Reclassify RemoteActionFileSystem as an in-memory filesystem, and ren…

…ame the ActionFileSystemType enum values to better match reality.

RemoteActionFileSystem, the action filesystem implementation used by Bazel, became an in-memory filesystem in revision 2876569. Its ActionFileSystemType must be recognized as such so that Skyframe creates output directories prior to local action execution.

The correspondence between old -> new enum values is as follows:

DISABLED -> DISABLED
STAGE_REMOTE_FILES -> REMOTE_FILE_SYSTEM
IN_MEMORY_FILE_SYSTEM -> IN_MEMORY_ONLY_FILE_SYSTEM
IN_MEMORY_FILE_SYSTEM_AND_STAGE_REMOTE_FILES -> STAGE_REMOTE_FILES_FILE_SYSTEM

Also fix a call site where a capability check was made by comparing with the enum value instead of calling the accessor.

PiperOrigin-RevId: 482270459
Change-Id: I8ba6a0f32d8570e81281e1e1a29b232df2ac6c85

src/main/java/com/google/devtools/build/lib/buildtool/ExecutionTool.java

@@ -301,7 +301,7 @@ public void prepareForExecution(UUID buildId)
         startLocalOutputBuild();
       }
     }
-    if (outputService == null || outputService.actionFileSystemType().supportLocalActions()) {
+    if (outputService == null || outputService.actionFileSystemType().supportsLocalActions()) {
       // Must be created after the output path is created above.
       createActionLogDirectory();
     }
@@ -388,7 +388,7 @@ void executeBuild(
       }
     }
 
-    if (outputService == null || outputService.actionFileSystemType().supportLocalActions()) {
+    if (outputService == null || outputService.actionFileSystemType().supportsLocalActions()) {
       // Must be created after the output path is created above.
       createActionLogDirectory();
     }

src/main/java/com/google/devtools/build/lib/remote/RemoteOutputService.java

@@ -51,7 +51,7 @@ void setActionInputFetcher(RemoteActionInputFetcher actionInputFetcher) {
   @Override
   public ActionFileSystemType actionFileSystemType() {
     return actionInputFetcher != null
-        ? ActionFileSystemType.STAGE_REMOTE_FILES
+        ? ActionFileSystemType.REMOTE_FILE_SYSTEM
         : ActionFileSystemType.DISABLED;
   }
 

src/main/java/com/google/devtools/build/lib/skyframe/ActionExecutionFunction.java

@@ -92,7 +92,6 @@
 import com.google.devtools.build.lib.util.io.FileOutErr;
 import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor;
 import com.google.devtools.build.lib.vfs.FileSystem;
-import com.google.devtools.build.lib.vfs.OutputService.ActionFileSystemType;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.Root;
 import com.google.devtools.build.skyframe.SkyFunction;
@@ -254,9 +253,7 @@ private SkyValue computeInternal(SkyKey skyKey, Environment env)
     CheckInputResults checkedInputs = null;
     NestedSet<Artifact> allInputs =
         state.allInputs.getAllInputs(
-            !skyframeActionExecutor
-                .actionFileSystemType()
-                .equals(ActionFileSystemType.STAGE_REMOTE_FILES));
+            skyframeActionExecutor.actionFileSystemType().supportsInputDiscovery());
 
     if (!state.actionInputCollectedEventSent) {
       env.getListener()

src/main/java/com/google/devtools/build/lib/skyframe/ActionOutputDirectoryHelper.java

