[Jython-checkins] jython: Let PyBuffer support try-with-resources.

[jeff.allen]

http://hg.python.org/jython/rev/100892193c90
changeset:   7291:100892193c90
parent:      7289:1f517f1e5a08
user:        Jeff Allen <ja.py at farowl.co.uk>
date:        Fri Jun 13 23:36:56 2014 +0100
summary:
  Let PyBuffer support try-with-resources.
Now extends AutoCloseable. Also adds Java test.

files:
  src/org/python/core/PyBuffer.java            |   6 +-
  src/org/python/core/buffer/BaseBuffer.java   |   5 +
  tests/java/org/python/core/PyBufferTest.java |  29 +++++++++-
  3 files changed, 38 insertions(+), 2 deletions(-)


diff --git a/src/org/python/core/PyBuffer.java b/src/org/python/core/PyBuffer.java
--- a/src/org/python/core/PyBuffer.java
+++ b/src/org/python/core/PyBuffer.java
@@ -5,7 +5,7 @@
  * the counterpart of the CPython <code>Py_buffer</code> struct. Several concrete types implement
  * this interface in order to provide tailored support for different storage organisations.
  */
-public interface PyBuffer extends PyBUF, BufferProtocol {
+public interface PyBuffer extends PyBUF, BufferProtocol, AutoCloseable {
 
     /*
      * The different behaviours required as the actual structure of the buffer changes (from one
@@ -183,6 +183,10 @@
      */
     void release();
 
+    /** An alias for {@link #release()} to satisfy {@link AutoCloseable}. */
+    @Override
+    void close();
+
     /**
      * True only if the buffer has been released with (the required number of calls to)
      * {@link #release()} or some equivalent operation. The consumer may be sharing the reference
diff --git a/src/org/python/core/buffer/BaseBuffer.java b/src/org/python/core/buffer/BaseBuffer.java
--- a/src/org/python/core/buffer/BaseBuffer.java
+++ b/src/org/python/core/buffer/BaseBuffer.java
@@ -522,6 +522,11 @@
     }
 
     @Override
+    public void close() {
+        release();
+    }
+
+    @Override
     public boolean isReleased() {
         return exports <= 0;
     }
diff --git a/tests/java/org/python/core/PyBufferTest.java b/tests/java/org/python/core/PyBufferTest.java
--- a/tests/java/org/python/core/PyBufferTest.java
+++ b/tests/java/org/python/core/PyBufferTest.java
@@ -701,8 +701,13 @@
 
         Set<PyBuffer> uniqueBuffers = new HashSet<PyBuffer>();
 
+        // Test a balanced sequence of acquire and release using try-with-resources
         for (BufferTestPair test : buffersToRead) {
-            // Test a pattern of acquire and release with one more release than acquire
+            doTestTryWithResources(test);
+        }
+
+        // Now test a pattern of acquire and release with one more release than acquire
+        for (BufferTestPair test : buffersToRead) {
             doTestRelease(test);
             uniqueBuffers.add(test.view);
         }
@@ -718,6 +723,28 @@
                 doTestGetAfterRelease(test);
             }
         }
+
+    }
+
+    /**
+     * Exercise try-with-resources on one BufferTestPair.
+     */
+    private void doTestTryWithResources(BufferTestPair test) {
+
+        if (verbosity > 0) {
+            System.out.println("try with resources: " + test);
+        }
+        int flags = PyBUF.STRIDES | PyBUF.FORMAT;
+        BufferProtocol sub = test.subject;
+
+        // The object will be exporting test.view and N other views we don't know about
+        try (PyBuffer c = sub.getBuffer(flags)) {   // = N+1 exports
+            try (PyBuffer b = sub.getBuffer(PyBUF.FULL_RO); PyBuffer d =c.getBuffer(flags)) {
+                checkExporting(sub);// = N+3 exports
+            }
+            checkExporting(sub);                    // = N+1 exports
+        }
+        checkExporting(sub);                        // = N export
     }
 
     /**

-- 
Repository URL: http://hg.python.org/jython