logdog/appengine/coordinator/flex/logs/service.go

// Copyright 2015 The LUCI Authors.
//
// 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.

package logs

import (
	"context"

	"github.com/golang/protobuf/proto"
	"google.golang.org/grpc/codes"

	"go.chromium.org/luci/grpc/grpcutil"
	logdog "go.chromium.org/luci/logdog/api/endpoints/coordinator/logs/v1"
	"go.chromium.org/luci/logdog/appengine/coordinator"
	"go.chromium.org/luci/logdog/appengine/coordinator/endpoints"
)

// Server is the user-facing log access and query endpoint service.
type server struct {
	// resultLimit is the maximum number of query results to return in a
	// single query. If zero, the default will be used.
	//
	// This is provided for testing purposes.
	resultLimit int
}

// New creates a new authenticating LogsServer instance.
func New() logdog.LogsServer {
	return &logdog.DecoratedLogs{
		Service: &server{},
		Prelude: func(ctx context.Context, methodName string, req proto.Message) (context.Context, error) {
			// Enter a datastore namespace based on the message type. All RPC messages
			// in LogsServer must implement ProjectBoundMessage. We panic if they
			// don't.
			project := req.(endpoints.ProjectBoundMessage).GetMessageProject()
			if project == "" {
				return nil, grpcutil.Errf(codes.InvalidArgument, "project is required")
			}
			if err := coordinator.WithProjectNamespace(&ctx, project); err != nil {
				return nil, grpcutil.GRPCifyAndLogErr(ctx, err)
			}
			return ctx, nil
		},
	}
}

func (s *server) limit(v int, d int) int {
	if s.resultLimit > 0 {
		d = s.resultLimit
	}
	if v <= 0 || v > d {
		return d
	}
	return v
}