| // Copyright (c) 2014, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| #ifndef RUNTIME_VM_HASH_TABLE_H_ |
| #define RUNTIME_VM_HASH_TABLE_H_ |
| |
| #include "platform/assert.h" |
| #include "vm/object.h" |
| |
| namespace dart { |
| |
| // OVERVIEW: |
| // |
| // Hash maps and hash sets all use RawArray as backing storage. At the lowest |
| // level is a generic open-addressing table that supports deletion. |
| // - HashTable |
| // The next layer provides ordering and iteration functionality: |
| // - UnorderedHashTable |
| // - LinkedListHashTable (TODO(koda): Implement.) |
| // The utility class HashTables handles growth and conversion. |
| // The next layer fixes the payload size and provides a natural interface: |
| // - HashMap |
| // - HashSet |
| // Combining either of these with an iteration strategy, we get the templates |
| // intended for use outside this file: |
| // - UnorderedHashMap |
| // - LinkedListHashMap |
| // - UnorderedHashSet |
| // - LinkedListHashSet |
| // Each of these can be finally specialized with KeyTraits to support any set of |
| // lookup key types (e.g., look up a char* in a set of String objects), and |
| // any equality and hash code computation. |
| // |
| // The classes all wrap an Array handle, and methods like HashSet::Insert can |
| // trigger growth into a new RawArray, updating the handle. Debug mode asserts |
| // that 'Release' was called once to access the final array before destruction. |
| // NOTE: The handle returned by 'Release' is cleared by ~HashTable. |
| // |
| // Example use: |
| // typedef UnorderedHashMap<FooTraits> FooMap; |
| // ... |
| // FooMap cache(get_foo_cache()); |
| // cache.UpdateOrInsert(name0, obj0); |
| // cache.UpdateOrInsert(name1, obj1); |
| // ... |
| // set_foo_cache(cache.Release()); |
| // |
| // If you *know* that no mutating operations were called, you can optimize: |
| // ... |
| // obj ^= cache.GetOrNull(name); |
| // ASSERT(cache.Release().raw() == get_foo_cache()); |
| // |
| // TODO(koda): When exposing these to Dart code, document and assert that |
| // KeyTraits methods must not run Dart code (since the C++ code doesn't check |
| // for concurrent modification). |
| |
| // Open-addressing hash table template using a RawArray as backing storage. |
| // |
| // The elements of the array are partitioned into entries: |
| // [ header | metadata | entry0 | entry1 | ... | entryN ] |
| // Each entry contains a key, followed by zero or more payload components, |
| // and has 3 possible states: unused, occupied, or deleted. |
| // The header tracks the number of entries in each state. |
| // Any object except Object::sentinel() and Object::transition_sentinel() |
| // may be stored as a key. Any object may be stored in a payload. |
| // |
| // Parameters |
| // KeyTraits: defines static methods |
| // bool IsMatch(const Key& key, const Object& obj) and |
| // uword Hash(const Key& key) for any number of desired lookup key types. |
| // kPayloadSize: number of components of the payload in each entry. |
| // kMetaDataSize: number of elements reserved (e.g., for iteration order data). |
| template <typename KeyTraits, intptr_t kPayloadSize, intptr_t kMetaDataSize> |
| class HashTable : public ValueObject { |
| public: |
| typedef KeyTraits Traits; |
