| // Copyright (C) 2015 The Android Open Source Project |
| // |
| // 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 log |
| |
| import ( |
| "io" |
| "os" |
| "path/filepath" |
| ) |
| |
| type syncer interface { |
| Sync() error |
| } |
| |
| func doSync(w io.Writer) { |
| if w != nil { |
| if s, ok := w.(syncer); ok { |
| s.Sync() |
| } |
| } |
| } |
| |
| // Writer returns a Logger that writes to the supplied streams. |
| func Writer(info, warn, err io.Writer, done func()) Logger { |
| out := make(chan interface{}, 64) |
| go func() { |
| if done != nil { |
| defer done() |
| } |
| for t := range out { |
| switch t := t.(type) { |
| case Entry: |
| switch t.Kind { |
| case Info: |
| io.WriteString(info, t.String()) |
| case Warning: |
| io.WriteString(warn, t.String()) |
| case Error: |
| io.WriteString(err, t.String()) |
| default: |
| io.WriteString(info, t.String()) |
| } |
| case FlushRequest: |
| doSync(info) |
| doSync(warn) |
| doSync(err) |
| close(t) |
| } |
| } |
| }() |
| nextUid := uint32(1) |
| return &channel{ |
| uid: 0, |
| nextUid: &nextUid, |
| scope: "", |
| out: out, |
| } |
| } |
| |
| // File creates a new Logger that will write messages to the specified file path. |
| // If a file exists at the specified path, then this file will be overwritten. |
| func File(path string) (Logger, error) { |
| os.MkdirAll(filepath.Dir(path), 0755) |
| file, err := os.Create(path) |
| if err != nil { |
| return nil, err |
| } |
| return Writer(file, file, file, func() { file.Close() }), nil |
| } |
| |
| // Std returns a Logger that writes to stdout and stderr. |
| func Std() Logger { |
| return Writer(os.Stdout, os.Stdout, os.Stderr, nil) |
| } |