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Posted to commits@subversion.apache.org by st...@apache.org on 2013/02/28 08:45:50 UTC
svn commit: r1451129 - in /subversion/branches/fsfs-format7/subversion:
include/private/svn_string_private.h libsvn_delta/xdelta.c
libsvn_subr/string.c
Author: stefan2
Date: Thu Feb 28 07:45:50 2013
New Revision: 1451129
URL: http://svn.apache.org/r1451129
Log:
On the fsfs-format7 branch: Move the string matching functions
from xdelta to libsvn_subr/string.
* subversion/include/private/svn_string_private.h
(svn_cstring__match_length,
svn_cstring__reverse_match_length): declare new private API
* subversion/libsvn_subr/string.c
(svn_cstring__match_length,
svn_cstring__reverse_match_length): take implementation from xdelta.c
* subversion/libsvn_delta/xdelta.c
(match_length,
reverse_match_length): remove here
(find_match,
store_delta_trailer,
compute_delta): update callers
Modified:
subversion/branches/fsfs-format7/subversion/include/private/svn_string_private.h
subversion/branches/fsfs-format7/subversion/libsvn_delta/xdelta.c
subversion/branches/fsfs-format7/subversion/libsvn_subr/string.c
Modified: subversion/branches/fsfs-format7/subversion/include/private/svn_string_private.h
URL: http://svn.apache.org/viewvc/subversion/branches/fsfs-format7/subversion/include/private/svn_string_private.h?rev=1451129&r1=1451128&r2=1451129&view=diff
==============================================================================
--- subversion/branches/fsfs-format7/subversion/include/private/svn_string_private.h (original)
+++ subversion/branches/fsfs-format7/subversion/include/private/svn_string_private.h Thu Feb 28 07:45:50 2013
@@ -210,6 +210,24 @@ svn_string__similarity(const svn_string_
svn_membuf_t *buffer, apr_size_t *rlcs);
+/* Return the lowest position at which A and B differ. If no difference
+ * can be found in the first MAX_LEN characters, MAX_LEN will be returned.
+ */
+apr_size_t
+svn_cstring__match_length(const char *a,
+ const char *b,
+ apr_size_t max_len);
+
+/* Return the number of bytes before A and B that don't differ. If no
+ * difference can be found in the first MAX_LEN characters, MAX_LEN will
+ * be returned. Please note that A-MAX_LEN and B-MAX_LEN must both be
+ * valid addresses.
+ */
+apr_size_t
+svn_cstring__reverse_match_length(const char *a,
+ const char *b,
+ apr_size_t max_len);
+
/** @} */
/** @} */
Modified: subversion/branches/fsfs-format7/subversion/libsvn_delta/xdelta.c
URL: http://svn.apache.org/viewvc/subversion/branches/fsfs-format7/subversion/libsvn_delta/xdelta.c?rev=1451129&r1=1451128&r2=1451129&view=diff
==============================================================================
--- subversion/branches/fsfs-format7/subversion/libsvn_delta/xdelta.c (original)
+++ subversion/branches/fsfs-format7/subversion/libsvn_delta/xdelta.c Thu Feb 28 07:45:50 2013
@@ -28,6 +28,7 @@
#include <apr_hash.h>
#include "svn_delta.h"
+#include "private/svn_string_private.h"
#include "delta.h"
/* This is pseudo-adler32. It is adler32 without the prime modulus.
@@ -222,73 +223,6 @@ init_blocks_table(const char *data,
add_block(blocks, init_adler32(data + i), i);
}
-/* Return the lowest position at which A and B differ. If no difference
- * can be found in the first MAX_LEN characters, MAX_LEN will be returned.
- */
-static apr_size_t
-match_length(const char *a, const char *b, apr_size_t max_len)
-{
- apr_size_t pos = 0;
-
-#if SVN_UNALIGNED_ACCESS_IS_OK
-
- /* Chunky processing is so much faster ...
- *
- * We can't make this work on architectures that require aligned access
- * because A and B will probably have different alignment. So, skipping
- * the first few chars until alignment is reached is not an option.
- */
- for (; pos + sizeof(apr_size_t) <= max_len; pos += sizeof(apr_size_t))
- if (*(const apr_size_t*)(a + pos) != *(const apr_size_t*)(b + pos))
- break;
-
-#endif
-
- for (; pos < max_len; ++pos)
- if (a[pos] != b[pos])
- break;
-
- return pos;
-}
-
-/* Return the number of bytes before A and B that don't differ. If no
- * difference can be found in the first MAX_LEN characters, MAX_LEN will
- * be returned. Please note that A-MAX_LEN and B-MAX_LEN must both be
- * valid addresses.
- */
-static apr_size_t
-reverse_match_length(const char *a, const char *b, apr_size_t max_len)
-{
- apr_size_t pos = 0;
-
-#if SVN_UNALIGNED_ACCESS_IS_OK
-
- /* Chunky processing is so much faster ...
- *
- * We can't make this work on architectures that require aligned access
- * because A and B will probably have different alignment. So, skipping
- * the first few chars until alignment is reached is not an option.
- */
- for (pos = sizeof(apr_size_t); pos <= max_len; pos += sizeof(apr_size_t))
- if (*(const apr_size_t*)(a - pos) != *(const apr_size_t*)(b - pos))
- break;
-
- pos -= sizeof(apr_size_t);
-
-#endif
-
- /* If we find a mismatch at -pos, pos-1 characters matched.
