| package log |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| import ( |
| "log" |
| "strings" |
| ) |
| |
| // StandardLogger returns a new Logger which will write the appropriate prefix for standard log Printf calls. |
| // This allows the given logger to prefix correctly when passed to third-party or standard library functions which only know about the standard Logger interface. |
| // It does this by wrapping logger's error print as a writer, and sets that as the new Logger's io.Writer. |
| // |
| // prefix is a prefix to add, which will be added immediately before messages, but after any existing prefix on logger and the timestamp. |
| // |
| func StandardLogger(logger *log.Logger, prefix string) *log.Logger { |
| return log.New(&standardLoggerWriter{realLogger: logger, prefix: prefix}, "", 0) |
| } |
| |
| type standardLoggerWriter struct { |
| realLogger *log.Logger |
| prefix string |
| } |
| |
| // Write writes to writer's underlying log, in the standard log format (note this is not the Event log format). |
| // The writer.realLogger may be nil, in which case this does nothing. |
| // This always returns len(p) and nil, claiming it successfully wrote even if it didn't. |
| func (writer *standardLoggerWriter) Write(p []byte) (n int, err error) { |
| logln(writer.realLogger, writer.prefix+strings.TrimSpace(string(p))) |
| return len(p), nil |
| } |