Index: src/unique.h |
diff --git a/src/unique.h b/src/unique.h |
deleted file mode 100644 |
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-// Copyright 2013 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_UNIQUE_H_ |
-#define V8_UNIQUE_H_ |
- |
-#include <ostream> // NOLINT(readability/streams) |
- |
-#include "src/base/functional.h" |
-#include "src/handles.h" |
-#include "src/utils.h" |
-#include "src/zone.h" |
- |
-namespace v8 { |
-namespace internal { |
- |
- |
-template <typename T> |
-class UniqueSet; |
- |
- |
-// Represents a handle to an object on the heap, but with the additional |
-// ability of checking for equality and hashing without accessing the heap. |
-// |
-// Creating a Unique<T> requires first dereferencing the handle to obtain |
-// the address of the object, which is used as the hashcode and the basis for |
-// comparison. The object can be moved later by the GC, but comparison |
-// and hashing use the old address of the object, without dereferencing it. |
-// |
-// Careful! Comparison of two Uniques is only correct if both were created |
-// in the same "era" of GC or if at least one is a non-movable object. |
-template <typename T> |
-class Unique final { |
- public: |
- Unique<T>() : raw_address_(NULL) {} |
- |
- // TODO(titzer): make private and introduce a uniqueness scope. |
- explicit Unique(Handle<T> handle) { |
- if (handle.is_null()) { |
- raw_address_ = NULL; |
- } else { |
- // This is a best-effort check to prevent comparing Unique<T>'s created |
- // in different GC eras; we require heap allocation to be disallowed at |
- // creation time. |
- // NOTE: we currently consider maps to be non-movable, so no special |
- // assurance is required for creating a Unique<Map>. |
- // TODO(titzer): other immortable immovable objects are also fine. |
- DCHECK(!AllowHeapAllocation::IsAllowed() || handle->IsMap()); |
- raw_address_ = reinterpret_cast<Address>(*handle); |
- DCHECK_NOT_NULL(raw_address_); // Non-null should imply non-zero address. |
- } |
- handle_ = handle; |
- } |
- |
- // Constructor for handling automatic up casting. |
- // Eg. Unique<JSFunction> can be passed when Unique<Object> is expected. |
- template <class S> Unique(Unique<S> uniq) { |
-#ifdef DEBUG |
- T* a = NULL; |
- S* b = NULL; |
- a = b; // Fake assignment to enforce type checks. |
- USE(a); |
-#endif |
- raw_address_ = uniq.raw_address_; |
- handle_ = uniq.handle_; |
- } |
- |
- template <typename U> |
- inline bool operator==(const Unique<U>& other) const { |
- DCHECK(IsInitialized() && other.IsInitialized()); |
- return raw_address_ == other.raw_address_; |
- } |
- |
- template <typename U> |
- inline bool operator!=(const Unique<U>& other) const { |
- DCHECK(IsInitialized() && other.IsInitialized()); |
- return raw_address_ != other.raw_address_; |
- } |
- |
- friend inline size_t hash_value(Unique<T> const& unique) { |
- DCHECK(unique.IsInitialized()); |
- return base::hash<void*>()(unique.raw_address_); |
- } |
- |
- inline intptr_t Hashcode() const { |
- DCHECK(IsInitialized()); |
- return reinterpret_cast<intptr_t>(raw_address_); |
- } |
- |
- inline bool IsNull() const { |
- DCHECK(IsInitialized()); |
- return raw_address_ == NULL; |
- } |
- |
- inline bool IsKnownGlobal(void* global) const { |
- DCHECK(IsInitialized()); |
- return raw_address_ == reinterpret_cast<Address>(global); |
- } |
- |
- inline Handle<T> handle() const { |
- return handle_; |
- } |
- |
- template <class S> static Unique<T> cast(Unique<S> that) { |
- // Allow fetching location() to unsafe-cast the handle. This is necessary |
- // since we can't concurrently safe-cast. Safe-casting requires looking at |
