Index: src/hashmap.h |
diff --git a/src/hashmap.h b/src/hashmap.h |
deleted file mode 100644 |
index f94def7c3c7a04cb4c0e534074c4f94b092a0f81..0000000000000000000000000000000000000000 |
--- a/src/hashmap.h |
+++ /dev/null |
@@ -1,356 +0,0 @@ |
-// Copyright 2012 the V8 project authors. All rights reserved. |
-// Use of this source code is governed by a BSD-style license that can be |
-// found in the LICENSE file. |
- |
-#ifndef V8_HASHMAP_H_ |
-#define V8_HASHMAP_H_ |
- |
-#include "src/allocation.h" |
-#include "src/base/bits.h" |
-#include "src/base/logging.h" |
-#include "src/utils.h" |
- |
-namespace v8 { |
-namespace internal { |
- |
-template<class AllocationPolicy> |
-class TemplateHashMapImpl { |
- public: |
- typedef bool (*MatchFun) (void* key1, void* key2); |
- |
- // The default capacity. This is used by the call sites which want |
- // to pass in a non-default AllocationPolicy but want to use the |
- // default value of capacity specified by the implementation. |
- static const uint32_t kDefaultHashMapCapacity = 8; |
- |
- // initial_capacity is the size of the initial hash map; |
- // it must be a power of 2 (and thus must not be 0). |
- TemplateHashMapImpl(MatchFun match, |
- uint32_t capacity = kDefaultHashMapCapacity, |
- AllocationPolicy allocator = AllocationPolicy()); |
- |
- ~TemplateHashMapImpl(); |
- |
- // HashMap entries are (key, value, hash) triplets. |
- // Some clients may not need to use the value slot |
- // (e.g. implementers of sets, where the key is the value). |
- struct Entry { |
- void* key; |
- void* value; |
- uint32_t hash; // The full hash value for key |
- int order; // If you never remove entries this is the insertion order. |
- }; |
- |
- // If an entry with matching key is found, returns that entry. |
- // Otherwise, NULL is returned. |
- Entry* Lookup(void* key, uint32_t hash) const; |
- |
- // If an entry with matching key is found, returns that entry. |
- // If no matching entry is found, a new entry is inserted with |
- // corresponding key, key hash, and NULL value. |
- Entry* LookupOrInsert(void* key, uint32_t hash, |
- AllocationPolicy allocator = AllocationPolicy()); |
- |
- // Removes the entry with matching key. |
- // It returns the value of the deleted entry |
- // or null if there is no value for such key. |
- void* Remove(void* key, uint32_t hash); |
- |
- // Empties the hash map (occupancy() == 0). |
- void Clear(); |
- |
- // The number of (non-empty) entries in the table. |
- uint32_t occupancy() const { return occupancy_; } |
- |
- // The capacity of the table. The implementation |
- // makes sure that occupancy is at most 80% of |
- // the table capacity. |
- uint32_t capacity() const { return capacity_; } |
- |
- // Iteration |
- // |
- // for (Entry* p = map.Start(); p != NULL; p = map.Next(p)) { |
- // ... |
- // } |
- // |
- // If entries are inserted during iteration, the effect of |
- // calling Next() is undefined. |
- Entry* Start() const; |
- Entry* Next(Entry* p) const; |
- |
- // Some match functions defined for convenience. |
- static bool PointersMatch(void* key1, void* key2) { |
- return key1 == key2; |
- } |
- |
- private: |
- MatchFun match_; |
- Entry* map_; |
- uint32_t capacity_; |
- uint32_t occupancy_; |
- |
- Entry* map_end() const { return map_ + capacity_; } |
- Entry* Probe(void* key, uint32_t hash) const; |
- void Initialize(uint32_t capacity, AllocationPolicy allocator); |
- void Resize(AllocationPolicy allocator); |
-}; |
- |
-typedef TemplateHashMapImpl<FreeStoreAllocationPolicy> HashMap; |
- |
-template<class AllocationPolicy> |
-TemplateHashMapImpl<AllocationPolicy>::TemplateHashMapImpl( |
- MatchFun match, uint32_t initial_capacity, AllocationPolicy allocator) { |
- match_ = match; |
- Initialize(initial_capacity, allocator); |
-} |
- |
- |
