提交 b57dbdbb 编写于 作者: P Premysl Hruby

remove disk-store related comments

上级 8af9fe84
......@@ -10,28 +10,6 @@ void SlotToKeyDel(robj *key);
* C-level DB API
*----------------------------------------------------------------------------*/
/* Important notes on lookup and disk store.
*
* When disk store is enabled on lookup we can have different cases.
*
* a) The key is in memory:
* - If the key is not in IO_SAVEINPROG state we can access it.
* As if it's just IO_SAVE this means we have the key in the IO queue
* but can't be accessed by the IO thread (it requires to be
* translated into an IO Job by the cache cron function.)
* - If the key is in IO_SAVEINPROG we can't touch the key and have
* to blocking wait completion of operations.
* b) The key is not in memory:
* - If it's marked as non existing on disk as well (negative cache)
* we don't need to perform the disk access.
* - if the key MAY EXIST, but is not in memory, and it is marked as IO_SAVE
* then the key can only be a deleted one. As IO_SAVE keys are never
* evicted (dirty state), so the only possibility is that key was deleted.
* - if the key MAY EXIST we need to blocking load it.
* We check that the key is not in IO_SAVEINPROG state before accessing
* the disk object. If it is in this state, we wait.
*/
robj *lookupKey(redisDb *db, robj *key) {
dictEntry *de = dictFind(db->dict,key->ptr);
if (de) {
......@@ -161,8 +139,6 @@ int dbDelete(redisDb *db, robj *key) {
}
}
/* Empty the whole database.
* If diskstore is enabled this function will just flush the in-memory cache. */
long long emptyDb() {
int j;
long long removed = 0;
......
......@@ -270,9 +270,7 @@ robj *tryObjectEncoding(robj *o) {
/* Ok, this object can be encoded...
*
* Can I use a shared object? Only if the object is inside a given
* range and if the back end in use is in-memory. For disk store every
* object in memory used as value should be independent.
* Can I use a shared object? Only if the object is inside a given range
*
* Note that we also avoid using shared integers when maxmemory is used
* because every object needs to have a private LRU field for the LRU
......
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