- */
- while (++pos <= max_len)
- if (a[0-pos] != b[0-pos])
- return pos - 1;
-
- /* No mismatch found -> at least MAX_LEN matching chars.
- */
- return max_len;
-}
-
-
/* Try to find a match for the target data B in BLOCKS, and then
extend the match as long as data in A and B at the match position
continues to match. We set the position in A we ended up in (in
@@ -322,9 +256,9 @@ find_match(const struct blocks *blocks,
max_delta = asize - apos - MATCH_BLOCKSIZE < bsize - bpos - MATCH_BLOCKSIZE
? asize - apos - MATCH_BLOCKSIZE
: bsize - bpos - MATCH_BLOCKSIZE;
- delta = match_length(a + apos + MATCH_BLOCKSIZE,
- b + bpos + MATCH_BLOCKSIZE,
- max_delta);
+ delta = svn_cstring__match_length(a + apos + MATCH_BLOCKSIZE,
+ b + bpos + MATCH_BLOCKSIZE,
+ max_delta);
/* See if we can extend backwards (max MATCH_BLOCKSIZE-1 steps because A's
content has been sampled only every MATCH_BLOCKSIZE positions). */
@@ -361,7 +295,8 @@ store_delta_trailer(svn_txdelta__ops_bat
if (max_len == 0)
return;
- end_match = reverse_match_length(a + asize, b + bsize, max_len);
+ end_match = svn_cstring__reverse_match_length(a + asize, b + bsize,
+ max_len);
if (end_match <= 4)
end_match = 0;
@@ -413,7 +348,7 @@ compute_delta(svn_txdelta__ops_baton_t *
/* Optimization: directly compare window starts. If more than 4
* bytes match, we can immediately create a matching windows.
* Shorter sequences result in a net data increase. */
- lo = match_length(a, b, asize > bsize ? bsize : asize);
+ lo = svn_cstring__match_length(a, b, asize > bsize ? bsize : asize);
if ((lo > 4) || (lo == bsize))
{
svn_txdelta__insert_op(build_baton, svn_txdelta_source,
@@ -467,7 +402,8 @@ compute_delta(svn_txdelta__ops_baton_t *
{
/* the match borders on the previous op. Maybe, we found a
* match that is better than / overlapping the previous one. */
- apr_size_t len = reverse_match_length(a + apos, b + lo, apos < lo ? apos : lo);
+ apr_size_t len = svn_cstring__reverse_match_length
+ (a + apos, b + lo, apos < lo ? apos : lo);
if (len > 0)
{
len = svn_txdelta__remove_copy(build_baton, len);
Modified: subversion/branches/fsfs-format7/subversion/libsvn_subr/string.c
URL: http://svn.apache.org/viewvc/subversion/branches/fsfs-format7/subversion/libsvn_subr/string.c?rev=1451129&r1=1451128&r2=1451129&view=diff
==============================================================================
--- subversion/branches/fsfs-format7/subversion/libsvn_subr/string.c (original)
+++ subversion/branches/fsfs-format7/subversion/libsvn_subr/string.c Thu Feb 28 07:45:50 2013
@@ -1282,3 +1282,67 @@ svn_string__similarity(const svn_string_
else
return 1000;
}
+
+apr_size_t
+svn_cstring__match_length(const char *a,
+ const char *b,
+ apr_size_t max_len)
+{
+ apr_size_t pos = 0;
+
+#if SVN_UNALIGNED_ACCESS_IS_OK
+
+ /* Chunky processing is so much faster ...
+ *
+ * We can't make this work on architectures that require aligned access
+ * because A and B will probably have different alignment. So, skipping
+ * the first few chars until alignment is reached is not an option.
+ */
+ for (; pos + sizeof(apr_size_t) <= max_len; pos += sizeof(apr_size_t))
+ if (*(const apr_size_t*)(a + pos) != *(const apr_size_t*)(b + pos))
+ break;
+
+#endif
+
+ for (; pos < max_len; ++pos)
+ if (a[pos] != b[pos])
+ break;
+
+ return pos;
+}
+
+apr_size_t
+svn_cstring__reverse_match_length(const char *a,
+ const char *b,
+ apr_size_t max_len)
+{
+ apr_size_t pos = 0;
+
+#if SVN_UNALIGNED_ACCESS_IS_OK
+
+ /* Chunky processing is so much faster ...
+ *
+ * We can't make this work on architectures that require aligned access
+ * because A and B will probably have different alignment. So, skipping
+ * the first few chars until alignment is reached is not an option.
+ */
+ for (pos = sizeof(apr_size_t); pos <= max_len; pos += sizeof(apr_size_t))
+ if (*(const apr_size_t*)(a - pos) != *(const apr_size_t*)(b - pos))
+ break;
+
+ pos -= sizeof(apr_size_t);
+
+#endif
+
+ /* If we find a mismatch at -pos, pos-1 characters matched.
+ */
+ while (++pos <= max_len)
+ if (a[0-pos] != b[0-pos])
+ return pos - 1;
+
+ /* No mismatch found -> at least MAX_LEN matching chars.
+ */
+ return max_len;
+}
+
+