| // Uses the passed in handles for all handle operations. |
| // 'Release' must be called at the end to obtain the final table |
| // after potential growth/shrinkage. |
| HashTable(Object* key, Smi* index, Array* data) |
| : key_handle_(key), |
| smi_handle_(index), |
| data_(data), |
| released_data_(NULL) {} |
| // Uses 'zone' for handle allocation. 'Release' must be called at the end |
| // to obtain the final table after potential growth/shrinkage. |
| HashTable(Zone* zone, RawArray* data) |
| : key_handle_(&Object::Handle(zone)), |
| smi_handle_(&Smi::Handle(zone)), |
| data_(&Array::Handle(zone, data)), |
| released_data_(NULL) {} |
| |
| // Returns the final table. The handle is cleared when this HashTable is |
| // destroyed. |
| Array& Release() { |
| ASSERT(data_ != NULL); |
| ASSERT(released_data_ == NULL); |
| // Ensure that no methods are called after 'Release'. |
| released_data_ = data_; |
| data_ = NULL; |
| return *released_data_; |
| } |
| |
| ~HashTable() { |
| // In DEBUG mode, calling 'Release' is mandatory. |
| ASSERT(data_ == NULL); |
| if (released_data_ != NULL) { |
| *released_data_ = Array::null(); |
| } |
| } |
| |
| // Returns a backing storage size such that 'num_occupied' distinct keys can |
| // be inserted into the table. |
| static intptr_t ArrayLengthForNumOccupied(intptr_t num_occupied) { |
| // Because we use quadratic (actually triangle number) probing it is |
| // important that the size is a power of two (otherwise we could fail to |
| // find an empty slot). This is described in Knuth's The Art of Computer |
| // Programming Volume 2, Chapter 6.4, exercise 20 (solution in the |
| // appendix, 2nd edition). |
| intptr_t num_entries = Utils::RoundUpToPowerOfTwo(num_occupied + 1); |
| return kFirstKeyIndex + (kEntrySize * num_entries); |
| } |
| |
| // Initializes an empty table. |
| void Initialize() const { |
| ASSERT(data_->Length() >= ArrayLengthForNumOccupied(0)); |
| *smi_handle_ = Smi::New(0); |
| data_->SetAt(kOccupiedEntriesIndex, *smi_handle_); |
| data_->SetAt(kDeletedEntriesIndex, *smi_handle_); |
| |
| #if !defined(PRODUCT) |
| data_->SetAt(kNumGrowsIndex, *smi_handle_); |
| data_->SetAt(kNumLT5LookupsIndex, *smi_handle_); |
| data_->SetAt(kNumLT25LookupsIndex, *smi_handle_); |
| data_->SetAt(kNumGT25LookupsIndex, *smi_handle_); |
| data_->SetAt(kNumProbesIndex, *smi_handle_); |
| #endif // !defined(PRODUCT) |
| |
| for (intptr_t i = kHeaderSize; i < data_->Length(); ++i) { |
| data_->SetAt(i, Object::sentinel()); |
| } |
| } |
| |
| // Returns whether 'key' matches any key in the table. |
| template <typename Key> |
| bool ContainsKey(const Key& key) const { |
| return FindKey(key) != -1; |
| } |
| |
| // Returns the entry that matches 'key', or -1 if none exists. |
| template <typename Key> |
| intptr_t FindKey(const Key& key) const { |
| const intptr_t num_entries = NumEntries(); |
| ASSERT(NumOccupied() < num_entries); |
| // TODO(koda): Add salt. |
| NOT_IN_PRODUCT(intptr_t collisions = 0;) |
| uword hash = KeyTraits::Hash(key); |
| ASSERT(Utils::IsPowerOfTwo(num_entries)); |
| intptr_t probe = hash & (num_entries - 1); |
| int probe_distance = 1; |
| while (true) { |
| if (IsUnused(probe)) { |
| NOT_IN_PRODUCT(UpdateCollisions(collisions);) |
| return -1; |
| } else if (!IsDeleted(probe)) { |
| *key_handle_ = GetKey(probe); |
