first commit

2023-05-19 00:42:48 +08:00
commit 53de9c6c51
243 changed files with 39485 additions and 0 deletions
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+'use strict';
+
+var RedisDistlockLocker = require('./provider/redis-distlock');
+var debug = require('../util/debug')('leader-locker');
+var EventEmitter = require('events').EventEmitter;
+var util = require('util');
+
+var LOCK = {
+    TTL: 5000
+};
+
+function Locker(locker, ttl) {
+    EventEmitter.call(this);
+    this.locker = locker;
+    this.ttl = (Number.isFinite(ttl) && ttl > 0) ? ttl : LOCK.TTL;
+    this.renewInterval = this.ttl / 5;
+    this.intervalIds = {};
+}
+util.inherits(Locker, EventEmitter);
+
+module.exports = Locker;
+
+Locker.prototype.lock = function(resource, callback) {
+    var self = this;
+    debug('Locker.lock(%s, %d)', resource, this.ttl);
+    this.locker.lock(resource, this.ttl, function (err, lock) {
+        if (!err) {
+            self.startRenewal(resource);
+        }
+        return callback(err, lock);
+    });
+};
+
+Locker.prototype.unlock = function(resource, callback) {
+    var self = this;
+    debug('Locker.unlock(%s)', resource);
+    this.locker.unlock(resource, function(err) {
+        self.stopRenewal(resource);
+        return callback(err);
+    });
+};
+
+Locker.prototype.startRenewal = function(resource) {
+    var self = this;
+    if (!this.intervalIds.hasOwnProperty(resource)) {
+        this.intervalIds[resource] = setInterval(function() {
+            debug('Trying to extend lock resource=%s', resource);
+            self.locker.lock(resource, self.ttl, function(err, _lock) {
+                if (err) {
+                    self.emit('error', err, resource);
+                    return self.stopRenewal(resource);
+                }
+                if (_lock) {
+                    debug('Extended lock resource=%s', resource);
+                }
+            });
+        }, this.renewInterval);
+    }
+};
+
+Locker.prototype.stopRenewal = function(resource) {
+    if (this.intervalIds.hasOwnProperty(resource)) {
+        clearInterval(this.intervalIds[resource]);
+        delete this.intervalIds[resource];
+    }
+};
+
+module.exports.create = function createLocker(type, config) {
+    if (type !== 'redis-distlock') {
+        throw new Error('Invalid type Locker type. Valid types are: "redis-distlock"');
+    }
+    var locker = new RedisDistlockLocker(config.pool);
+    return new Locker(locker, config.ttl);
+};