rbd.py: add some missing functions

discard, flush, and striping info slipped through the cracks before,
but are useful and trivial to add.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>

diff --git a/src/pybind/rbd.py b/src/pybind/rbd.py
index b542b12efc536ed7bce77397632ae744b9d2d8d1..c5cef9dee42efd5c3bc70dea62d35b5953db2e75 100644 (file)
--- a/src/pybind/rbd.py
+++ b/src/pybind/rbd.py
@@ -671,12 +671,12 @@ class Image(object):
         RBD_DIFF_CB = CFUNCTYPE(c_int, c_uint64, c_size_t, c_int, c_void_p)
         cb_holder = DiffIterateCB(iterate_cb)
         cb = RBD_DIFF_CB(cb_holder.callback)
-        ret = self.librbd.diff_iterate(self.image,
-                                       c_char_p(from_snapshot),
-                                       c_uint64(offset),
-                                       c_uint64(length),
-                                       cb,
-                                       c_void_p(None))
+        ret = self.librbd.rbd_diff_iterate(self.image,
+                                           c_char_p(from_snapshot),
+                                           c_uint64(offset),
+                                           c_uint64(length),
+                                           cb,
+                                           c_void_p(None))
         if ret < 0:
             msg = 'error generating diff from snapshot %s' % from_snapshot
             raise make_ex(ret, msg)
@@ -710,6 +710,40 @@ class Image(object):
 returned %d, but %d was the maximum number of bytes it could have \
 written." % (self.name, ret, length))
 
+    def discard(self, offset, length):
+        """
+        Trim the range from the image. It will be logically filled
+        with zeroes.
+        """
+        ret = self.librbd.rbd_discard(self.image,
+                                      c_uint64(offset),
+                                      c_uint64(length))
+        if ret < 0:
+            msg = 'error discarding region %d~%d' % (offset, length)
+            raise make_ex(ret, msg)
+
+    def flush(self):
+        """
+        Block until all writes are fully flushed if caching is enabled.
+        """
+        ret = self.librbd.rbd_flush(self.image)
+        if ret < 0:
+            raise make_ex(ret, 'error flushing image')
+
+    def stripe_unit(self):
+        """
+        Returns the stripe unit used for the image.
+        """
+        ret = self.librbd.rbd_get_stripe_unit()
+        return ret.value
+
+    def stripe_count(self):
+        """
+        Returns the stripe count used for the image.
+        """
+        ret = self.librbd.rbd_get_stripe_count()
+        return ret.value
+
     def flatten(self):
         """
         Flatten clone image (copy all blocks from parent to child)

diff --git a/src/test/pybind/test_rbd.py b/src/test/pybind/test_rbd.py
index 9c59f218b468ba342cc50b5cad73e60acb6834c4..ea3e5fc5e040edc64507dddb4fd9de49a8760c2f 100644 (file)
--- a/src/test/pybind/test_rbd.py
+++ b/src/test/pybind/test_rbd.py
@@ -460,19 +460,25 @@ class TestImage(object):
         check_diff(self.image, 0, IMG_SIZE, None, [(0, 256, True)])
         self.image.write('b' * 256, 256)
         check_diff(self.image, 0, IMG_SIZE, None, [(0, 512, True)])
-        
+        self.image.discard(128, 256)
+        check_diff(self.image, 0, IMG_SIZE, None, [(0, 512, True)])
 
-def check_diff(image, offset, length, from_snapshot, expected):
-    cb_holder = DiffExtents()
-    image.diff_iterate(0, IMG_SIZE, None, cb_holder.callback)
-    eq(cb_holder.extents, expected)
+        self.image.create_snap('snap1')
+        self.image.discard(0, 1 << IMG_ORDER)
+        self.image.create_snap('snap2')
+        self.image.set_snap('snap2')
+        check_diff(self.image, 0, IMG_SIZE, 
+                   'snap1', [(0, 512, False)])
+        self.image.remove_snap('snap1')
+        self.image.remove_snap('snap2')
 
-class DiffExtents(object):
-    def __init__(self):
-        self.extents = []
 
-    def callback(self, offset, length, exists):
-        self.extents.append((offset, length, exists))
+def check_diff(image, offset, length, from_snapshot, expected):
+    extents = []
+    def cb(offset, length, exists):
+        extents.append((offset, length, exists))
+    image.diff_iterate(0, IMG_SIZE, None, cb)
+    eq(extents, expected)
 
 class TestClone(object):