AdGuardHome/internal/querylog/querylogfile.go
Ainar Garipov a572876775 Pull request: all: fix lint and naming issues
Merge in DNS/adguard-home from 2276-fix-lint to master

Updates #2276.

Squashed commit of the following:

commit 433f44cc7b674a20ed60a9d29466ba888b3ef66e
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Dec 7 14:14:28 2020 +0300

    querylog: improve code and documentation

commit 851df97d2a87de5e7180a502055ee6f1a6defdca
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Fri Dec 4 20:36:32 2020 +0300

    all: fix lint and naming issues
2020-12-07 14:32:06 +03:00

139 lines
2.9 KiB
Go

package querylog
import (
"bytes"
"encoding/json"
"os"
"time"
"github.com/AdguardTeam/golibs/log"
)
// flushLogBuffer flushes the current buffer to file and resets the current buffer
func (l *queryLog) flushLogBuffer(fullFlush bool) error {
if !l.conf.FileEnabled {
return nil
}
l.fileFlushLock.Lock()
defer l.fileFlushLock.Unlock()
// flush remainder to file
l.bufferLock.Lock()
needFlush := len(l.buffer) >= int(l.conf.MemSize)
if !needFlush && !fullFlush {
l.bufferLock.Unlock()
return nil
}
flushBuffer := l.buffer
l.buffer = nil
l.flushPending = false
l.bufferLock.Unlock()
err := l.flushToFile(flushBuffer)
if err != nil {
log.Error("Saving querylog to file failed: %s", err)
return err
}
return nil
}
// flushToFile saves the specified log entries to the query log file
func (l *queryLog) flushToFile(buffer []*logEntry) error {
if len(buffer) == 0 {
log.Debug("querylog: there's nothing to write to a file")
return nil
}
start := time.Now()
var b bytes.Buffer
e := json.NewEncoder(&b)
for _, entry := range buffer {
err := e.Encode(entry)
if err != nil {
log.Error("Failed to marshal entry: %s", err)
return err
}
}
elapsed := time.Since(start)
log.Debug("%d elements serialized via json in %v: %d kB, %v/entry, %v/entry", len(buffer), elapsed, b.Len()/1024, float64(b.Len())/float64(len(buffer)), elapsed/time.Duration(len(buffer)))
var err error
var zb bytes.Buffer
filename := l.logFile
zb = b
l.fileWriteLock.Lock()
defer l.fileWriteLock.Unlock()
f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0o644)
if err != nil {
log.Error("failed to create file \"%s\": %s", filename, err)
return err
}
defer f.Close()
n, err := f.Write(zb.Bytes())
if err != nil {
log.Error("Couldn't write to file: %s", err)
return err
}
log.Debug("querylog: ok \"%s\": %v bytes written", filename, n)
return nil
}
func (l *queryLog) rotate() error {
from := l.logFile
to := l.logFile + ".1"
if _, err := os.Stat(from); os.IsNotExist(err) {
// do nothing, file doesn't exist
return nil
}
err := os.Rename(from, to)
if err != nil {
log.Error("querylog: failed to rename file: %s", err)
return err
}
log.Debug("querylog: renamed %s -> %s", from, to)
return nil
}
func (l *queryLog) readFileFirstTimeValue() int64 {
f, err := os.Open(l.logFile)
if err != nil {
return -1
}
defer f.Close()
buf := make([]byte, 500)
r, err := f.Read(buf)
if err != nil {
return -1
}
buf = buf[:r]
val := readJSONValue(string(buf), "T")
t, err := time.Parse(time.RFC3339Nano, val)
if err != nil {
return -1
}
log.Debug("querylog: the oldest log entry: %s", val)
return t.Unix()
}
func (l *queryLog) periodicRotate() {
intervalSeconds := uint64(l.conf.Interval) * 24 * 60 * 60
for {
oldest := l.readFileFirstTimeValue()
if uint64(oldest)+intervalSeconds <= uint64(time.Now().Unix()) {
_ = l.rotate()
}
time.Sleep(24 * time.Hour)
}
}