diff --git a/writer.go b/writer.go index 72e8e3a1..36032d06 100644 --- a/writer.go +++ b/writer.go @@ -4,6 +4,7 @@ import ( "bufio" "io" "runtime" + "strings" ) // Writer at INFO level. See WriterLevel for details. @@ -20,15 +21,18 @@ func (logger *Logger) WriterLevel(level Level) *io.PipeWriter { return NewEntry(logger).WriterLevel(level) } +// Writer returns an io.Writer that writes to the logger at the info log level func (entry *Entry) Writer() *io.PipeWriter { return entry.WriterLevel(InfoLevel) } +// WriterLevel returns an io.Writer that writes to the logger at the given log level func (entry *Entry) WriterLevel(level Level) *io.PipeWriter { reader, writer := io.Pipe() var printFunc func(args ...interface{}) + // Determine which log function to use based on the specified log level switch level { case TraceLevel: printFunc = entry.Trace @@ -48,23 +52,50 @@ func (entry *Entry) WriterLevel(level Level) *io.PipeWriter { printFunc = entry.Print } + // Start a new goroutine to scan the input and write it to the logger using the specified print function. + // It splits the input into chunks of up to 64KB to avoid buffer overflows. go entry.writerScanner(reader, printFunc) + + // Set a finalizer function to close the writer when it is garbage collected runtime.SetFinalizer(writer, writerFinalizer) return writer } +// writerScanner scans the input from the reader and writes it to the logger func (entry *Entry) writerScanner(reader *io.PipeReader, printFunc func(args ...interface{})) { scanner := bufio.NewScanner(reader) + + // Set the buffer size to the maximum token size to avoid buffer overflows + scanner.Buffer(make([]byte, bufio.MaxScanTokenSize), bufio.MaxScanTokenSize) + + // Define a split function to split the input into chunks of up to 64KB + chunkSize := 64 * 1024 // 64KB + splitFunc := func(data []byte, atEOF bool) (int, []byte, error) { + if len(data) > chunkSize { + return chunkSize, data[:chunkSize], nil + } + return 0, nil, nil + } + + //Use the custom split function to split the input + scanner.Split(splitFunc) + + // Scan the input and write it to the logger using the specified print function for scanner.Scan() { - printFunc(scanner.Text()) + printFunc(strings.TrimRight(scanner.Text(), "\r\n")) } + + // If there was an error while scanning the input, log an error if err := scanner.Err(); err != nil { entry.Errorf("Error while reading from Writer: %s", err) } + + // Close the reader when we are done reader.Close() } +// WriterFinalizer is a finalizer function that closes then given writer when it is garbage collected func writerFinalizer(writer *io.PipeWriter) { writer.Close() }