spanner: add object caching (#2362)

packages/spanner/src/database.js

@@ -232,7 +232,10 @@ Database.formatName_ = function(instanceName, name) {
  * });
  */
 Database.prototype.close = function(callback) {
+  var self = this;
+
   this.pool_.clear().then(function() {
+    self.parent.databases_.delete(self.id);
     callback(null);
   }, function(err) {
     callback(err || new Error('Unable to close database connection.'));
@@ -327,9 +330,11 @@ Database.prototype.createTable = function(schema, callback) {
  * });
  */
 Database.prototype.delete = function(callback) {
-  return this.api.Database.dropDatabase({
+  var reqOpts = {
     database: this.formattedName_
-  }, callback);
+  };
+
+  return this.api.Database.dropDatabase(reqOpts, callback);
 };
 
 /**

packages/spanner/src/index.js

@@ -43,6 +43,7 @@ var Instance = require('./instance.js');
 
 var v1 = require('./v1');
 
+
 /**
  * [Cloud Spanner](https://cloud.google.com/spanner) is a highly scalable,
  * transactional, managed, NewSQL database service. Cloud Spanner solves the
@@ -91,6 +92,8 @@ function Spanner(options) {
   };
 
   commonGrpc.Service.call(this, config, options);
+
+  this.instances_ = new Map();
 }
 
 util.inherits(Spanner, commonGrpc.Service);
@@ -464,7 +467,11 @@ Spanner.prototype.instance = function(name) {
     throw new Error('A name is required to access an Instance object.');
   }
 
-  return new Instance(this, name);
+  if (!this.instances_.has(name)) {
+    this.instances_.set(name, new Instance(this, name));
+  }
+
+  return this.instances_.get(name);
 };
 
 /**

packages/spanner/src/instance.js

@@ -142,6 +142,8 @@ function Instance(spanner, name) {
       spanner.createInstance(self.formattedName_, options, callback);
     }
   });
+
+  this.databases_ = new Map();
 }
 
 util.inherits(Instance, commonGrpc.ServiceObject);
@@ -283,7 +285,11 @@ Instance.prototype.database = function(name, poolOptions) {
     throw new Error('A name is required to access a Database object.');
   }
 
-  return new Database(this, name, poolOptions);
+  if (!this.databases_.has(name)) {
+    this.databases_.set(name, new Database(this, name, poolOptions));
+  }
+
+  return this.databases_.get(name);
 };
 
 /**
@@ -312,9 +318,19 @@ Instance.prototype.database = function(name, poolOptions) {
  * });
  */
 Instance.prototype.delete = function(callback) {
-  return this.api.Instance.deleteInstance({
+  var self = this;
+
+  var reqOpts = {
     name: this.formattedName_
-  }, callback);
+  };
+
+  return this.api.Instance.deleteInstance(reqOpts, function(err, resp) {
+    if (!err) {
+      self.parent.instances_.delete(self.id);
+    }
+
+    callback(err, resp);
+  });
 };
 
 /**

packages/spanner/src/session-pool.js

@@ -500,7 +500,7 @@ SessionPool.prototype.getNextAvailableSession_ = function(options, callback) {
     return;
   }
 
-  this.pollForSession_(callback);
+  this.pollForSession_(options, callback);
 };
 
 /**
@@ -511,8 +511,9 @@ SessionPool.prototype.getNextAvailableSession_ = function(options, callback) {
  * @param {function} callback - The callback function to be executed when a
  *     session is available.
  */
-SessionPool.prototype.pollForSession_ = function(callback) {
+SessionPool.prototype.pollForSession_ = function(options, callback) {
   this.pendingAcquires.push({
+    options: options,
     callback: callback,
     timeout: this.acquireTimeout
   });
@@ -531,7 +532,8 @@ SessionPool.prototype.pollForSession_ = function(callback) {
       self.writePool && self.writePool.free;
 
     if (hasFreeSession) {
-      self.getNextAvailableSession_(self.pendingAcquires.shift().callback);
+      var acquireReq = self.pendingAcquires.shift();
+      self.getNextAvailableSession_(acquireReq.options, acquireReq.callback);
     }
 
     if (!self.pendingAcquires.length) {

packages/spanner/src/transaction.js

@@ -371,7 +371,6 @@ Transaction.prototype.requestStream = function(config) {
       return;
     }
 
