all: refactoring with latest update on dns package

All the server core functionalities (caches and forwarding) now
implemented inside "dns.Server".  The main function of this package are
for reading options from configuration file (or from command line options)
and watching changes from system resolv.conf.

There are also some major changes on configuration file.

*  "server.parent"  option now use URI format instead of IP:PORT.
   This will allow parent name servers to be UDP, TCP, and/or DoH
   simultaneusly.

*  "server.doh.parent" and "server.parent.connection" are removed,
   redundant with new "server.parent" format.

*  "cache.threshold" is renamed to "cache.prune_threshold".

1 files changed, 0 insertions, 167 deletions

diff --git a/cacheworker.go b/cacheworker.go
deleted file mode 100644
index 2bcfa78..0000000
--- a/cacheworker.go
+++ /dev/null
@@ -1,167 +0,0 @@
-// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package rescached
-
-import (
-	"fmt"
-	"log"
-	"time"
-
-	libbytes "github.com/shuLhan/share/lib/bytes"
-	"github.com/shuLhan/share/lib/debug"
-	"github.com/shuLhan/share/lib/dns"
-)
-
-const (
-	maxWorkerQueue = 32
-)
-
-//
-// cacheWorker is a worker that manage cache in map and list.
-// Any addition, update, or remove to cache go through this worker.
-//
-type cacheWorker struct {
-	upsertQueue chan *dns.Message
-	caches      *caches
-	cachesList  *cachesList
-	pruneDelay  time.Duration
-}
-
-//
-// newCacheWorker create and initialize worker with a timer to prune the cache
-// (cacheDelay) and a duration for cache to be considered to be pruned.
-//
-func newCacheWorker(pruneDelay, cacheThreshold time.Duration) *cacheWorker {
-	return &cacheWorker{
-		upsertQueue: make(chan *dns.Message, maxWorkerQueue),
-		caches:      newCaches(),
-		cachesList:  newCachesList(cacheThreshold),
-		pruneDelay:  pruneDelay,
-	}
-}
-
-func (cw *cacheWorker) start() {
-	go cw.pruneWorker()
-
-	for msg := range cw.upsertQueue {
-		_ = cw.upsert(msg, false)
-	}
-}
-
-func (cw *cacheWorker) pruneWorker() {
-	ticker := time.NewTicker(cw.pruneDelay)
-
-	defer ticker.Stop()
-
-	for t := range ticker.C {
-		fmt.Printf("= pruning at %v\n", t)
-
-		cw.prune()
-	}
-}
-
-//
-// upsert update or insert a DNS message to caches in map and in the list.
-// It will return true if response is added or updated in cache, otherwise it
-// will return false.
-//
-func (cw *cacheWorker) upsert(msg *dns.Message, isLocal bool) bool {
-	if msg == nil {
-		return false
-	}
-	if msg.Header.RCode != dns.RCodeOK {
-		log.Printf("! Response error: %d %s\n", msg.Header.RCode,
-			msg.Question)
-		return false
-	}
-
-	libbytes.ToLower(&msg.Question.Name)
-	qname := string(msg.Question.Name)
-
-	lres, res := cw.caches.get(qname, msg.Question.Type, msg.Question.Class)
-	if lres == nil {
-		cw.push(qname, msg, isLocal)
-		return true
-	}
-	// Cache list contains other type.
-	if res == nil {
-		res = lres.add(msg, isLocal)
-		if !isLocal {
-			cw.cachesList.push(res)
-		}
-		return true
-	}
-
-	_ = lres.update(res, msg)
-
-	if !isLocal {
-		cw.cachesList.fix(res)
-
-		if debug.Value >= 1 {
-			fmt.Printf("+ update :  Total:%-4d ID:%-5d %s\n",
-				cw.cachesList.length(), res.message.Header.ID,
-				res.message.Question)
-		}
-	}
-
-	return true
-}
-
-//
-// push new DNS message with domain-name "qname" as a key on map.
-// If isLocal is false, the message will also pushed to cachesList.
-//
-func (cw *cacheWorker) push(qname string, msg *dns.Message, isLocal bool) {
-	res := newResponse(msg)
-	if isLocal {
-		res.receivedAt = 0
-	}
-
-	cw.caches.add(qname, res)
-
-	if !isLocal {
-		cw.cachesList.push(res)
-
-		if debug.Value >= 1 {
-			fmt.Printf("+ insert :  Total:%-4d ID:%-5d %s\n",
-				cw.cachesList.length(), res.message.Header.ID,
-				res.message.Question)
-		}
-	}
-}
-
-func (cw *cacheWorker) remove(res *response) {
-	if res == nil || res.message == nil {
-		return
-	}
-	if res.el != nil {
-		return
-	}
-
-	qname := string(res.message.Question.Name)
-
-	cw.caches.remove(qname, res.message.Question.Type,
-		res.message.Question.Class)
-
-	if debug.Value > 0 {
-		fmt.Printf("= pruning: %4d %10d %s\n", cw.cachesList.length(),
-			res.accessedAt, res.message.Question)
-	}
-
-	res.el = nil
-	res.message = nil
-}
-
-func (cw *cacheWorker) prune() {
-	lres := cw.cachesList.prune()
-	if len(lres) == 0 {
-		return
-	}
-
-	for _, res := range lres {
-		cw.remove(res)
-	}
-	fmt.Printf("= pruning %d records\n", len(lres))
-}