1 files changed, 72 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/RepositoryDelegatorFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/RepositoryDelegatorFunction.java
new file mode 100644
index 0000000000..f0af0c64ec
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/RepositoryDelegatorFunction.java
@@ -0,0 +1,72 @@
+// Copyright 2014 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.bazel.repository;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.devtools.build.lib.packages.NoSuchPackageException;
+import com.google.devtools.build.lib.packages.PackageIdentifier.RepositoryName;
+import com.google.devtools.build.lib.packages.Rule;
+import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.skyframe.SkyFunction;
+import com.google.devtools.build.skyframe.SkyFunctionException;
+import com.google.devtools.build.skyframe.SkyFunctionException.Transience;
+import com.google.devtools.build.skyframe.SkyKey;
+import com.google.devtools.build.skyframe.SkyValue;
+
+import java.io.IOException;
+
+/**
+ * Implements delegation to the correct repository fetcher.
+ */
+public class RepositoryDelegatorFunction implements SkyFunction {
+
+  // Mapping of rule class name to SkyFunction.
+  private final ImmutableMap<String, RepositoryFunction> handlers;
+
+  public RepositoryDelegatorFunction(
+      ImmutableMap<String, RepositoryFunction> handlers) {
+    this.handlers = handlers;
+  }
+
+  @Override
+  public SkyValue compute(SkyKey skyKey, Environment env) throws SkyFunctionException {
+    RepositoryName repositoryName = (RepositoryName) skyKey.argument();
+    Rule rule = RepositoryFunction.getRule(repositoryName, null, env);
+    if (rule == null) {
+      return null;
+    }
+    RepositoryFunction handler = handlers.get(rule.getRuleClass());
+    if (handler == null) {
+      throw new IllegalStateException("Could not find handler for " + rule);
+    }
+    SkyKey key = new SkyKey(handler.getSkyFunctionName(), repositoryName);
+
+    try {
+      return env.getValueOrThrow(
+          key, NoSuchPackageException.class, IOException.class, EvalException.class);
+    } catch (NoSuchPackageException e) {
+      throw new RepositoryFunction.RepositoryFunctionException(e, Transience.PERSISTENT);
+    } catch (IOException e) {
+      throw new RepositoryFunction.RepositoryFunctionException(e, Transience.PERSISTENT);
+    } catch (EvalException e) {
+      throw new RepositoryFunction.RepositoryFunctionException(e, Transience.PERSISTENT);
+    }
+  }
+
+  @Override
+  public String extractTag(SkyKey skyKey) {
+    return null;
+  }
+}