| if (KeyTraits::IsMatch(key, *key_handle_)) { |
| NOT_IN_PRODUCT(UpdateCollisions(collisions);) |
| return probe; |
| } |
| NOT_IN_PRODUCT(collisions += 1;) |
| } |
| // Advance probe. See ArrayLengthForNumOccupied comment for |
| // explanation of how we know this hits all slots. |
| probe = (probe + probe_distance) & (num_entries - 1); |
| probe_distance++; |
| } |
| UNREACHABLE(); |
| return -1; |
| } |
| |
| // Sets *entry to either: |
| // - an occupied entry matching 'key', and returns true, or |
| // - an unused/deleted entry where a matching key may be inserted, |
| // and returns false. |
| template <typename Key> |
| bool FindKeyOrDeletedOrUnused(const Key& key, intptr_t* entry) const { |
| const intptr_t num_entries = NumEntries(); |
| ASSERT(entry != NULL); |
| ASSERT(NumOccupied() < num_entries); |
| NOT_IN_PRODUCT(intptr_t collisions = 0;) |
| uword hash = KeyTraits::Hash(key); |
| ASSERT(Utils::IsPowerOfTwo(num_entries)); |
| intptr_t probe = hash & (num_entries - 1); |
| int probe_distance = 1; |
| intptr_t deleted = -1; |
| while (true) { |
| if (IsUnused(probe)) { |
| *entry = (deleted != -1) ? deleted : probe; |
| NOT_IN_PRODUCT(UpdateCollisions(collisions);) |
| return false; |
| } else if (IsDeleted(probe)) { |
| if (deleted == -1) { |
| deleted = probe; |
| } |
| } else { |
| *key_handle_ = GetKey(probe); |
| if (KeyTraits::IsMatch(key, *key_handle_)) { |
| *entry = probe; |
| NOT_IN_PRODUCT(UpdateCollisions(collisions);) |
| return true; |
| } |
| NOT_IN_PRODUCT(collisions += 1;) |
| } |
| // Advance probe. See ArrayLengthForNumOccupied comment for |
| // explanation of how we know this hits all slots. |
| probe = (probe + probe_distance) & (num_entries - 1); |
| probe_distance++; |
| } |
| UNREACHABLE(); |
| return false; |
| } |
| |
| // Sets the key of a previously unoccupied entry. This must not be the last |
| // unoccupied entry. |
| void InsertKey(intptr_t entry, const Object& key) const { |
| ASSERT(!IsOccupied(entry)); |
| AdjustSmiValueAt(kOccupiedEntriesIndex, 1); |
| if (IsDeleted(entry)) { |
| AdjustSmiValueAt(kDeletedEntriesIndex, -1); |
| } else { |
| ASSERT(IsUnused(entry)); |
| } |
| InternalSetKey(entry, key); |
| ASSERT(IsOccupied(entry)); |
| ASSERT(NumOccupied() < NumEntries()); |
| } |
| |
| bool IsUnused(intptr_t entry) const { |
| return InternalGetKey(entry) == Object::sentinel().raw(); |
| } |
| bool IsOccupied(intptr_t entry) const { |
| return !IsUnused(entry) && !IsDeleted(entry); |
| } |
| bool IsDeleted(intptr_t entry) const { |
| return InternalGetKey(entry) == Object::transition_sentinel().raw(); |
| } |
| |
| RawObject* GetKey(intptr_t entry) const { |
| ASSERT(IsOccupied(entry)); |
| return InternalGetKey(entry); |
| } |
| RawObject* GetPayload(intptr_t entry, intptr_t component) const { |
| ASSERT(IsOccupied(entry)); |
| return data_->At(PayloadIndex(entry, component)); |
| } |
| void UpdatePayload(intptr_t entry, |
| intptr_t component, |
| const Object& value) const { |
| ASSERT(IsOccupied(entry)); |
| ASSERT(0 <= component && component < kPayloadSize); |
| data_->SetAt(PayloadIndex(entry, component), value); |
| } |
| // Deletes both the key and payload of the specified entry. |
| void DeleteEntry(intptr_t entry) const { |
| ASSERT(IsOccupied(entry)); |
| for (intptr_t i = 0; i < kPayloadSize; ++i) { |
