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Posted to commits@subversion.apache.org by st...@apache.org on 2015/05/20 10:27:49 UTC
svn commit: r1680487 -
/subversion/branches/1.10-cache-improvements/subversion/libsvn_subr/cache-membuffer.c
Author: stefan2
Date: Wed May 20 08:27:49 2015
New Revision: 1680487
URL: http://svn.apache.org/r1680487
Log:
On the 1.10-cache-improvements branch:
Eliminate the need to store the prefix key string separately.
Instead, either take from the prefix pool or the start of common key.
Note that this does not change the contents of the common key but instead
simply eliminates duplicate storage of the prefix key string.
* subversion/libsvn_subr/cache-membuffer.c
(store_key_part): Expect the caller to provide the plain prefix key
and derive all info from that instead of full_key_t
instance. Name the scratch pool appropriately.
(DEBUG_CACHE_MEMBUFFER_INIT_TAG): Update caller macro using a new
function - see below.
(svn_membuffer_cache_t): We don't need to store the prefix string
separately anymore.
(get_prefix_key): New function to retrieve the prefix key string.
(combine_long_key,
combine_key): Update struct access to the pre-processed prefix info.
(svn_membuffer_cache_get_info): Use the new util function to get
access to the prefix key.
(svn_cache__create_membuffer_cache): If needed at all, store the prefix
key string directly in the combined
key instead of copying it there.
Modified:
subversion/branches/1.10-cache-improvements/subversion/libsvn_subr/cache-membuffer.c
Modified: subversion/branches/1.10-cache-improvements/subversion/libsvn_subr/cache-membuffer.c
URL: http://svn.apache.org/viewvc/subversion/branches/1.10-cache-improvements/subversion/libsvn_subr/cache-membuffer.c?rev=1680487&r1=1680486&r2=1680487&view=diff
==============================================================================
--- subversion/branches/1.10-cache-improvements/subversion/libsvn_subr/cache-membuffer.c (original)
+++ subversion/branches/1.10-cache-improvements/subversion/libsvn_subr/cache-membuffer.c Wed May 20 08:27:49 2015
@@ -433,13 +433,12 @@ typedef struct entry_tag_t
/* Initialize all members of TAG except for the content hash.
*/
static svn_error_t *store_key_part(entry_tag_t *tag,
- const full_key_t *prefix_key,
+ const char *prefix,
const void *key,
apr_size_t key_len,
- apr_pool_t *pool)
+ apr_pool_t *scratch_pool)
{
svn_checksum_t *checksum;
- const char *prefix = prefix_key->full_key.data;
apr_size_t prefix_len = strlen(prefix);
if (prefix_len > sizeof(tag->prefix_tail))
@@ -450,12 +449,16 @@ static svn_error_t *store_key_part(entry
SVN_ERR(svn_checksum(&checksum,
svn_checksum_md5,
+ prefix,
+ strlen(prefix),
+ scratch_pool));
+ memcpy(tag->prefix_hash, checksum->digest, sizeof(tag->prefix_hash));
+
+ SVN_ERR(svn_checksum(&checksum,
+ svn_checksum_md5,
key,
key_len,
- pool));
-
- memcpy(tag->prefix_hash, prefix_key->entry_key.fingerprint,
- sizeof(tag->prefix_hash));
+ scratch_pool));
memcpy(tag->key_hash, checksum->digest, sizeof(tag->key_hash));
memset(tag->prefix_tail, 0, sizeof(tag->key_hash));
@@ -516,7 +519,7 @@ static svn_error_t* assert_equal_tags(co
entry_tag_t *tag = &_tag; \
if (key) \
SVN_ERR(store_key_part(tag, \
- &cache->prefix, \
+ get_prefix_key(cache), \
key, \
cache->key_len == APR_HASH_KEY_STRING \
? strlen((const char *) key) \
@@ -2770,11 +2773,11 @@ typedef struct svn_membuffer_cache_t
*/
svn_cache__deserialize_func_t deserializer;
- /* Prepend this byte sequence to any key passed to us.
+ /* Prepend this to any key passed to us.
* This makes our keys different from all keys used by svn_membuffer_cache_t
* instances that we don't want to share cached data with.
*/
- full_key_t prefix;
+ entry_key_t prefix;
/* length of the keys that will be passed to us through the
* svn_cache_t interface. May be APR_HASH_KEY_STRING.
@@ -2793,6 +2796,15 @@ typedef struct svn_membuffer_cache_t
svn_mutex__t *mutex;
} svn_membuffer_cache_t;
+/* Return the prefix key used by CACHE. */
+static const char *
+get_prefix_key(const svn_membuffer_cache_t *cache)
+{
+ return (cache->prefix.prefix_idx == NO_INDEX
+ ? cache->combined_key.full_key.data
+ : cache->membuffer->prefix_pool->values[cache->prefix.prefix_idx]);
+}
+
/* Basically calculate a hash value for KEY of length KEY_LEN, combine it
* with the CACHE->PREFIX and write the result in CACHE->COMBINED_KEY.
