Merge "Add entry iteration method to TrieMap." into lmp-dev

main
Keisuke Kuroyanagi 2014-07-30 10:38:05 +00:00 committed by Android (Google) Code Review
commit 5a7b634aaf
3 changed files with 215 additions and 2 deletions

View File

@ -98,6 +98,43 @@ bool TrieMap::put(const int key, const uint64_t value, const int bitmapEntryInde
return putInternal(unsignedKey, value, getBitShuffledKey(unsignedKey), bitmapEntryIndex,
readEntry(bitmapEntryIndex), 0 /* level */);
}
/**
* Iterate next entry in a certain level.
*
* @param iterationState the iteration state that will be read and updated in this method.
* @param outKey the output key
* @return Result instance. mIsValid is false when all entries are iterated.
*/
const TrieMap::Result TrieMap::iterateNext(std::vector<TableIterationState> *const iterationState,
int *const outKey) const {
while (!iterationState->empty()) {
TableIterationState &state = iterationState->back();
if (state.mTableSize <= state.mCurrentIndex) {
// Move to parent.
iterationState->pop_back();
} else {
const int entryIndex = state.mTableIndex + state.mCurrentIndex;
state.mCurrentIndex += 1;
const Entry entry = readEntry(entryIndex);
if (entry.isBitmapEntry()) {
// Move to child.
iterationState->emplace_back(popCount(entry.getBitmap()), entry.getTableIndex());
} else {
if (outKey) {
*outKey = entry.getKey();
}
if (!entry.hasTerminalLink()) {
return Result(entry.getValue(), true, INVALID_INDEX);
}
const int valueEntryIndex = entry.getValueEntryIndex();
const Entry valueEntry = readEntry(valueEntryIndex);
return Result(valueEntry.getValueOfValueEntry(), true, valueEntryIndex + 1);
}
}
}
// Visited all entries.
return Result(0, false, INVALID_INDEX);
}
/**
* Shuffle bits of the key in the fixed order.

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@ -44,6 +44,117 @@ class TrieMap {
mNextLevelBitmapEntryIndex(nextLevelBitmapEntryIndex) {}
};
/**
* Struct to record iteration state in a table.
*/
struct TableIterationState {
int mTableSize;
int mTableIndex;
int mCurrentIndex;
TableIterationState(const int tableSize, const int tableIndex)
: mTableSize(tableSize), mTableIndex(tableIndex), mCurrentIndex(0) {}
};
class TrieMapRange;
class TrieMapIterator {
public:
class IterationResult {
public:
IterationResult(const TrieMap *const trieMap, const int key, const uint64_t value,
const int nextLeveBitmapEntryIndex)
: mTrieMap(trieMap), mKey(key), mValue(value),
mNextLevelBitmapEntryIndex(nextLeveBitmapEntryIndex) {}
const TrieMapRange getEntriesInNextLevel() const {
return TrieMapRange(mTrieMap, mNextLevelBitmapEntryIndex);
}
bool hasNextLevelMap() const {
return mNextLevelBitmapEntryIndex != INVALID_INDEX;
}
AK_FORCE_INLINE int key() const {
return mKey;
}
AK_FORCE_INLINE uint64_t value() const {
return mValue;
}
private:
const TrieMap *const mTrieMap;
const int mKey;
const uint64_t mValue;
const int mNextLevelBitmapEntryIndex;
};
TrieMapIterator(const TrieMap *const trieMap, const int bitmapEntryIndex)
: mTrieMap(trieMap), mStateStack(), mBaseBitmapEntryIndex(bitmapEntryIndex),
mKey(0), mValue(0), mIsValid(false), mNextLevelBitmapEntryIndex(INVALID_INDEX) {
if (!trieMap) {
return;
}
const Entry bitmapEntry = mTrieMap->readEntry(mBaseBitmapEntryIndex);
mStateStack.emplace_back(
mTrieMap->popCount(bitmapEntry.getBitmap()), bitmapEntry.getTableIndex());
this->operator++();
}
const IterationResult operator*() const {
return IterationResult(mTrieMap, mKey, mValue, mNextLevelBitmapEntryIndex);
}
bool operator!=(const TrieMapIterator &other) const {
// Caveat: This works only for for loops.
return mIsValid || other.mIsValid;
}
const TrieMapIterator &operator++() {
const Result result = mTrieMap->iterateNext(&mStateStack, &mKey);
mValue = result.mValue;
mIsValid = result.mIsValid;
mNextLevelBitmapEntryIndex = result.mNextLevelBitmapEntryIndex;
return *this;
}
private:
DISALLOW_DEFAULT_CONSTRUCTOR(TrieMapIterator);
DISALLOW_ASSIGNMENT_OPERATOR(TrieMapIterator);
const TrieMap *const mTrieMap;
std::vector<TrieMap::TableIterationState> mStateStack;
const int mBaseBitmapEntryIndex;
int mKey;
uint64_t mValue;
bool mIsValid;
int mNextLevelBitmapEntryIndex;
};
/**
* Class to support iterating entries in TrieMap by range base for loops.
*/
class TrieMapRange {
public:
TrieMapRange(const TrieMap *const trieMap, const int bitmapEntryIndex)
: mTrieMap(trieMap), mBaseBitmapEntryIndex(bitmapEntryIndex) {};
TrieMapIterator begin() const {
return TrieMapIterator(mTrieMap, mBaseBitmapEntryIndex);
}
const TrieMapIterator end() const {
return TrieMapIterator(nullptr, INVALID_INDEX);
}
private:
DISALLOW_DEFAULT_CONSTRUCTOR(TrieMapRange);
DISALLOW_ASSIGNMENT_OPERATOR(TrieMapRange);
const TrieMap *const mTrieMap;
const int mBaseBitmapEntryIndex;
};
static const int INVALID_INDEX;
static const uint64_t MAX_VALUE;
@ -73,6 +184,14 @@ class TrieMap {
bool put(const int key, const uint64_t value, const int bitmapEntryIndex);
const TrieMapRange getEntriesInRootLevel() const {
return getEntriesInSpecifiedLevel(ROOT_BITMAP_ENTRY_INDEX);
}
const TrieMapRange getEntriesInSpecifiedLevel(const int bitmapEntryIndex) const {
return TrieMapRange(this, bitmapEntryIndex);
}
private:
DISALLOW_COPY_AND_ASSIGN(TrieMap);
@ -171,6 +290,8 @@ class TrieMap {
bool addNewEntryByExpandingTable(const uint32_t key, const uint64_t value,
const int tableIndex, const uint32_t bitmap, const int bitmapEntryIndex,
const int label);
const Result iterateNext(std::vector<TableIterationState> *const iterationState,
int *const outKey) const;
AK_FORCE_INLINE const Entry readEntry(const int entryIndex) const {
return Entry(readField0(entryIndex), readField1(entryIndex));