| UpdatePayload(entry, i, Object::transition_sentinel()); |
| } |
| InternalSetKey(entry, Object::transition_sentinel()); |
| AdjustSmiValueAt(kOccupiedEntriesIndex, -1); |
| AdjustSmiValueAt(kDeletedEntriesIndex, 1); |
| } |
| intptr_t NumEntries() const { |
| return (data_->Length() - kFirstKeyIndex) / kEntrySize; |
| } |
| intptr_t NumUnused() const { |
| return NumEntries() - NumOccupied() - NumDeleted(); |
| } |
| intptr_t NumOccupied() const { return GetSmiValueAt(kOccupiedEntriesIndex); } |
| intptr_t NumDeleted() const { return GetSmiValueAt(kDeletedEntriesIndex); } |
| Object& KeyHandle() const { return *key_handle_; } |
| Smi& SmiHandle() const { return *smi_handle_; } |
| |
| #if !defined(PRODUCT) |
| intptr_t NumGrows() const { return GetSmiValueAt(kNumGrowsIndex); } |
| intptr_t NumLT5Collisions() const { |
| return GetSmiValueAt(kNumLT5LookupsIndex); |
| } |
| intptr_t NumLT25Collisions() const { |
| return GetSmiValueAt(kNumLT25LookupsIndex); |
| } |
| intptr_t NumGT25Collisions() const { |
| return GetSmiValueAt(kNumGT25LookupsIndex); |
| } |
| intptr_t NumProbes() const { return GetSmiValueAt(kNumProbesIndex); } |
| void UpdateGrowth() const { |
| if (KeyTraits::ReportStats()) { |
| AdjustSmiValueAt(kNumGrowsIndex, 1); |
| } |
| } |
| void UpdateCollisions(intptr_t collisions) const { |
| if (KeyTraits::ReportStats()) { |
| if (data_->raw()->IsVMHeapObject()) { |
| return; |
| } |
| AdjustSmiValueAt(kNumProbesIndex, collisions + 1); |
| if (collisions < 5) { |
| AdjustSmiValueAt(kNumLT5LookupsIndex, 1); |
| } else if (collisions < 25) { |
| AdjustSmiValueAt(kNumLT25LookupsIndex, 1); |
| } else { |
| AdjustSmiValueAt(kNumGT25LookupsIndex, 1); |
| } |
| } |
| } |
| void PrintStats() const { |
| if (!KeyTraits::ReportStats()) { |
| return; |
| } |
| const intptr_t num5 = NumLT5Collisions(); |
| const intptr_t num25 = NumLT25Collisions(); |
| const intptr_t num_more = NumGT25Collisions(); |
| // clang-format off |
| OS::PrintErr("Stats for %s table :\n" |
| " Size of table = %" Pd ",Number of Occupied entries = %" Pd "\n" |
| " Number of Grows = %" Pd "\n" |
| " Number of lookups with < 5 collisions = %" Pd "\n" |
| " Number of lookups with < 25 collisions = %" Pd "\n" |
| " Number of lookups with > 25 collisions = %" Pd "\n" |
| " Average number of probes = %g\n", |
| KeyTraits::Name(), |
| NumEntries(), NumOccupied(), NumGrows(), |
| num5, num25, num_more, |
| static_cast<double>(NumProbes()) / (num5 + num25 + num_more)); |
| // clang-format on |
| } |
| #endif // !PRODUCT |
| |
| protected: |
| static const intptr_t kOccupiedEntriesIndex = 0; |
| static const intptr_t kDeletedEntriesIndex = 1; |
| #if defined(PRODUCT) |
| static const intptr_t kHeaderSize = kDeletedEntriesIndex + 1; |
| #else |
| static const intptr_t kNumGrowsIndex = 2; |
| static const intptr_t kNumLT5LookupsIndex = 3; |
| static const intptr_t kNumLT25LookupsIndex = 4; |
| static const intptr_t kNumGT25LookupsIndex = 5; |
| static const intptr_t kNumProbesIndex = 6; |
| static const intptr_t kHeaderSize = kNumProbesIndex + 1; |
| #endif |
| static const intptr_t kMetaDataIndex = kHeaderSize; |
| static const intptr_t kFirstKeyIndex = kHeaderSize + kMetaDataSize; |
| static const intptr_t kEntrySize = 1 + kPayloadSize; |
| |
| intptr_t KeyIndex(intptr_t entry) const { |
