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-rw-r--r--include/utils/GenerationCache.h114
1 files changed, 53 insertions, 61 deletions
diff --git a/include/utils/GenerationCache.h b/include/utils/GenerationCache.h
index bb9ddd6..40722d1 100644
--- a/include/utils/GenerationCache.h
+++ b/include/utils/GenerationCache.h
@@ -34,17 +34,17 @@ public:
template<typename EntryKey, typename EntryValue>
struct Entry: public LightRefBase<Entry<EntryKey, EntryValue> > {
- Entry() { }
- Entry(const Entry<EntryKey, EntryValue>& e):
- key(e.key), value(e.value), parent(e.parent), child(e.child) { }
- Entry(sp<Entry<EntryKey, EntryValue> > e):
- key(e->key), value(e->value), parent(e->parent), child(e->child) { }
+ Entry(const Entry<EntryKey, EntryValue>& e) :
+ key(e.key), value(e.value),
+ parent(e.parent), child(e.child) { }
+ Entry(const EntryKey& key, const EntryValue& value) :
+ key(key), value(value) { }
EntryKey key;
EntryValue value;
- sp<Entry<EntryKey, EntryValue> > parent;
- sp<Entry<EntryKey, EntryValue> > child;
+ sp<Entry<EntryKey, EntryValue> > parent; // next older entry
+ sp<Entry<EntryKey, EntryValue> > child; // next younger entry
}; // struct Entry
/**
@@ -62,23 +62,20 @@ public:
void setOnEntryRemovedListener(OnEntryRemoved<K, V>* listener);
- void clear();
+ size_t size() const;
- bool contains(K key) const;
- V get(K key);
- K getKeyAt(uint32_t index) const;
- bool put(K key, V value);
- V remove(K key);
- V removeOldest();
- V getValueAt(uint32_t index) const;
+ void clear();
- uint32_t size() const;
+ bool contains(const K& key) const;
+ const K& getKeyAt(size_t index) const;
+ const V& getValueAt(size_t index) const;
- void addToCache(sp<Entry<K, V> > entry, K key, V value);
- void attachToCache(sp<Entry<K, V> > entry);
- void detachFromCache(sp<Entry<K, V> > entry);
+ const V& get(const K& key);
+ bool put(const K& key, const V& value);
- V removeAt(ssize_t index);
+ void removeAt(ssize_t index);
+ bool remove(const K& key);
+ bool removeOldest();
private:
KeyedVector<K, sp<Entry<K, V> > > mCache;
@@ -88,11 +85,16 @@ private:
sp<Entry<K, V> > mOldest;
sp<Entry<K, V> > mYoungest;
+
+ void attachToCache(const sp<Entry<K, V> >& entry);
+ void detachFromCache(const sp<Entry<K, V> >& entry);
+
+ const V mNullValue;
}; // class GenerationCache
template<typename K, typename V>
GenerationCache<K, V>::GenerationCache(uint32_t maxCapacity): mMaxCapacity(maxCapacity),
- mListener(NULL) {
+ mListener(NULL), mNullValue(NULL) {
};
template<typename K, typename V>
@@ -130,45 +132,44 @@ void GenerationCache<K, V>::clear() {
}
template<typename K, typename V>
-bool GenerationCache<K, V>::contains(K key) const {
+bool GenerationCache<K, V>::contains(const K& key) const {
return mCache.indexOfKey(key) >= 0;
}
template<typename K, typename V>
-K GenerationCache<K, V>::getKeyAt(uint32_t index) const {
+const K& GenerationCache<K, V>::getKeyAt(size_t index) const {
return mCache.keyAt(index);
}
template<typename K, typename V>
-V GenerationCache<K, V>::getValueAt(uint32_t index) const {
+const V& GenerationCache<K, V>::getValueAt(size_t index) const {
return mCache.valueAt(index)->value;
}
template<typename K, typename V>
