parser.go

 1package parser
 2
 3import (
 4	"errors"
 5	"fmt"
 6	"io"
 7
 8	"github.com/go-logfmt/logfmt"
 9
10	"github.com/TheEdgeOfRage/logfmt/config"
11)
12
13type Parser struct {
14	cfg    *config.Config
15	input  io.Reader
16	output io.Writer
17}
18
19func NewParser(cfg *config.Config, input io.Reader, output io.Writer) *Parser {
20	if cfg.BufferSize == 0 {
21		cfg.BufferSize = 1048576
22	}
23	return &Parser{
24		cfg:    cfg,
25		input:  input,
26		output: output,
27	}
28}
29
30// Start starts the parser, reading from the input stream and printing the log output to the output stream line by line
31func (p *Parser) Start() error {
32	decoder := logfmt.NewDecoderSize(p.input, p.cfg.BufferSize)
33	for decoder.ScanRecord() {
34		record, err := NewRecord(decoder, p.cfg)
35		if err != nil {
36			return err
37		}
38		if record.level < p.cfg.LogLevel {
39			continue
40		}
41		if len(p.cfg.Filter) > 0 && !record.MatchesFilter(p.cfg.Filter) {
42			continue
43		}
44		line := record.String(p.cfg)
45		if line != "" {
46			_, err = fmt.Fprintf(p.output, "%s\n", record.String(p.cfg))
47			if err != nil {
48				return fmt.Errorf("failed to print log to output: %w", err)
49			}
50		}
51	}
52
53	if errors.Is(decoder.Err(), io.EOF) {
54		return nil
55	}
56	return decoder.Err()
57}