Separate BEP fetching and parsing

This is to enable independent changes to both processes.

1. Introduce a `BuildResultHelper.getBepStream()` method that knows
   how to get a BEP stream. Each `BuildResultHelper` gets its own
   implementation.

2. Re-implement other methods like `getBuildOutput()` to operate on
   externally supplied `BuildEventStreamProvider`. These methods should
   not eventually depend on a specific implementation of
   `BuildResultHelper` and will be moved out soon.

3. Update tests accordingly.

Bug: n/a
Test: existing
Change-Id: I48f6cf5d19889e60c6795c1b097243cd7006c686

AOSP: 47436ebddcad73d6a5d4bf1d8ab8a8ccbe1c2235

aswb/src/com/google/idea/blaze/android/run/deployinfo/BlazeApkDeployInfoProtoHelper.java

@@ -49,8 +49,8 @@ public AndroidDeployInfo readDeployInfoProtoForTarget(
       throws GetDeployInfoException {
     ImmutableList<OutputArtifact> outputArtifacts;
     ParsedBepOutput bepOutput;
-    try {
-      bepOutput = buildResultHelper.getBuildOutput(Optional.empty(), Interners.STRING);
+    try (final var bepStream = buildResultHelper.getBepStream(Optional.empty())) {
+      bepOutput = buildResultHelper.getBuildOutput(bepStream, Interners.STRING);
       outputArtifacts = bepOutput.getDirectArtifactsForTarget(target, pathFilter).asList();
     } catch (GetArtifactsException e) {
       throw new GetDeployInfoException(e.getMessage());

aswb/src/com/google/idea/blaze/android/run/test/BlazeAndroidTestLaunchTask.java

@@ -211,8 +211,10 @@ public void run(@NotNull BlazeLaunchContext launchContext)
                         if (retVal != 0) {
                           context.setHasError();
                         } else {
-                          testResultsHolder.setTestResults(
-                              buildResultHelper.getTestResults(Optional.empty()));
+                          try (final var bepStream = buildResultHelper.getBepStream(Optional.empty())) {
+                            testResultsHolder.setTestResults(
+                              buildResultHelper.getTestResults(bepStream));
+                          }
                         }
                         ListenableFuture<Void> unusedFuture =
                             FileCaches.refresh(

base/src/com/google/idea/blaze/base/buildview/BazelExecService.kt

@@ -175,7 +175,7 @@ class BazelExecService(private val project: Project) : Disposable {
     LOG.assertTrue(cmdBuilder.name == BlazeCommandName.BUILD)
 
     return executionScope(ctx) { provider ->
-      cmdBuilder.addBlazeFlags(provider.getBuildFlags())
+      cmdBuilder.addBlazeFlags(provider.buildFlags)
 
       val parseJob = parseEvents(ctx, provider)
 
@@ -185,11 +185,13 @@ class BazelExecService(private val project: Project) : Disposable {
       parseJob.cancelAndJoin()
 
       if (result.status == BuildResult.Status.FATAL_ERROR) {
-        BlazeBuildOutputs.noOutputs(result)
-      } else {
+        return@executionScope BlazeBuildOutputs.noOutputs(result)
+      }
+
+      provider.getBepStream(Optional.empty()).use { bepStream ->
         BlazeBuildOutputs.fromParsedBepOutput(
           result,
-          provider.getBuildOutput(Optional.empty(), Interners.STRING),
+          provider.getBuildOutput(bepStream, Interners.STRING),
         )
       }
     }

base/src/com/google/idea/blaze/base/command/CommandLineBlazeCommandRunner.java

@@ -94,7 +94,10 @@ public BlazeBuildOutputs run(
           Optional.ofNullable(context.getScope(SharedStringPoolScope.class))
               .map(SharedStringPoolScope::getStringInterner)
               .orElse(null);
-      ParsedBepOutput buildOutput = buildResultHelper.getBuildOutput(Optional.empty(), stringInterner);
+      ParsedBepOutput buildOutput;
+      try (final var bepStream = buildResultHelper.getBepStream(Optional.empty())) {
+        buildOutput = buildResultHelper.getBuildOutput(bepStream, stringInterner);
+      }
       context.output(PrintOutput.log("BEP outputs retrieved (%s).", StringUtilRt.formatFileSize(buildOutput.getBepBytesConsumed())));
       return BlazeBuildOutputs.fromParsedBepOutput(buildResult, buildOutput);
     } catch (GetArtifactsException e) {
@@ -128,8 +131,8 @@ public BlazeTestResults runTest(
       return BlazeTestResults.NO_RESULTS;
     }
     context.output(PrintOutput.log("Build command finished. Retrieving BEP outputs..."));
-    try {
-      return buildResultHelper.getTestResults(Optional.empty());
+    try(final var bepStream = buildResultHelper.getBepStream(Optional.empty())) {
+      return buildResultHelper.getTestResults(bepStream);
     } catch (GetArtifactsException e) {
       context.output(PrintOutput.log("Failed to get build outputs: " + e.getMessage()));
       context.setHasError();

base/src/com/google/idea/blaze/base/command/buildresult/BuildEventProtocolOutputReader.java

