yac缓存

Yac是用于PHP的共享和无锁内存用户数据缓存。它可以用来替换APC或本地memcached。

要求

• PHP 7 +

Install

$/path/to/phpize
$./configure --with-php-config=/path/to/php-config
$make && make install

Note

1. Yac是无锁缓存，您应该尽量避免或减少多个进程设置一个相同键的概率

1. Yac使用部分crc，您最好重新排列缓存内容，将最重要 (可变) 的字节放在头部或尾部

Restrictions

1. 缓存key不能大于 48 (YAC_MAX_KEY_LEN) bytes

1. 缓存内容不能大于 64M (YAC_MAX_VALUE_RAW_LEN) bytes

1. 压缩后的缓存值不能大于1M 1M (YAC_MAX_VALUE_COMPRESSED_LEN) bytes

ini配置

yac.enable = 1yac.keys_memory_size = 4M ; 4M can get 30K key slots, 32M can get 100K key slotsyac.values_memory_size = 64Myac.compress_threshold = -1yac.enable_cli = 0 ; 是否使用cli启用yac，默认为0yac.serializer = php ; yac2.2.0以来，yac使用的特定seralizer json(-- enable-json) 、msgpack(-- enable-msgpack) 或igbinary(-- enable-igbinary)

常量

YAC_VERSIONYAC_MAX_KEY_LEN = 48 ; if your key is longer than this, maybe you can use md5 result as the keyYAC_MAX_VALUE_RAW_LEN = 64MYAC_MAX_VALUE_COMPRESSED_LEN = 1MYAC_SERIALIZER_PHP = 0   ; since yac-2.2.0YAC_SERIALIZER_JSON = 1  ; since yac-2.2.0YAC_SERIALIZER_MSGPACK = 2 ; since yac-2.2.0YAC_SERIALIZER_IGBINARY = 3 ; since yac-2.2.0YAC_SERIALIZER  ; serializer according to yac.serializer, default is YAC_SERIALIZER_PHP

注意cli下会出现的问题

如果 cli情况下 一定ini配置开启cli-enable
<?php
use Doraemon\pockets\datebase\ShareCache;
//实例化缓存封装类
$cache  = new ShareCache('test');
//设置缓存
$cache->set([1,2,3,5,6]);
//获取缓存
$a = $cache->get();//备注 1.由于yac的缓存是共享的，所以在多个项目中使用时，需要注意key的唯一性，否则会出现缓存覆盖的情况
//备注 2.由于cli在执行后会自动退出，所以在cli中使用时，需要注意缓存的有效期，当再次执行时候换存是拿不到的
//例如//例
//step 1
<?php
use Doraemon\pockets\datebase\ShareCache;
$cache  = new ShareCache('test');
//设置缓存
$cache->set([1,2,3,5,6]);
//php step1.php //执行后会自动退出,缓存失效<?php
use Doraemon\pockets\datebase\ShareCache;
//step 2
$cache  = new ShareCache('test');
//设置缓存
$arr = $cache->get();
var_dump($arr);// 空
//php step2.php //执行事后上一个进程已经退出，所以缓存失效

方法

Yac::__construct

   Yac::__construct([string $prefix = ""])

Yac的构造函数，您可以指定一个前缀，该前缀将用于在执行设置/获取/删除时预先添加到任何键

<?php$yac = new Yac("myproduct_");
?>

Yac::set

   Yac::set($key, $value[, $ttl = 0])Yac::set(array $kvs[, $ttl = 0])

将一个值存储到Yac缓存中，键是缓存唯一的，因此使用相同的键存储第二个值将覆盖原始值。

成功时返回true，错误时返回false (如无内存，无法获得cas write right)

<?php
$yac = new Yac();
$yac->set("foo", "bar");
$yac->set(array("dummy" => "foo","dummy2" => "foo",));
?>

Note:

如Yac 2.1，如果cas竞争失败，可能会失败，您可能需要执行以下操作:

while (!($yac->set("important", "value")));

Yac::get

   Yac::get(array|string $key[, &$cas = NULL])

从缓存中获取存储变量。如果一个数组被传递，那么每个元素都被获取并返回。成功时返回值，错误时返回false

<?php
$yac = new Yac();
$yac->set("foo", "bar");
$yac->set(array("dummy" => "foo","dummy2" => "foo",));
$yac->get("dummy");
$yac->get(array("dummy", "dummy2"));
?>

Yac::delete

   Yac::delete(array|string $keys[, $delay=0])

从缓存中删除存储的变量。如果指定了延迟，则该值将在 $delay秒后删除。

Yac::flush

   Yac::flush()

立即使所有现有项目无效。它实际上并没有释放任何资源，它只将所有项目标记为无效。

Yac::info

   Yac::info(void)

获取缓存信息

<?php....var_dump($yac->info());/* will return an array like:array(11) {["memory_size"]=> int(541065216)["slots_memory_size"]=> int(4194304)["values_memory_size"]=> int(536870912)["segment_size"]=> int(4194304)["segment_num"]=> int(128)["miss"]=> int(0)["hits"]=> int(955)["fails"]=> int(0)["kicks"]=> int(0)["slots_size"]=> int(32768)["slots_used"]=> int(955)}*/

<?phpnamespace Test\Cacheuse Yac;
use RuntimeException;/*** 共享缓存类* Date: 2023/2/22* Time: 16:13* docs:*/
class ShareCache
{public bool $isEnable = true;public string $key = '';/**** 共享内存块实例化。*/public function __construct($key){if (!extension_loaded("yac")) {$this->isEnable = false;throw new RuntimeException('yac 扩展不存在！');}if (!$key) {throw new RuntimeException('key 不能为空！');}$this->key = md5($key);}/**** 获取共享内存块的值。*/public function get(){if ($this->isEnable) {return (new Yac('db_'))->get($this->key);}throw new RuntimeException('yac is not enable ,skip getCache');}/**** 设置共享内存块的值。*/public function set($var): bool{if ($this->isEnable) {return (new Yac('db_'))->set($this->key, $var, 3600);}throw new RuntimeException('yac is not enable ,skip setCache');}/**** 删除共享内存块的值。*/public function del(): bool{if ($this->isEnable) {return (new Yac('db_'))->delete($this->key);}throw new RuntimeException('yac is not enable ,skip delCache');}/**** 获取共享内存块的信息。*/public function info(): array{if ($this->isEnable) {return (new Yac('db_'))->info();}throw new RuntimeException('yac is not enable ,skip info');}/**** 清空共享内存块的值。*/public function flush(): bool{if ($this->isEnable) {return (new Yac)->flush();}throw new RuntimeException('yac is not enable ,skip flush');}}