Upgrade V8 to 5.1.281.57 DO NOT MERGE
FPIIM-449
Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/src/collector.h b/src/collector.h
new file mode 100644
index 0000000..8454aae
--- /dev/null
+++ b/src/collector.h
@@ -0,0 +1,247 @@
+// Copyright 2016 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_COLLECTOR_H_
+#define V8_COLLECTOR_H_
+
+#include "src/checks.h"
+#include "src/list.h"
+#include "src/vector.h"
+
+namespace v8 {
+namespace internal {
+
+/*
+ * A class that collects values into a backing store.
+ * Specialized versions of the class can allow access to the backing store
+ * in different ways.
+ * There is no guarantee that the backing store is contiguous (and, as a
+ * consequence, no guarantees that consecutively added elements are adjacent
+ * in memory). The collector may move elements unless it has guaranteed not
+ * to.
+ */
+template <typename T, int growth_factor = 2, int max_growth = 1 * MB>
+class Collector {
+ public:
+ explicit Collector(int initial_capacity = kMinCapacity)
+ : index_(0), size_(0) {
+ current_chunk_ = Vector<T>::New(initial_capacity);
+ }
+
+ virtual ~Collector() {
+ // Free backing store (in reverse allocation order).
+ current_chunk_.Dispose();
+ for (int i = chunks_.length() - 1; i >= 0; i--) {
+ chunks_.at(i).Dispose();
+ }
+ }
+
+ // Add a single element.
+ inline void Add(T value) {
+ if (index_ >= current_chunk_.length()) {
+ Grow(1);
+ }
+ current_chunk_[index_] = value;
+ index_++;
+ size_++;
+ }
+
+ // Add a block of contiguous elements and return a Vector backed by the
+ // memory area.
+ // A basic Collector will keep this vector valid as long as the Collector
+ // is alive.
+ inline Vector<T> AddBlock(int size, T initial_value) {
+ DCHECK(size > 0);
+ if (size > current_chunk_.length() - index_) {
+ Grow(size);
+ }
+ T* position = current_chunk_.start() + index_;
+ index_ += size;
+ size_ += size;
+ for (int i = 0; i < size; i++) {
+ position[i] = initial_value;
+ }
+ return Vector<T>(position, size);
+ }
+
+ // Add a contiguous block of elements and return a vector backed
+ // by the added block.
+ // A basic Collector will keep this vector valid as long as the Collector
+ // is alive.
+ inline Vector<T> AddBlock(Vector<const T> source) {
+ if (source.length() > current_chunk_.length() - index_) {
+ Grow(source.length());
+ }
+ T* position = current_chunk_.start() + index_;
+ index_ += source.length();
+ size_ += source.length();
+ for (int i = 0; i < source.length(); i++) {
+ position[i] = source[i];
+ }
+ return Vector<T>(position, source.length());
+ }
+
+ // Write the contents of the collector into the provided vector.
+ void WriteTo(Vector<T> destination) {
+ DCHECK(size_ <= destination.length());
+ int position = 0;
+ for (int i = 0; i < chunks_.length(); i++) {
+ Vector<T> chunk = chunks_.at(i);
+ for (int j = 0; j < chunk.length(); j++) {
+ destination[position] = chunk[j];
+ position++;
+ }
+ }
+ for (int i = 0; i < index_; i++) {
+ destination[position] = current_chunk_[i];
+ position++;
+ }
+ }
+
+ // Allocate a single contiguous vector, copy all the collected
+ // elements to the vector, and return it.
+ // The caller is responsible for freeing the memory of the returned
+ // vector (e.g., using Vector::Dispose).
+ Vector<T> ToVector() {
+ Vector<T> new_store = Vector<T>::New(size_);
+ WriteTo(new_store);
+ return new_store;
+ }
+
+ // Resets the collector to be empty.
+ virtual void Reset() {
+ for (int i = chunks_.length() - 1; i >= 0; i--) {
+ chunks_.at(i).Dispose();
+ }
+ chunks_.Rewind(0);
+ index_ = 0;
+ size_ = 0;
+ }
+
+ // Total number of elements added to collector so far.
+ inline int size() { return size_; }
+
+ protected:
+ static const int kMinCapacity = 16;
+ List<Vector<T> > chunks_;
+ Vector<T> current_chunk_; // Block of memory currently being written into.
+ int index_; // Current index in current chunk.
+ int size_; // Total number of elements in collector.
