jruby · Apr 19, 2018 · Apr 19, 2018
Showing with 38 additions and 0 deletions.

+21 −0 core/src/main/java/org/jruby/ext/jruby/JRubyUtilLibrary.java

+8 −0 core/src/main/java/org/jruby/runtime/load/LoadService.java

+9 −0 test/jruby/test_jruby_core_ext.rb
diff --git a/core/src/main/java/org/jruby/ext/jruby/JRubyUtilLibrary.java b/core/src/main/java/org/jruby/ext/jruby/JRubyUtilLibrary.java
@@ -110,6 +110,11 @@ public static IRubyObject unseeded_hash(ThreadContext context, IRubyObject recv)
         }
     }
 
+    /**
+     * Provide stats on how many method and constant invalidations have occurred globally.
+     *
+     * This was added for Pry in https://github.com/jruby/jruby/issues/4384
+     */
     @JRubyMethod(name = "cache_stats", module = true)
     public static IRubyObject cache_stats(ThreadContext context, IRubyObject self) {
         Ruby runtime = context.runtime;
@@ -120,4 +125,20 @@ public static IRubyObject cache_stats(ThreadContext context, IRubyObject self) {
 
         return stat;
     }
+
+    /**
+     * Return a list of files and extensions that JRuby treats as internal (or "built-in"), skipping load path and
+     * filesystem search.
+     *
+     * This was added for Bootsnap in https://github.com/Shopify/bootsnap/issues/162
+     */
+    @JRubyMethod(module = true)
+    public static RubyArray internal_libraries(ThreadContext context, IRubyObject self) {
+        Ruby runtime = context.runtime;
+        List<String> builtinLibraries = runtime.getLoadService().getBuiltinLibraries();
+
+        IRubyObject[] names = builtinLibraries.stream().map(name -> runtime.newString(name)).toArray(i->new IRubyObject[i]);
+
+        return runtime.newArrayNoCopy(names);
+    }
 }
diff --git a/core/src/main/java/org/jruby/runtime/load/LoadService.java b/core/src/main/java/org/jruby/runtime/load/LoadService.java
@@ -51,6 +51,7 @@
 import java.util.jar.JarFile;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import java.util.zip.ZipException;
 
 import org.jruby.Ruby;
@@ -628,6 +629,13 @@ public void removeBuiltinLibrary(String name) {
         builtinLibraries.remove(name);
     }
 
+    /**
+     * Get a list of all libraries JRuby considers "built-in".
+     */
+    public List<String> getBuiltinLibraries() {
+        return builtinLibraries.keySet().stream().collect(Collectors.toList());
+    }
+
     public void removeInternalLoadedFeature(String name) {
         loadedFeatures.deleteString(runtime.getCurrentContext(), name);
     }

diff --git a/test/jruby/test_jruby_core_ext.rb b/test/jruby/test_jruby_core_ext.rb
@@ -1,4 +1,5 @@
 require 'test/unit'
+require 'jruby/util'
 
 class TestJRubyCoreExt < Test::Unit::TestCase
 
@@ -76,6 +77,14 @@ def test_with_current_runtime_as_global
     assert_equal other_runtime, org.jruby.Ruby.global_runtime
   end
 
+  def test_internal_libraries
+    internal_libraries = JRuby::Util.internal_libraries
+
+    assert_equal Array, internal_libraries.class
+    assert_true internal_libraries.size > 0
+    assert_include internal_libraries, "cgi/escape.jar"
+  end
+
   private
 
   def assert_same_contents(expect, actual)