logger.go

// Copyright 2024 The original author or 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 gslog

import (
	"context"

	"cloud.google.com/go/logging"
)

// Logger is wraps the set of methods that are used when interacting with a
// logging.Logger.  This interface facilitates stubbing out calls to the Logger
// for the purposes of testing and benchmarking.
type Logger interface {
	Log
	LogSync

	// Flush blocks until all currently buffered log entries are sent.
	//
	// If any errors occurred since the last call to Flush from any Logger, or the
	// creation of the client if this is the first call, then Flush returns a non-nil
	// error with summary information about the errors. This information is unlikely to
	// be actionable. For more accurate error reporting, set Client.OnError.
	Flush() error
}

// Log wraps the asynchronous buffered logging of records to
// Google Cloud Logging.
type Log interface {
	// Log buffers the Entry for output to the logging service. It never blocks.
	Log(e logging.Entry)
}

// LogSync wraps the synchronous logging of records to
// Google Cloud Logging.
type LogSync interface {
	// LogSync logs the Entry synchronously without any buffering. Because LogSync is slow
	// and will block, it is intended primarily for debugging or critical errors.
	// Prefer Log for most uses.
	LogSync(ctx context.Context, e logging.Entry) error
}

// The LoggerFunc type is an adapter to allow the use of
// ordinary functions as a Logger. If fn is a function
// with the appropriate signature, LoggerFunc(fn) is a
// Logger that calls fn.
type LoggerFunc func(e logging.Entry)

// Log implements Log.Log.
func (fn LoggerFunc) Log(e logging.Entry) {
	fn(e)
}

// LogSync implements LogSync.LogSync.
func (fn LoggerFunc) LogSync(_ context.Context, e logging.Entry) error {
	fn(e)

	return nil
}

// Flush implements Logger.Flush.
func (fn LoggerFunc) Flush() error {
	return nil
}