[Libguestfs] [libnbd PATCH v3 4/5] python: Support len(nbd.Buffer(n))

[Eric Blake]

b.size() is atypical, Python programmers generally expect to be able
to do len(b).  Keep the old spelling for backwards compatibility.
---
 generator/Python.ml         | 4 ++++
 python/t/580-aio-is-zero.py | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/generator/Python.ml b/generator/Python.ml
index cd7f0e3..975cab4 100644
--- a/generator/Python.ml
+++ b/generator/Python.ml
@@ -745,6 +745,10 @@ let
         return bytearray(self._o)

     def size(self):
+        '''Return the size of an AIO buffer.'''
+        return len(self)
+
+    def __len__(self):
         '''Return the size of an AIO buffer.'''
         return len(self._o)

diff --git a/python/t/580-aio-is-zero.py b/python/t/580-aio-is-zero.py
index 1a9a7d3..dd57e30 100644
--- a/python/t/580-aio-is-zero.py
+++ b/python/t/580-aio-is-zero.py
@@ -24,6 +24,7 @@ import nbd
 ba = bytearray(2**20)
 buf = nbd.Buffer.from_bytearray(ba)
 assert buf.size() == 2**20
+assert len(buf) == 2**20
 assert buf.is_zero()

 # The above buffer is 2**20 (= 1MB), slices of it should also be zero.
@@ -74,5 +75,6 @@ assert buf.is_zero(2**21-1, 1)
 # used with aio_pread; but it will be zeroed if accessed prematurely
 buf = nbd.Buffer(1024)
 assert buf.size() == 1024
+assert len(buf) == 1024
 assert buf.is_zero()
 assert nbd.Buffer.from_bytearray(buf.to_bytearray()).is_zero()
-- 
2.36.1