From 52f3773408d92a5f3cb938a15e486b7859a56ba3 Mon Sep 17 00:00:00 2001
From: moparisthebest <admin@moparisthebest.com>
Date: Sat, 13 Apr 2019 00:05:14 -0400
Subject: [PATCH] Refactor MinTtlResolver out of CacheResolver

---
 .../java/com/moparisthebest/dns/DnsProxy.java | 12 +++---
 .../dns/resolve/CacheResolver.java            | 14 ++-----
 .../dns/resolve/MinTtlResolver.java           | 37 +++++++++++++++++++
 3 files changed, 46 insertions(+), 17 deletions(-)
 create mode 100644 jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/MinTtlResolver.java

diff --git a/jDnsProxy/src/main/java/com/moparisthebest/dns/DnsProxy.java b/jDnsProxy/src/main/java/com/moparisthebest/dns/DnsProxy.java
index 6d8db1a..80cf300 100644
--- a/jDnsProxy/src/main/java/com/moparisthebest/dns/DnsProxy.java
+++ b/jDnsProxy/src/main/java/com/moparisthebest/dns/DnsProxy.java
@@ -2,10 +2,7 @@ package com.moparisthebest.dns;
 
 import com.moparisthebest.dns.listen.Listener;
 import com.moparisthebest.dns.net.ParsedUrl;
-import com.moparisthebest.dns.resolve.BlockingQueueResolver;
-import com.moparisthebest.dns.resolve.CacheResolver;
-import com.moparisthebest.dns.resolve.QueueProcessingResolver;
-import com.moparisthebest.dns.resolve.Resolver;
+import com.moparisthebest.dns.resolve.*;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -66,8 +63,11 @@ public class DnsProxy {
         final ExecutorService executor = scheduledExecutorService;//ForkJoinPool.commonPool();
 
         final CacheResolver resolver = new CacheResolver(
-                new BlockingQueueResolver(packetQueueLength).startQueueProcessingResolvers(executor, queueProcessingResolvers),
-                minTtl, staleResponseTtl, staleResponseTimeout,
+                MinTtlResolver.of(minTtl,
+                    new BlockingQueueResolver(packetQueueLength)
+                            .startQueueProcessingResolvers(executor, queueProcessingResolvers)
+                ),
+                staleResponseTtl, staleResponseTimeout,
                 scheduledExecutorService, cacheFile, cacheDelayMinutes)
                 ;
 
diff --git a/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/CacheResolver.java b/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/CacheResolver.java
index 698f2cd..38f35de 100644
--- a/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/CacheResolver.java
+++ b/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/CacheResolver.java
@@ -14,7 +14,7 @@ import static com.moparisthebest.dns.Util.supplyAsyncOnTimeOut;
 
 public class CacheResolver implements Resolver, AutoCloseable {
 
-    private final int minTtl, staleResponseTtl;
+    private final int staleResponseTtl;
     private final long staleResponseTimeout;
 
     private final Resolver delegate;
@@ -23,10 +23,9 @@ public class CacheResolver implements Resolver, AutoCloseable {
 
     private final ConcurrentMap<String, CachedPacket> cache = new ConcurrentHashMap<>();
 
-    public CacheResolver(final Resolver delegate, final int minTtl, final int staleResponseTtl, final long staleResponseTimeout, final ScheduledExecutorService scheduledExecutorService,
+    public CacheResolver(final Resolver delegate, final int staleResponseTtl, final long staleResponseTimeout, final ScheduledExecutorService scheduledExecutorService,
                          final String cacheFile, final long cacheDelayMinutes) throws IOException {
         this.delegate = delegate;
-        this.minTtl = minTtl;
         this.staleResponseTtl = staleResponseTtl;
         this.staleResponseTimeout = staleResponseTimeout;
         this.scheduledExecutorService = scheduledExecutorService;
@@ -129,14 +128,7 @@ public class CacheResolver implements Resolver, AutoCloseable {
     }
 
     private <E extends RequestResponse> CompletableFuture<E> requestAndCache(final E requestResponse, final Executor executor) {
-        CompletableFuture<E> request = delegate.resolveAsync(requestResponse, executor);
-        if(minTtl > 0) {
-            request = request.thenApply(s -> {
-                s.getResponse().modTtls((ttl) -> Math.max(ttl, minTtl));
-                //s.getResponse().modTtls((ttl) -> 30);
-                return s;
-            });
-        }
+        final CompletableFuture<E> request = delegate.resolveAsync(requestResponse, executor);
         request.thenAcceptAsync(s -> {
             final Packet response = s.getResponse().copy(); // todo: do we need to copy?
             final long currentTime = currentTimeSeconds();
diff --git a/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/MinTtlResolver.java b/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/MinTtlResolver.java
new file mode 100644
index 0000000..1564a94
--- /dev/null
+++ b/jDnsProxy/src/main/java/com/moparisthebest/dns/resolve/MinTtlResolver.java
@@ -0,0 +1,37 @@
+package com.moparisthebest.dns.resolve;
+
+import com.moparisthebest.dns.dto.Packet;
+
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+
+public class MinTtlResolver implements Resolver {
+
+    private final int minTtl;
+
+    private final Resolver delegate;
+
+    public static Resolver of(final int minTtl, final Resolver delegate) {
+        // anything less than 1 just don't wrap
+        return minTtl < 1 ? delegate : new MinTtlResolver(minTtl, delegate);
+    }
+
+    private MinTtlResolver(final int minTtl, final Resolver delegate) {
+        this.minTtl = minTtl;
+        this.delegate = delegate;
+    }
+
+    @Override
+    public <E extends RequestResponse> CompletableFuture<E> resolveAsync(final E requestResponse, final Executor executor) {
+        return delegate.resolveAsync(requestResponse, executor).thenApply(s -> {
+                s.getResponse().modTtls((ttl) -> Math.max(ttl, minTtl));
+                //s.getResponse().modTtls((ttl) -> 30);
+                return s;
+            });
+    }
+
+    @Override
+    public Packet resolve(final Packet request) throws Exception {
+        return delegate.resolve(request).modTtls((ttl) -> Math.max(ttl, minTtl));
+    }
+}