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make the token page size be variable instead of fixed 8192

Browse Source 
also changed the token-page layout a little bit to remove
a not-needed field.

This reduces the number of malloc()/free() calls substantially
with minimal increase in memory consumption (~2%).
For the tail of large sources, the number of malloc calls goes
typically from ~10000 to ~100 (e.g.: bryce_big.jpg: 22711 -> 105)

Change-Id: Ib847f41e618ed8c303d26b76da982fbc48de45b9
This commit is contained in:
skal
2014-05-05 14:26:14 -07:00
parent f948d08c81
commit 5fe628d35d
3 changed files with 38 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
src/enc/token.c
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@ -27,23 +27,27 @@
#if !defined(DISABLE_TOKEN_BUFFER)
// we use pages to reduce the number of memcpy()
#define MAX_NUM_TOKEN 8192 // max number of token per page
#define MIN_PAGE_SIZE 8192 // minimum number of token per page
#define FIXED_PROBA_BIT (1u << 14)
typedef uint16_t token_t; // bit#15: bit
// bit #14: constant proba or idx
// bits 0..13: slot or constant proba
struct VP8Tokens {
uint16_t tokens_[MAX_NUM_TOKEN]; // bit#15: bit
// bit #14: constant proba or idx
// bits 0..13: slot or constant proba
VP8Tokens* next_;
VP8Tokens* next_; // pointer to next page
};
// Token data is located in memory just after the next_ field.
// This macro is used to return their address and hide the trick.
#define TOKEN_DATA(p) ((token_t*)&(p)[1])
//------------------------------------------------------------------------------
void VP8TBufferInit(VP8TBuffer* const b) {
void VP8TBufferInit(VP8TBuffer* const b, int page_size) {
b->tokens_ = NULL;
b->pages_ = NULL;
b->last_page_ = &b->pages_;
b->left_ = 0;
b->page_size_ = (page_size < MIN_PAGE_SIZE) ? MIN_PAGE_SIZE : page_size;
b->error_ = 0;
}
@ -55,22 +59,26 @@ void VP8TBufferClear(VP8TBuffer* const b) {
WebPSafeFree((void*)p);
p = next;
}
VP8TBufferInit(b);
VP8TBufferInit(b, b->page_size_);
}
}
static int TBufferNewPage(VP8TBuffer* const b) {
VP8Tokens* const page =
b->error_ ? NULL : (VP8Tokens*)WebPSafeMalloc(1ULL, sizeof(*page));
VP8Tokens* page = NULL;
const size_t size = sizeof(*page) + b->page_size_ * sizeof(token_t);
if (!b->error_) {
page = (VP8Tokens*)WebPSafeMalloc(1ULL, size);
}
if (page == NULL) {
b->error_ = 1;
return 0;
}
page->next_ = NULL;
*b->last_page_ = page;
b->last_page_ = &page->next_;
b->left_ = MAX_NUM_TOKEN;
b->tokens_ = page->tokens_;
page->next_ = NULL;
b->left_ = b->page_size_;
b->tokens_ = TOKEN_DATA(page);
return 1;
}
@ -197,8 +205,9 @@ void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats) {
while (p != NULL) {
const int N = (p->next_ == NULL) ? b->left_ : 0;
int n = MAX_NUM_TOKEN;
const token_t* const tokens = TOKEN_DATA(p);
while (n-- > N) {
const uint16_t token = p->tokens_[n];
const token_t token = tokens[n];
if (!(token & FIXED_PROBA_BIT)) {
Record((token >> 15) & 1, stats + (token & 0x3fffu));
}
@ -220,9 +229,10 @@ int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw,
while (p != NULL) {
const VP8Tokens* const next = p->next_;
const int N = (next == NULL) ? b->left_ : 0;
int n = MAX_NUM_TOKEN;
int n = b->page_size_;
const token_t* const tokens = TOKEN_DATA(p);
while (n-- > N) {
const uint16_t token = p->tokens_[n];
const token_t token = tokens[n];
const int bit = (token >> 15) & 1;
if (token & FIXED_PROBA_BIT) {
VP8PutBit(bw, bit, token & 0xffu); // constant proba
@ -245,9 +255,10 @@ size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas) {
while (p != NULL) {
const VP8Tokens* const next = p->next_;
const int N = (next == NULL) ? b->left_ : 0;
int n = MAX_NUM_TOKEN;
int n = b->page_size_;
const token_t* const tokens = TOKEN_DATA(p);
while (n-- > N) {
const uint16_t token = p->tokens_[n];
const token_t token = tokens[n];
const int bit = token & (1 << 15);
if (token & FIXED_PROBA_BIT) {
size += VP8BitCost(bit, token & 0xffu);