Move gaelogging from luci/luci-go to luci/gae

impl/prod/logger.go

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package prod
+
+import (
+        "fmt"
+
+        "github.com/luci/luci-go/common/logging"
+        "golang.org/x/net/context"
+        "google.golang.org/appengine/log"
+)
+
+// useLogging adds a logging.Logger implementation to the context which logs to
+// appengine's log handler.
+func useLogging(c context.Context) context.Context {
+        return logging.SetFactory(c, func(ic context.Context) logging.Logger {
+                return &loggerImpl{AEContext(ic)}
+        })
+}
+
+type loggerImpl struct {
+        aeCtx context.Context
+}
+
+func (gl *loggerImpl) Debugf(format string, args ...interface{}) {
+        gl.LogCall(logging.Debug, 1, format, args)
+}
+func (gl *loggerImpl) Infof(format string, args ...interface{}) {
+        gl.LogCall(logging.Info, 1, format, args)
+}
+func (gl *loggerImpl) Warningf(format string, args ...interface{}) {
+        gl.LogCall(logging.Warning, 1, format, args)
+}
+func (gl *loggerImpl) Errorf(format string, args ...interface{}) {
+        gl.LogCall(logging.Error, 1, format, args)
+}
+
+// TODO(riannucci): prefix with caller's code location.
+func (gl *loggerImpl) LogCall(l logging.Level, calldepth int, format string, args []interface{}) {
+        if gl.aeCtx == nil || !logging.IsLogging(gl.aeCtx, l) {
+                return
+        }
+
+        var logf func(context.Context, string, ...interface{})
+        switch l {
+        case logging.Debug:
+                logf = log.Debugf
+        case logging.Info:
+                logf = log.Infof
+        case logging.Warning:
+                logf = log.Warningf
+
+        case logging.Error:
+                fallthrough
+        default:
+                logf = log.Errorf
+        }
+
+        fields := logging.GetFields(gl.aeCtx)
+        if len(fields) > 0 {
+                logf(gl.aeCtx, "%s :: %s", fmt.Sprintf(format, args...), fields.FieldString(true))
+        } else {
+                logf(gl.aeCtx, format, args...)
+        }
+}