| ASSERT(0 <= entry && entry < NumEntries()); |
| return kFirstKeyIndex + (kEntrySize * entry); |
| } |
| |
| intptr_t PayloadIndex(intptr_t entry, intptr_t component) const { |
| ASSERT(0 <= component && component < kPayloadSize); |
| return KeyIndex(entry) + 1 + component; |
| } |
| |
| RawObject* InternalGetKey(intptr_t entry) const { |
| return data_->At(KeyIndex(entry)); |
| } |
| |
| void InternalSetKey(intptr_t entry, const Object& key) const { |
| data_->SetAt(KeyIndex(entry), key); |
| } |
| |
| intptr_t GetSmiValueAt(intptr_t index) const { |
| ASSERT(!data_->IsNull()); |
| ASSERT(!data_->At(index)->IsHeapObject()); |
| return Smi::Value(Smi::RawCast(data_->At(index))); |
| } |
| |
| void SetSmiValueAt(intptr_t index, intptr_t value) const { |
| *smi_handle_ = Smi::New(value); |
| data_->SetAt(index, *smi_handle_); |
| } |
| |
| void AdjustSmiValueAt(intptr_t index, intptr_t delta) const { |
| SetSmiValueAt(index, (GetSmiValueAt(index) + delta)); |
| } |
| |
| Object* key_handle_; |
| Smi* smi_handle_; |
| // Exactly one of these is non-NULL, depending on whether Release was called. |
| Array* data_; |
| Array* released_data_; |
| |
| friend class HashTables; |
| }; |
| |
| // Table with unspecified iteration order. No payload overhead or metadata. |
| template <typename KeyTraits, intptr_t kUserPayloadSize> |
| class UnorderedHashTable : public HashTable<KeyTraits, kUserPayloadSize, 0> { |
| public: |
| typedef HashTable<KeyTraits, kUserPayloadSize, 0> BaseTable; |
| static const intptr_t kPayloadSize = kUserPayloadSize; |
| explicit UnorderedHashTable(RawArray* data) |
| : BaseTable(Thread::Current()->zone(), data) {} |
| UnorderedHashTable(Zone* zone, RawArray* data) : BaseTable(zone, data) {} |
| UnorderedHashTable(Object* key, Smi* value, Array* data) |
| : BaseTable(key, value, data) {} |
| // Note: Does not check for concurrent modification. |
| class Iterator { |
| public: |
| explicit Iterator(const UnorderedHashTable* table) |
| : table_(table), entry_(-1) {} |
| bool MoveNext() { |
| while (entry_ < (table_->NumEntries() - 1)) { |
| ++entry_; |
| if (table_->IsOccupied(entry_)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| intptr_t Current() { return entry_; } |
| |
| private: |
| const UnorderedHashTable* table_; |
| intptr_t entry_; |
| }; |
| |
| // No extra book-keeping needed for Initialize, InsertKey, DeleteEntry. |
| }; |
| |
| class HashTables : public AllStatic { |
| public: |
| // Allocates and initializes a table. |
| template <typename Table> |
| static RawArray* New(intptr_t initial_capacity, |
| Heap::Space space = Heap::kNew) { |
| Table table( |
| Thread::Current()->zone(), |
| Array::New(Table::ArrayLengthForNumOccupied(initial_capacity), space)); |
| table.Initialize(); |
| return table.Release().raw(); |
| } |
| |
| template <typename Table> |
| static RawArray* New(const Array& array) { |
| Table table(Thread::Current()->zone(), array.raw()); |
| table.Initialize(); |
| return table.Release().raw(); |
| } |
| |
| // Clears 'to' and inserts all elements from 'from', in iteration order. |
| // The tables must have the same user payload size. |
| template <typename From, typename To> |
| static void Copy(const From& from, const To& to) { |
| COMPILE_ASSERT(From::kPayloadSize == To::kPayloadSize); |
