XCache is a fast, stable PHP opcode cacher that has been proven and is now running on production servers under high load. https://xcache.lighttpd.net/
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

269 lines
5.5 KiB

#include <php.h>
#include <stdlib.h>
#include "mem.h"
#include "align.h"
#define PADD(p, a) (((char*)p) + a)
// {{{ mem
struct _xc_block_t {
#ifdef ALLOC_DEBUG
unsigned int magic;
#endif
xc_memsize_t size; /* reserved even after alloc */
xc_block_t *next; /* not used after alloc */
};
struct _xc_mem_t {
xc_memsize_t size;
xc_memsize_t avail; /* total free */
xc_block_t headblock[1]; /* just as a pointer to first block*/
};
#ifndef offsetof
# define offsetof(type, field) ((int) ((char *) &((type *) 0)->field))
#endif
#define SizeOf(type, field) sizeof( ((type *) 0)->field )
#define BLOCK_HEADER_SIZE() (ALIGN( offsetof(xc_block_t, size) + SizeOf(xc_block_t, size) ))
#define BLOCK_MAGIC ((unsigned int) 0x87655678)
/* }}} */
static inline void xc_block_setup(xc_block_t *b, xc_memsize_t size, xc_block_t *next) /* {{{ */
{
#ifdef ALLOC_DEBUG
b->magic = BLOCK_MAGIC;
#endif
b->size = size;
b->next = next;
}
/* }}} */
#ifdef ALLOC_DEBUG
static void xc_block_check(xc_block_t *b) /* {{{ */
{
if (b->magic != BLOCK_MAGIC) {
fprintf(stderr, "0x%X != 0x%X magic wrong \n", b->magic, BLOCK_MAGIC);
}
}
/* }}} */
#else
# define xc_block_check(b) do { } while(0)
#endif
void *xc_mem_malloc(xc_mem_t *mem, xc_memsize_t size) /* {{{ */
{
xc_block_t *prev, *cur;
xc_block_t *newb, *b;
xc_memsize_t realsize;
xc_memsize_t minsize;
void *p;
/* [xc_block_t:size|size] */
realsize = BLOCK_HEADER_SIZE() + size;
/* realsize is ALIGNed so next block start at ALIGNed address */
realsize = ALIGN(realsize);
do {
p = NULL;
if (mem->avail < realsize) {
break;
}
b = NULL;
minsize = INT_MAX;
/* prev|cur */
for (prev = mem->headblock; prev->next; prev = cur) {
/* while (prev->next != 0) { */
cur = prev->next;
xc_block_check(cur);
if (cur->size == realsize) {
/* found a perfect fit, stop searching */
b = prev;
break;
}
/* make sure we can split on the block */
else if (cur->size > (sizeof(xc_block_t) + realsize) &&
cur->size < minsize) {
/* cur is acceptable and memller */
b = prev;
minsize = cur->size;
}
prev = cur;
}
if (b == NULL) {
break;
}
prev = b;
cur = prev->next;
p = PADD(cur, BLOCK_HEADER_SIZE());
/* update the block header */
mem->avail -= realsize;
/*perfect fit, just unlink */
if (cur->size == realsize) {
prev->next = cur->next;
break;
}
/* make new free block after alloced space */
/* save, as it might be overwrited by newb (cur->size is ok) */
b = cur->next;
/* prev|cur |next=b */
newb = (xc_block_t *)PADD(cur, realsize);
xc_block_setup(newb, cur->size - realsize, b);
cur->size = realsize;
/* prev|cur|newb|next
* `--^
*/
#ifdef ALLOC_DEBUG
fprintf(stderr, "avail: %d (%dKB). size: %d %d (%dKB) new next: %p offset: %d %dKB\n"
, mem->avail, mem->avail/1024
, size
, realsize, realsize/1024
, newb
, ((char*)newb - mem->rw), ((char*)newb - mem->rw) / 1024
);
#endif
prev->next = newb;
/* prev|cur|newb|next
* `-----^
*/
} while (0);
return p;
}
/* }}} */
int xc_mem_free(xc_mem_t *mem, const void *p) /* {{{ return block size freed */
{
xc_block_t *cur, *b;
int size;
cur = (xc_block_t *) (((char *) p) - BLOCK_HEADER_SIZE());
xc_block_check(cur);
assert((char*)mem < (char*)cur && (char*)cur < (char*)mem + mem->size);
/* find free block right before the p */
b = mem->headblock;
while (b->next != 0 && b->next < cur) {
b = b->next;
}
/* restore block */
cur->next = b->next;
b->next = cur;
size = cur->size;
mem->avail += size;
/* combine prev|cur */
if (PADD(b, b->size) == (char *)cur) {
b->size += cur->size;
b->next = cur->next;
cur = b;
}
/* combine cur|next */
b = cur->next;
if (PADD(cur, cur->size) == (char *)b) {
cur->size += b->size;
cur->next = b->next;
}
return size;
}
/* }}} */
void *xc_mem_calloc(xc_mem_t *mem, xc_memsize_t memb, xc_memsize_t size) /* {{{ */
{
xc_memsize_t realsize = memb * size;
void *p = xc_mem_malloc(mem, realsize);
memset(p, 0, realsize);
return p;
}
/* }}} */
void *xc_mem_realloc(xc_mem_t *mem, const void *p, xc_memsize_t size) /* {{{ */
{
void *newp = xc_mem_malloc(mem, size);
memcpy(newp, p, size);
xc_mem_free(mem, p);
return newp;
}
/* }}} */
char *xc_mem_strndup(xc_mem_t *mem, const char *str, xc_memsize_t len) /* {{{ */
{
void *p = xc_mem_malloc(mem, len + 1);
memcpy(p, str, len + 1);
return p;
}
/* }}} */
char *xc_mem_strdup(xc_mem_t *mem, const char *str) /* {{{ */
{
return xc_mem_strndup(mem, str, strlen(str));
}
/* }}} */
xc_memsize_t xc_mem_avail(xc_mem_t *mem) /* {{{ */
{
return mem->avail;
}
/* }}} */
xc_memsize_t xc_mem_size(xc_mem_t *mem) /* {{{ */
{
return mem->size;
}
/* }}} */
const xc_block_t *xc_mem_freeblock_first(xc_mem_t *mem) /* {{{ */
{
return mem->headblock->next;
}
/* }}} */
const xc_block_t *xc_mem_freeblock_next(const xc_block_t *block) /* {{{ */
{
return block->next;
}
/* }}} */
xc_memsize_t xc_mem_block_size(const xc_block_t *block) /* {{{ */
{
return block->size;
}
/* }}} */
xc_memsize_t xc_mem_block_offset(const xc_mem_t *mem, const xc_block_t *block) /* {{{ */
{
return ((char *) block) - ((char *) mem);
}
/* }}} */
xc_mem_t *xc_mem_init(void *ptr, xc_memsize_t size) /* {{{ */
{
xc_mem_t *mem = (xc_mem_t *) ptr;
xc_block_t *b;
mem->size = size;
mem->avail = size - ALIGN(sizeof(xc_mem_t));
/* pointer to first block */
b = mem->headblock;
xc_block_setup(b, 0, (xc_block_t *)(mem + ALIGN(sizeof(xc_mem_t))));
/* first block*/
b = b->next;
xc_block_setup(b, mem->avail, 0);
return mem;
}
/* }}} */
void xc_mem_destroy(xc_mem_t *mem) /* {{{ */
{
}
/* }}} */