-template<class AllocationPolicy> |
-TemplateHashMapImpl<AllocationPolicy>::~TemplateHashMapImpl() { |
- AllocationPolicy::Delete(map_); |
-} |
- |
- |
-template <class AllocationPolicy> |
-typename TemplateHashMapImpl<AllocationPolicy>::Entry* |
-TemplateHashMapImpl<AllocationPolicy>::Lookup(void* key, uint32_t hash) const { |
- Entry* p = Probe(key, hash); |
- return p->key != NULL ? p : NULL; |
-} |
- |
- |
-template <class AllocationPolicy> |
-typename TemplateHashMapImpl<AllocationPolicy>::Entry* |
-TemplateHashMapImpl<AllocationPolicy>::LookupOrInsert( |
- void* key, uint32_t hash, AllocationPolicy allocator) { |
- // Find a matching entry. |
- Entry* p = Probe(key, hash); |
- if (p->key != NULL) { |
- return p; |
- } |
- |
- // No entry found; insert one. |
- p->key = key; |
- p->value = NULL; |
- p->hash = hash; |
- p->order = occupancy_; |
- occupancy_++; |
- |
- // Grow the map if we reached >= 80% occupancy. |
- if (occupancy_ + occupancy_ / 4 >= capacity_) { |
- Resize(allocator); |
- p = Probe(key, hash); |
- } |
- |
- return p; |
-} |
- |
- |
-template<class AllocationPolicy> |
-void* TemplateHashMapImpl<AllocationPolicy>::Remove(void* key, uint32_t hash) { |
- // Lookup the entry for the key to remove. |
- Entry* p = Probe(key, hash); |
- if (p->key == NULL) { |
- // Key not found nothing to remove. |
- return NULL; |
- } |
- |
- void* value = p->value; |
- // To remove an entry we need to ensure that it does not create an empty |
- // entry that will cause the search for another entry to stop too soon. If all |
- // the entries between the entry to remove and the next empty slot have their |
- // initial position inside this interval, clearing the entry to remove will |
- // not break the search. If, while searching for the next empty entry, an |
- // entry is encountered which does not have its initial position between the |
- // entry to remove and the position looked at, then this entry can be moved to |
- // the place of the entry to remove without breaking the search for it. The |
- // entry made vacant by this move is now the entry to remove and the process |
- // starts over. |
- // Algorithm from http://en.wikipedia.org/wiki/Open_addressing. |
- |
- // This guarantees loop termination as there is at least one empty entry so |
- // eventually the removed entry will have an empty entry after it. |
- DCHECK(occupancy_ < capacity_); |
- |
- // p is the candidate entry to clear. q is used to scan forwards. |
- Entry* q = p; // Start at the entry to remove. |
- while (true) { |
- // Move q to the next entry. |
- q = q + 1; |
- if (q == map_end()) { |
- q = map_; |
- } |
- |
- // All entries between p and q have their initial position between p and q |
- // and the entry p can be cleared without breaking the search for these |
- // entries. |
- if (q->key == NULL) { |
- break; |
- } |
- |
- // Find the initial position for the entry at position q. |
- Entry* r = map_ + (q->hash & (capacity_ - 1)); |
- |
- // If the entry at position q has its initial position outside the range |
- // between p and q it can be moved forward to position p and will still be |
- // found. There is now a new candidate entry for clearing. |
- if ((q > p && (r <= p || r > q)) || |
- (q < p && (r <= p && r > q))) { |
- *p = *q; |
- p = q; |
- } |
- } |
- |
- // Clear the entry which is allowed to en emptied. |
- p->key = NULL; |
- occupancy_--; |
- return value; |
-} |
- |
- |
-template<class AllocationPolicy> |
-void TemplateHashMapImpl<AllocationPolicy>::Clear() { |
- // Mark all entries as empty. |
- const Entry* end = map_end(); |
- for (Entry* p = map_; p < end; p++) { |
- p->key = NULL; |
- } |
- occupancy_ = 0; |
-} |
- |
- |
-template<class AllocationPolicy> |
-typename TemplateHashMapImpl<AllocationPolicy>::Entry* |
- TemplateHashMapImpl<AllocationPolicy>::Start() const { |
