From a15f21ca1cd0acabf77a4e9750dd77b2b870a6f4 Mon Sep 17 00:00:00 2001
From: Eugene Bujak <hmage@hmage.net>
Date: Mon, 8 Oct 2018 20:02:09 +0300
Subject: [PATCH] code review -- move constants into named constants
---
coredns_plugin/querylog.go | 20 +++++++++++++-------
coredns_plugin/querylog_file.go | 9 ++-------
coredns_plugin/querylog_top.go | 18 +++++++++---------
3 files changed, 24 insertions(+), 23 deletions(-)
diff --git a/coredns_plugin/querylog.go b/coredns_plugin/querylog.go
index 0ff676f8..9e45315f 100644
--- a/coredns_plugin/querylog.go
+++ b/coredns_plugin/querylog.go
@@ -4,6 +4,7 @@ import (
"encoding/json"
"fmt"
"log"
+ "net"
"net/http"
"os"
"path"
@@ -19,9 +20,14 @@ import (
)
const (
- logBufferCap = 5000 // maximum capacity of logBuffer before it's flushed to disk
- queryLogCacheSize = 1000 // maximum API response for /querylog
- queryLogCacheTime = time.Minute
+ logBufferCap = 5000 // maximum capacity of logBuffer before it's flushed to disk
+ queryLogTimeLimit = time.Hour * 24 // how far in the past we care about querylogs
+ queryLogRotationPeriod = time.Hour * 24 // rotate the log every 24 hours
+ queryLogFileName = "querylog.json" // .gz added during compression
+ queryLogCacheSize = 1000 // maximum API response for /querylog
+ queryLogCacheTime = time.Minute // if requested more often than this, give out cached response
+ queryLogTopSize = 500 // Keep in memory only top N values
+ queryLogAPIPort = "8618" // 8618 is sha512sum of "querylog" then each byte summed
)
var (
@@ -112,7 +118,7 @@ func handleQueryLog(w http.ResponseWriter, r *http.Request) {
logBufferLock.RUnlock()
if len(values) < queryLogCacheSize {
- values = appendFromLogFile(values, queryLogCacheSize, time.Hour*24)
+ values = appendFromLogFile(values, queryLogCacheSize, queryLogTimeLimit)
}
queryLogLock.Lock()
queryLogCache = values
@@ -223,14 +229,14 @@ func handleQueryLog(w http.ResponseWriter, r *http.Request) {
if err != nil {
errortext := fmt.Sprintf("Unable to write response json: %s", err)
log.Println(errortext)
- http.Error(w, errortext, 500)
+ http.Error(w, errortext, http.StatusInternalServerError)
}
}
func startQueryLogServer() {
- listenAddr := "127.0.0.1:8618" // 8618 is sha512sum of "querylog" then each byte summed
+ listenAddr := net.JoinHostPort("127.0.0.1", queryLogAPIPort)
- go periodicQueryLogRotate(queryLogRotationPeriod)
+ go periodicQueryLogRotate()
go periodicHourlyTopRotate()
http.HandleFunc("/querylog", handleQueryLog)
diff --git a/coredns_plugin/querylog_file.go b/coredns_plugin/querylog_file.go
index fffd050a..7025fcd3 100644
--- a/coredns_plugin/querylog_file.go
+++ b/coredns_plugin/querylog_file.go
@@ -13,11 +13,6 @@ import (
"github.com/go-test/deep"
)
-const (
- queryLogRotationPeriod = time.Hour * 24 // rotate the log every 24 hours
- queryLogFileName = "querylog.json" // .gz added during compression
-)
-
var (
fileWriteLock sync.Mutex
)
@@ -135,8 +130,8 @@ func rotateQueryLog() error {
return nil
}
-func periodicQueryLogRotate(t time.Duration) {
- for range time.Tick(t) {
+func periodicQueryLogRotate() {
+ for range time.Tick(queryLogRotationPeriod) {
err := rotateQueryLog()
if err != nil {
log.Printf("Failed to rotate querylog: %s", err)
diff --git a/coredns_plugin/querylog_top.go b/coredns_plugin/querylog_top.go
index 89426e14..e2bfa53e 100644
--- a/coredns_plugin/querylog_top.go
+++ b/coredns_plugin/querylog_top.go
@@ -5,6 +5,9 @@ import (
"fmt"
"log"
"net/http"
+ "os"
+ "path"
+ "runtime"
"sort"
"strconv"
"strings"
@@ -30,9 +33,9 @@ type hourTop struct {
}
func (top *hourTop) init() {
- top.domains = gcache.New(500).LRU().Build()
- top.blocked = gcache.New(500).LRU().Build()
- top.clients = gcache.New(500).LRU().Build()
+ top.domains = gcache.New(topLRUsize).LRU().Build()
+ top.blocked = gcache.New(topLRUsize).LRU().Build()
+ top.clients = gcache.New(topLRUsize).LRU().Build()
}
type dayTop struct {
@@ -227,7 +230,7 @@ func loadTopFromFiles() error {
}
needMore := func() bool { return true }
- err := genericLoader(onEntry, needMore, time.Hour*24)
+ err := genericLoader(onEntry, needMore, queryLogTimeLimit)
if err != nil {
log.Printf("Failed to load entries from querylog: %s", err)
return err
@@ -340,20 +343,17 @@ func (d *dayTop) hoursReadUnlock() { tracelock(); d.hoursLock.RUnlock() }
func (d *dayTop) loadedWriteLock() { tracelock(); d.loadedLock.Lock() }
func (d *dayTop) loadedWriteUnlock() { tracelock(); d.loadedLock.Unlock() }
-// func (d *dayTop) loadedReadLock() { tracelock(); d.loadedLock.RLock() }
-// func (d *dayTop) loadedReadUnlock() { tracelock(); d.loadedLock.RUnlock() }
-
func (h *hourTop) Lock() { tracelock(); h.mutex.Lock() }
func (h *hourTop) RLock() { tracelock(); h.mutex.RLock() }
func (h *hourTop) RUnlock() { tracelock(); h.mutex.RUnlock() }
func (h *hourTop) Unlock() { tracelock(); h.mutex.Unlock() }
func tracelock() {
- /*
+ if false { // not commented out to make code checked during compilation
pc := make([]uintptr, 10) // at least 1 entry needed
runtime.Callers(2, pc)
f := path.Base(runtime.FuncForPC(pc[1]).Name())
lockf := path.Base(runtime.FuncForPC(pc[0]).Name())
fmt.Fprintf(os.Stderr, "%s(): %s\n", f, lockf)
- */
+ }
}