mirror of https://github.com/nodejs/node.git
131 lines
3.5 KiB
C++
131 lines
3.5 KiB
C++
// Copyright Joyent, Inc. and other Node contributors.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a
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// copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to permit
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// persons to whom the Software is furnished to do so, subject to the
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// following conditions:
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//
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// The above copyright notice and this permission notice shall be included
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// in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
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// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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// USE OR OTHER DEALINGS IN THE SOFTWARE.
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#include "v8.h"
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#include "node.h"
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#include "node_buffer.h"
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#include "slab_allocator.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <assert.h>
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using v8::Handle;
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using v8::HandleScope;
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using v8::Integer;
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using v8::Local;
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using v8::Null;
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using v8::Object;
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using v8::Persistent;
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using v8::String;
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using v8::Value;
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using v8::V8;
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namespace node {
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SlabAllocator::SlabAllocator(unsigned int size) {
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size_ = ROUND_UP(size ? size : 1, 8192);
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initialized_ = false;
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}
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SlabAllocator::~SlabAllocator() {
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if (!initialized_) return;
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if (V8::IsDead()) return;
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slab_sym_.Dispose();
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slab_sym_.Clear();
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slab_.Dispose();
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slab_.Clear();
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}
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void SlabAllocator::Initialize() {
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HandleScope scope;
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char sym[256];
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snprintf(sym, sizeof(sym), "slab_%p", this); // namespace object key
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offset_ = 0;
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last_ptr_ = NULL;
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initialized_ = true;
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slab_sym_ = Persistent<String>::New(String::New(sym));
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}
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static Local<Object> NewSlab(unsigned int size) {
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HandleScope scope;
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Local<Value> arg = Integer::NewFromUnsigned(ROUND_UP(size, 16));
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Local<Object> buf = Buffer::constructor_template
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->GetFunction()
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->NewInstance(1, &arg);
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return scope.Close(buf);
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}
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char* SlabAllocator::Allocate(Handle<Object> obj, unsigned int size) {
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HandleScope scope;
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assert(!obj.IsEmpty());
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if (size == 0) return NULL;
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if (!initialized_) Initialize();
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if (size > size_) {
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Local<Object> buf = NewSlab(size);
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obj->SetHiddenValue(slab_sym_, buf);
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return Buffer::Data(buf);
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}
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if (slab_.IsEmpty() || offset_ + size > size_) {
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slab_.Dispose();
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slab_.Clear();
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slab_ = Persistent<Object>::New(NewSlab(size_));
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offset_ = 0;
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last_ptr_ = NULL;
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}
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obj->SetHiddenValue(slab_sym_, slab_);
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last_ptr_ = Buffer::Data(slab_) + offset_;
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offset_ += size;
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return last_ptr_;
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}
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Local<Object> SlabAllocator::Shrink(Handle<Object> obj,
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char* ptr,
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unsigned int size) {
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HandleScope scope;
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Local<Value> slab_v = obj->GetHiddenValue(slab_sym_);
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obj->SetHiddenValue(slab_sym_, Null());
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assert(!slab_v.IsEmpty());
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assert(slab_v->IsObject());
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Local<Object> slab = slab_v->ToObject();
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assert(ptr != NULL);
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if (ptr == last_ptr_) {
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last_ptr_ = NULL;
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offset_ = ptr - Buffer::Data(slab) + ROUND_UP(size, 16);
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}
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return scope.Close(slab);
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}
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} // namespace node
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