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/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
*
* This file is released under the LGPL.
*/
#include "lib.h"
#include "pool.h"
#include <assert.h>
struct block {
struct block *next;
size_t size;
void *data;
};
struct pool {
int begun;
struct block *object;
struct block *blocks;
struct block *tail;
};
/* by default things come out aligned for doubles */
#define DEFAULT_ALIGNMENT __alignof__ (double)
struct pool *pool_create(size_t chunk_hint)
{
struct pool *mem = dbg_malloc(sizeof(*mem));
if (!mem) {
log_error("Couldn't create memory pool (size %u)",
sizeof(*mem));
return NULL;
}
mem->begun = 0;
mem->object = 0;
mem->blocks = mem->tail = NULL;
return mem;
}
static void _free_blocks(struct block *b)
{
struct block *n;
while (b) {
n = b->next;
dbg_free(b->data);
dbg_free(b);
b = n;
}
}
void pool_destroy(struct pool *p)
{
_free_blocks(p->blocks);
dbg_free(p);
}
void *pool_alloc(struct pool *p, size_t s)
{
return pool_alloc_aligned(p, s, DEFAULT_ALIGNMENT);
}
static void _append_block(struct pool *p, struct block *b)
{
if (p->tail) {
p->tail->next = b;
p->tail = b;
} else
p->blocks = p->tail = b;
}
static struct block *_new_block(size_t s, unsigned alignment)
{
static char *_oom = "Out of memory";
/* FIXME: I'm currently ignoring the alignment arg. */
size_t len = sizeof(struct block) + s;
struct block *b = dbg_malloc(len);
/*
* Too lazy to implement alignment for debug version, and
* I don't think LVM will use anything but default
* align.
*/
assert(alignment == DEFAULT_ALIGNMENT);
if (!b) {
log_err(_oom);
return NULL;
}
if (!(b->data = dbg_malloc(s))) {
log_err(_oom);
dbg_free(b);
return NULL;
}
b->next = NULL;
b->size = s;
return b;
}
void *pool_alloc_aligned(struct pool *p, size_t s, unsigned alignment)
{
struct block *b = _new_block(s, alignment);
if (!b)
return NULL;
_append_block(p, b);
return b->data;
}
void pool_empty(struct pool *p)
{
_free_blocks(p->blocks);
p->blocks = p->tail = NULL;
}
void pool_free(struct pool *p, void *ptr)
{
struct block *b, *prev = NULL;
for (b = p->blocks; b; b = b->next) {
if (b->data == ptr)
break;
prev = b;
}
/*
* If this fires then you tried to free a
* pointer that either wasn't from this
* pool, or isn't the start of a block.
*/
assert(b);
_free_blocks(b);
if (prev) {
p->tail = prev;
prev->next = NULL;
} else
p->blocks = p->tail = NULL;
}
int pool_begin_object(struct pool *p, size_t init_size)
{
assert(!p->begun);
p->begun = 1;
return 1;
}
int pool_grow_object(struct pool *p, const void *buffer, size_t delta)
{
struct block *new;
size_t size = delta;
assert(p->begun);
if (p->object)
size += p->object->size;
if (!(new = _new_block(size, DEFAULT_ALIGNMENT))) {
log_err("Couldn't extend object.");
return 0;
}
if (p->object) {
memcpy(new->data, p->object->data, p->object->size);
dbg_free(p->object);
}
p->object = new;
return 1;
}
void *pool_end_object(struct pool *p)
{
assert(p->begun);
_append_block(p, p->object);
p->begun = 0;
p->object = NULL;
return p->tail->data;
}
void pool_abandon_object(struct pool *p)
{
assert(p->begun);
dbg_free(p->object);
p->begun = 0;
p->object = NULL;
}
char *pool_strdup(struct pool *p, const char *str)
{
char *ret = pool_alloc(p, strlen(str) + 1);
if (ret)
strcpy(ret, str);
return ret;
}
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