service/vendor/github.com/sirupsen/logrus/writer.go

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2023-12-21 22:17:40 +08:00
package logrus
import (
"bufio"
"io"
"runtime"
"strings"
)
// Writer at INFO level. See WriterLevel for details.
func (logger *Logger) Writer() *io.PipeWriter {
return logger.WriterLevel(InfoLevel)
}
// WriterLevel returns an io.Writer that can be used to write arbitrary text to
// the logger at the given log level. Each line written to the writer will be
// printed in the usual way using formatters and hooks. The writer is part of an
// io.Pipe and it is the callers responsibility to close the writer when done.
// This can be used to override the standard library logger easily.
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
case DebugLevel:
printFunc = entry.Debug
case InfoLevel:
printFunc = entry.Info
case WarnLevel:
printFunc = entry.Warn
case ErrorLevel:
printFunc = entry.Error
case FatalLevel:
printFunc = entry.Fatal
case PanicLevel:
printFunc = entry.Panic
default:
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 := bufio.MaxScanTokenSize // 64KB
splitFunc := func(data []byte, atEOF bool) (int, []byte, error) {
if len(data) >= chunkSize {
return chunkSize, data[:chunkSize], nil
}
return bufio.ScanLines(data, atEOF)
}
// 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(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()
}