用PHP实现memcache客户端(续)

来源:互联网 发布:数据库修改语句有哪些 编辑:程序博客网 时间:2024/05/20 15:12

1、说明

睡了一觉,回想了下昨天的代码,发现有些地方写得不好:

  • 出现错误时不必抛出异常,免得打断了正常的执行流程,而是仅仅记录错误信息,把异常交给使用者处理,这样更灵活
  • socket_create, socket_read, socket_write都有可能出现网络错误,有的代码没有去处理这些可能的错误
  • 没有提供关闭连接的函数
  • 创建socket的动作应该放在connect函数中

本次修改除了修正以上不足之外,还增加了delete, incr, decr, stats命令。

本代码根据 memcached协议中文版一文所述内容编写,在本机上测试通过,感谢作者翻译!!

2、代码

class MyMemcacheClient {    private $host;    private $port;    private $socket;    private $error;    public function __construct() {    }    public function __destruct() {        $this->close();    }    /**     * 获取最后一次的socket错误     * @return string 最后一次socket错误字符串     */    public function setSocketError() {        $errno = socket_last_error($this->socket);        $this->error = "[$errno]" . socket_strerror($errno);    }    /**     * 获取最后一次错误信息;     * @return string 最后一次错误信息     */    public function getLastError() {        return $this->error;    }    /**     * 链接memcached服务器     * @param  string  $host memcached监听的ip     * @param  integer $port memcached监听的端口     * @return boolean     true表示连接成功,false表示连接失败     */    public function connect($host = '127.0.0.1', $port = 11211) {        $this->host = $host;        $this->port = $port;        $this->socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);        if ($this->socket === false) {            $this->setSocketError();            return false;        }        $result = socket_connect($this->socket, $host, $port);        if ($result === false) {            $this->setSocketError();            return false;        } else {            return true;        }    }    /**     * 执行set|add|replace命令     * @param string  $cmd   命令(set|add|replace)     * @param string  $key   键     * @param string  $value 值     * @param nteger   $ttl  生存时间     * @return boolean true for success, false for fail     */    private function _set_add_replace($cmd, $key, $value, $ttl = 10) {        $line1 = sprintf("$cmd %s 0 %d %d\r\n", $key, $ttl, strlen($value));        $line2 = $value . "\r\n";        $data = $line1 . $line2;        $result = socket_write($this->socket, $data, strlen($data));        if ($result === false) {            $this->setSocketError();            return false;        }        $response = socket_read($this->socket, 1024, PHP_NORMAL_READ);        /** 读取最后一个 \n 字符 */        socket_read($this->socket, 1, PHP_BINARY_READ);        if ($response === false) {            $this->setSocketError();            return false;        }        /** 操作成功会返回STORED\r\n */        if (!strncmp($response, 'STORED', 6)) {            return true;        }        return false;    }    public function set($key, $value, $ttl = 10) {        return $this->_set_add_replace('set', $key, $value, $ttl);    }    public function add($key, $value, $ttl = 10) {        return $this->_set_add_replace('add', $key, $value, $ttl);    }    public function replace($key, $value, $ttl = 10) {        return $this->_set_add_replace('replace', $key, $value, $ttl);    }    /**     * 获取一个键的值     * @param  string $key 键     * @return string|boolean    值, false表示没有这个键或者已过期     */    public function get($key) {        $data = sprintf("get %s\r\n", $key);        $result = socket_write($this->socket, $data, strlen($data));        if ($result === false) {            $this->setSocketError();            return false;        }        $line1 = socket_read($this->socket, 1024, PHP_NORMAL_READ);        /** 读取最后一个 \n 字符 */        socket_read($this->socket, 1, PHP_BINARY_READ);        if ($line1 === false) {            $this->setSocketError();            return false;        }        /** 获取成功,第一行返回 VALUE <key> <flags> <bytes>\r\n */        if (!strncmp($line1, "VALUE", 5)) {            $line1 = rtrim($line1, "\r\n");            $arr = explode(' ', $line1);            /** 获取数据长度 */            $dataLen = intval(end($arr));            /** 获取数据 */            $response = socket_read($this->socket, $dataLen, PHP_BINARY_READ);            /** 读取最后7个字符 \r\nEND\r\n  */            socket_read($this->socket, 7, PHP_BINARY_READ);            if ($response === false) {                $this->setSocketError();                return false;            }            return $response;        } else {            return false;        }    }    /**     * 设置所有的键过期     * @return boolean success     */    public function flushAll() {        $data = "flush_all\r\n";        $result = socket_write($this->socket, $data, strlen($data));        /** 读取返回结果,固定为 OK\r\n  */        socket_read($this->socket, 4, PHP_BINARY_READ);        return true;    }    /**     * 删除一个键     * @param  string  $key   键     * @param  integer $delay 延时     * @return boolean        true for success, false for fail     */    public function delete($key, $delay = 5) {        $data = sprintf("delete %s %d\r\n", $key, $delay);        $result = socket_write($this->socket, $data, strlen($data));        if ($result === false) {            $this->setSocketError();            return false;        }        $response = socket_read($this->socket, 20, PHP_NORMAL_READ);        if ($response === false) {            $this->setSocketError();            return false;        }        socket_read($this->socket, 1, PHP_BINARY_READ);        if (!strncmp($response, "DELETED", 7)) {            return true;        } else {            return false;        }    }    /**     * incr,decr命令的封装     * @param  string $cmd   操作,incr|decr     * @param  string $key   键     * @param  integer $value 增加或减少的值     * @return boolean|integer       操作失败,返回false,操作成功,返回整数(操作后的值)     */    private function _incr_decr($cmd, $key, $value) {        $data = "$cmd $key $value\r\n";        $result = socket_write($this->socket, $data, strlen($data));        if ($result === false) {            $this->setSocketError();            return false;        }        $response = socket_read($this->socket, 1024, PHP_NORMAL_READ);        if ($response === false) {            $this->setSocketError();            return false;        }        socket_read($this->socket, 1, PHP_BINARY_READ);        if ($response != "NOT_FOUND\r") {            return intval($response);        } else {            return false;        }    }    public function incr($key, $value = 1) {        return $this->_incr_decr("incr", $key, $value);    }    public function decr($key, $value = 1) {        return $this->_incr_decr("decr", $key, $value);    }    /**     * 返回统计信息     * @return boolean|array 失败,返回false,成功,返回数组,格式 key => value     */    public function stats() {        $data = $arg ? "stats $arg\r\n" : "stats\r\n";        $result = socket_write($this->socket, $data, strlen($data));        if ($result === false) {            $this->setSocketError();            return false;        }        $stats = [];        while(true) {            $line = socket_read($this->socket, 1024, PHP_NORMAL_READ);            if (false === $line) {                break;            }            if ($line == "END\r") {                socket_read($this->socket, 1, PHP_BINARY_READ);                break;            } else {                $arr = explode(' ', rtrim($line, "\r"));                $stats[$arr[1]] = $arr[2];                socket_read($this->socket, 1, PHP_BINARY_READ);            }        }        return $stats;    }    /**     * 关闭连接     * @return void 没有返回值     */    public function close() {        $this->socket && socket_close($this->socket);    }}

