Allow OptionsChecksumCache to fail to prime itself, resulting in a SerializationException.

PiperOrigin-RevId: 565814705
Change-Id: Id4f43c31f2f51c8a871bbbbdfffc6e570404d710

Author: justinhorvitz

src/main/java/com/google/devtools/build/lib/analysis/config/BuildOptions.java

@@ -715,8 +715,10 @@ public Class<BuildOptions> getEncodedClass() {
     @Override
     public void serialize(
         SerializationContext context, BuildOptions options, CodedOutputStream codedOut)
-        throws IOException {
-      context.getDependency(OptionsChecksumCache.class).prime(options);
+        throws SerializationException, IOException {
+      if (!context.getDependency(OptionsChecksumCache.class).prime(options)) {
+        throw new SerializationException("Failed to prime cache for " + options.checksum());
+      }
       codedOut.writeStringNoTag(options.checksum());
     }
 
@@ -740,15 +742,22 @@ public interface OptionsChecksumCache {
 
     /**
      * Called during deserialization to transform a checksum into a {@link BuildOptions} instance.
+     *
+     * <p>Returns {@code null} when the given checksum is unknown, in which case the codec throws
+     * {@link SerializationException}.
      */
+    @Nullable
     BuildOptions getOptions(String checksum);
 
     /**
      * Notifies the cache that it may be necessary to deserialize the given options diff's checksum.
      *
      * <p>Called each time an {@link BuildOptions} instance is serialized.
+     *
+     * @return whether this cache was successfully primed, if {@code false} the codec will throw
+     *     {@link SerializationException}
      */
-    void prime(BuildOptions options);
+    boolean prime(BuildOptions options);
   }
 
   /**
@@ -760,13 +769,15 @@ public static final class MapBackedChecksumCache implements OptionsChecksumCache
     private final ConcurrentMap<String, BuildOptions> map = new ConcurrentHashMap<>();
 
     @Override
+    @Nullable
     public BuildOptions getOptions(String checksum) {
       return map.get(checksum);
     }
 
     @Override
-    public void prime(BuildOptions options) {
+    public boolean prime(BuildOptions options) {
       map.putIfAbsent(options.checksum(), options);
+      return true;
     }
   }
 }

src/test/java/com/google/devtools/build/lib/analysis/config/BuildOptionsTest.java

@@ -217,6 +217,29 @@ private static ImmutableList.Builder<Class<? extends FragmentOptions>> makeOptio
         .add(CppOptions.class);
   }
 
+  @Test
+  public void serialize_primeFails_throws() throws Exception {
+    OptionsChecksumCache failToPrimeCache =
+        new OptionsChecksumCache() {
+          @Override
+          public BuildOptions getOptions(String checksum) {
+            throw new UnsupportedOperationException();
+          }
+
+          @Override
+          public boolean prime(BuildOptions options) {
+            return false;
+          }
+        };
+    BuildOptions options = BuildOptions.of(BUILD_CONFIG_OPTIONS);
+    SerializationContext serializationContext =
+        new SerializationContext(
+            ImmutableClassToInstanceMap.of(OptionsChecksumCache.class, failToPrimeCache));
+
+    assertThrows(
+        SerializationException.class, () -> TestUtils.toBytes(serializationContext, options));
+  }
+
   @Test
   public void deserialize_unprimedCache_throws() throws Exception {
     BuildOptions options = BuildOptions.of(BUILD_CONFIG_OPTIONS);
@@ -252,7 +275,7 @@ public void deserialize_primedCache_returnsPrimedInstance() throws Exception {
 
     // Different checksum cache than the one used for serialization, but it has been primed.
     OptionsChecksumCache checksumCache = new MapBackedChecksumCache();
-    checksumCache.prime(options);
+    assertThat(checksumCache.prime(options)).isTrue();
     DeserializationContext deserializationContext =
         new DeserializationContext(
             ImmutableClassToInstanceMap.of(OptionsChecksumCache.class, checksumCache));