system/core: fix iterator for LruCache
Was failing to return the first element
Change-Id: Ic803f5d463a56519212014d0d190407cf4b859cf
diff --git a/include/utils/LruCache.h b/include/utils/LruCache.h
index 7818b4e..20a379e 100644
--- a/include/utils/LruCache.h
+++ b/include/utils/LruCache.h
@@ -99,17 +99,29 @@
TValue mNullValue;
public:
+ // To be used like:
+ // while (it.next()) {
+ // it.value(); it.key();
+ // }
class Iterator {
public:
- Iterator(const LruCache<TKey, TValue>& cache): mCache(cache), mIterator(mCache.mSet->begin()) {
+ Iterator(const LruCache<TKey, TValue>& cache):
+ mCache(cache), mIterator(mCache.mSet->begin()), mBeginReturned(false) {
}
bool next() {
if (mIterator == mCache.mSet->end()) {
return false;
}
- std::advance(mIterator, 1);
- return mIterator != mCache.mSet->end();
+ if (!mBeginReturned) {
+ // mIterator has been initialized to the beginning and
+ // hasn't been returned. Do not advance:
+ mBeginReturned = true;
+ } else {
+ std::advance(mIterator, 1);
+ }
+ bool ret = (mIterator != mCache.mSet->end());
+ return ret;
}
const TValue& value() const {
@@ -122,6 +134,7 @@
private:
const LruCache<TKey, TValue>& mCache;
typename LruCacheSet::iterator mIterator;
+ bool mBeginReturned;
};
};
diff --git a/libutils/tests/LruCache_test.cpp b/libutils/tests/LruCache_test.cpp
index 2ed84d7..580b980 100644
--- a/libutils/tests/LruCache_test.cpp
+++ b/libutils/tests/LruCache_test.cpp
@@ -293,4 +293,110 @@
EXPECT_EQ(3, callback.callbackCount);
}
+TEST_F(LruCacheTest, IteratorCheck) {
+ LruCache<int, int> cache(100);
+
+ cache.put(1, 4);
+ cache.put(2, 5);
+ cache.put(3, 6);
+ EXPECT_EQ(3U, cache.size());
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ int v = it.value();
+ // Check we haven't seen the value before.
+ EXPECT_TRUE(returnedValues.find(v) == returnedValues.end());
+ returnedValues.insert(v);
+ }
+ EXPECT_EQ(std::unordered_set<int>({4, 5, 6}), returnedValues);
+}
+
+TEST_F(LruCacheTest, EmptyCacheIterator) {
+ // Check that nothing crashes...
+ LruCache<int, int> cache(100);
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ returnedValues.insert(it.value());
+ }
+ EXPECT_EQ(std::unordered_set<int>(), returnedValues);
+}
+
+TEST_F(LruCacheTest, OneElementCacheIterator) {
+ // Check that nothing crashes...
+ LruCache<int, int> cache(100);
+ cache.put(1, 2);
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ returnedValues.insert(it.value());
+ }
+ EXPECT_EQ(std::unordered_set<int>({ 2 }), returnedValues);
+}
+
+TEST_F(LruCacheTest, OneElementCacheRemove) {
+ LruCache<int, int> cache(100);
+ cache.put(1, 2);
+
+ cache.remove(1);
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ returnedValues.insert(it.value());
+ }
+ EXPECT_EQ(std::unordered_set<int>({ }), returnedValues);
+}
+
+TEST_F(LruCacheTest, Remove) {
+ LruCache<int, int> cache(100);
+ cache.put(1, 4);
+ cache.put(2, 5);
+ cache.put(3, 6);
+
+ cache.remove(2);
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ returnedValues.insert(it.value());
+ }
+ EXPECT_EQ(std::unordered_set<int>({ 4, 6 }), returnedValues);
+}
+
+TEST_F(LruCacheTest, RemoveYoungest) {
+ LruCache<int, int> cache(100);
+ cache.put(1, 4);
+ cache.put(2, 5);
+ cache.put(3, 6);
+
+ cache.remove(3);
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ returnedValues.insert(it.value());
+ }
+ EXPECT_EQ(std::unordered_set<int>({ 4, 5 }), returnedValues);
+}
+
+TEST_F(LruCacheTest, RemoveNonMember) {
+ LruCache<int, int> cache(100);
+ cache.put(1, 4);
+ cache.put(2, 5);
+ cache.put(3, 6);
+
+ cache.remove(7);
+
+ LruCache<int, int>::Iterator it(cache);
+ std::unordered_set<int> returnedValues;
+ while (it.next()) {
+ returnedValues.insert(it.value());
+ }
+ EXPECT_EQ(std::unordered_set<int>({ 4, 5, 6 }), returnedValues);
+}
+
}