@@ -43,11 +43,6 @@
 public final class BuildEventProtocolOutputReader {
 
   private BuildEventProtocolOutputReader() {}
-  /** Returns all test results from a BEP-formatted {@link InputStream}. */
-  public static BlazeTestResults parseTestResults(InputStream inputStream)
-      throws BuildEventStreamException {
-    return parseTestResults(BuildEventStreamProvider.fromInputStream(inputStream));
-  }
   /**
    * Returns all test results from {@link BuildEventStreamProvider}.
    *

base/src/com/google/idea/blaze/base/command/buildresult/BuildEventStreamProvider.java

@@ -21,10 +21,11 @@
 import com.google.idea.blaze.exception.BuildException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Optional;
 import javax.annotation.Nullable;
 
 /** Provides {@link BuildEventStreamProtos.BuildEvent} */
-public interface BuildEventStreamProvider {
+public interface BuildEventStreamProvider extends AutoCloseable {
 
   /** An exception parsing a stream of build events. */
   class BuildEventStreamException extends BuildException {
@@ -47,9 +48,29 @@ static BuildEventStreamProtos.BuildEvent parseNextEventFromStream(InputStream st
     }
   }
 
+  /**
+   * Creates a {@link BuildEventStreamProvider} from the given {@code stream}.
+   *
+   * <p>Note: takes ownership of the {@code stream} and closes it when is being closed.
+   */
   static BuildEventStreamProvider fromInputStream(InputStream stream) {
     CountingInputStream countingStream = new CountingInputStream(stream);
     return new BuildEventStreamProvider() {
+      @Override
+      public void close() {
+        try {
+          stream.close();
+        }
+        catch (IOException e) {
+          throw new RuntimeException(e);
+        }
+      }
+
+      @Override
+      public Object getId() {
+        return Optional.empty();
+      }
+
       @Nullable
       @Override
       public BuildEvent getNext() throws BuildEventStreamException {
@@ -63,9 +84,17 @@ public long getBytesConsumed() {
     };
   }
 
+  /**
+   * @return an object that represents the identity of the build to the user.
+   */
+  Object getId();
+
   /** Returns the next build event in the stream, or null if there are none remaining. */
   @Nullable
   BuildEventStreamProtos.BuildEvent getNext() throws BuildEventStreamException;
 
   long getBytesConsumed();
+
+  @Override
+  void close();
 }

base/src/com/google/idea/blaze/base/command/buildresult/BuildResultHelper.java

@@ -16,6 +16,7 @@
 package com.google.idea.blaze.base.command.buildresult;
 
 import com.google.common.collect.Interner;
+import com.google.errorprone.annotations.MustBeClosed;
 import com.google.idea.blaze.base.run.testlogs.BlazeTestResults;
 import com.google.idea.blaze.base.scope.BlazeContext;
 import com.google.idea.blaze.exception.BuildException;
@@ -34,31 +35,38 @@ public interface BuildResultHelper extends AutoCloseable {
    */
   List<String> getBuildFlags();
 
+
+  /**
+   * Gets the BEP stream for the build. May only be called once. May only be called after the build is complete.
+   */
+  @MustBeClosed
+  BuildEventStreamProvider getBepStream(Optional<String> completionBuildId) throws GetArtifactsException;
+
   /**
-   * Parses the BEP output data and returns the corresponding {@link ParsedBepOutput}. May only be
-   * called once, after the build is complete.
+   * Parses the BEP stream and returns the corresponding {@link ParsedBepOutput}. May only be
+   * called once on a given stream.
    *
    * <p>As BEP retrieval can be memory-intensive for large projects, implementations of
    * getBuildOutput may restrict parallelism for cases in which many builds are executed in parallel
    * (e.g. remote builds).
    */
   ParsedBepOutput getBuildOutput(
-      Optional<String> completionBuildId, Interner<String> stringInterner)
+    BuildEventStreamProvider bepStream, Interner<String> stringInterner)
       throws GetArtifactsException;
 
   /**
-   * Retrieves test results, parses them and returns the corresponding {@link BlazeTestResults}. May
-   * only be called once, after the build is complete.
+   * Parses BEP stream and returns the corresponding {@link BlazeTestResults}. May
+   * only be called once on a given stream.
    */
-  BlazeTestResults getTestResults(Optional<String> completedBuildId) throws GetArtifactsException;
+  BlazeTestResults getTestResults(BuildEventStreamProvider bepStream) throws GetArtifactsException;
 
   /** Deletes the local BEP output file associated with the test results */
   default void deleteTemporaryOutputFiles() {}
 
