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authorHumble Devassy Chirammal <humble.devassy@gmail.com>2016-03-18 03:07:06 -0700
committerGerrit Code Review <review@dev.gluster.org>2016-03-18 03:07:06 -0700
commit9466403495084eb9a197c1fe30bfa40a68b8feec (patch)
tree701c26b0861f800ea6c196bb81a2e21caf369263 /gluster
parent1815ad27684435a0612c987b5d6d8893417593f8 (diff)
parent14c16992b563a77330478bcc6fecdb54df4300b5 (diff)
Merge "Add readinto() API"
Diffstat (limited to 'gluster')
-rwxr-xr-xgluster/gfapi.py23
1 files changed, 23 insertions, 0 deletions
diff --git a/gluster/gfapi.py b/gluster/gfapi.py
index fa0e1b3..d6f847d 100755
--- a/gluster/gfapi.py
+++ b/gluster/gfapi.py
@@ -328,6 +328,29 @@ class File(object):
err = ctypes.get_errno()
raise OSError(err, os.strerror(err))
+ def readinto(self, buf):
+ """
+ Read up to len(buf) bytes into buf which must be a bytearray.
+ (buf cannot be a string as strings are immutable in python)
+
+ This method is useful when you have to read a large file over
+ multiple read calls. While read() allocates a buffer every time
+ it's invoked, readinto() copies data to an already allocated
+ buffer passed to it.
+
+ Returns the number of bytes read (0 for EOF).
+ """
+ if type(buf) is bytearray:
+ buf_ptr = (ctypes.c_ubyte * len(buf)).from_buffer(buf)
+ else:
+ # TODO: Allow reading other types such as array.array
+ raise TypeError("buffer must of type bytearray")
+ nread = api.glfs_read(self.fd, buf_ptr, len(buf_ptr), 0)
+ if nread < 0:
+ err = ctypes.get_errno()
+ raise OSError(err, os.strerror(err))
+ return nread
+
def write(self, data, flags=0):
"""
Write data to the file.