From 7570fc2e13637d741006836d149449f7b86c6f79 Mon Sep 17 00:00:00 2001
From: Rob Zienert <rzienert@netflix.com>
Date: Fri, 20 Oct 2017 10:47:51 -0700
Subject: [PATCH] fix(cats): Remove unmodifiable collections from modifiable
 codepaths

---
 .../netflix/spinnaker/cats/agent/DefaultCacheResult.java   | 4 ++--
 .../spinnaker/cats/provider/DefaultProviderCache.java      | 4 ++--
 .../spinnaker/cats/dynomite/cache/DynomiteCache.java       | 5 +----
 .../spinnaker/cats/redis/cache/AbstractRedisCache.java     | 7 +++----
 4 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/agent/DefaultCacheResult.java b/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/agent/DefaultCacheResult.java
index 07be5f3de3f..ad8bd78a451 100644
--- a/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/agent/DefaultCacheResult.java
+++ b/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/agent/DefaultCacheResult.java
@@ -19,7 +19,7 @@
 import com.netflix.spinnaker.cats.cache.CacheData;
 
 import java.util.Collection;
-import java.util.Collections;
+import java.util.HashMap;
 import java.util.Map;
 
 /**
@@ -30,7 +30,7 @@ public class DefaultCacheResult implements CacheResult {
     private final Map<String, Collection<String>> evictions;
 
     public DefaultCacheResult(Map<String, Collection<CacheData>> cacheResults) {
-      this(cacheResults, Collections.emptyMap());
+      this(cacheResults, new HashMap<>());
     }
     public DefaultCacheResult(Map<String, Collection<CacheData>> cacheResults, Map<String, Collection<String>> evictions) {
         this.cacheResults = cacheResults;
diff --git a/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/provider/DefaultProviderCache.java b/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/provider/DefaultProviderCache.java
index 25f4f5bc801..6c4a2bf8f4c 100644
--- a/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/provider/DefaultProviderCache.java
+++ b/cats/cats-core/src/main/java/com/netflix/spinnaker/cats/provider/DefaultProviderCache.java
@@ -189,11 +189,11 @@ private Collection<CacheData> buildResponse(Collection<CacheData> source) {
     private Collection<String> getExistingSourceIdentifiers(String type, String sourceAgentType) {
         CacheData all = backingStore.get(type, ALL_ID);
         if (all == null) {
-            return Collections.emptySet();
+            return new HashSet<>();
         }
         Collection<String> relationship = all.getRelationships().get(sourceAgentType);
         if (relationship == null) {
-            return Collections.emptySet();
+            return new HashSet<>();
         }
         return relationship;
     }
diff --git a/cats/cats-dynomite/src/main/java/com/netflix/spinnaker/cats/dynomite/cache/DynomiteCache.java b/cats/cats-dynomite/src/main/java/com/netflix/spinnaker/cats/dynomite/cache/DynomiteCache.java
index 7d162b9f087..ec0e1b5ebea 100644
--- a/cats/cats-dynomite/src/main/java/com/netflix/spinnaker/cats/dynomite/cache/DynomiteCache.java
+++ b/cats/cats-dynomite/src/main/java/com/netflix/spinnaker/cats/dynomite/cache/DynomiteCache.java
@@ -217,9 +217,7 @@ protected void evictItems(String type, List<String> identifiers, Collection<Stri
       .run(() -> redisClientDelegate.withPipeline(pipeline -> {
         DynoJedisPipeline p = (DynoJedisPipeline) pipeline;
 
-        boolean pipelineHasOps = false;
         for (List<String> idPartition : Lists.partition(identifiers, options.getMaxDelSize())) {
-          pipelineHasOps = true;
           String[] ids = idPartition.toArray(new String[idPartition.size()]);
           pipeline.srem(allOfTypeId(type), ids);
           sremOperations.incrementAndGet();
@@ -228,14 +226,13 @@ protected void evictItems(String type, List<String> identifiers, Collection<Stri
         }
 
         for (String id : identifiers) {
-          pipelineHasOps = true;
           pipeline.del(itemId(type, id));
           delOperations.incrementAndGet();
           pipeline.del(itemHashesId(type, id));
           delOperations.incrementAndGet();
         }
 
-        if (pipelineHasOps) {
+        if (!identifiers.isEmpty()) {
           p.sync();
         }
       }));
diff --git a/cats/cats-redis/src/main/java/com/netflix/spinnaker/cats/redis/cache/AbstractRedisCache.java b/cats/cats-redis/src/main/java/com/netflix/spinnaker/cats/redis/cache/AbstractRedisCache.java
index 19ff515bee2..690b5fc962e 100644
--- a/cats/cats-redis/src/main/java/com/netflix/spinnaker/cats/redis/cache/AbstractRedisCache.java
+++ b/cats/cats-redis/src/main/java/com/netflix/spinnaker/cats/redis/cache/AbstractRedisCache.java
@@ -29,7 +29,6 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -64,7 +63,7 @@ protected AbstractRedisCache(String prefix, RedisClientDelegate redisClientDeleg
 
   @Override
   public void merge(String type, CacheData item) {
-    mergeAll(type, Collections.singletonList(item));
+    mergeAll(type, Arrays.asList(item));
   }
 
   @Override
@@ -76,7 +75,7 @@ public void mergeAll(String type, Collection<CacheData> items) {
 
   @Override
   public void evict(String type, String id) {
-    evictAll(type, Collections.singletonList(id));
+    evictAll(type, Arrays.asList(id));
   }
 
   @Override
@@ -97,7 +96,7 @@ public CacheData get(String type, String id) {
 
   @Override
   public CacheData get(String type, String id, CacheFilter cacheFilter) {
-    Collection<CacheData> result = getAll(type, Collections.singletonList(id), cacheFilter);
+    Collection<CacheData> result = getAll(type, Arrays.asList(id), cacheFilter);
     if (result.isEmpty()) {
       return null;
     }