Skip computing digests when --use_action_cache=false.

Does this by delegating responsibility for constructing ActionCache.Entry
instances to the ActionCache, and having the StubActionCache return null.

Tests show a 1-2% elapsed-time reduction for clean builds: []

Doesn't use interface default methods, because we still need JDK7 for Mac.

--
PiperOrigin-RevId: 147722062
MOS_MIGRATED_REVID=147722062

1 files changed, 28 insertions, 14 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/actions/util/ActionCacheTestHelper.java b/src/test/java/com/google/devtools/build/lib/actions/util/ActionCacheTestHelper.java
index eddd94d5b0..59f14d1dd8 100644
--- a/src/test/java/com/google/devtools/build/lib/actions/util/ActionCacheTestHelper.java
+++ b/src/test/java/com/google/devtools/build/lib/actions/util/ActionCacheTestHelper.java
@@ -14,8 +14,9 @@
 package com.google.devtools.build.lib.actions.util;
 
 import com.google.devtools.build.lib.actions.cache.ActionCache;
-
+import com.google.devtools.build.lib.actions.cache.ActionCache.Entry;
 import java.io.PrintStream;
+import java.util.Map;
 
 /**
  * Utilities for tests that use the action cache.
@@ -23,18 +24,31 @@ import java.io.PrintStream;
 public class ActionCacheTestHelper {
   private ActionCacheTestHelper() {}
 
-  /** A cache which does not remember anything.  Causes perpetual rebuilds! */
+  /** A cache which does not remember anything. Causes perpetual rebuilds! */
   public static final ActionCache AMNESIAC_CACHE =
-    new ActionCache() {
-      @Override
-      public void put(String fingerprint, Entry entry) {}
-      @Override
-      public Entry get(String fingerprint) { return null; }
-      @Override
-      public void remove(String key) {}
-      @Override
-      public long save() { return -1; }
-      @Override
-      public void dump(PrintStream out) { }
-    };
+      new ActionCache() {
+        @Override
+        public void put(String fingerprint, Entry entry) {}
+
+        @Override
+        public Entry get(String fingerprint) {
+          return null;
+        }
+
+        @Override
+        public void remove(String key) {}
+
+        @Override
+        public long save() {
+          return -1;
+        }
+
+        @Override
+        public void dump(PrintStream out) {}
+
+        @Override
+        public Entry newEntry(String key, Map<String, String> env, boolean discoversInputs) {
+          return new Entry(key, env, discoversInputs);
+        }
+      };
 }