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gfx/skia/trunk/src/core/SkChunkAlloc.cpp@6474c204b198 (annotated)

gfx/skia/trunk/src/core/SkChunkAlloc.cpp

Wed, 31 Dec 2014 06:09:35 +0100

author

Michael Schloh von Bennewitz <michael@schloh.com>

date

Wed, 31 Dec 2014 06:09:35 +0100

changeset 0

6474c204b198

permissions

-rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

michael@0	1	/*
michael@0	2	* Copyright 2006 The Android Open Source Project
michael@0	3	*
michael@0	4	* Use of this source code is governed by a BSD-style license that can be
michael@0	5	* found in the LICENSE file.
michael@0	6	*/
michael@0	7
michael@0	8	#include "SkChunkAlloc.h"
michael@0	9
michael@0	10	// Don't malloc any chunks smaller than this
michael@0	11	#define MIN_CHUNKALLOC_BLOCK_SIZE 1024
michael@0	12
michael@0	13	// Return the new min blocksize given the current value
michael@0	14	static size_t increase_next_size(size_t size) {
michael@0	15	return size + (size >> 1);
michael@0	16	}
michael@0	17
michael@0	18	///////////////////////////////////////////////////////////////////////////////
michael@0	19
michael@0	20	struct SkChunkAlloc::Block {
michael@0	21	Block* fNext;
michael@0	22	size_t fFreeSize;
michael@0	23	char* fFreePtr;
michael@0	24	// data[] follows
michael@0	25
michael@0	26	char* startOfData() {
michael@0	27	return reinterpret_cast<char*>(this + 1);
michael@0	28	}
michael@0	29
michael@0	30	static void FreeChain(Block* block) {
michael@0	31	while (block) {
michael@0	32	Block* next = block->fNext;
michael@0	33	sk_free(block);
michael@0	34	block = next;
michael@0	35	}
michael@0	36	};
michael@0	37
michael@0	38	bool contains(const void* addr) const {
michael@0	39	const char* ptr = reinterpret_cast<const char*>(addr);
michael@0	40	return ptr >= (const char*)(this + 1) && ptr < fFreePtr;
michael@0	41	}
michael@0	42	};
michael@0	43
michael@0	44	///////////////////////////////////////////////////////////////////////////////
michael@0	45
michael@0	46	SkChunkAlloc::SkChunkAlloc(size_t minSize) {
michael@0	47	if (minSize < MIN_CHUNKALLOC_BLOCK_SIZE) {
michael@0	48	minSize = MIN_CHUNKALLOC_BLOCK_SIZE;
michael@0	49	}
michael@0	50
michael@0	51	fBlock = NULL;
michael@0	52	fMinSize = minSize;
michael@0	53	fChunkSize = fMinSize;
michael@0	54	fTotalCapacity = 0;
michael@0	55	fTotalUsed = 0;
michael@0	56	fBlockCount = 0;
michael@0	57	}
michael@0	58
michael@0	59	SkChunkAlloc::~SkChunkAlloc() {
michael@0	60	this->reset();
michael@0	61	}
michael@0	62
michael@0	63	void SkChunkAlloc::reset() {
michael@0	64	Block::FreeChain(fBlock);
michael@0	65	fBlock = NULL;
michael@0	66	fChunkSize = fMinSize; // reset to our initial minSize
michael@0	67	fTotalCapacity = 0;
michael@0	68	fTotalUsed = 0;
michael@0	69	fBlockCount = 0;
michael@0	70	}
michael@0	71
michael@0	72	SkChunkAlloc::Block* SkChunkAlloc::newBlock(size_t bytes, AllocFailType ftype) {
michael@0	73	size_t size = bytes;
michael@0	74	if (size < fChunkSize) {
michael@0	75	size = fChunkSize;
michael@0	76	}
michael@0	77
michael@0	78	Block* block = (Block*)sk_malloc_flags(sizeof(Block) + size,
michael@0	79	ftype == kThrow_AllocFailType ? SK_MALLOC_THROW : 0);
michael@0	80
michael@0	81	if (block) {
michael@0	82	// block->fNext = fBlock;
michael@0	83	block->fFreeSize = size;
michael@0	84	block->fFreePtr = block->startOfData();
michael@0	85
michael@0	86	fTotalCapacity += size;
michael@0	87	fBlockCount += 1;
michael@0	88
michael@0	89	fChunkSize = increase_next_size(fChunkSize);
michael@0	90	}
michael@0	91	return block;
michael@0	92	}
michael@0	93
michael@0	94	void* SkChunkAlloc::alloc(size_t bytes, AllocFailType ftype) {
michael@0	95	fTotalUsed += bytes;
michael@0	96
michael@0	97	bytes = SkAlign4(bytes);
michael@0	98
michael@0	99	Block* block = fBlock;
michael@0	100
michael@0	101	if (block == NULL || bytes > block->fFreeSize) {
michael@0	102	block = this->newBlock(bytes, ftype);
michael@0	103	if (NULL == block) {
michael@0	104	return NULL;
michael@0	105	}
michael@0	106	block->fNext = fBlock;
michael@0	107	fBlock = block;
michael@0	108	}
michael@0	109
michael@0	110	SkASSERT(block && bytes <= block->fFreeSize);
michael@0	111	char* ptr = block->fFreePtr;
michael@0	112
michael@0	113	block->fFreeSize -= bytes;
michael@0	114	block->fFreePtr = ptr + bytes;
michael@0	115	return ptr;
michael@0	116	}
michael@0	117
michael@0	118	size_t SkChunkAlloc::unalloc(void* ptr) {
michael@0	119	size_t bytes = 0;
michael@0	120	Block* block = fBlock;
michael@0	121	if (block) {
michael@0	122	char* cPtr = reinterpret_cast<char*>(ptr);
michael@0	123	char* start = block->startOfData();
michael@0	124	if (start <= cPtr && cPtr < block->fFreePtr) {
michael@0	125	bytes = block->fFreePtr - cPtr;
michael@0	126	block->fFreeSize += bytes;
michael@0	127	block->fFreePtr = cPtr;
michael@0	128	}
michael@0	129	}
michael@0	130	return bytes;
michael@0	131	}
michael@0	132
michael@0	133	bool SkChunkAlloc::contains(const void* addr) const {
michael@0	134	const Block* block = fBlock;
michael@0	135	while (block) {
michael@0	136	if (block->contains(addr)) {
michael@0	137	return true;
michael@0	138	}
michael@0	139	block = block->fNext;
michael@0	140	}
michael@0	141	return false;
michael@0	142	}