gfapi.py: support dynamic loading of versioned libraries

Currently gfapi.py only loads libraries by filename ending in ".so".  On
an installed system without development packages, the <lib>.so filenames
are not available. ctypes.util.find_library() can be used to detect the
files dynamically.

In addition to this, also fixing some minor indention errors and package
the library into the Python site-packages path. Python applications and
libraries can now access libgfapi through 'from glusterfs import gfapi'.

Change-Id: I71e38dabd3ade5dcf24813bf2fc25cda91b571c6
BUG: 1005146
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/5835
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

api/examples/Makefile.am

@@ -1,4 +1,6 @@
-noinst_PROGRAMS = glfsxmp
+EXTRA_PROGRAMS = glfsxmp
 glfsxmp_SOURCES = glfsxmp.c
 glfsxmp_CFLAGS = $(GLFS_CFLAGS) -Wall
-glfsxmp_LDADD = $(GLFS_LIBS)
+glfsxmp_LDADD = $(GLFS_LIBS)
+
+EXTRA_DIST = gfapi.py

api/examples/gfapi.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python
 
 from ctypes import *
+from ctypes.util import find_library
 import os
 import sys
 import time
@@ -8,9 +9,9 @@ import types
 
 # Looks like ctypes is having trouble with dependencies, so just force them to
 # load with RTLD_GLOBAL until I figure that out.
-glfs = CDLL("libglusterfs.so",RTLD_GLOBAL)
-xdr = CDLL("libgfxdr.so",RTLD_GLOBAL)
-api = CDLL("libgfapi.so",RTLD_GLOBAL)
+glfs = CDLL(find_library("glusterfs"),RTLD_GLOBAL)
+xdr = CDLL(find_library("gfxdr"),RTLD_GLOBAL)
+api = CDLL(find_library("gfapi"),RTLD_GLOBAL)
 
 # Wow, the Linux kernel folks really play nasty games with this structure.  If
 # you look at the man page for stat(2) and then at this definition you'll note
@@ -98,10 +99,12 @@ class File(object):
         def write (self, data, flags=0):
                 return api.glfs_write(self.fd,data,len(data),flags)
 
-	def fallocate (self, mode, offset, len):
-		return api.glfs_fallocate(self.fd, mode, offset, len)
-	def discard (self, offset, len):
-		return api.glfs_discard(self.fd, offset, len)
+        def fallocate (self, mode, offset, len):
+            return api.glfs_fallocate(self.fd, mode, offset, len)
+
+        def discard (self, offset, len):
+            return api.glfs_discard(self.fd, offset, len)
+
 
 class Dir(object):
 
@@ -381,7 +384,7 @@ if __name__ == "__main__":
                 test_setxattr,
                 test_getxattr,
                 test_listxattr,
-		test_fallocate,
+                test_fallocate,
         )
 
         ok_to_fail = (

api/examples/setup.py.in

@@ -0,0 +1,29 @@
+from distutils.core import setup
+
+# generate a __init__.py for the package namespace
+fo = open('__init__.py', 'w')
+fo.write('__version__ = "@PACKAGE_VERSION@"\n')
+fo.close()
+
+DESC = """GlusterFS is a clustered file-system capable of scaling to
+several petabytes. It aggregates various storage bricks over Infiniband
+RDMA or TCP/IP interconnect into one large parallel network file system.
+GlusterFS is one of the most sophisticated file systems in terms of
+features and extensibility.  It borrows a powerful concept called
+Translators from GNU Hurd kernel. Much of the code in GlusterFS is in
+user space and easily manageable.
+
+This package contains the Python interface to the libgfapi library."""
+
+setup(
+    name='glusterfs-api',
+    version='@PACKAGE_VERSION@',
+    description='Python client library for the GlusterFS libgfapi',
+    long_description=DESC,
+    author='Gluster Community',
+    author_email='gluster-devel@nongnu.org',
+    license='LGPLv3',
+    url='http://gluster.org/',
+    package_dir={'gluster':''},
+    packages=['gluster']
+)