- return Next(map_ - 1); |
-} |
- |
- |
-template<class AllocationPolicy> |
-typename TemplateHashMapImpl<AllocationPolicy>::Entry* |
- TemplateHashMapImpl<AllocationPolicy>::Next(Entry* p) const { |
- const Entry* end = map_end(); |
- DCHECK(map_ - 1 <= p && p < end); |
- for (p++; p < end; p++) { |
- if (p->key != NULL) { |
- return p; |
- } |
- } |
- return NULL; |
-} |
- |
- |
-template <class AllocationPolicy> |
-typename TemplateHashMapImpl<AllocationPolicy>::Entry* |
-TemplateHashMapImpl<AllocationPolicy>::Probe(void* key, uint32_t hash) const { |
- DCHECK(key != NULL); |
- |
- DCHECK(base::bits::IsPowerOfTwo32(capacity_)); |
- Entry* p = map_ + (hash & (capacity_ - 1)); |
- const Entry* end = map_end(); |
- DCHECK(map_ <= p && p < end); |
- |
- DCHECK(occupancy_ < capacity_); // Guarantees loop termination. |
- while (p->key != NULL && (hash != p->hash || !match_(key, p->key))) { |
- p++; |
- if (p >= end) { |
- p = map_; |
- } |
- } |
- |
- return p; |
-} |
- |
- |
-template<class AllocationPolicy> |
-void TemplateHashMapImpl<AllocationPolicy>::Initialize( |
- uint32_t capacity, AllocationPolicy allocator) { |
- DCHECK(base::bits::IsPowerOfTwo32(capacity)); |
- map_ = reinterpret_cast<Entry*>(allocator.New(capacity * sizeof(Entry))); |
- if (map_ == NULL) { |
- v8::internal::FatalProcessOutOfMemory("HashMap::Initialize"); |
- return; |
- } |
- capacity_ = capacity; |
- Clear(); |
-} |
- |
- |
-template<class AllocationPolicy> |
-void TemplateHashMapImpl<AllocationPolicy>::Resize(AllocationPolicy allocator) { |
- Entry* map = map_; |
- uint32_t n = occupancy_; |
- |
- // Allocate larger map. |
- Initialize(capacity_ * 2, allocator); |
- |
- // Rehash all current entries. |
- for (Entry* p = map; n > 0; p++) { |
- if (p->key != NULL) { |
- Entry* entry = LookupOrInsert(p->key, p->hash, allocator); |
- entry->value = p->value; |
- entry->order = p->order; |
- n--; |
- } |
- } |
- |
- // Delete old map. |
- AllocationPolicy::Delete(map); |
-} |
- |
- |
-// A hash map for pointer keys and values with an STL-like interface. |
-template<class Key, class Value, class AllocationPolicy> |
-class TemplateHashMap: private TemplateHashMapImpl<AllocationPolicy> { |
- public: |
- STATIC_ASSERT(sizeof(Key*) == sizeof(void*)); // NOLINT |
- STATIC_ASSERT(sizeof(Value*) == sizeof(void*)); // NOLINT |
- struct value_type { |
- Key* first; |
- Value* second; |
- }; |
- |
- class Iterator { |
- public: |
- Iterator& operator++() { |
- entry_ = map_->Next(entry_); |
- return *this; |
- } |
- |
- value_type* operator->() { return reinterpret_cast<value_type*>(entry_); } |
- bool operator!=(const Iterator& other) { return entry_ != other.entry_; } |
- |
- private: |
- Iterator(const TemplateHashMapImpl<AllocationPolicy>* map, |
- typename TemplateHashMapImpl<AllocationPolicy>::Entry* entry) : |
- map_(map), entry_(entry) { } |
- |
- const TemplateHashMapImpl<AllocationPolicy>* map_; |
- typename TemplateHashMapImpl<AllocationPolicy>::Entry* entry_; |
- |
- friend class TemplateHashMap; |
- }; |
- |
- TemplateHashMap( |
- typename TemplateHashMapImpl<AllocationPolicy>::MatchFun match, |
- AllocationPolicy allocator = AllocationPolicy()) |
- : TemplateHashMapImpl<AllocationPolicy>( |
- match, |
- TemplateHashMapImpl<AllocationPolicy>::kDefaultHashMapCapacity, |
- allocator) { } |
- |
- Iterator begin() const { return Iterator(this, this->Start()); } |
- Iterator end() const { return Iterator(this, NULL); } |
- Iterator find(Key* key, bool insert = false, |
- AllocationPolicy allocator = AllocationPolicy()) { |
- if (insert) { |
- return Iterator(this, this->LookupOrInsert(key, key->Hash(), allocator)); |
- } |
- return Iterator(this, this->Lookup(key, key->Hash())); |
- } |
-}; |
- |
-} // namespace internal |
-} // namespace v8 |
- |
-#endif // V8_HASHMAP_H_ |