| to.Initialize(); |
| ASSERT(from.NumOccupied() < to.NumEntries()); |
| typename From::Iterator it(&from); |
| Object& obj = Object::Handle(); |
| while (it.MoveNext()) { |
| intptr_t from_entry = it.Current(); |
| obj = from.GetKey(from_entry); |
| intptr_t to_entry = -1; |
| const Object& key = obj; |
| bool present = to.FindKeyOrDeletedOrUnused(key, &to_entry); |
| ASSERT(!present); |
| to.InsertKey(to_entry, obj); |
| for (intptr_t i = 0; i < From::kPayloadSize; ++i) { |
| obj = from.GetPayload(from_entry, i); |
| to.UpdatePayload(to_entry, i, obj); |
| } |
| } |
| } |
| |
| template <typename Table> |
| static void EnsureLoadFactor(double high, const Table& table) { |
| // We count deleted elements because they take up space just |
| // like occupied slots in order to cause a rehashing. |
| const double current = (1 + table.NumOccupied() + table.NumDeleted()) / |
| static_cast<double>(table.NumEntries()); |
| const bool too_many_deleted = table.NumOccupied() <= table.NumDeleted(); |
| if (current < high && !too_many_deleted) { |
| return; |
| } |
| // Normally we double the size here, but if less than half are occupied |
| // then it won't grow (this would imply that there were quite a lot of |
| // deleted slots). We don't want to constantly rehash if we are adding |
| // and deleting entries at just under the load factor limit, so we may |
| // double the size even though the number of occupied slots would not |
| // necessarily justify it. For example if the max load factor is 71% and |
| // the table is 70% full we will double the size to avoid a rehash every |
| // time 1% has been added and deleted. |
| const intptr_t new_capacity = table.NumOccupied() * 2 + 1; |
| ASSERT(table.NumOccupied() == 0 || |
| ((1.0 + table.NumOccupied()) / |
| Utils::RoundUpToPowerOfTwo(new_capacity)) <= high); |
| Table new_table(New<Table>(new_capacity, // Is rounded up to power of 2. |
| table.data_->IsOld() ? Heap::kOld : Heap::kNew)); |
| Copy(table, new_table); |
| *table.data_ = new_table.Release().raw(); |
| NOT_IN_PRODUCT(table.UpdateGrowth(); table.PrintStats();) |
| } |
| |
| // Serializes a table by concatenating its entries as an array. |
| template <typename Table> |
| static RawArray* ToArray(const Table& table, bool include_payload) { |
| const intptr_t entry_size = include_payload ? (1 + Table::kPayloadSize) : 1; |
| Array& result = Array::Handle(Array::New(table.NumOccupied() * entry_size)); |
| typename Table::Iterator it(&table); |
| Object& obj = Object::Handle(); |
| intptr_t result_index = 0; |
| while (it.MoveNext()) { |
| intptr_t entry = it.Current(); |
| obj = table.GetKey(entry); |
| result.SetAt(result_index++, obj); |
| if (include_payload) { |
| for (intptr_t i = 0; i < Table::kPayloadSize; ++i) { |
| obj = table.GetPayload(entry, i); |
| result.SetAt(result_index++, obj); |
| } |
| } |
| } |
| return result.raw(); |
| } |
| }; |
| |
| template <typename BaseIterTable> |
| class HashMap : public BaseIterTable { |
| public: |
| explicit HashMap(RawArray* data) |
| : BaseIterTable(Thread::Current()->zone(), data) {} |
| HashMap(Zone* zone, RawArray* data) : BaseIterTable(zone, data) {} |
| HashMap(Object* key, Smi* value, Array* data) |
| : BaseIterTable(key, value, data) {} |
| template <typename Key> |
| RawObject* GetOrNull(const Key& key, bool* present = NULL) const { |
