php-src/ext/session/mod_mm.c
2001-02-26 06:11:02 +00:00

356 lines
6.7 KiB
C

/*
+----------------------------------------------------------------------+
| PHP version 4.0 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2001 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 2.02 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available at through the world-wide-web at |
| http://www.php.net/license/2_02.txt. |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Authors: Sascha Schumann <sascha@schumann.cx> |
+----------------------------------------------------------------------+
*/
#include "php.h"
#ifdef HAVE_LIBMM
#include <mm.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include "php_session.h"
#include "mod_mm.h"
#define PS_MM_PATH "/tmp/session_mm"
/*
* this list holds all data associated with one session
*/
typedef struct ps_sd {
struct ps_sd *next, *prev;
time_t ctime;
char *key;
void *data;
size_t datalen;
} ps_sd;
typedef struct {
MM *mm;
ps_sd **hash;
} ps_mm;
static ps_mm *ps_mm_instance = NULL;
/* should be a prime */
#define HASH_SIZE 577
#if 0
#define ps_mm_debug(a...) fprintf(stderr, a)
#else
#define ps_mm_debug
#endif
#define BITS_IN_int (sizeof(int) * CHAR_BIT)
#define THREE_QUARTERS ((int) ((BITS_IN_int * 3) / 4))
#define ONE_EIGTH ((int) (BITS_IN_int / 8))
#define HIGH_BITS (~((unsigned int)(~0) >> ONE_EIGTH))
/*
* Weinberger's generic hash algorithm, adapted by Holub
* (published in [Holub 1990])
*/
static unsigned int ps_sd_hash(const char *data)
{
unsigned int val, i;
for (val = 0; *data; data++) {
val = (val << ONE_EIGTH) + *data;
if ((i = val & HIGH_BITS) != 0)
val = (val ^ (i >> THREE_QUARTERS)) & ~HIGH_BITS;
}
return val;
}
static ps_sd *ps_sd_new(ps_mm *data, const char *key, const void *sdata, size_t sdatalen)
{
unsigned int h;
ps_sd *sd;
h = ps_sd_hash(key) % HASH_SIZE;
sd = mm_malloc(data->mm, sizeof(*sd));
if (!sd)
return NULL;
sd->ctime = 0;
sd->data = mm_malloc(data->mm, sdatalen);
if (!sd->data) {
mm_free(data->mm, sd);
return NULL;
}
sd->datalen = sdatalen;
sd->key = mm_strdup(data->mm, key);
if (!sd->key) {
mm_free(data->mm, sd->data);
mm_free(data->mm, sd);
return NULL;
}
memcpy(sd->data, sdata, sdatalen);
if ((sd->next = data->hash[h]))
sd->next->prev = sd;
sd->prev = NULL;
ps_mm_debug("inserting %s(%p) into %d\n", key, sd, h);
data->hash[h] = sd;
return sd;
}
static void ps_sd_destroy(ps_mm *data, ps_sd *sd)
{
unsigned int h;
h = ps_sd_hash(sd->key) % HASH_SIZE;
if (sd->next)
sd->next->prev = sd->prev;
if (sd->prev)
sd->prev->next = sd->next;
if (data->hash[h] == sd)
data->hash[h] = sd->next;
mm_free(data->mm, sd->key);
if (sd->data)
mm_free(data->mm, sd->data);
mm_free(data->mm, sd);
}
static ps_sd *ps_sd_lookup(ps_mm *data, const char *key, int rw)
{
unsigned int h;
ps_sd *ret;
h = ps_sd_hash(key) % HASH_SIZE;
for (ret = data->hash[h]; ret; ret = ret->next)
if (!strcmp(ret->key, key))
break;
if (ret && rw && ret != data->hash[h]) {
