Inlined RepositoryFunction#getExternalPackage

This method was used only twice. Now there is only one entry point for requesting
a rule in the external package (RepositoryFunction#getRule(String, Environment)).
This is a step towards supporting loading skylark rules in the workspace file from
remote repository.

--
MOS_MIGRATED_REVID=112407797

2 files changed, 36 insertions, 22 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/MavenServerFunction.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/MavenServerFunction.java
index c0b9414c32..b2280fa447 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/MavenServerFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/MavenServerFunction.java
@@ -19,10 +19,10 @@ import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
 import com.google.devtools.build.lib.bazel.rules.workspace.MavenServerRule;
 import com.google.devtools.build.lib.packages.AggregatingAttributeMapper;
-import com.google.devtools.build.lib.packages.Package;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.rules.repository.RepositoryFunction;
 import com.google.devtools.build.lib.rules.repository.RepositoryFunction.RepositoryFunctionException;
+import com.google.devtools.build.lib.rules.repository.RepositoryFunction.RepositoryNotFoundException;
 import com.google.devtools.build.lib.skyframe.FileValue;
 import com.google.devtools.build.lib.syntax.Type;
 import com.google.devtools.build.lib.util.Fingerprint;
@@ -66,15 +66,19 @@ public class MavenServerFunction implements SkyFunction {
   }
 
   @Nullable
+  @Override
   public SkyValue compute(SkyKey skyKey, Environment env)
       throws SkyFunctionException {
     String repository = (String) skyKey.argument();
-    Package externalPackage = RepositoryFunction.getExternalPackage(env);
-    if (externalPackage == null) {
-      return null;
+    Rule repositoryRule;
+    try {
+       repositoryRule = RepositoryFunction.getRule(repository, env);
+       if (repositoryRule == null) {
+         return null;
+       }
+    } catch (RepositoryNotFoundException ex) {
+      repositoryRule = null;
     }
-    Rule repositoryRule = externalPackage.getRule(repository);
-
     String serverName;
     String url;
     Map<String, FileValue> settingsFiles;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java b/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java
index c67c254225..13e47368a6 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/repository/RepositoryFunction.java
@@ -89,7 +89,7 @@ public abstract class RepositoryFunction {
    * <p>This exception should be used by child classes to limit the types of exceptions
    * {@link RepositoryDelegatorFunction} has to know how to catch.</p>
    */
-  public static final class RepositoryFunctionException extends SkyFunctionException {
+  public static class RepositoryFunctionException extends SkyFunctionException {
     public RepositoryFunctionException(NoSuchPackageException cause, Transience transience) {
       super(cause, transience);
     }
@@ -109,6 +109,19 @@ public abstract class RepositoryFunction {
     }
   }
 
+  /**
+   * Exception thrown when something a repository rule cannot be found.
+   */
+  public static final class RepositoryNotFoundException extends RepositoryFunctionException {
+    public RepositoryNotFoundException(String repositoryName) {
+      super(
+          new BuildFileContainsErrorsException(
+              Label.EXTERNAL_PACKAGE_IDENTIFIER,
+              "The repository named '" + repositoryName + "' could not be resolved"),
+          Transience.PERSISTENT);
+    }
+  }
+
   private BlazeDirectories directories;
 
   private byte[] computeRuleKey(Rule rule, byte[] ruleSpecificData) {
@@ -352,8 +365,13 @@ public abstract class RepositoryFunction {
     }
   }
 
+  /**
+   * Uses a remote repository name to fetch the corresponding Rule describing how to get it.
+   * 
+   * This should be the unique entry point for resolving a remote repository function.
+   */
   @Nullable
-  public static Package getExternalPackage(Environment env)
+  public static Rule getRule(String repository, Environment env)
       throws RepositoryFunctionException {
     SkyKey packageKey = PackageValue.key(Label.EXTERNAL_PACKAGE_IDENTIFIER);
     PackageValue packageValue;
@@ -377,7 +395,11 @@ public abstract class RepositoryFunction {
               Label.EXTERNAL_PACKAGE_IDENTIFIER, "Could not load //external package"),
           Transience.PERSISTENT);
     }
-    return externalPackage;
+    Rule rule = externalPackage.getRule(repository);
+    if (rule == null) {
+      throw new RepositoryNotFoundException(repository);
+    }
+    return rule;
   }
 
   @Nullable
@@ -402,19 +424,7 @@ public abstract class RepositoryFunction {
   public static Rule getRule(
       RepositoryName repositoryName, @Nullable String ruleClassName, Environment env)
       throws RepositoryFunctionException {
-    Package externalPackage = getExternalPackage(env);
-    if (externalPackage == null) {
-      return null;
-    }
-
-    Rule rule = externalPackage.getRule(repositoryName.strippedName());
-    if (rule == null) {
-      throw new RepositoryFunctionException(
-          new BuildFileContainsErrorsException(
-              Label.EXTERNAL_PACKAGE_IDENTIFIER,
-              "The repository named '" + repositoryName + "' could not be resolved"),
-          Transience.PERSISTENT);
-    }
+    Rule rule = getRule(repositoryName.strippedName(), env);
     Preconditions.checkState(ruleClassName == null || rule.getRuleClass().equals(ruleClassName),
         "Got %s, was expecting a %s", rule, ruleClassName);
     return rule;