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@ -54,7 +54,7 @@ TEST(TrieMapTest, TestSetAndGetLarge) {
EXPECT_TRUE(trieMap.putRoot(i, i));
}
for (int i = 0; i < ELEMENT_COUNT; ++i) {
EXPECT_EQ(trieMap.getRoot(i).mValue, static_cast<uint64_t>(i));
EXPECT_EQ(static_cast<uint64_t>(i), trieMap.getRoot(i).mValue);
}
}
@ -78,7 +78,7 @@ TEST(TrieMapTest, TestRandSetAndGetLarge) {
testKeyValuePairs[key] = value;
}
for (const auto &v : testKeyValuePairs) {
EXPECT_EQ(trieMap.getRoot(v.first).mValue, v.second);
EXPECT_EQ(v.second, trieMap.getRoot(v.first).mValue);
}
}
@ -163,6 +163,61 @@ TEST(TrieMapTest, TestMultiLevel) {
}
}
}
// Iteration
for (const auto &firstLevelEntry : trieMap.getEntriesInRootLevel()) {
EXPECT_EQ(trieMap.getRoot(firstLevelEntry.key()).mValue, firstLevelEntry.value());
EXPECT_EQ(firstLevelEntries[firstLevelEntry.key()], firstLevelEntry.value());
firstLevelEntries.erase(firstLevelEntry.key());
for (const auto &secondLevelEntry : firstLevelEntry.getEntriesInNextLevel()) {
EXPECT_EQ(twoLevelMap[firstLevelEntry.key()][secondLevelEntry.key()],
secondLevelEntry.value());
twoLevelMap[firstLevelEntry.key()].erase(secondLevelEntry.key());
for (const auto &thirdLevelEntry : secondLevelEntry.getEntriesInNextLevel()) {
EXPECT_EQ(threeLevelMap[firstLevelEntry.key()][secondLevelEntry.key()]
[thirdLevelEntry.key()], thirdLevelEntry.value());
threeLevelMap[firstLevelEntry.key()][secondLevelEntry.key()].erase(
thirdLevelEntry.key());
}
}
}
// Ensure all entries have been traversed.
EXPECT_TRUE(firstLevelEntries.empty());
for (const auto &secondLevelEntry : twoLevelMap) {
EXPECT_TRUE(secondLevelEntry.second.empty());
}
for (const auto &secondLevelEntry : threeLevelMap) {
for (const auto &thirdLevelEntry : secondLevelEntry.second) {
EXPECT_TRUE(thirdLevelEntry.second.empty());
}
}
}
TEST(TrieMapTest, TestIteration) {
static const int ELEMENT_COUNT = 200000;
TrieMap trieMap;
std::unordered_map<int, uint64_t> testKeyValuePairs;
// Use the uniform integer distribution [S_INT_MIN, S_INT_MAX].
std::uniform_int_distribution<int> keyDistribution(S_INT_MIN, S_INT_MAX);
auto keyRandomNumberGenerator = std::bind(keyDistribution, std::mt19937());
// Use the uniform distribution [0, TrieMap::MAX_VALUE].
std::uniform_int_distribution<uint64_t> valueDistribution(0, TrieMap::MAX_VALUE);
auto valueRandomNumberGenerator = std::bind(valueDistribution, std::mt19937());
for (int i = 0; i < ELEMENT_COUNT; ++i) {
const int key = keyRandomNumberGenerator();
const uint64_t value = valueRandomNumberGenerator();
EXPECT_TRUE(trieMap.putRoot(key, value));
testKeyValuePairs[key] = value;
}
for (const auto &entry : trieMap.getEntriesInRootLevel()) {
EXPECT_EQ(trieMap.getRoot(entry.key()).mValue, entry.value());
EXPECT_EQ(testKeyValuePairs[entry.key()], entry.value());
testKeyValuePairs.erase(entry.key());
}
EXPECT_TRUE(testKeyValuePairs.empty());
}
} // namespace