Implement fake pack 'p' behavior

We can't provide an actual pointer, so this just encodes the identity hashcode as a long.
headius · Nov 2, 2023 · 956f8cb · 956f8cb
1 parent 931c4fc
commit 956f8cb
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Showing 2 changed files with 38 additions and 4 deletions.
diff --git a/core/src/main/java/org/jruby/util/Pack.java b/core/src/main/java/org/jruby/util/Pack.java
@@ -478,6 +478,44 @@ public void encode(Ruby runtime, IRubyObject o, ByteList result){
         };
         converters['q' + BE] = tmp;
         if (Platform.BIT_WIDTH == 64) converters['j' + BE] = tmp;
+
+        // pointer; we can't provide a real pointer, so we just use identity hashcode
+        tmp = new QuadConverter(8) {
+            @Override
+            public IRubyObject decode(Ruby runtime, ByteBuffer format) {
+                return runtime.getNil();
+            }
+
+            @Override
+            public void encode(Ruby runtime, IRubyObject from, ByteList result) {
+                if (from.isNil()) {
+                    encodeLongBigEndian(result, 0);
+                } else {
+                    encodeLongBigEndian(result, System.identityHashCode(from));
+                }
+            }
+        };
+
+        converters['p'] = tmp;
+
+        // pointer; we can't provide a real pointer, so we just use identity hashcode
+        tmp = new QuadConverter(8) {
+            @Override
+            public IRubyObject decode(Ruby runtime, ByteBuffer format) {
+                return runtime.getNil();
+            }
+
+            @Override
+            public void encode(Ruby runtime, IRubyObject from, ByteList result) {
+                if (from.isNil()) {
+                    encodeLongBigEndian(result, 0);
+                } else {
+                    encodeLongBigEndian(result, System.identityHashCode(from.convertToString()));
+                }
+            }
+        };
+
+        converters['P'] = tmp;
     }
 
     public static int unpackInt_i(ByteBuffer enc) {

diff --git a/spec/tags/ruby/core/array/pack/p_tags.txt b/spec/tags/ruby/core/array/pack/p_tags.txt
@@ -1,6 +1,2 @@
 fails:Array#pack with format 'P' round-trips a string through pack and unpack
-fails:Array#pack with format 'P' with nil gives a null pointer
 fails:Array#pack with format 'p' round-trips a string through pack and unpack
-fails:Array#pack with format 'p' with nil gives a null pointer
-fails:Array#pack with format 'P' produces as many bytes as there are in a pointer
-fails:Array#pack with format 'p' produces as many bytes as there are in a pointer