bee/util.go

// Copyright 2013 bee 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 main

import (
	"fmt"
	"os"
	"path/filepath"
	"runtime"
)

// Go is a basic promise implementation: it wraps calls a function in a goroutine
// and returns a channel which will later return the function's return value.
func Go(f func() error) chan error {
	ch := make(chan error)
	go func() {
		ch <- f()
	}()
	return ch
}

// if os.env DEBUG set, debug is on
func Debugf(format string, a ...interface{}) {
	if os.Getenv("DEBUG") != "" {
		_, file, line, ok := runtime.Caller(1)
		if !ok {
			file = "<unknown>"
			line = -1
		} else {
			file = filepath.Base(file)
		}
		fmt.Fprintf(os.Stderr, fmt.Sprintf("[debug] %s:%d %s\n", file, line, format), a...)
	}
}