RhinoStringPool

java.lang.Object

com.google.javascript.rhino.RhinoStringPool

public final class RhinoStringPool extends Object

An interning pool for strings used by the Rhino package.

As of 2021-03-16 and again as of 2024-12-09, this custom pool is measurably more performant than `String::intern`.

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static final class

RhinoStringPool.LazyInternedStringList

A list of strings that is lazily interned into a RhinoStringPool as they are accessed.
Method Summary

Modifier and Type

Method

Description

static String

addOrGet(String s)

static boolean

uncheckedEquals(String a, String b)

Check if two strings are the same according to interning.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details
- uncheckedEquals
  
  public static boolean uncheckedEquals(String a, String b)
  
  Check if two strings are the same according to interning.
  The caller is responsible for ensuring that strings passed to this method are actually interned. This method mainly exists to highlight where equality checks depend on interning for correctness.
  Ideally we could use something like a branded-type, for interned strings, to verify correct usage. However, Java doesn't support type-brands, and using like wrapper objects would undermine performance. This also needs to be ergonomic enough that callers don't resort to using `==` directly.
- addOrGet
  
  public static String addOrGet(String s)