-    requestStream.end();
     userStream.destroy();
 
     if (self.shouldRetry_(err)) {

packages/spanner/system-test/spanner.js

@@ -3070,7 +3070,75 @@ var spanner = new Spanner(env);
         });
       });
 
-      it('should retry an aborted transaction', function(done) {
+      it('should retry an aborted txn when reading fails', function(done) {
+        var query = `SELECT * FROM ${table.name}`;
+        var attempts = 0;
+
+        var expectedRow = {
+          Key: 'k888',
+          NumberValue: null,
+          StringValue: 'abc'
+        };
+
+        database.runTransaction(function(err, transaction) {
+          assert.ifError(err);
+
+          transaction.run(query, function(err) {
+            assert.ifError(err);
+
+            var action = attempts++ === 0 ? runOtherTransaction : wrap;
+
+            action(function(err) {
+              assert.ifError(err);
+
+              transaction.run(query, function(err, rows) {
+                assert.ifError(err);
+
+                transaction.insert(table.name, {
+                  Key: generateName('key'),
+                  StringValue: generateName('val')
+                });
+
+                transaction.commit(function(err) {
+                  assert.ifError(err);
+
+                  var lastRow = rows.pop().toJSON();
+
+                  assert.deepEqual(lastRow, expectedRow);
+                  assert.strictEqual(attempts, 2);
+
+                  done();
+                });
+              });
+            });
+          });
+        });
+
+        function runOtherTransaction(callback) {
+          database.runTransaction(function(err, transaction) {
+            if (err) {
+              callback(err);
+              return;
+            }
+
+            transaction.run(query, function(err) {
+              if (err) {
+                callback(err);
+                return;
+              }
+
+              transaction.insert(table.name, expectedRow);
+              transaction.commit(callback);
+            });
+          });
+        }
+
+        function wrap(callback) {
+          setImmediate(callback);
+        }
+      });
+
+      it('should retry an aborted txn when commit fails', function(done) {
         var query = `SELECT * FROM ${table.name}`;
         var attempts = 0;
 

packages/spanner/test/database.js

@@ -78,7 +78,8 @@ describe('Database', function() {
 
   var INSTANCE = {
     api: {},
-    formattedName_: 'instance-name'
+    formattedName_: 'instance-name',
+    databases_: new Map()
   };
 
   var NAME = 'table-name';
@@ -199,15 +200,31 @@ describe('Database', function() {
 
   describe('close', function() {
     describe('success', function() {
-      it('should close the database', function(done) {
+      beforeEach(function() {
+        database.parent = INSTANCE;
         database.pool_ = {
           clear: function() {
             return Promise.resolve();
           }
         };
+      });
 
+      it('should close the database', function(done) {
         database.close(done);
       });
+
+      it('should remove the database cache', function(done) {
+        var cache = INSTANCE.databases_;
+
+        cache.set(database.id, database);
+        assert(cache.has(database.id));
+
+        database.close(function(err) {
+          assert.ifError(err);
+          assert.strictEqual(cache.has(database.id), false);
+          done();
+        });
+      });
     });
 
     describe('error', function() {

packages/spanner/test/index.js

@@ -121,6 +121,10 @@ describe('Spanner', function() {
   });
 
   describe('instantiation', function() {
+    it('should localize an instance map', function() {
+      assert(spanner.instances_ instanceof Map);
+    });
+
     it('should promisify all the things', function() {
       assert(promisified);
     });
@@ -639,11 +643,28 @@ describe('Spanner', function() {
       }, /A name is required to access an Instance object\./);
     });
 
-    it('should return an Instance object', function() {
+    it('should create and cache an Instance', function() {
+      var cache = spanner.instances_;
+
+      assert.strictEqual(cache.has(NAME), false);
+
       var instance = spanner.instance(NAME);
+
       assert(instance instanceof FakeInstance);
       assert.strictEqual(instance.calledWith_[0], spanner);
       assert.strictEqual(instance.calledWith_[1], NAME);
+      assert.strictEqual(instance, cache.get(NAME));
+    });
+
+    it('should re-use cached objects', function() {
+      var cache = spanner.instances_;
+      var fakeInstance = {};
+
+      cache.set(NAME, fakeInstance);
+
+      var instance = spanner.instance(NAME);
+
+      assert.strictEqual(instance, fakeInstance);
     });
   });