Adding batch support to new service interface

Author: Sergio Gomes

lib/google/api_client/service.rb

@@ -17,6 +17,7 @@
 require 'google/api_client/service/resource'
 require 'google/api_client/service/request'
 require 'google/api_client/service/result'
+require 'google/api_client/service/batch'
 
 module Google
   class APIClient
@@ -150,34 +151,54 @@ def initialize(api_name, api_version, options = {})
       # @return [Faraday::Connection]
       attr_accessor :connection
 
+      ##
+      # Prepares a Google::APIClient::BatchRequest object to make batched calls.
+      # @param [Array] calls
+      #   Optional array of Google::APIClient::Service::Request to initialize
+      #   the batch request with.
+      # @param [Proc] block
+      #   Callback for every call's response. Won't be called if a call defined
+      #   a callback of its own.
+      #
+      # @yield [Google::APIClient::Service::Result]
+      #   block to be called when result ready
+      def batch(calls = nil, &block)
+        Google::APIClient::Service::BatchRequest.new(self, calls, &block)
+      end
+
       ##
       # Executes an API request.
       # Do not call directly; this method is only used by Request objects when
       # executing.
       #
-      # @param [Google::APIClient::Service::Request] request
+      # @param [Google::APIClient::Service::Request,
+      #         Google::APIClient::Service::BatchCall] request
       #   The request to be executed.
       def execute(request)
-        params = {:api_method => request.method,
-          :parameters => request.parameters,
-          :connection => @connection}
-        if request.respond_to? :body
-          if request.body.respond_to? :to_hash
-            params[:body_object] = request.body
-          else
-            params[:body] = request.body
+        if request.instance_of? Google::APIClient::Service::Request
+          params = {:api_method => request.method,
+            :parameters => request.parameters,
+            :connection => @connection}
+          if request.respond_to? :body
+            if request.body.respond_to? :to_hash
+              params[:body_object] = request.body
+            else
+              params[:body] = request.body
+            end
           end
-        end
-        if request.respond_to? :media
-          params[:media] = request.media
-        end
-        [:authenticated, :gzip].each do |option|
-          if @options.include? option
-            params[option] = @options[option]
+          if request.respond_to? :media
+            params[:media] = request.media
+          end
+          [:authenticated, :gzip].each do |option|
+            if @options.include? option
+              params[option] = @options[option]
+            end
           end
+          result = @client.execute(params)
+          return Google::APIClient::Service::Result.new(request, result)
+        elsif request.instance_of? Google::APIClient::Service::BatchRequest
+          @client.execute(request.base_batch)
         end
-        result = @client.execute(params)
-        return Google::APIClient::Service::Result.new(request, result)
       end
     end
   end

lib/google/api_client/service/batch.rb

@@ -0,0 +1,103 @@
+# Copyright 2013 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require 'google/api_client/service/result'
+require 'google/api_client/batch'
+
+module Google
+  class APIClient
+    class Service
+
+      ##
+      # Helper class to contain the result of an individual batched call.
+      #
+      class BatchedCallResult < Result
+        # @return [String] UUID of the call
+        def call_index
+          return @base_result.response.call_id.to_i - 1
+        end
+      end
+
+      ##
+      #
+      #
+      class BatchRequest
+        ##
+        # Creates a new batch request.
+        # This class shouldn't be instantiated directly, but rather through
+        # Service.batch.
+        #
+        # @param [Array] calls
+        #   List of Google::APIClient::Service::Request to be made.
+        # @param [Proc] block
+        #   Callback for every call's response. Won't be called if a call
+        #   defined a callback of its own.
+        #
+        # @yield [Google::APIClient::Service::Result]
+        #   block to be called when result ready
+        def initialize(service, calls, &block)
+          @service = service
+          @base_batch = Google::APIClient::BatchRequest.new
+          @global_callback = block if block_given?
+
+          if calls && calls.length > 0
+            calls.each do |call|
+              add(call)
+            end
+          end
+        end
+
+        ##
+        # Add a new call to the batch request.
+        #
+        # @param [Google::APIClient::Service::Request] call
+        #   the call to be added.
+        # @param [Proc] block
+        #   callback for this call's response.
+        #
+        # @return [Google::APIClient::Service::BatchRequest]
+        #   the BatchRequest, for chaining
+        #
+        # @yield [Google::APIClient::Service::Result]
+        #   block to be called when result ready
+        def add(call, &block)
+          if !block_given? && @global_callback.nil?
+            raise BatchError, 'Request needs a block'
+          end
+          callback = block || @global_callback
+          base_call = {
+            :api_method => call.method,
+            :parameters => call.parameters
+          }
+          @base_batch.add(base_call) do |base_result|
+            result = Google::APIClient::Service::BatchedCallResult.new(
+                call, base_result)
+            callback.call(result)
+          end
+          return self
+        end
+
+        ##
+        # Executes the batch request.
+        def execute
+          @service.execute(self)
+        end
+
+        attr_reader :base_batch
+
+      end
+
+    end
+  end
+end

spec/google/api_client/service_spec.rb

@@ -473,3 +473,100 @@
     end
   end
 end
+
+describe Google::APIClient::Service::BatchRequest do
+  describe 'with the discovery API' do
+    before do
+      @discovery = Google::APIClient::Service.new('discovery', 'v1',
+          {:application_name => APPLICATION_NAME, :authorization => nil})
+    end
+
+    describe 'with two valid requests' do
+      before do
+        @calls = [
+          @discovery.apis.get_rest(:api => 'plus', :version => 'v1'),
+          @discovery.apis.get_rest(:api => 'discovery', :version => 'v1')
+        ]
+      end
+
+      it 'should execute both when using a global callback' do
+        block_called = 0
+        batch = @discovery.batch(@calls) do |result|
+          block_called += 1
+          result.status.should == 200
+        end
+
+        batch.execute
+        block_called.should == 2
+      end
+
+      it 'should execute both when using individual callbacks' do
+        call1_returned, call2_returned = false, false
+        batch = @discovery.batch
+
+        batch.add(@calls[0]) do |result|
+          call1_returned = true
+          result.status.should == 200
+          result.call_index.should == 0
+        end
+
+        batch.add(@calls[1]) do |result|
+          call2_returned = true
+          result.status.should == 200
+          result.call_index.should == 1
+        end
+
+        batch.execute
+        call1_returned.should == true
+        call2_returned.should == true
+      end
+    end
+
+    describe 'with a valid request and an invalid one' do
+      before do
+        @calls = [
+          @discovery.apis.get_rest(:api => 'plus', :version => 'v1'),
+          @discovery.apis.get_rest(:api => 'invalid', :version => 'invalid')
+        ]
+      end
+
+      it 'should execute both when using a global callback' do
+        block_called = 0
+        batch = @discovery.batch(@calls) do |result|
+          block_called += 1
+          if result.call_index == 0
+            result.status.should == 200
+          else
+            result.status.should >= 400
+            result.status.should < 500
+          end
+        end
+
+        batch.execute
+        block_called.should == 2
+      end
+
+      it 'should execute both when using individual callbacks' do
+        call1_returned, call2_returned = false, false
+        batch = @discovery.batch
+
+        batch.add(@calls[0]) do |result|
+          call1_returned = true
+          result.status.should == 200
+          result.call_index.should == 0
+        end
+
+        batch.add(@calls[1]) do |result|
+          call2_returned = true
+          result.status.should >= 400
+          result.status.should < 500
+          result.call_index.should == 1
+        end
+
+        batch.execute
+        call1_returned.should == true
+        call2_returned.should == true
+      end
+    end
+  end
+end