| intptr_t entry = BaseIterTable::FindKey(key); |
| if (present != NULL) { |
| *present = (entry != -1); |
| } |
| return (entry == -1) ? Object::null() : BaseIterTable::GetPayload(entry, 0); |
| } |
| template <typename Key> |
| RawObject* GetOrDie(const Key& key) const { |
| intptr_t entry = BaseIterTable::FindKey(key); |
| if (entry == -1) UNREACHABLE(); |
| return BaseIterTable::GetPayload(entry, 0); |
| } |
| bool UpdateOrInsert(const Object& key, const Object& value) const { |
| EnsureCapacity(); |
| intptr_t entry = -1; |
| bool present = BaseIterTable::FindKeyOrDeletedOrUnused(key, &entry); |
| if (!present) { |
| BaseIterTable::InsertKey(entry, key); |
| } |
| BaseIterTable::UpdatePayload(entry, 0, value); |
| return present; |
| } |
| // Update the value of an existing key. Note that 'key' need not be an Object. |
| template <typename Key> |
| void UpdateValue(const Key& key, const Object& value) const { |
| intptr_t entry = BaseIterTable::FindKey(key); |
| ASSERT(entry != -1); |
| BaseIterTable::UpdatePayload(entry, 0, value); |
| } |
| // If 'key' is not present, maps it to 'value_if_absent'. Returns the final |
| // value in the map. |
| RawObject* InsertOrGetValue(const Object& key, |
| const Object& value_if_absent) const { |
| EnsureCapacity(); |
| intptr_t entry = -1; |
| if (!BaseIterTable::FindKeyOrDeletedOrUnused(key, &entry)) { |
| BaseIterTable::InsertKey(entry, key); |
| BaseIterTable::UpdatePayload(entry, 0, value_if_absent); |
| return value_if_absent.raw(); |
| } else { |
| return BaseIterTable::GetPayload(entry, 0); |
| } |
| } |
| // Like InsertOrGetValue, but calls NewKey to allocate a key object if needed. |
| template <typename Key> |
| RawObject* InsertNewOrGetValue(const Key& key, |
| const Object& value_if_absent) const { |
| EnsureCapacity(); |
| intptr_t entry = -1; |
| if (!BaseIterTable::FindKeyOrDeletedOrUnused(key, &entry)) { |
| BaseIterTable::KeyHandle() = |
| BaseIterTable::BaseTable::Traits::NewKey(key); |
| BaseIterTable::InsertKey(entry, BaseIterTable::KeyHandle()); |
| BaseIterTable::UpdatePayload(entry, 0, value_if_absent); |
| return value_if_absent.raw(); |
| } else { |
| return BaseIterTable::GetPayload(entry, 0); |
| } |
| } |
| |
| template <typename Key> |
| bool Remove(const Key& key) const { |
| intptr_t entry = BaseIterTable::FindKey(key); |
| if (entry == -1) { |
| return false; |
| } else { |
| BaseIterTable::DeleteEntry(entry); |
| return true; |
| } |
| } |
| |
| void Clear() const { BaseIterTable::Initialize(); } |
| |
| protected: |
| void EnsureCapacity() const { |
| static const double kMaxLoadFactor = 0.71; |
| HashTables::EnsureLoadFactor(kMaxLoadFactor, *this); |
| } |
| }; |
| |
| template <typename KeyTraits> |
| class UnorderedHashMap : public HashMap<UnorderedHashTable<KeyTraits, 1> > { |
| public: |
| typedef HashMap<UnorderedHashTable<KeyTraits, 1> > BaseMap; |
| explicit UnorderedHashMap(RawArray* data) |
| : BaseMap(Thread::Current()->zone(), data) {} |
| UnorderedHashMap(Zone* zone, RawArray* data) : BaseMap(zone, data) {} |
| UnorderedHashMap(Object* key, Smi* value, Array* data) |
| : BaseMap(key, value, data) {} |
| }; |
| |
| template <typename BaseIterTable> |
| class HashSet : public BaseIterTable { |
| public: |
| explicit HashSet(RawArray* data) |
