Prevent the sequence count on a client from being larger then an uint…

…32, which would cause a range error

lib/memjs/memjs.js

@@ -127,7 +127,7 @@ Client.prototype.get = function(key, callback) {
     });
   }
   var logger = this.options.logger;
-  this.seq++;
+  this.incrSeq();
   var request = makeRequestBuffer(0, key, '', '', this.seq);
   this.perform(key, request, this.seq, function(err, response) {
     if (err) {
@@ -179,7 +179,7 @@ Client.prototype.set = function(key, value, options, callback) {
   expires = options.expires;
 
   // TODO: support flags, support version (CAS)
-  this.seq++;
+  this.incrSeq();
   var expiration = makeExpiration(expires || this.options.expires);
   var extras = Buffer.concat([Buffer.from('00000000', 'hex'), expiration]);
   var request = makeRequestBuffer(1, key, extras, value, this.seq);
@@ -231,7 +231,7 @@ Client.prototype.add = function(key, value, options, callback) {
   expires = options.expires;
 
   // TODO: support flags, support version (CAS)
-  this.seq++;
+  this.incrSeq();
   var expiration = makeExpiration(expires || this.options.expires);
   var extras = Buffer.concat([Buffer.from('00000000', 'hex'), expiration]);
   var request = makeRequestBuffer(2, key, extras, value, this.seq);
@@ -286,7 +286,7 @@ Client.prototype.replace = function(key, value, options, callback) {
   expires = options.expires;
 
   // TODO: support flags, support version (CAS)
-  this.seq++;
+  this.incrSeq();
   var expiration = makeExpiration(expires || this.options.expires);
   var extras = Buffer.concat([Buffer.from('00000000', 'hex'), expiration]);
   var request = makeRequestBuffer(3, key, extras, value, this.seq);
@@ -325,7 +325,7 @@ Client.prototype.delete = function(key, callback) {
   }
   // TODO: Support version (CAS)
   var logger = this.options.logger;
-  this.seq++;
+  this.incrSeq();
   var request = makeRequestBuffer(4, key, '', '', this.seq);
   this.perform(key, request, this.seq, function(err, response) {
     if (err) {
@@ -385,7 +385,7 @@ Client.prototype.increment = function(key, amount, options, callback) {
   expires = options.expires;
 
   // TODO: support version (CAS)
-  this.seq++;
+  this.incrSeq();
   initial = initial || 0;
   expires = expires || this.options.expires;
   var extras = makeAmountInitialAndExpiration(amount, initial, expires);
@@ -447,7 +447,7 @@ Client.prototype.decrement = function(key, amount, options, callback) {
   initial = options.initial;
   expires = options.expires;
 
-  this.seq++;
+  this.incrSeq();
   initial = initial || 0;
   expires = expires || this.options.expires;
   var extras = makeAmountInitialAndExpiration(amount, initial, expires);
@@ -484,7 +484,7 @@ Client.prototype.append = function(key, value, callback) {
   }
   // TODO: support version (CAS)
   var logger = this.options.logger;
-  this.seq++;
+  this.incrSeq();
   var request = makeRequestBuffer(0x0E, key, '', value, this.seq);
   this.perform(key, request, this.seq, function(err, response) {
     if (err) {
@@ -520,7 +520,7 @@ Client.prototype.prepend = function(key, value, callback) {
   }
   // TODO: support version (CAS)
   var logger = this.options.logger;
-  this.seq++;
+  this.incrSeq();
   var request = makeRequestBuffer(0x0E, key, '', value, this.seq);
   this.perform(key, request, this.seq, function(err, response) {
     if (err) {
@@ -556,7 +556,7 @@ Client.prototype.touch = function(key, expires, callback) {
   }
   // TODO: support version (CAS)
   var logger = this.options.logger;
-  this.seq++;
+  this.incrSeq();
   var extras = makeExpiration(expires || this.options.expires);
   var request = makeRequestBuffer(0x1C, key, extras, '', this.seq);
   this.perform(key, request, this.seq, function(err, response) {
@@ -594,7 +594,7 @@ Client.prototype.flush = function(callback) {
     return promisify(function(callback) { self.flush(function(err, results) { callback(err, results); }); });
   }
   // TODO: support expiration
-  this.seq++;
+  this.incrSeq();
   var request = makeRequestBuffer(0x08, '', '', '', this.seq);
   var count   = this.servers.length;
   var result  = {};
@@ -636,7 +636,7 @@ Client.prototype.flush = function(callback) {
 // mapping the stat name to the value of the statistic as a string.
 Client.prototype.statsWithKey = function(key, callback) {
   var logger = this.options.logger;
-  this.seq++;
+  this.incrSeq();
   var request = makeRequestBuffer(0x10, key, '', '', this.seq);
   var i;
 
@@ -712,7 +712,7 @@ Client.prototype.resetStats = function(callback) {
 // fail and are retried, leading to the quit command winning and closing the
 // connection before the retries complete.
 Client.prototype.quit = function() {
-  this.seq++;
+  this.incrSeq();
   // TODO: Nicer perhaps to do QUITQ (0x17) but need a new callback for when
   // write is done.
   var request = makeRequestBuffer(0x07, '', '', '', this.seq); // QUIT
@@ -796,6 +796,17 @@ Client.prototype.perform = function(key, request, seq, callback, retries) {
   serv.write(request);
 };
 
+// Increment the seq value
+Client.prototype.incrSeq = function() {
+  // Prevent seq from being larger than 2^31
+  // so that range errors do not occur. In event
+  // this occurs we simply roll over the value.
+  if (this.seq >  Math.pow(2,31)) {
+    this.seq = 0;
+  }
+  this.seq++;
+};
+
 exports.Client = Client;
 exports.Server = Server;
 exports.Utils = require('./utils');

test/client_test.js

@@ -727,4 +727,30 @@ test('Failover', function(t) {
   });
 
 });
+
+test('Very Large Client Seq', function(t) {
+  var n = 0;
+  var dummyServer = new MemJS.Server();
+  dummyServer.write = function(requestBuf) {
+    var request = MemJS.Utils.parseMessage(requestBuf);
+    t.equal('hello', request.key.toString());
+    t.equal('world', request.val.toString());
+    t.equal('0000000000000400', request.extras.toString('hex'));
+    n += 1;
+    dummyServer.respond({header: {status: 0, opaque: request.header.opaque}});
+  };
+
+  var client = new MemJS.Client([dummyServer], {expires: 1024});
+  client.seq = Math.pow(2,33);
+  var assertor = function(err, val) {
+    t.equal(null, err);
+    t.equal(true, val);
+    t.equal(1, n, 'Ensure add is called');
+  };
+  client.add('hello', 'world', {}, assertor);
+  n = 0;
+  return client.add('hello', 'world', {}).then(function(success) {
+    assertor(null, success);
+  });
+});
 return;