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Lock now considers the creation time and compares against a ttl so

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a lock is not keep forever in case of failure.

Pending: lazy removal of expired locks.
This commit is contained in:
Raul Ochoa 2014-09-25 19:00:35 +02:00
parent 3e571b4ce8
commit b4bee864d2
2 changed files with 115 additions and 21 deletions
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42
lib/cartodb/template_maps.js
View File

@ -44,6 +44,8 @@ function TemplateMaps(redis_pool, signed_maps, opts) {
// User template locks (HASH:tpl_id->ctime)
this.key_usr_tpl_lck = dot.template("map_tpl|{{=it.owner}}|locks");
this.lock_ttl = this.opts['lock_ttl'] || 5000;
}
var o = TemplateMaps.prototype;
@ -93,26 +95,26 @@ o._redisCmd = function(redisFunc, redisArgs, callback) {
// @param callback function(err, obtained)
o._obtainTemplateLock = function(owner, tpl_id, callback) {
var that = this;
var gotLock = false;
Step (
function obtainLock() {
var ctime = Date.now();
that._redisCmd('HSETNX', [that.key_usr_tpl_lck({owner:owner}), tpl_id, ctime], this);
},
function checkLock(err, locked) {
if ( err ) throw err;
if ( ! locked ) {
// Already locked
// TODO: unlock if expired ?
throw new Error("Template '" + tpl_id + "' of user '" + owner + "' is locked");
}
return gotLock = true;
},
function finish(err) {
callback(err, gotLock);
}
);
var that = this,
lockKey = this.key_usr_tpl_lck({owner:owner});
Step (
function obtainLock() {
that._redisCmd('HGET', [lockKey, tpl_id], this);
},
function checkLock(err, lockTime) {
if (err) { throw err; }
var _newLockTime = Date.now();
if (!lockTime || ((_newLockTime - lockTime) > that.lock_ttl)) {
that._redisCmd('HSET', [lockKey, tpl_id, _newLockTime], this);
} else {
throw new Error("Template '" + tpl_id + "' of user '" + owner + "' is locked");
}
},
function finish(err, hsetValue) {
callback(err, !!hsetValue);
}
);
};
// @param callback function(err, deleted)

92
test/unit/cartodb/template_maps.test.js
View File

@ -13,6 +13,14 @@ suite('template_maps', function() {
var redis_pool = RedisPool(global.environment.redis);
var signed_maps = new SignedMaps(redis_pool);
var validTemplate = {
version:'0.0.1',
name: 'first',
auth: {},
layergroup: {}
};
var owner = 'me';
test('does not accept template with unsupported version', function(done) {
var tmap = new TemplateMaps(redis_pool, signed_maps);
assert.ok(tmap);
@ -503,4 +511,88 @@ suite('template_maps', function() {
);
});
var redisCmdFunc = TemplateMaps.prototype._redisCmd;
function runWithRedisStubbed(stubbedCommands, func) {
TemplateMaps.prototype._redisCmd = function(redisFunc, redisArgs, callback) {
redisFunc = redisFunc.toLowerCase();
if (stubbedCommands.hasOwnProperty(redisFunc)) {
callback(null, stubbedCommands[redisFunc]);
} else {
throw 'Unknown command';
}
};
func();
TemplateMaps.prototype._redisCmd = redisCmdFunc;
}
test('_obtainTemplateLock with no previous value, happy case', function(done) {
runWithRedisStubbed({hget: null, hset: 1}, function() {
var templateMaps = new TemplateMaps(redis_pool, signed_maps);
templateMaps._obtainTemplateLock(owner, validTemplate.name, function(err, gotLock) {
assert.ok(!err);
assert.ok(gotLock);
done();
});
});
});
test('_obtainTemplateLock no lock for non expired ttl, simulates obtaining two locks at same time', function(done) {
runWithRedisStubbed({hget: Date.now()}, function() {
var templateMaps = new TemplateMaps(redis_pool, signed_maps);
templateMaps._obtainTemplateLock(owner, validTemplate.name, function(err, gotLock) {
assert.ok(!!err);
assert.equal(gotLock, false);
done();
});
});
});
test('_obtainTemplateLock no lock for non expired ttl, last millisecond of valid ttl', function(done) {
var nowValue = Date.now(),
nowFunc = Date.now;
Date.now = function() {
return nowValue;
};
var lockTtl = 1000;
runWithRedisStubbed({hget: Date.now() - lockTtl, hset: true}, function() {
var templateMaps = new TemplateMaps(redis_pool, signed_maps, {lock_ttl: lockTtl});
templateMaps._obtainTemplateLock(owner, validTemplate.name, function(err, gotLock) {
assert.ok(!!err);
assert.equal(gotLock, false);
Date.now = nowFunc;
done();
});
});
});
test('_obtainTemplateLock gets lock for expired ttl, first millisecond of invalid ttl', function(done) {
var nowValue = Date.now(),
nowFunc = Date.now;
Date.now = function() {
return nowValue;
};
var lockTtl = 1000;
runWithRedisStubbed({hget: Date.now() - lockTtl - 1, hset: true}, function() {
var templateMaps = new TemplateMaps(redis_pool, signed_maps, {lock_ttl: lockTtl});
templateMaps._obtainTemplateLock(owner, validTemplate.name, function(err, gotLock) {
assert.ok(!err);
assert.ok(gotLock);
Date.now = nowFunc;
done();
});
});
});
});