public function __construct($config = '')
{
if (empty($config)) {
$config = Zc::C(ZcConfigConst::DbConfig);
}
$this->config = $config;
// 初始化DB缓存
if (isset($this->config['db_cache'])) {
$cc = $this->config['db_cache'];
$this->cache = Zc::getCache($cc['biz_name'], $cc['cache_type'], $cc['timestamp'], $cc['options']);
}
// 重新计算分布式DB的配置和权重
foreach ($this->config['connections'] as $groupName => &$groupConfig) {
$this->groupMapping[$groupName]['master'] = array('role' => 'master', 'db_id' => $groupConfig['master']['db_id'], 'read_weight' => isset($groupConfig['master']['read_weight']) ? $groupConfig['master']['read_weight'] : false);
$this->dbIdMapping[$groupConfig['master']['db_id']] =& $groupConfig['master'];
$this->dbIdMapping[$groupConfig['master']['db_id']]['role'] = 'master';
if (!empty($groupConfig['slaves'])) {
foreach ($groupConfig['slaves'] as &$slaveConfig) {
$this->dbIdMapping[$slaveConfig['db_id']] =& $slaveConfig;
$this->dbIdMapping[$slaveConfig['db_id']]['role'] = 'slave';
$this->groupMapping[$groupName][] = array('role' => 'slave', 'db_id' => $slaveConfig['db_id'], 'read_weight' => isset($slaveConfig['read_weight']) ? $slaveConfig['read_weight'] : false);
}
}
}
//重新计算下每台机器要分配的读权重
foreach ($this->groupMapping as $groupName => &$group) {
$countWeight = 0;
$setCount = 0;
foreach ($group as &$host) {
if ($host['read_weight'] !== false) {
$setCount++;
}
$countWeight += $host['read_weight'];
}
if ($setCount === 0) {
$setCount = count($group);
$countWeight = 100;
}
$unsetWeight = (int) ($countWeight / $setCount);
$currValve = 0;
foreach ($group as &$host) {
if ($host['read_weight'] === false) {
$host['read_weight'] = $unsetWeight;
}
$currValve += $host['read_weight'];
$host['read_valve'] = $currValve;
}
$this->groupMaxValve[$groupName] = $currValve;
}
}