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-rw-r--r--xdiff/xutils.c222
1 files changed, 151 insertions, 71 deletions
diff --git a/xdiff/xutils.c b/xdiff/xutils.c
index bc12f29895..9504eaecb8 100644
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@ -20,14 +20,12 @@
*
*/
+#include <limits.h>
+#include <assert.h>
#include "xinclude.h"
-#define XDL_GUESS_NLINES 256
-
-
-
long xdl_bogosqrt(long n) {
long i;
@@ -71,12 +69,6 @@ void *xdl_mmfile_first(mmfile_t *mmf, long *size)
}
-void *xdl_mmfile_next(mmfile_t *mmf, long *size)
-{
- return NULL;
-}
-
-
long xdl_mmfile_size(mmfile_t *mmf)
{
return mmf->size;
@@ -130,47 +122,12 @@ void *xdl_cha_alloc(chastore_t *cha) {
return data;
}
-
-void *xdl_cha_first(chastore_t *cha) {
- chanode_t *sncur;
-
- if (!(cha->sncur = sncur = cha->head))
- return NULL;
-
- cha->scurr = 0;
-
- return (char *) sncur + sizeof(chanode_t) + cha->scurr;
-}
-
-
-void *xdl_cha_next(chastore_t *cha) {
- chanode_t *sncur;
-
- if (!(sncur = cha->sncur))
- return NULL;
- cha->scurr += cha->isize;
- if (cha->scurr == sncur->icurr) {
- if (!(sncur = cha->sncur = sncur->next))
- return NULL;
- cha->scurr = 0;
- }
-
- return (char *) sncur + sizeof(chanode_t) + cha->scurr;
-}
-
-
-long xdl_guess_lines(mmfile_t *mf) {
+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 < XDL_GUESS_NLINES;) {
- if (cur >= top) {
- tsize += (long) (cur - data);
- if (!(cur = data = xdl_mmfile_next(mf, &size)))
- break;
- top = data + size;
- }
+ for (top = data + size; nl < sample && cur < top; ) {
nl++;
if (!(cur = memchr(cur, '\n', top - cur)))
cur = top;
@@ -190,8 +147,10 @@ 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 s1 == s2 && !memcmp(l1, l2, s1);
+ return 0;
i1 = 0;
i2 = 0;
@@ -209,18 +168,18 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
if (l1[i1++] != l2[i2++])
return 0;
skip_ws:
- while (i1 < s1 && isspace(l1[i1]))
+ while (i1 < s1 && XDL_ISSPACE(l1[i1]))
i1++;
- while (i2 < s2 && isspace(l2[i2]))
+ while (i2 < s2 && XDL_ISSPACE(l2[i2]))
i2++;
}
} else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
while (i1 < s1 && i2 < s2) {
- if (isspace(l1[i1]) && isspace(l2[i2])) {
+ if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
/* Skip matching spaces and try again */
- while (i1 < s1 && isspace(l1[i1]))
+ while (i1 < s1 && XDL_ISSPACE(l1[i1]))
i1++;
- while (i2 < s2 && isspace(l2[i2]))
+ while (i2 < s2 && XDL_ISSPACE(l2[i2]))
i2++;
continue;
}
@@ -239,13 +198,13 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
* while there still are characters remaining on both lines.
*/
if (i1 < s1) {
- while (i1 < s1 && isspace(l1[i1]))
+ while (i1 < s1 && XDL_ISSPACE(l1[i1]))
i1++;
if (s1 != i1)
return 0;
}
if (i2 < s2) {
- while (i2 < s2 && isspace(l2[i2]))
+ while (i2 < s2 && XDL_ISSPACE(l2[i2]))
i2++;
return (s2 == i2);
}
@@ -258,10 +217,10 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data,
char const *ptr = *data;
for (; ptr < top && *ptr != '\n'; ptr++) {
- if (isspace(*ptr)) {
+ if (XDL_ISSPACE(*ptr)) {
const char *ptr2 = ptr;
int at_eol;
- while (ptr + 1 < top && isspace(ptr[1])
+ while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
&& ptr[1] != '\n')
ptr++;
at_eol = (top <= ptr + 1 || ptr[1] == '\n');
@@ -290,6 +249,109 @@ 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;
@@ -307,6 +369,7 @@ 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;
@@ -338,20 +401,6 @@ int xdl_num_out(char *out, long val) {
return str - out;
}
-
-long xdl_atol(char const *str, char const **next) {
- long val, base;
- char const *top;
-
- for (top = str; XDL_ISDIGIT(*top); top++);
- if (next)
- *next = top;
- for (val = 0, base = 1, top--; top >= str; top--, base *= 10)
- val += base * (long)(*top - '0');
- return val;
-}
-
-
int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
const char *func, long funclen, xdemitcb_t *ecb) {
int nb = 0;
@@ -400,3 +449,34 @@ int xdl_emit_hunk_hdr(long s1, long c1, long s2, long c2,
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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-30 13:35:27 +0000