用PHP实现memcache客户端（续）

2019-11-08 18:53:21

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来源：转载

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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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