- // the heap which may be moving concurrently to the compiler thread. |
- AllowHandleDereference allow_deref; |
- return Unique<T>(that.raw_address_, |
- Handle<T>(reinterpret_cast<T**>(that.handle_.location()))); |
- } |
- |
- inline bool IsInitialized() const { |
- return raw_address_ != NULL || handle_.is_null(); |
- } |
- |
- // TODO(titzer): this is a hack to migrate to Unique<T> incrementally. |
- static Unique<T> CreateUninitialized(Handle<T> handle) { |
- return Unique<T>(NULL, handle); |
- } |
- |
- static Unique<T> CreateImmovable(Handle<T> handle) { |
- return Unique<T>(reinterpret_cast<Address>(*handle), handle); |
- } |
- |
- private: |
- Unique(Address raw_address, Handle<T> handle) |
- : raw_address_(raw_address), handle_(handle) {} |
- |
- Address raw_address_; |
- Handle<T> handle_; |
- |
- friend class UniqueSet<T>; // Uses internal details for speed. |
- template <class U> |
- friend class Unique; // For comparing raw_address values. |
-}; |
- |
-template <typename T> |
-inline std::ostream& operator<<(std::ostream& os, Unique<T> uniq) { |
- return os << Brief(*uniq.handle()); |
-} |
- |
- |
-template <typename T> |
-class UniqueSet final : public ZoneObject { |
- public: |
- // Constructor. A new set will be empty. |
- UniqueSet() : size_(0), capacity_(0), array_(NULL) { } |
- |
- // Capacity constructor. A new set will be empty. |
- UniqueSet(int capacity, Zone* zone) |
- : size_(0), capacity_(capacity), |
- array_(zone->NewArray<Unique<T> >(capacity)) { |
- DCHECK(capacity <= kMaxCapacity); |
- } |
- |
- // Singleton constructor. |
- UniqueSet(Unique<T> uniq, Zone* zone) |
- : size_(1), capacity_(1), array_(zone->NewArray<Unique<T> >(1)) { |
- array_[0] = uniq; |
- } |
- |
- // Add a new element to this unique set. Mutates this set. O(|this|). |
- void Add(Unique<T> uniq, Zone* zone) { |
- DCHECK(uniq.IsInitialized()); |
- // Keep the set sorted by the {raw_address} of the unique elements. |
- for (int i = 0; i < size_; i++) { |
- if (array_[i] == uniq) return; |
- if (array_[i].raw_address_ > uniq.raw_address_) { |
- // Insert in the middle. |
- Grow(size_ + 1, zone); |
- for (int j = size_ - 1; j >= i; j--) array_[j + 1] = array_[j]; |
- array_[i] = uniq; |
- size_++; |
- return; |
- } |
- } |
- // Append the element to the the end. |
- Grow(size_ + 1, zone); |
- array_[size_++] = uniq; |
- } |
- |
- // Remove an element from this set. Mutates this set. O(|this|) |
- void Remove(Unique<T> uniq) { |
- for (int i = 0; i < size_; i++) { |
- if (array_[i] == uniq) { |
- while (++i < size_) array_[i - 1] = array_[i]; |
- size_--; |
- return; |
- } |
- } |
- } |
- |
- // Compare this set against another set. O(|this|). |
- bool Equals(const UniqueSet<T>* that) const { |
- if (that->size_ != this->size_) return false; |
- for (int i = 0; i < this->size_; i++) { |
- if (this->array_[i] != that->array_[i]) return false; |
- } |
- return true; |
- } |
- |
- // Check whether this set contains the given element. O(|this|) |
- // TODO(titzer): use binary search for large sets to make this O(log|this|) |
- template <typename U> |
- bool Contains(const Unique<U> elem) const { |
- for (int i = 0; i < this->size_; ++i) { |
- Unique<T> cand = this->array_[i]; |
- if (cand.raw_address_ >= elem.raw_address_) { |
- return cand.raw_address_ == elem.raw_address_; |
- } |
- } |
- return false; |
- } |
- |
- // Check if this set is a subset of the given set. O(|this| + |that|). |
- bool IsSubset(const UniqueSet<T>* that) const { |
- if (that->size_ < this->size_) return false; |
- int j = 0; |
- for (int i = 0; i < this->size_; i++) { |
- Unique<T> sought = this->array_[i]; |
- while (true) { |
- if (sought == that->array_[j++]) break; |
