Cache memoryview hash

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/unittest_tags/test_memoryview.txt

@@ -28,6 +28,7 @@
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_delitem
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_gc
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_getbuf_fail
+*graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_hash
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_hash_writable
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_iter
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceSliceTest.test_release
@@ -43,6 +44,7 @@
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_delitem
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_gc
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_getbuf_fail
+*graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_hash
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_hash_writable
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_iter
 *graalpython.lib-python.3.test.test_memoryview.BytesMemorySliceTest.test_release
@@ -58,6 +60,7 @@
 *graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_delitem
 *graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_gc
 *graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_getbuf_fail
+*graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_hash
 *graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_hash_writable
 *graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_iter
 *graalpython.lib-python.3.test.test_memoryview.BytesMemoryviewTest.test_release

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/memoryview/IntrinsifiedPMemoryView.java

@@ -45,6 +45,9 @@ public class IntrinsifiedPMemoryView extends PythonBuiltinObject {
     private BufferReference reference;
     private int flags;
 
+    // Cached hash value, required to compy with CPython's semantics
+    private int cachedHash = -1;
+
     public IntrinsifiedPMemoryView(Object cls, Shape instanceShape, MemoryViewNodes.BufferReferences references, ManagedBuffer managedBuffer, Object owner,
                     int len, boolean readonly, int itemsize, String formatString, int ndim, Object bufPointer,
                     int offset, int[] shape, int[] strides, int[] suboffsets, int flags) {
@@ -225,6 +228,14 @@ public BufferReference getReference() {
         return reference;
     }
 
+    public int getCachedHash() {
+        return cachedHash;
+    }
+
+    public void setCachedHash(int cachedHash) {
+        this.cachedHash = cachedHash;
+    }
+
     public void setReleased() {
         flags |= FLAG_RELEASED;
         if (reference != null) {

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/memoryview/MemoryViewBuiltins.java

@@ -551,15 +551,20 @@ static String repr(IntrinsifiedPMemoryView self) {
     public static abstract class HashNode extends PythonUnaryBuiltinNode {
         @Specialization
         int hash(IntrinsifiedPMemoryView self,
+                        @Cached ConditionProfile cachedProfile,
                         @Cached ConditionProfile writableProfile,
                         @Cached MemoryViewNodes.ToJavaBytesNode toJavaBytesNode) {
+            if (cachedProfile.profile(self.getCachedHash() != -1)) {
+                return self.getCachedHash();
+            }
             self.checkReleased(this);
             if (writableProfile.profile(!self.isReadOnly())) {
                 throw raise(ValueError, ErrorMessages.CANNOT_HASH_WRITEABLE_MEMORYVIEW);
             } else {
                 // TODO avoid copying
-                // TODO save the value
-                return hashArray(toJavaBytesNode.execute(self));
+                int hash = hashArray(toJavaBytesNode.execute(self));
+                self.setCachedHash(hash);
+                return hash;
             }
         }