data->hash[h]->prev = ret;
ret->next = data->hash[h];
data->hash[h] = ret;
ps_mm_debug("optimizing\n");
}
ps_mm_debug(stderr, "lookup(%s): ret=%p,h=%d\n", key, ret, h);
return ret;
}
ps_module ps_mod_mm = {
PS_MOD(mm)
};
#define PS_MM_DATA ps_mm *data = PS_GET_MOD_DATA()
static int ps_mm_initialize(ps_mm *data, const char *path)
{
data->mm = mm_create(0, path);
if (!data->mm) {
return FAILURE;
}
data->hash = mm_calloc(data->mm, HASH_SIZE, sizeof(*data->hash));
if (!data->hash) {
mm_destroy(data->mm);
return FAILURE;
}
return SUCCESS;
}
static void ps_mm_destroy(ps_mm *data)
{
int h;
ps_sd *sd, *next;
for (h = 0; h < HASH_SIZE; h++)
for (sd = data->hash[h]; sd; sd = next) {
next = sd->next;
ps_sd_destroy(data, sd);
}
mm_free(data->mm, data->hash);
mm_destroy(data->mm);
}
PHP_GINIT_FUNCTION(ps_mm)
{
ps_mm_instance = calloc(sizeof(*ps_mm_instance), 1);
if (ps_mm_initialize(ps_mm_instance, PS_MM_PATH) != SUCCESS) {
ps_mm_instance = NULL;
return FAILURE;
}
return SUCCESS;
}
PHP_GSHUTDOWN_FUNCTION(ps_mm)
{
if (ps_mm_instance) {
ps_mm_destroy(ps_mm_instance);
free(ps_mm_instance);
return SUCCESS;
}
return FAILURE;
}
PS_OPEN_FUNC(mm)
{
ps_mm_debug("open: ps_mm_instance=%p\n", ps_mm_instance);
if (!ps_mm_instance)
return FAILURE;
PS_SET_MOD_DATA(ps_mm_instance);
return SUCCESS;
}
PS_CLOSE_FUNC(mm)
{
PS_SET_MOD_DATA(NULL);
return SUCCESS;
}
PS_READ_FUNC(mm)
{
PS_MM_DATA;
ps_sd *sd;
int ret = FAILURE;
mm_lock(data->mm, MM_LOCK_RD);
sd = ps_sd_lookup(data, key, 0);
if (sd) {
*vallen = sd->datalen;
*val = emalloc(sd->datalen);
memcpy(*val, sd->data, sd->datalen);
ret = SUCCESS;
}
mm_unlock(data->mm);
return ret;
}
PS_WRITE_FUNC(mm)
{
PS_MM_DATA;
ps_sd *sd;
if (vallen == 0) return SUCCESS;
mm_lock(data->mm, MM_LOCK_RW);
sd = ps_sd_lookup(data, key, 1);
if (!sd) {
sd = ps_sd_new(data, key, val, vallen);
ps_mm_debug(stderr, "new one for %s\n", key);
} else {
ps_mm_debug(stderr, "found existing one for %s\n", key);
mm_free(data->mm, sd->data);
sd->datalen = vallen;
sd->data = mm_malloc(data->mm, vallen);
if (!sd->data) {
ps_sd_destroy(data, sd);
sd = NULL;
} else
memcpy(sd->data, val, vallen);
}
if (sd)
time(&sd->ctime);
mm_unlock(data->mm);
return sd ? SUCCESS : FAILURE;
}
PS_DESTROY_FUNC(mm)
{
PS_MM_DATA;
ps_sd *sd;
mm_lock(data->mm, MM_LOCK_RW);
sd = ps_sd_lookup(data, key, 0);
if (sd)
ps_sd_destroy(data, sd);
mm_unlock(data->mm);
return SUCCESS;
}
PS_GC_FUNC(mm)
{
PS_MM_DATA;
int h;
time_t now;
ps_sd *sd, *next;
*nrdels = 0;
ps_mm_debug("gc\n");
mm_lock(data->mm, MM_LOCK_RW);
time(&now);
for (h = 0; h < HASH_SIZE; h++)
for (sd = data->hash[h]; sd; sd = next) {
next = sd->next;
ps_mm_debug("looking at %s\n", sd->key);
if ((now - sd->ctime) > maxlifetime) {
ps_sd_destroy(data, sd);
*nrdels++;
}
}
mm_unlock(data->mm);
return SUCCESS;
}
zend_module_entry php_session_mm_module = {
"Session MM",
NULL,
NULL, NULL,
NULL, NULL,
NULL,
PHP_GINIT(ps_mm), PHP_GSHUTDOWN(ps_mm),
STANDARD_MODULE_PROPERTIES_EX
};
#endif