proxmox-mirrors/libgit2
1
0
Fork 0
mirror of https://git.proxmox.com/git/libgit2 synced 2025-08-11 10:25:14 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

pack: limit the amount of memory the base delta cache can use

Browse Source 
Currently limited to 16MB (like git) and to objects up to 1MB in
size.
This commit is contained in:
Carlos Martín Nieto 2012-12-21 13:46:48 +01:00
parent c8f79c2bdf
commit 0ed7562006
2 changed files with 38 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
src/pack.c
View File

@ -65,8 +65,8 @@ static void free_cache_object(void *o)
{
git_pack_cache_entry *e = (git_pack_cache_entry *)o;
assert(e->refcount.val == 0);
if (e != NULL) {
assert(e->refcount.val == 0);
git__free(e->raw.data);
git__free(e);
}
@ -107,28 +107,60 @@ static git_pack_cache_entry *cache_get(git_pack_cache *cache, size_t offset)
if (k != kh_end(cache->entries)) { /* found it */
entry = kh_value(cache->entries, k);
git_atomic_inc(&entry->refcount);
entry->uses++;
entry->last_usage = cache->use_ctr++;
}
git_mutex_unlock(&cache->lock);
return entry;
}
/* Run with the cache lock held */
static void free_lowest_entry(git_pack_cache *cache)
{
git_pack_cache_entry *lowest = NULL, *entry;
khiter_t k, lowest_k;
for (k = kh_begin(cache->entries); k != kh_end(cache->entries); k++) {
if (!kh_exist(cache->entries, k))
continue;
entry = kh_value(cache->entries, k);
if (lowest == NULL || entry->last_usage < lowest->last_usage) {
lowest_k = k;
lowest = entry;
}
}
if (!lowest) /* there's nothing to free */
return;
cache->memory_used -= lowest->raw.len;
kh_del(off, cache->entries, lowest_k);
free_cache_object(lowest);
}
static int cache_add(git_pack_cache *cache, git_rawobj *base, git_off_t offset)
{
git_pack_cache_entry *entry;
int error, exists = 0;
khiter_t k;
if (base->len > GIT_PACK_CACHE_SIZE_LIMIT)
return -1;
entry = new_cache_object(base);
if (entry) {
git_mutex_lock(&cache->lock);
/* Add it to the cache if nobody else has */
exists = kh_get(off, cache->entries, offset) != kh_end(cache->entries);
if (!exists) {
while (cache->memory_used + base->len > cache->memory_limit)
free_lowest_entry(cache);
k = kh_put(off, cache->entries, offset, &error);
assert(error != 0);
kh_value(cache->entries, k) = entry;
cache->memory_used += entry->raw.len;
}
git_mutex_unlock(&cache->lock);
/* Somebody beat us to adding it into the cache */

6
src/pack.h
View File

@ -54,7 +54,7 @@ struct git_pack_idx_header {
};
typedef struct git_pack_cache_entry {
int uses; /* enough? */
size_t last_usage; /* enough? */
git_atomic refcount;
git_rawobj raw;
} git_pack_cache_entry;
@ -63,11 +63,13 @@ typedef struct git_pack_cache_entry {
GIT__USE_OFFMAP;
#define GIT_PACK_CACHE_MEMORY_LIMIT 2 * 1024 * 1024;
#define GIT_PACK_CACHE_MEMORY_LIMIT 16 * 1024 * 1024
#define GIT_PACK_CACHE_SIZE_LIMIT 1024 * 1024 /* don't bother caching anything over 1MB */
typedef struct {
size_t memory_used;
size_t memory_limit;
size_t use_ctr;
git_mutex lock;
git_offmap *entries;
} git_pack_cache;