Add logger class

lib/mongo.rb

@@ -5,6 +5,7 @@
 require 'mongo/collection'
 require 'mongo/database'
 require 'mongo/event'
+require 'mongo/logger'
 require 'mongo/pool'
 require 'mongo/protocol'
 require 'mongo/scope'

lib/mongo/logger.rb

@@ -0,0 +1,130 @@
+# Copyright (C) 2009-2014 MongoDB, 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.
+
+module Mongo
+
+  # Provides ability to log messages.
+  #
+  # @since 3.0.0
+  class Logger
+
+    class << self
+
+      # Log a debug level message.
+      #
+      # @example Log a debug level message.
+      #   Logger.debug('mongo', 'message', '10ms')
+      #
+      # @param [ String ] prefix The category prefix.
+      # @param [ String ] payload The log message.
+      # @param [ String ] runtime The time of the operation.
+      #
+      # @since 3.0.0
+      def debug(prefix, payload, runtime)
+        logger.debug("#{prefix} | #{payload} | runtime: #{runtime}")
+      end
+
+      # Log a error level message.
+      #
+      # @example Log a error level message.
+      #   Logger.error('mongo', 'message', '10ms')
+      #
+      # @param [ String ] prefix The category prefix.
+      # @param [ String ] payload The log message.
+      # @param [ String ] runtime The time of the operation.
+      #
+      # @since 3.0.0
+      def error(prefix, payload, runtime)
+        logger.error("#{prefix} | #{payload} | runtime: #{runtime}")
+      end
+
+      # Log a fatal level message.
+      #
+      # @example Log a fatal level message.
+      #   Logger.fatal('mongo', 'message', '10ms')
+      #
+      # @param [ String ] prefix The category prefix.
+      # @param [ String ] payload The log message.
+      # @param [ String ] runtime The time of the operation.
+      #
+      # @since 3.0.0
+      def fatal(prefix, payload, runtime)
+        logger.fatal("#{prefix} | #{payload} | runtime: #{runtime}")
+      end
+
+      # Log a info level message.
+      #
+      # @example Log a info level message.
+      #   Logger.info('mongo', 'message', '10ms')
+      #
+      # @param [ String ] prefix The category prefix.
+      # @param [ String ] payload The log message.
+      # @param [ String ] runtime The time of the operation.
+      #
+      # @since 3.0.0
+      def info(prefix, payload, runtime)
+        logger.info("#{prefix} | #{payload} | runtime: #{runtime}")
+      end
+
+      # Log a warn level message.
+      #
+      # @example Log a warn level message.
+      #   Logger.warn('mongo', 'message', '10ms')
+      #
+      # @param [ String ] prefix The category prefix.
+      # @param [ String ] payload The log message.
+      # @param [ String ] runtime The time of the operation.
+      #
+      # @since 3.0.0
+      def warn(prefix, payload, runtime)
+        logger.warn("#{prefix} | #{payload} | runtime: #{runtime}")
+      end
+
+      # Get the wrapped logger. If none was set will return a default debug
+      # level logger.
+      #
+      # @example Get the wrapped logger.
+      #   Mongo::Logger.logger
+      #
+      # @return [ ::Logger ] The wrapped logger.
+      #
+      # @since 3.0.0
+      def logger
+        @logger ||= default_logger
+      end
+
+      # Set the logger.
+      #
+      # @example Set the wrapped logger.
+      #   Mongo::Logger.logger = logger
+      #
+      # @param [ ::Logger ] other The logger to set.
+      #
+      # @return [ ::Logger ] The wrapped logger.
+      #
+      # @since 3.0.0
+      def logger=(other)
+        @logger = other
+      end
+
+      private
+
+      def default_logger
+        logger = ::Logger.new($stdout)
+        logger.level = ::Logger::DEBUG
+        logger
+      end
+    end
+  end
+end

spec/mongo/logger_spec.rb

@@ -0,0 +1,85 @@
+require 'spec_helper'
+
+describe Mongo::Logger do
+
+  let(:logger) do
+    described_class.logger
+  end
+
+  describe '.debug' do
+
+    it 'logs a debug message' do
+      expect(logger).to receive(:debug).with("mongo.query | message | runtime: 10ms")
+      described_class.debug('mongo.query', 'message', '10ms')
+    end
+  end
+
+  describe '.error' do
+
+    it 'logs a error message' do
+      expect(logger).to receive(:error).with("mongo.query | message | runtime: 10ms")
+      described_class.error('mongo.query', 'message', '10ms')
+    end
+  end
+
+  describe '.fatal' do
+
+    it 'logs a fatal message' do
+      expect(logger).to receive(:fatal).with("mongo.query | message | runtime: 10ms")
+      described_class.fatal('mongo.query', 'message', '10ms')
+    end
+  end
+
+  describe '.info' do
+
+    it 'logs a info message' do
+      expect(logger).to receive(:info).with("mongo.query | message | runtime: 10ms")
+      described_class.info('mongo.query', 'message', '10ms')
+    end
+  end
+
+  describe '.logger' do
+
+    context 'when no logger has been set' do
+
+      it 'returns the default logger' do
+        expect(logger.level).to eq(Logger::DEBUG)
+      end
+    end
+
+    context 'when a logger has been set' do
+
+      let(:info) do
+        Logger.new($stdout).tap do |log|
+          log.level = Logger::INFO
+        end
+      end
+
+      let(:debug) do
+        Logger.new($stdout).tap do |log|
+          log.level = Logger::DEBUG
+        end
+      end
+
+      before do
+        described_class.logger = info
+      end
+
+      after do
+        described_class.logger = debug
+      end
+
+      it 'returns the provided logger' do
+        expect(logger.level).to eq(Logger::INFO)
+      end
+    end
+  end
+
+  describe '.warn' do
+
+    it 'logs a warn message' do
+      expect(logger).to receive(:warn).with("mongo.query | message | runtime: 10ms")
+      described_class.warn('mongo.query', 'message', '10ms')
+    end
+  end
+end