* This could replace combine_key() entirely but we actually use it only
@@ -2805,7 +2817,7 @@ combine_long_key(svn_membuffer_cache_t *
{
apr_uint32_t *digest_buffer;
char *key_copy;
- apr_size_t prefix_len = cache->prefix.entry_key.key_len;
+ apr_size_t prefix_len = cache->prefix.key_len;
apr_size_t aligned_key_len;
/* handle variable-length keys */
@@ -2829,9 +2841,9 @@ combine_long_key(svn_membuffer_cache_t *
/* Combine with prefix. */
cache->combined_key.entry_key.fingerprint[0]
- ^= cache->prefix.entry_key.fingerprint[0];
+ ^= cache->prefix.fingerprint[0];
cache->combined_key.entry_key.fingerprint[1]
- ^= cache->prefix.entry_key.fingerprint[1];
+ ^= cache->prefix.fingerprint[1];
}
/* Basically calculate a hash value for KEY of length KEY_LEN, combine it
@@ -2846,7 +2858,7 @@ combine_key(svn_membuffer_cache_t *cache
apr_uint64_t data[2];
/* Do we have to compare full keys? */
- if (cache->prefix.entry_key.prefix_idx == NO_INDEX)
+ if (cache->prefix.prefix_idx == NO_INDEX)
{
combine_long_key(cache, key, key_len);
return;
@@ -2878,9 +2890,9 @@ combine_key(svn_membuffer_cache_t *cache
/* combine with this cache's namespace */
cache->combined_key.entry_key.fingerprint[0]
- = data[0] ^ cache->prefix.entry_key.fingerprint[0];
+ = data[0] ^ cache->prefix.fingerprint[0];
cache->combined_key.entry_key.fingerprint[1]
- = data[1] ^ cache->prefix.entry_key.fingerprint[1];
+ = data[1] ^ cache->prefix.fingerprint[1];
}
/* Implement svn_cache__vtable_t.get (not thread-safe)
@@ -3127,7 +3139,7 @@ svn_membuffer_cache_get_info(void *cache
/* cache front-end specific data */
- info->id = apr_pstrdup(result_pool, cache->prefix.full_key.data);
+ info->id = apr_pstrdup(result_pool, get_prefix_key(cache));
/* collect info from shared cache back-end */
@@ -3347,43 +3359,40 @@ svn_cache__create_membuffer_cache(svn_ca
prefix_orig_len = strlen(prefix) + 1;
prefix_len = ALIGN_VALUE(prefix_orig_len);
- svn_membuf__create(&cache->prefix.full_key, prefix_len, result_pool);
- memcpy((char *)cache->prefix.full_key.data, prefix, prefix_orig_len);
- memset((char *)cache->prefix.full_key.data + prefix_orig_len, 0,
- prefix_len - prefix_orig_len);
-
/* Construct the folded prefix key. */
SVN_ERR(svn_checksum(&checksum,
svn_checksum_md5,
prefix,
strlen(prefix),
scratch_pool));
- memcpy(cache->prefix.entry_key.fingerprint, checksum->digest,
- sizeof(cache->prefix.entry_key.fingerprint));
- cache->prefix.entry_key.key_len = prefix_len;
+ memcpy(cache->prefix.fingerprint, checksum->digest,
+ sizeof(cache->prefix.fingerprint));
+ cache->prefix.key_len = prefix_len;
/* Fix-length keys of up to 16 bytes may be handled without storing the
* full key separately for each item. */
if ( (klen != APR_HASH_KEY_STRING)
&& (klen <= sizeof(cache->combined_key.entry_key.fingerprint))
&& !short_lived)
- SVN_ERR(prefix_pool_get(&cache->prefix.entry_key.prefix_idx,
+ SVN_ERR(prefix_pool_get(&cache->prefix.prefix_idx,
membuffer->prefix_pool,
prefix));
else
- cache->prefix.entry_key.prefix_idx = NO_INDEX;
+ cache->prefix.prefix_idx = NO_INDEX;
/* If key combining is not guaranteed to produce unique results, we have
* to handle full keys. Otherwise, leave it NULL. */
- if (cache->prefix.entry_key.prefix_idx == NO_INDEX)
+ if (cache->prefix.prefix_idx == NO_INDEX)
{
/* Initialize the combined key. Pre-allocate some extra room in the
* full key such that we probably don't need to re-alloc. */
- cache->combined_key.entry_key = cache->prefix.entry_key;
+ cache->combined_key.entry_key = cache->prefix;
svn_membuf__create(&cache->combined_key.full_key, prefix_len + 200,
result_pool);
- memcpy(cache->combined_key.full_key.data, cache->prefix.full_key.data,
- prefix_len);
+ memcpy((char *)cache->combined_key.full_key.data, prefix,
+ prefix_orig_len);
+ memset((char *)cache->combined_key.full_key.data + prefix_orig_len, 0,
+ prefix_len - prefix_orig_len);
}
else
{
@@ -3391,8 +3400,7 @@ svn_cache__create_membuffer_cache(svn_ca
* key, so leave it NULL and set its length to 0 to prevent access to
* it. Keep the fingerprint 0 as well b/c it will always be set anew
* by combine_key(). */
- cache->combined_key.entry_key.prefix_idx
- = cache->prefix.entry_key.prefix_idx;
+ cache->combined_key.entry_key.prefix_idx = cache->prefix.prefix_idx;
cache->combined_key.entry_key.key_len = 0;
}