
@@ -293,6 +398,7 @@ 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;