   /**
-   * Parses the BEP output data to collect all build flags used. Return all flags that pass filters
+   * Parses the BEP stream and  collects all build flags used. Return all flags that pass filters
    */
-  BuildFlags getBlazeFlags(Optional<String> completedBuildId) throws GetFlagsException;
+  BuildFlags getBlazeFlags(BuildEventStreamProvider bepStream) throws GetFlagsException;
 
   /**
    * Parses the BEP output data to collect message on stdout.

base/src/com/google/idea/blaze/base/command/buildresult/BuildResultHelperBep.java

@@ -17,15 +17,13 @@
 
 import com.google.common.collect.Interner;
 import com.google.idea.blaze.base.command.buildresult.BuildEventStreamProvider.BuildEventStreamException;
-import com.google.idea.blaze.base.io.InputStreamProvider;
 import com.google.idea.blaze.base.run.testlogs.BlazeTestResults;
 import com.intellij.openapi.diagnostic.Logger;
 import com.intellij.openapi.project.Project;
 import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.IOException;
-import java.io.InputStream;
+import java.io.FileNotFoundException;
 import java.util.List;
 import java.util.Optional;
 import org.jetbrains.annotations.VisibleForTesting;
@@ -56,22 +54,32 @@ public List<String> getBuildFlags() {
   }
 
   @Override
-  public ParsedBepOutput getBuildOutput(Optional<String> completedBuildId, Interner<String> stringInterner)
+  public BuildEventStreamProvider getBepStream(Optional<String> completionBuildId) throws GetArtifactsException {
+    try {
+      return BuildEventStreamProvider.fromInputStream(new BufferedInputStream(new FileInputStream(outputFile)));
+    }
+    catch (FileNotFoundException e) {
+      logger.error(e);
+      throw new GetArtifactsException(e.getMessage());
+    }
+  }
+
+  @Override
+  public ParsedBepOutput getBuildOutput(BuildEventStreamProvider bepStream, Interner<String> stringInterner)
       throws GetArtifactsException {
-    try (InputStream inputStream = new BufferedInputStream(new FileInputStream(outputFile))) {
-      return ParsedBepOutput.parseBepArtifacts(inputStream);
-    } catch (IOException | BuildEventStreamException e) {
+    try {
+      return ParsedBepOutput.parseBepArtifacts(bepStream, stringInterner);
+    } catch (BuildEventStreamException e) {
       logger.error(e);
       throw new GetArtifactsException(e.getMessage());
     }
   }
 
   @Override
-  public BlazeTestResults getTestResults(Optional<String> completedBuildId) {
-    try (InputStream inputStream =
-        new BufferedInputStream(InputStreamProvider.getInstance().forFile(outputFile))) {
-      return BuildEventProtocolOutputReader.parseTestResults(inputStream);
-    } catch (IOException | BuildEventStreamException e) {
+  public BlazeTestResults getTestResults(BuildEventStreamProvider bepStream) {
+    try  {
+      return BuildEventProtocolOutputReader.parseTestResults(bepStream);
+    } catch (BuildEventStreamException e) {
       logger.warn(e);
       return BlazeTestResults.NO_RESULTS;
     }
@@ -85,10 +93,10 @@ public void deleteTemporaryOutputFiles() {
   }
 
   @Override
-  public BuildFlags getBlazeFlags(Optional<String> completedBuildId) throws GetFlagsException {
-    try (InputStream inputStream = new BufferedInputStream(new FileInputStream(outputFile))) {
-      return BuildFlags.parseBep(inputStream);
-    } catch (IOException | BuildEventStreamException e) {
+  public BuildFlags getBlazeFlags(BuildEventStreamProvider bepStream) throws GetFlagsException {
+    try {
+      return BuildFlags.parseBep(bepStream);
+    } catch (BuildEventStreamException e) {
       throw new GetFlagsException(e);
     }
   }

base/src/com/google/idea/blaze/base/command/buildresult/ParsedBepOutput.java

@@ -110,12 +110,6 @@ public void end() {
           0,
           ImmutableSet.of());
 
-  /** Parses BEP events into {@link ParsedBepOutput} */
-  public static ParsedBepOutput parseBepArtifacts(InputStream bepStream)
-      throws BuildEventStreamException {
-    return parseBepArtifacts(BuildEventStreamProvider.fromInputStream(bepStream));
-  }
-
   /** Parses BEP events into {@link ParsedBepOutput} */
   public static ParsedBepOutput parseBepArtifacts(BuildEventStreamProvider stream)
       throws BuildEventStreamException {

base/src/com/google/idea/blaze/base/run/testlogs/LocalBuildEventProtocolTestFinderStrategy.java

@@ -34,7 +34,9 @@ public LocalBuildEventProtocolTestFinderStrategy(BuildResultHelper buildResultHe
 
   @Override
   public BlazeTestResults findTestResults() throws GetArtifactsException {
-    return buildResultHelper.getTestResults(Optional.empty());
+    try (final var bepStream = buildResultHelper.getBepStream(Optional.empty())) {
+      return buildResultHelper.getTestResults(bepStream);
+    }
   }
 
   @Override