Have DigestMap support multiple hash functions.

RELNOTES: None
PiperOrigin-RevId: 208837641

1 files changed, 4 insertions, 2 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/collect/nestedset/NestedSetFingerprintCache.java b/src/main/java/com/google/devtools/build/lib/collect/nestedset/NestedSetFingerprintCache.java
index 8eb4131793..e0481b98f6 100644
--- a/src/main/java/com/google/devtools/build/lib/collect/nestedset/NestedSetFingerprintCache.java
+++ b/src/main/java/com/google/devtools/build/lib/collect/nestedset/NestedSetFingerprintCache.java
@@ -20,6 +20,7 @@ import com.google.common.collect.Multiset;
 import com.google.devtools.build.lib.actions.CommandLineItem;
 import com.google.devtools.build.lib.actions.CommandLineItem.MapFn;
 import com.google.devtools.build.lib.util.Fingerprint;
+import com.google.devtools.build.lib.vfs.DigestHashFunction;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
@@ -27,7 +28,6 @@ import java.util.concurrent.ConcurrentHashMap;
 
 /** Computes fingerprints for nested sets, reusing sub-computations from children. */
 public class NestedSetFingerprintCache {
-  private static final int DIGEST_SIZE = 16;
   private static final int EMPTY_SET_DIGEST = 104_395_303;
 
   /** Memoize the subresults. We have to have one cache per type of command item map function. */
@@ -121,6 +121,8 @@ public class NestedSetFingerprintCache {
                 mapFnClass.getName()));
       }
     }
-    return new DigestMap(DIGEST_SIZE, 1024);
+    // TODO(b/112460990): Use the value from DigestHashFunction.getDefault(), but check for
+    // contention.
+    return new DigestMap(DigestHashFunction.MD5, 1024);
   }
 }