[7.0.0] Fix analysis time regression with Bzlmod lockfile (#20021)

This commit fixes a regression in analysis time caused by
19c0c80. Since
`BazelModuleResolutionEvent` and `ModuleExtensionResolutionEvent` are
both marked as `storeForReplay`, they are stored in a nested set for
essentially all analysis phase nodes. This resulted in frequent (i.e.,
per target) calls to their `hashCode` methods, which are not cached and
delegated to the likewise uncached methods on large `ImmutableMap` and
`ImmutableTable` instances.

Since there is no need for these events to be deduplicated, switching to
reference equality resolves this issue.

The following analysis phase measurements for a synthetic project with a
single "hub and spokes" module extension and 2,000 repos illustrate the
effect:

* without lockfile: 4.3s
* with lockfile before this commit: 8.3s
* with lockfile after this commit: 4.2s

Fixes #19952

Closes #19970.

Commit
435d1c2

PiperOrigin-RevId: 578734010
Change-Id: I870867c5c509389632793b0d5fe5c43ddc6176f3

Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/BazelModuleResolutionEvent.java

@@ -14,28 +14,46 @@
 
 package com.google.devtools.build.lib.bazel.bzlmod;
 
-import com.google.auto.value.AutoValue;
 import com.google.common.collect.ImmutableTable;
 import com.google.devtools.build.lib.events.ExtendedEventHandler.Postable;
 
 /**
  * After resolving bazel module this event is sent from {@link BazelDepGraphFunction} holding the
  * lockfile value with module updates, and the module extension usages. It will be received in
  * {@link BazelLockFileModule} to be used to update the lockfile content
+ *
+ * <p>Instances of this class are retained in Skyframe nodes and subject to frequent {@link
+ * java.util.Set}-based deduplication. As such, it <b>must</b> have a cheap implementation of {@link
+ * #hashCode()} and {@link #equals(Object)}. It currently uses reference equality since the logic
+ * that creates instances of this class already ensures that there is only one instance per build.
  */
-@AutoValue
-public abstract class BazelModuleResolutionEvent implements Postable {
+public final class BazelModuleResolutionEvent implements Postable {
+
+  private final BazelLockFileValue lockfileValue;
+  private final ImmutableTable<ModuleExtensionId, ModuleKey, ModuleExtensionUsage>
+      extensionUsagesById;
+
+  private BazelModuleResolutionEvent(
+      BazelLockFileValue lockfileValue,
+      ImmutableTable<ModuleExtensionId, ModuleKey, ModuleExtensionUsage> extensionUsagesById) {
+    this.lockfileValue = lockfileValue;
+    this.extensionUsagesById = extensionUsagesById;
+  }
 
   public static BazelModuleResolutionEvent create(
       BazelLockFileValue lockFileValue,
       ImmutableTable<ModuleExtensionId, ModuleKey, ModuleExtensionUsage> extensionUsagesById) {
-    return new AutoValue_BazelModuleResolutionEvent(lockFileValue, extensionUsagesById);
+    return new BazelModuleResolutionEvent(lockFileValue, extensionUsagesById);
   }
 
-  public abstract BazelLockFileValue getLockfileValue();
+  public BazelLockFileValue getLockfileValue() {
+    return lockfileValue;
+  }
 
-  public abstract ImmutableTable<ModuleExtensionId, ModuleKey, ModuleExtensionUsage>
-      getExtensionUsagesById();
+  public ImmutableTable<ModuleExtensionId, ModuleKey, ModuleExtensionUsage>
+      getExtensionUsagesById() {
+    return extensionUsagesById;
+  }
 
   @Override
   public boolean storeForReplay() {

src/main/java/com/google/devtools/build/lib/bazel/bzlmod/ModuleExtensionResolutionEvent.java

@@ -14,30 +14,53 @@
 
 package com.google.devtools.build.lib.bazel.bzlmod;
 
-import com.google.auto.value.AutoValue;
 import com.google.devtools.build.lib.events.ExtendedEventHandler.Postable;
 
 /**
  * After evaluating any module extension this event is sent from {@link SingleExtensionEvalFunction}
  * holding the extension id and the resolution data LockFileModuleExtension. It will be received in
- * {@link BazelLockFileModule} to be used to update the lockfile content
+ * {@link BazelLockFileModule} to be used to update the lockfile content.
+ *
+ * <p>Instances of this class are retained in Skyframe nodes and subject to frequent {@link
+ * java.util.Set}-based deduplication. As such, it <b>must</b> have a cheap implementation of {@link
+ * #hashCode()} and {@link #equals(Object)}. It currently uses reference equality since the logic
+ * that creates instances of this class already ensures that there is only one instance per
+ * extension id.
  */
-@AutoValue
-public abstract class ModuleExtensionResolutionEvent implements Postable {
+public final class ModuleExtensionResolutionEvent implements Postable {
+
+  private final ModuleExtensionId extensionId;
+  private final ModuleExtensionEvalFactors extensionFactors;
+  private final LockFileModuleExtension moduleExtension;
+
+  private ModuleExtensionResolutionEvent(
+      ModuleExtensionId extensionId,
+      ModuleExtensionEvalFactors extensionFactors,
+      LockFileModuleExtension moduleExtension) {
+    this.extensionId = extensionId;
+    this.extensionFactors = extensionFactors;
+    this.moduleExtension = moduleExtension;
+  }
 
   public static ModuleExtensionResolutionEvent create(
       ModuleExtensionId extensionId,
       ModuleExtensionEvalFactors extensionFactors,
       LockFileModuleExtension lockfileModuleExtension) {
-    return new AutoValue_ModuleExtensionResolutionEvent(
+    return new ModuleExtensionResolutionEvent(
         extensionId, extensionFactors, lockfileModuleExtension);
   }
 
-  public abstract ModuleExtensionId getExtensionId();
+  public ModuleExtensionId getExtensionId() {
+    return extensionId;
+  }
 
-  public abstract ModuleExtensionEvalFactors getExtensionFactors();
+  public ModuleExtensionEvalFactors getExtensionFactors() {
+    return extensionFactors;
+  }
 
-  public abstract LockFileModuleExtension getModuleExtension();
+  public LockFileModuleExtension getModuleExtension() {
+    return moduleExtension;
+  }
 
   @Override
   public boolean storeForReplay() {

src/main/java/com/google/devtools/build/lib/events/Reportable.java

@@ -47,6 +47,9 @@ public interface Reportable {
    *
    * <p>This method is not relevant for events which do not originate from {@link
    * com.google.devtools.build.skyframe.SkyFunction} evaluation.
+   *
+   * <p>Classes returning {@code true} should have cheap {@link Object#hashCode()} and {@link
+   * Object#equals(Object)} implementations.
    */
   default boolean storeForReplay() {
     return false;