+
+ // Creates a new current chunk, and stores the old chunk in the chunks_ list.
+ void Grow(int min_capacity) {
+ DCHECK(growth_factor > 1);
+ int new_capacity;
+ int current_length = current_chunk_.length();
+ if (current_length < kMinCapacity) {
+ // The collector started out as empty.
+ new_capacity = min_capacity * growth_factor;
+ if (new_capacity < kMinCapacity) new_capacity = kMinCapacity;
+ } else {
+ int growth = current_length * (growth_factor - 1);
+ if (growth > max_growth) {
+ growth = max_growth;
+ }
+ new_capacity = current_length + growth;
+ if (new_capacity < min_capacity) {
+ new_capacity = min_capacity + growth;
+ }
+ }
+ NewChunk(new_capacity);
+ DCHECK(index_ + min_capacity <= current_chunk_.length());
+ }
+
+ // Before replacing the current chunk, give a subclass the option to move
+ // some of the current data into the new chunk. The function may update
+ // the current index_ value to represent data no longer in the current chunk.
+ // Returns the initial index of the new chunk (after copied data).
+ virtual void NewChunk(int new_capacity) {
+ Vector<T> new_chunk = Vector<T>::New(new_capacity);
+ if (index_ > 0) {
+ chunks_.Add(current_chunk_.SubVector(0, index_));
+ } else {
+ current_chunk_.Dispose();
+ }
+ current_chunk_ = new_chunk;
+ index_ = 0;
+ }
+};
+
+/*
+ * A collector that allows sequences of values to be guaranteed to
+ * stay consecutive.
+ * If the backing store grows while a sequence is active, the current
+ * sequence might be moved, but after the sequence is ended, it will
+ * not move again.
+ * NOTICE: Blocks allocated using Collector::AddBlock(int) can move
+ * as well, if inside an active sequence where another element is added.
+ */
+template <typename T, int growth_factor = 2, int max_growth = 1 * MB>
+class SequenceCollector : public Collector<T, growth_factor, max_growth> {
+ public:
+ explicit SequenceCollector(int initial_capacity)
+ : Collector<T, growth_factor, max_growth>(initial_capacity),
+ sequence_start_(kNoSequence) {}
+
+ virtual ~SequenceCollector() {}
+
+ void StartSequence() {
+ DCHECK(sequence_start_ == kNoSequence);
+ sequence_start_ = this->index_;
+ }
+
+ Vector<T> EndSequence() {
+ DCHECK(sequence_start_ != kNoSequence);
+ int sequence_start = sequence_start_;
+ sequence_start_ = kNoSequence;
+ if (sequence_start == this->index_) return Vector<T>();
+ return this->current_chunk_.SubVector(sequence_start, this->index_);
+ }
+
+ // Drops the currently added sequence, and all collected elements in it.
+ void DropSequence() {
+ DCHECK(sequence_start_ != kNoSequence);
+ int sequence_length = this->index_ - sequence_start_;
+ this->index_ = sequence_start_;
+ this->size_ -= sequence_length;
+ sequence_start_ = kNoSequence;
+ }
+
+ virtual void Reset() {
+ sequence_start_ = kNoSequence;
+ this->Collector<T, growth_factor, max_growth>::Reset();
+ }
+
+ private:
+ static const int kNoSequence = -1;
+ int sequence_start_;
+
+ // Move the currently active sequence to the new chunk.
+ virtual void NewChunk(int new_capacity) {
+ if (sequence_start_ == kNoSequence) {
+ // Fall back on default behavior if no sequence has been started.
+ this->Collector<T, growth_factor, max_growth>::NewChunk(new_capacity);
+ return;
+ }
+ int sequence_length = this->index_ - sequence_start_;
+ Vector<T> new_chunk = Vector<T>::New(sequence_length + new_capacity);
+ DCHECK(sequence_length < new_chunk.length());
+ for (int i = 0; i < sequence_length; i++) {
+ new_chunk[i] = this->current_chunk_[sequence_start_ + i];
+ }
+ if (sequence_start_ > 0) {
+ this->chunks_.Add(this->current_chunk_.SubVector(0, sequence_start_));
+ } else {
+ this->current_chunk_.Dispose();
+ }
+ this->current_chunk_ = new_chunk;
+ this->index_ = sequence_length;
+ sequence_start_ = 0;
+ }
+};
+
+} // namespace internal
+} // namespace v8
+
+#endif // V8_COLLECTOR_H_