Make ProtoStringInterner static.

Requiring an instance to be created is not necessary and makes using it a little more awkward in some cases. We never expect to use it with an interner other than that provided by `StringInterner` anyway.

PiperOrigin-RevId: 613156938

querysync/java/com/google/idea/blaze/qsync/query/QuerySummary.java

@@ -18,6 +18,7 @@
 import static com.google.common.collect.ImmutableMap.toImmutableMap;
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.common.collect.Multimaps.flatteningToMultimap;
+import static com.google.idea.blaze.common.proto.ProtoStringInterner.intern;
 import static java.util.Objects.requireNonNull;
 
 import com.google.auto.value.AutoValue;
@@ -34,7 +35,6 @@
 import com.google.devtools.build.lib.query2.proto.proto2api.Build;
 import com.google.devtools.build.lib.query2.proto.proto2api.Build.Target;
 import com.google.idea.blaze.common.Label;
-import com.google.idea.blaze.common.proto.ProtoStringInterner;
 import com.google.idea.blaze.qsync.query.Query.SourceFile;
 import java.io.BufferedInputStream;
 import java.io.File;
@@ -136,8 +136,7 @@ public static QuerySummary create(InputStream protoInputStream) throws IOExcepti
     Map<String, Query.Rule> ruleMap = Maps.newHashMap();
     Set<String> packagesWithErrors = Sets.newHashSet();
     Build.Target target;
-    ProtoStringInterner interner = new ProtoStringInterner();
-    while ((target = interner.intern(Target.parseDelimitedFrom(protoInputStream))) != null) {
+    while ((target = intern(Target.parseDelimitedFrom(protoInputStream))) != null) {
       switch (target.getType()) {
         case SOURCE_FILE:
           Query.SourceFile sourceFile =
@@ -337,8 +336,7 @@ public Builder putAllPackagesWithErrors(Set<Path> packagesWithErrors) {
     }
 
     public QuerySummary build() {
-      ProtoStringInterner interner = new ProtoStringInterner();
-      return QuerySummary.create(interner.intern(builder.build()));
+      return QuerySummary.create(intern(builder.build()));
     }
   }
 }

shared/java/com/google/idea/blaze/common/proto/ProtoStringInterner.java

@@ -27,24 +27,17 @@
 /**
  * Eliminates duplicate strings inside a proto message by interning them.
  *
- * <p>All fields in a proto message are examined and strings passed through a {@link Interner} to
- * ensure that identical strings use the same instance in memory. This then allows duplicated
+ * <p>All fields in a proto message are examined and strings passed through {@link StringInterner}
+ * to ensure that identical strings use the same instance in memory. This then allows duplicated
  * strings to be garbage collected.
  */
 public class ProtoStringInterner {
 
-  private final Interner<String> stringInterner;
-
-  public ProtoStringInterner(Interner<String> interner) {
-    this.stringInterner = interner;
-  }
-
-  public ProtoStringInterner() {
-    this(StringInterner.INSTANCE);
-  }
+  private ProtoStringInterner() {}
 
   @SuppressWarnings("unchecked") // casts of proto field values should be safe.
-  public <T extends Message> T intern(T message) {
+  public static <T extends Message> T intern(T message) {
+    Interner<String> stringInterner = StringInterner.INSTANCE;
     if (message == null) {
       return null;
     }
@@ -68,7 +61,7 @@ public <T extends Message> T intern(T message) {
           if (field.isRepeated()) {
             List<Message> originalList = (List<Message>) original;
             List<Message> internedList =
-                originalList.stream().map(this::intern).collect(toImmutableList());
+                originalList.stream().map(ProtoStringInterner::intern).collect(toImmutableList());
             if (!IntStream.range(0, internedList.size())
                 .allMatch(i -> internedList.get(i) == originalList.get(i))) {
               interned = internedList;

shared/javatests/com/google/idea/blaze/common/proto/ProtoStringInternerTest.java

@@ -47,32 +47,28 @@ public void sanity_check() throws ParseException {
 
   @Test
   public void basic_string() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
-    MyMessage message1 = interner.intern(parse("string: 'value'"));
-    MyMessage message2 = interner.intern(parse("string: 'value'"));
+    MyMessage message1 = ProtoStringInterner.intern(parse("string: 'value'"));
+    MyMessage message2 = ProtoStringInterner.intern(parse("string: 'value'"));
     assertThat(message1.getString()).isSameInstanceAs(message2.getString());
   }
 
   @Test
   public void no_strings_message_not_copied() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
     MyMessage original = parse("integer: 42");
-    MyMessage interned = interner.intern(original);
+    MyMessage interned = ProtoStringInterner.intern(original);
     assertThat(interned).isSameInstanceAs(original);
   }
 
   @Test
   public void repeated_strings() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
     MyMessage original = parse("strings: 'one'", "strings: 'one'", "strings: 'two'");
-    MyMessage interned = interner.intern(original);
+    MyMessage interned = ProtoStringInterner.intern(original);
     assertThat(interned).isEqualTo(original);
     assertThat(interned.getStrings(0)).isSameInstanceAs(interned.getStrings(1));
   }
 
   @Test
   public void string_map_values() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
     MyMessage original =
         parse(
             "string_map {",
@@ -88,40 +84,37 @@ public void string_map_values() throws ParseException {
             "  value: 'puppies'",
             "}");
 
-    MyMessage interned = interner.intern(original);
+    MyMessage interned = ProtoStringInterner.intern(original);
     assertThat(interned).isEqualTo(original);
     assertThat(interned.getStringMapMap().get("one"))
         .isSameInstanceAs(interned.getStringMapMap().get("two"));
   }
 
   @Test
   public void string_map_keys() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
     MyMessage original =
         parse("string: 'one'", "string_map {", "  key: 'one'", "  value: 'kittens'", "}");
 
-    MyMessage interned = interner.intern(original);
+    MyMessage interned = ProtoStringInterner.intern(original);
     assertThat(interned).isEqualTo(original);
     assertThat(interned.getString())
         .isSameInstanceAs(Iterables.getOnlyElement(interned.getStringMapMap().keySet()));
   }
 
   @Test
   public void nested_string() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
     MyMessage original = parse("string: 'hello'", "sub_message {", "  sub_string: 'hello'", "}");
 
-    MyMessage interned = interner.intern(original);
+    MyMessage interned = ProtoStringInterner.intern(original);
     assertThat(interned).isEqualTo(original);
     assertThat(interned.getString()).isSameInstanceAs(interned.getSubMessage().getSubString());
   }
 
   @Test
   public void nested_repeated_field_no_strings_not_copied() throws ParseException {
-    ProtoStringInterner interner = new ProtoStringInterner();
     MyMessage original =
         parse("sub_messages {", "  sub_int: 1", "}", "sub_messages {", "  sub_int: 2", "}");
-    MyMessage interned = interner.intern(original);
+    MyMessage interned = ProtoStringInterner.intern(original);
     assertThat(interned).isSameInstanceAs(original);
   }
 }