3、测试

  • 测试代码
try {    $memcache = new MyMemcacheClient();    if (false === $memcache->connect()) {        throw new Exception("connect to memcached failed: " . $memcache->getlastError());    }    $memcache->flushAll();    echo "a=", $memcache->get("a"), PHP_EOL;    if (false === $memcache->set("a", "This is a")) {        echo "set a failed: ", $memcache->getLastError(), PHP_EOL;    } else {        echo "a: ", $memcache->get("a"), PHP_EOL;    }    $memcache->set('total', 10, 30);    echo "total: ", $memcache->get("total"), PHP_EOL;    $memcache->incr("total", 2);    echo "total: ", $memcache->get("total"), PHP_EOL;    $memcache->decr("total", 1);    echo "total: ", $memcache->get("total"), PHP_EOL;    if (false === $memcache->delete("total")) {        echo "delete total failed", PHP_EOL;    } else {        echo "delete total success! total: ", $memcache->get("total"), PHP_EOL;    }    $stats = $memcache->stats();    foreach($stats as $k => $v) {        echo $k,": ", $v, PHP_EOL;    }    $memcache->close();} catch (Exception $e) {    echo $e->getMessage();}
  • 测试结果
a=a: This is atotal: 10total: 12total: 11delete total success! total: pid: 11812uptime: 2890time: 1487218922version: 1.2.6pointer_size: 32curr_items: 2total_items: 60bytes: 115curr_connections: 3total_connections: 33connection_structures: 4cmd_get: 154cmd_set: 60get_hits: 120get_misses: 34evictions: 0bytes_read: 4196bytes_written: 8247limit_maxbytes: 134217728threads: 1
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