-V GenerationCache<K, V>::get(K key) {
+const V& GenerationCache<K, V>::get(const K& key) {
ssize_t index = mCache.indexOfKey(key);
if (index >= 0) {
- sp<Entry<K, V> > entry = mCache.valueAt(index);
- if (entry.get()) {
- detachFromCache(entry);
- attachToCache(entry);
- return entry->value;
- }
+ const sp<Entry<K, V> >& entry = mCache.valueAt(index);
+ detachFromCache(entry);
+ attachToCache(entry);
+ return entry->value;
}
- return NULL;
+ return mNullValue;
}
template<typename K, typename V>
-bool GenerationCache<K, V>::put(K key, V value) {
+bool GenerationCache<K, V>::put(const K& key, const V& value) {
if (mMaxCapacity != kUnlimitedCapacity && mCache.size() >= mMaxCapacity) {
removeOldest();
}
ssize_t index = mCache.indexOfKey(key);
if (index < 0) {
- sp<Entry<K, V> > entry = new Entry<K, V>;
- addToCache(entry, key, value);
+ sp<Entry<K, V> > entry = new Entry<K, V>(key, value);
+ mCache.add(key, entry);
+ attachToCache(entry);
return true;
}
@@ -176,49 +177,44 @@ bool GenerationCache<K, V>::put(K key, V value) {
}
template<typename K, typename V>
-void GenerationCache<K, V>::addToCache(sp<Entry<K, V> > entry, K key, V value) {
- entry->key = key;
- entry->value = value;
- mCache.add(key, entry);
- attachToCache(entry);
-}
-
-template<typename K, typename V>
-V GenerationCache<K, V>::remove(K key) {
+bool GenerationCache<K, V>::remove(const K& key) {
ssize_t index = mCache.indexOfKey(key);
if (index >= 0) {
- return removeAt(index);
+ removeAt(index);
+ return true;
}
- return NULL;
+ return false;
}
template<typename K, typename V>
-V GenerationCache<K, V>::removeAt(ssize_t index) {
+void GenerationCache<K, V>::removeAt(ssize_t index) {
sp<Entry<K, V> > entry = mCache.valueAt(index);
if (mListener) {
(*mListener)(entry->key, entry->value);
}
mCache.removeItemsAt(index, 1);
detachFromCache(entry);
-
- return entry->value;
}
template<typename K, typename V>
-V GenerationCache<K, V>::removeOldest() {
+bool GenerationCache<K, V>::removeOldest() {
if (mOldest.get()) {
ssize_t index = mCache.indexOfKey(mOldest->key);
if (index >= 0) {
- return removeAt(index);
+ removeAt(index);
+ return true;
}
+ ALOGE("GenerationCache: removeOldest failed to find the item in the cache "
+ "with the given key, but we know it must be in there. "
+ "Is the key comparator kaput?");
}
- return NULL;
+ return false;
}
template<typename K, typename V>
-void GenerationCache<K, V>::attachToCache(sp<Entry<K, V> > entry) {
+void GenerationCache<K, V>::attachToCache(const sp<Entry<K, V> >& entry) {
if (!mYoungest.get()) {
mYoungest = mOldest = entry;
} else {
@@ -229,20 +225,16 @@ void GenerationCache<K, V>::attachToCache(sp<Entry<K, V> > entry) {
}
template<typename K, typename V>
-void GenerationCache<K, V>::detachFromCache(sp<Entry<K, V> > entry) {
+void GenerationCache<K, V>::detachFromCache(const sp<Entry<K, V> >& entry) {
if (entry->parent.get()) {
entry->parent->child = entry->child;
+ } else {
+ mOldest = entry->child;
}
if (entry->child.get()) {
entry->child->parent = entry->parent;
- }
-
- if (mOldest == entry) {
- mOldest = entry->child;
- }
-
- if (mYoungest == entry) {
+ } else {
mYoungest = entry->parent;
}
generated by cgit v1.1 at 2025-08-16 03:31:03 +0000