- // Fail whenever there are more elements in {this} than {that}. |
- if ((this->size_ - i) > (that->size_ - j)) return false; |
- } |
- } |
- return true; |
- } |
- |
- // Returns a new set representing the intersection of this set and the other. |
- // O(|this| + |that|). |
- UniqueSet<T>* Intersect(const UniqueSet<T>* that, Zone* zone) const { |
- if (that->size_ == 0 || this->size_ == 0) return new(zone) UniqueSet<T>(); |
- |
- UniqueSet<T>* out = new(zone) UniqueSet<T>( |
- Min(this->size_, that->size_), zone); |
- |
- int i = 0, j = 0, k = 0; |
- while (i < this->size_ && j < that->size_) { |
- Unique<T> a = this->array_[i]; |
- Unique<T> b = that->array_[j]; |
- if (a == b) { |
- out->array_[k++] = a; |
- i++; |
- j++; |
- } else if (a.raw_address_ < b.raw_address_) { |
- i++; |
- } else { |
- j++; |
- } |
- } |
- |
- out->size_ = k; |
- return out; |
- } |
- |
- // Returns a new set representing the union of this set and the other. |
- // O(|this| + |that|). |
- UniqueSet<T>* Union(const UniqueSet<T>* that, Zone* zone) const { |
- if (that->size_ == 0) return this->Copy(zone); |
- if (this->size_ == 0) return that->Copy(zone); |
- |
- UniqueSet<T>* out = new(zone) UniqueSet<T>( |
- this->size_ + that->size_, zone); |
- |
- int i = 0, j = 0, k = 0; |
- while (i < this->size_ && j < that->size_) { |
- Unique<T> a = this->array_[i]; |
- Unique<T> b = that->array_[j]; |
- if (a == b) { |
- out->array_[k++] = a; |
- i++; |
- j++; |
- } else if (a.raw_address_ < b.raw_address_) { |
- out->array_[k++] = a; |
- i++; |
- } else { |
- out->array_[k++] = b; |
- j++; |
- } |
- } |
- |
- while (i < this->size_) out->array_[k++] = this->array_[i++]; |
- while (j < that->size_) out->array_[k++] = that->array_[j++]; |
- |
- out->size_ = k; |
- return out; |
- } |
- |
- // Returns a new set representing all elements from this set which are not in |
- // that set. O(|this| * |that|). |
- UniqueSet<T>* Subtract(const UniqueSet<T>* that, Zone* zone) const { |
- if (that->size_ == 0) return this->Copy(zone); |
- |
- UniqueSet<T>* out = new(zone) UniqueSet<T>(this->size_, zone); |
- |
- int i = 0, j = 0; |
- while (i < this->size_) { |
- Unique<T> cand = this->array_[i]; |
- if (!that->Contains(cand)) { |
- out->array_[j++] = cand; |
- } |
- i++; |
- } |
- |
- out->size_ = j; |
- return out; |
- } |
- |
- // Makes an exact copy of this set. O(|this|). |
- UniqueSet<T>* Copy(Zone* zone) const { |
- UniqueSet<T>* copy = new(zone) UniqueSet<T>(this->size_, zone); |
- copy->size_ = this->size_; |
- memcpy(copy->array_, this->array_, this->size_ * sizeof(Unique<T>)); |
- return copy; |
- } |
- |
- void Clear() { |
- size_ = 0; |
- } |
- |
- inline int size() const { |
- return size_; |
- } |
- |
- inline Unique<T> at(int index) const { |
- DCHECK(index >= 0 && index < size_); |
- return array_[index]; |
- } |
- |
- private: |
- // These sets should be small, since operations are implemented with simple |
- // linear algorithms. Enforce a maximum size. |
- static const int kMaxCapacity = 65535; |
- |
- uint16_t size_; |
- uint16_t capacity_; |
- Unique<T>* array_; |
- |
- // Grow the size of internal storage to be at least {size} elements. |
- void Grow(int size, Zone* zone) { |
- CHECK(size < kMaxCapacity); // Enforce maximum size. |
- if (capacity_ < size) { |
- int new_capacity = 2 * capacity_ + size; |
- if (new_capacity > kMaxCapacity) new_capacity = kMaxCapacity; |
- Unique<T>* new_array = zone->NewArray<Unique<T> >(new_capacity); |
- if (size_ > 0) { |
- memcpy(new_array, array_, size_ * sizeof(Unique<T>)); |
- } |
- capacity_ = new_capacity; |
- array_ = new_array; |
- } |
- } |
-}; |
- |
-} // namespace internal |
-} // namespace v8 |
- |
-#endif // V8_UNIQUE_H_ |