| /* |
| * 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. |
| */ |
| |
| package main |
| |
| import ( |
| "bufio" |
| "encoding/json" |
| "errors" |
| "fmt" |
| "io" |
| "org/apache/htrace/common" |
| "os" |
| ) |
| |
| // A file used for input. |
| // Transparently supports using stdin for input. |
| type InputFile struct { |
| *os.File |
| path string |
| } |
| |
| // Open an input file. Stdin will be used when path is - |
| func OpenInputFile(path string) (*InputFile, error) { |
| if path == "-" { |
| return &InputFile{File: os.Stdin, path: path}, nil |
| } |
| file, err := os.Open(path) |
| if err != nil { |
| return nil, err |
| } |
| return &InputFile{File: file, path: path}, nil |
| } |
| |
| func (file *InputFile) Close() { |
| if file.path != "-" { |
| file.File.Close() |
| } |
| } |
| |
| // A file used for output. |
| // Transparently supports using stdout for output. |
| type OutputFile struct { |
| *os.File |
| path string |
| } |
| |
| // Create an output file. Stdout will be used when path is - |
| func CreateOutputFile(path string) (*OutputFile, error) { |
| if path == "-" { |
| return &OutputFile{File: os.Stdout, path: path}, nil |
| } |
| file, err := os.Create(path) |
| if err != nil { |
| return nil, err |
| } |
| return &OutputFile{File: file, path: path}, nil |
| } |
| |
| func (file *OutputFile) Close() error { |
| if file.path != "-" { |
| return file.File.Close() |
| } |
| return nil |
| } |
| |
| // FailureDeferringWriter is a writer which allows us to call Printf multiple |
| // times and then check if all the printfs succeeded at the very end, rather |
| // than checking after each call. We will not attempt to write more data |
| // after the first write failure. |
| type FailureDeferringWriter struct { |
| io.Writer |
| err error |
| } |
| |
| func NewFailureDeferringWriter(writer io.Writer) *FailureDeferringWriter { |
| return &FailureDeferringWriter{writer, nil} |
| } |
| |
| func (w *FailureDeferringWriter) Printf(format string, v ...interface{}) { |
| if w.err != nil { |
| return |
| } |
| str := fmt.Sprintf(format, v...) |
| _, err := w.Writer.Write([]byte(str)) |
| if err != nil { |
| w.err = err |
| } |
| } |
| |
| func (w *FailureDeferringWriter) Error() error { |
| return w.err |
| } |
| |
| // Read a file full of whitespace-separated span JSON into a slice of spans. |
| func readSpansFile(path string) (common.SpanSlice, error) { |
| file, err := OpenInputFile(path) |
| if err != nil { |
| return nil, err |
| } |
| defer file.Close() |
| return readSpans(bufio.NewReader(file)) |
| } |
| |
| // Read whitespace-separated span JSON into a slice of spans. |
| func readSpans(reader io.Reader) (common.SpanSlice, error) { |
| spans := make(common.SpanSlice, 0) |
| dec := json.NewDecoder(reader) |
| for { |
| var span common.Span |
| err := dec.Decode(&span) |
| if err != nil { |
| if err != io.EOF { |
| return nil, errors.New(fmt.Sprintf("Decode error after decoding %d "+ |
| "span(s): %s", len(spans), err.Error())) |
| } |
| break |
| } |
| spans = append(spans, &span) |
| } |
| return spans, nil |
| } |