| : BaseIterTable(Thread::Current()->zone(), data) {} |
| HashSet(Zone* zone, RawArray* data) : BaseIterTable(zone, data) {} |
| HashSet(Object* key, Smi* value, Array* data) |
| : BaseIterTable(key, value, data) {} |
| bool Insert(const Object& key) { |
| EnsureCapacity(); |
| intptr_t entry = -1; |
| bool present = BaseIterTable::FindKeyOrDeletedOrUnused(key, &entry); |
| if (!present) { |
| BaseIterTable::InsertKey(entry, key); |
| } |
| return present; |
| } |
| |
| // If 'key' is not present, insert and return it. Else, return the existing |
| // key in the set (useful for canonicalization). |
| RawObject* InsertOrGet(const Object& key) const { |
| EnsureCapacity(); |
| intptr_t entry = -1; |
| if (!BaseIterTable::FindKeyOrDeletedOrUnused(key, &entry)) { |
| BaseIterTable::InsertKey(entry, key); |
| return key.raw(); |
| } else { |
| return BaseIterTable::GetKey(entry); |
| } |
| } |
| |
| // Like InsertOrGet, but calls NewKey to allocate a key object if needed. |
| template <typename Key> |
| RawObject* InsertNewOrGet(const Key& key) const { |
| EnsureCapacity(); |
| intptr_t entry = -1; |
| if (!BaseIterTable::FindKeyOrDeletedOrUnused(key, &entry)) { |
| BaseIterTable::KeyHandle() = |
| BaseIterTable::BaseTable::Traits::NewKey(key); |
| BaseIterTable::InsertKey(entry, BaseIterTable::KeyHandle()); |
| return BaseIterTable::KeyHandle().raw(); |
| } else { |
| return BaseIterTable::GetKey(entry); |
| } |
| } |
| |
| template <typename Key> |
| RawObject* GetOrNull(const Key& key, bool* present = NULL) const { |
| intptr_t entry = BaseIterTable::FindKey(key); |
| if (present != NULL) { |
| *present = (entry != -1); |
| } |
| return (entry == -1) ? Object::null() : BaseIterTable::GetKey(entry); |
| } |
| |
| template <typename Key> |
| bool Remove(const Key& key) const { |
| intptr_t entry = BaseIterTable::FindKey(key); |
| if (entry == -1) { |
| return false; |
| } else { |
| BaseIterTable::DeleteEntry(entry); |
| return true; |
| } |
| } |
| |
| void Clear() const { BaseIterTable::Initialize(); } |
| |
| protected: |
| void EnsureCapacity() const { |
| static const double kMaxLoadFactor = 0.71; |
| HashTables::EnsureLoadFactor(kMaxLoadFactor, *this); |
| } |
| }; |
| |
| template <typename KeyTraits> |
| class UnorderedHashSet : public HashSet<UnorderedHashTable<KeyTraits, 0> > { |
| public: |
| typedef HashSet<UnorderedHashTable<KeyTraits, 0> > BaseSet; |
| explicit UnorderedHashSet(RawArray* data) |
| : BaseSet(Thread::Current()->zone(), data) { |
| ASSERT(data != Array::null()); |
| } |
| UnorderedHashSet(Zone* zone, RawArray* data) : BaseSet(zone, data) {} |
| UnorderedHashSet(Object* key, Smi* value, Array* data) |
| : BaseSet(key, value, data) {} |
| |
| void Dump() const { |
| Object& entry = Object::Handle(); |
| for (intptr_t i = 0; i < this->data_->Length(); i++) { |
| entry = this->data_->At(i); |
| if (entry.raw() == Object::sentinel().raw() || |
| entry.raw() == Object::transition_sentinel().raw() || entry.IsSmi()) { |
| // empty, deleted, num_used/num_deleted |
| OS::PrintErr("%" Pd ": %s\n", i, entry.ToCString()); |
| } else { |
| intptr_t hash = KeyTraits::Hash(entry); |
| OS::PrintErr("%" Pd ": %" Pd ", %s\n", i, hash, entry.ToCString()); |
| } |
| } |
| } |
| }; |
| |
| } // namespace dart |
| |
| #endif // RUNTIME_VM_HASH_TABLE_H_ |