Add an LRU cache plus hashing primitives
This patch adds a hashtable-based LRU cache. This should be
significantly higher performance than the GenerationCache it is intended
to replace. It is a large part of the fix for bug 7271109
TextLayoutCache low-level performance issues.
We added a new method to BasicHashtable to detect when rehashing is
needed, because the internal linked list pointers would get invalidated
by that rehashing.
Also, the hash_type specialized to pointers had a small flaw.
Change-Id: I950c2083f96519777b851dbe157100e0a334caec
diff --git a/include/utils/BasicHashtable.h b/include/utils/BasicHashtable.h
index fdf9738..7a6c96c 100644
--- a/include/utils/BasicHashtable.h
+++ b/include/utils/BasicHashtable.h
@@ -328,6 +328,14 @@
BasicHashtableImpl::rehash(minimumCapacity, loadFactor);
}
+ /* Determines whether there is room to add another entry without rehashing.
+ * When this returns true, a subsequent add() operation is guaranteed to
+ * complete without performing a rehash.
+ */
+ inline bool hasMoreRoom() const {
+ return mCapacity > mFilledBuckets;
+ }
+
protected:
static inline const TEntry& entryFor(const Bucket& bucket) {
return reinterpret_cast<const TEntry&>(bucket.entry);