forked from scionproto/scion
/
logentry.go
124 lines (113 loc) · 3.42 KB
/
logentry.go
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// Copyright 2018 Anapaya Systems
//
// Licensed 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 logparse
import (
"bufio"
"fmt"
"io"
"regexp"
"strings"
"time"
"github.com/scionproto/scion/go/lib/common"
"github.com/scionproto/scion/go/lib/log"
)
var (
lineRegex = regexp.MustCompile(` \[(\w+)\] (.+)`)
)
// LogEntry is one entry in a log.
type LogEntry struct {
Timestamp time.Time
// Element describes the source of this LogEntry, e.g. the file name.
Element string
Level log.Lvl
Lines []string
}
func (l LogEntry) String() string {
return fmt.Sprintf("%s [%s] %s\n", l.Timestamp.Format(common.TimeFmt), l.Level, l.Lines)
}
// ParseFrom parses log lines from the reader.
//
// 2017-05-16T13:18:16.539536145+0000 [DBUG] Topology loaded topo=
// > Loc addrs:
// > 127.0.0.65:30066
// > Interfaces:
// > IFID: 41 Link: CORE Local: 127.0.0.6:50000 Remote: 127.0.0.7:50000 IA: 1-ff00:0:312
// 2017-05-16T13:18:16.539658666+0000 [INFO] Starting up id=br1-ff00:0:311-1
//
// Lines starting with "> " or a space are assumed to be continuations, i.e.
// they belong with the line(s) above them.
//
// The fileName is used for logging.
// The element is put in LogEntry.Element.
// Parsed entries are passed to the entryConsumer.
func ParseFrom(reader io.Reader, fileName, element string, entryConsumer func(LogEntry)) {
var prevEntry *LogEntry
scanner := bufio.NewScanner(reader)
for lineno := 1; scanner.Scan(); lineno++ {
line := scanner.Text()
if isContinuation(line) {
// If this is a continuation at the start of the reader, just drop it
if prevEntry == nil {
continue
}
prevEntry.Lines = append(prevEntry.Lines, line)
continue
}
if prevEntry != nil {
entryConsumer(*prevEntry)
}
prevEntry = parseInitialEntry(line, fileName, element, lineno)
}
if prevEntry != nil {
entryConsumer(*prevEntry)
}
}
// parseInitialEntry parses a line with the pattern <TS> [<Level>] <Entry>.
func parseInitialEntry(line, fileName, element string, lineno int) *LogEntry {
tsLen := len(common.TimeFmt)
if len(line) < tsLen {
log.Error(fmt.Sprintf("Short line at %s:%d: '%+v'", fileName, lineno, line))
}
ts, err := time.Parse(common.TimeFmt, line[:tsLen])
if err != nil {
log.Error(fmt.Sprintf("%s:%d: Could not parse timestamp %+v: %+v",
fileName, lineno, line[:tsLen], err))
return nil
}
matches := lineRegex.FindStringSubmatch(line[tsLen:])
if matches == nil || len(matches) < 3 {
log.Error(fmt.Sprintf("Line %s:%d does not match regexep: %s",
fileName, lineno, lineRegex))
return nil
}
lvl, err := log.LvlFromString(matches[1])
if err != nil {
log.Error(fmt.Sprintf("%s:%d: Unknown log level: %v", fileName, lineno, err))
}
return &LogEntry{
Timestamp: ts,
Element: element,
Level: lvl,
Lines: []string{matches[2]},
}
}
func isContinuation(line string) bool {
return strings.HasPrefix(line, "> ") || strings.HasPrefix(line, " ")
}
func min(a, b int) int {
if a < b {
return a
}
return b
}