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r4956: - moved the definition of the mangle context structure into a pvfs_shortname

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- made the mangle cache size configurable
This commit is contained in:
Andrew Tridgell 2005-01-24 03:33:36 +00:00 committed by Gerald (Jerry) Carter
parent 2eba223bda
commit 4adbd01812
2 changed files with 35 additions and 36 deletions
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46
source/ntvfs/posix/pvfs_shortname.c
View File

@ -71,11 +71,6 @@
#define FLAG_POSSIBLE3 64
#define FLAG_POSSIBLE4 128
/* by default have a max of 512 entries in the cache. */
#ifndef MANGLE_CACHE_SIZE
#define MANGLE_CACHE_SIZE 512
#endif
#define DEFAULT_MANGLE_PREFIX 4
#define MANGLE_BASECHARS "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
@ -87,6 +82,31 @@ static const char *reserved_names[] =
"LPT1", "LPT2", "LPT3", "NUL", "PRN", NULL };
struct pvfs_mangle_context {
uint8_t char_flags[256];
/*
this determines how many characters are used from the original
filename in the 8.3 mangled name. A larger value leads to a weaker
hash and more collisions. The largest possible value is 6.
*/
int mangle_prefix;
uint32_t mangle_modulus;
/* we will use a very simple direct mapped prefix cache. The big
advantage of this cache structure is speed and low memory usage
The cache is indexed by the low-order bits of the hash, and confirmed by
hashing the resulting cache entry to match the known hash
*/
uint32_t cache_size;
char **prefix_cache;
uint32_t *prefix_cache_hashes;
/* this is used to reverse the base 36 mapping */
unsigned char base_reverse[256];
};
/*
hash a string of the specified length. The string does not need to be
null terminated
@ -105,7 +125,7 @@ static uint32_t mangle_hash(struct pvfs_mangle_context *ctx,
static void cache_insert(struct pvfs_mangle_context *ctx,
const char *prefix, int length, uint32_t hash)
{
int i = hash % MANGLE_CACHE_SIZE;
int i = hash % ctx->cache_size;
if (ctx->prefix_cache[i]) {
talloc_free(ctx->prefix_cache[i]);
@ -120,7 +140,7 @@ static void cache_insert(struct pvfs_mangle_context *ctx,
*/
static const char *cache_lookup(struct pvfs_mangle_context *ctx, uint32_t hash)
{
int i = hash % MANGLE_CACHE_SIZE;
int i = hash % ctx->cache_size;
if (!ctx->prefix_cache[i] || hash != ctx->prefix_cache_hashes[i]) {
@ -592,17 +612,21 @@ NTSTATUS pvfs_mangle_init(struct pvfs_state *pvfs)
if (ctx == NULL) {
return NT_STATUS_NO_MEMORY;
}
ctx->prefix_cache = talloc_array_p(ctx, char *, MANGLE_CACHE_SIZE);
/* by default have a max of 512 entries in the cache. */
ctx->cache_size = lp_parm_int(-1, "mangle", "cachesize", 512);
ctx->prefix_cache = talloc_array(ctx, char *, ctx->cache_size);
if (ctx->prefix_cache == NULL) {
return NT_STATUS_NO_MEMORY;
}
ctx->prefix_cache_hashes = talloc_array_p(ctx, uint32_t, MANGLE_CACHE_SIZE);
ctx->prefix_cache_hashes = talloc_array(ctx, uint32_t, ctx->cache_size);
if (ctx->prefix_cache_hashes == NULL) {
return NT_STATUS_NO_MEMORY;
}
memset(ctx->prefix_cache, 0, sizeof(char *)*MANGLE_CACHE_SIZE);
memset(ctx->prefix_cache_hashes, 0, sizeof(uint32_t)*MANGLE_CACHE_SIZE);
memset(ctx->prefix_cache, 0, sizeof(char *) * ctx->cache_size);
memset(ctx->prefix_cache_hashes, 0, sizeof(uint32_t) * ctx->cache_size);
ctx->mangle_prefix = lp_parm_int(-1, "mangle", "prefix", -1);
if (ctx->mangle_prefix < 0 || ctx->mangle_prefix > 6) {

25
source/ntvfs/posix/vfs_posix.h
View File

@ -164,31 +164,6 @@ struct pvfs_file {
};
struct pvfs_mangle_context {
uint8_t char_flags[256];
/*
this determines how many characters are used from the original
filename in the 8.3 mangled name. A larger value leads to a weaker
hash and more collisions. The largest possible value is 6.
*/
int mangle_prefix;
uint32_t mangle_modulus;
/* we will use a very simple direct mapped prefix cache. The big
advantage of this cache structure is speed and low memory usage
The cache is indexed by the low-order bits of the hash, and confirmed by
hashing the resulting cache entry to match the known hash
*/
char **prefix_cache;
uint32_t *prefix_cache_hashes;
/* this is used to reverse the base 36 mapping */
unsigned char base_reverse[256];
};
/* flags to pvfs_resolve_name() */
#define PVFS_RESOLVE_WILDCARD (1<<0)
#define PVFS_RESOLVE_STREAMS (1<<1)