@@ -60,9 +60,9 @@ private enum DirectoryState {
   }
 
   /**
-   * Creates output directories for an {@link
-   * com.google.devtools.build.lib.vfs.OutputService.ActionFileSystemType#IN_MEMORY_FILE_SYSTEM}.
-   * The action-local filesystem starts empty, so we expect the output directory creation to always
+   * Creates output directories for an in-memory action file system ({@link
+   * com.google.devtools.build.lib.vfs.OutputService.ActionFileSystemType#inMemoryFileSystem}). The
+   * action-local filesystem starts empty, so we expect the output directory creation to always
    * succeed. There can be no interference from state left behind by prior builds or other actions
    * intra-build.
    */
@@ -96,8 +96,8 @@ void createActionFsOutputDirectories(
    * rewinding, actions that output tree artifacts need to recreate the directories because they are
    * deleted as part of the {@link com.google.devtools.build.lib.actions.Action#prepare} step.
    *
-   * <p>Note that this does not need to be called if using {@link
-   * com.google.devtools.build.lib.vfs.OutputService.ActionFileSystemType#IN_MEMORY_FILE_SYSTEM}.
+   * <p>Note that this does not need to be called if using an in-memory action file system ({@link
+   * com.google.devtools.build.lib.vfs.OutputService.ActionFileSystemType#inMemoryFileSystem}).
    */
   void invalidateTreeArtifactDirectoryCreation(ImmutableSet<Artifact> actionOutputs) {
     for (Artifact output : actionOutputs) {

src/main/java/com/google/devtools/build/lib/skyframe/SkyframeActionExecutor.java

@@ -1006,7 +1006,7 @@ public ActionStepOrResult run(Environment env)
             statusReporter.updateStatus(event);
           }
           env.getListener().post(event);
-          if (actionFileSystemType().supportLocalActions()) {
+          if (actionFileSystemType().supportsLocalActions()) {
             try (SilentCloseable d = profiler.profile(ProfilerTask.INFO, "action.prepare")) {
               // This call generally deletes any files at locations that are declared outputs of the
               // action, although some actions perform additional work, while others intentionally

src/main/java/com/google/devtools/build/lib/vfs/OutputService.java

@@ -48,35 +48,42 @@ public interface OutputService {
   /** Properties of the action file system implementation provided by this output service. */
   enum ActionFileSystemType {
 
-    /** Action file system is disabled */
+    /** The action file system is disabled. */
     DISABLED,
 
     /**
-     * The action file system implementation does not take over the output base but complements the
-     * file system by being able to stage remote outputs accessed as inputs by local actions, as
-     * used by Bazel.
+     * The action file system implementation is purely in-memory, taking full control of the output
+     * base. It's not able to stage remote outputs accessed as inputs by local actions, but is able
+     * to do input discovery. Used by Blaze.
      */
-    STAGE_REMOTE_FILES,
+    IN_MEMORY_ONLY_FILE_SYSTEM,
 
     /**
-     * The action file system implementation is fully featured in-memory file system implementation
-     * and takes full control of the output base, as used by Blaze.
+     * The action file system implementation mixes an in-memory and a local file system. It uses the
+     * in-memory filesystem for in-process and remote actions, but is also aware of outputs from
+     * local actions. It's able to stage remote outputs accessed as inputs by local actions and to
+     * do input discovery. Used by Blaze.
      */
-    IN_MEMORY_FILE_SYSTEM,
+    STAGE_REMOTE_FILES_FILE_SYSTEM,
 
     /**
-     * The action file system implementation mixes in-memory and local file system. It uses
-     * in-memory filesystem for in-process and remote actions but is also aware of outputs from
-     * local actions. It's able to stage remote outputs accessed as inputs by local actions.
+     * The action file system implementation mixes an in-memory and a local file system. It uses the
+     * in-memory filesystem for in-process and remote actions, but is also aware of outputs from
+     * local actions. It's able to stage remote outputs accessed as inputs by local actions, but
+     * unable to do input discovery. Used by Bazel.
      */
-    IN_MEMORY_FILE_SYSTEM_AND_STAGE_REMOTE_FILES;
+    REMOTE_FILE_SYSTEM;
 
     public boolean inMemoryFileSystem() {
-      return this == IN_MEMORY_FILE_SYSTEM || this == IN_MEMORY_FILE_SYSTEM_AND_STAGE_REMOTE_FILES;
+      return this != DISABLED;
+    }
+
+    public boolean supportsLocalActions() {
+      return this != IN_MEMORY_ONLY_FILE_SYSTEM;
     }
 
-    public boolean supportLocalActions() {
-      return this != IN_MEMORY_FILE_SYSTEM;
+    public boolean supportsInputDiscovery() {
+      return this != REMOTE_FILE_SYSTEM;
     }
 
     public boolean isEnabled() {