Iterate over filetypes without creating an iterator. As this is some…

…times

    used in the inner loop when iterating over large sets, the amount of garbage
    created here is important.

    RELNOTES: None.
    PiperOrigin-RevId: 240734371

dataset/GitHub_Java/bazelbuild.bazel/src/main/java/com/google/devtools/build/lib/util/FileType.java

@@ -22,6 +22,7 @@
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec.VisibleForSerialization;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import javax.annotation.concurrent.Immutable;
 
@@ -43,12 +44,12 @@ public static FileType of(final String ext) {
     return new SingletonFileType(ext);
   }
 
-  public static FileType of(final ImmutableList<String> extensions) {
-    return new ListFileType(extensions);
+  public static FileType of(final List<String> extensions) {
+    return new ListFileType(ImmutableList.copyOf(extensions));
   }
 
   public static FileType of(final String... extensions) {
-    return of(ImmutableList.copyOf(extensions));
+    return of(Arrays.asList(extensions));
   }
 
   @AutoCodec.VisibleForSerialization
@@ -67,7 +68,7 @@ public boolean apply(String path) {
     }
 
     @Override
-    public ImmutableList<String> getExtensions() {
+    public List<String> getExtensions() {
       return ImmutableList.of(ext);
     }
   }
@@ -94,8 +95,8 @@ public boolean apply(String path) {
     }
 
     @Override
-    public ImmutableList<String> getExtensions() {
-      return extensions;
+    public List<String> getExtensions() {
+      return ImmutableList.copyOf(extensions);
     }
 
     @Override
@@ -121,12 +122,12 @@ public String toString() {
 
   /**
    * Get a list of filename extensions this matcher handles. The first entry in the list (if
-   * available) is the primary extension that code can use to construct output file names. The list
-   * can be empty for some matchers.
+   * available) is the primary extension that code can use to construct output file names.
+   * The list can be empty for some matchers.
    *
    * @return a list of filename extensions
    */
-  public ImmutableList<String> getExtensions() {
+  public List<String> getExtensions() {
     return ImmutableList.of();
   }