/usr/lib/python2.6/site-packages/boto/s3
Edit: /usr/lib/python2.6/site-packages/boto/s3/keyfile.py (4427B)
# Copyright 2013 Google Inc.
# Copyright 2011, Nexenta Systems Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish, dis-
# tribute, sublicense, and/or sell copies of the Software, and to permit
# persons to whom the Software is furnished to do so, subject to the fol-
# lowing conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
"""
Wrapper class to expose a Key being read via a partial implementaiton of the
Python file interface. The only functions supported are those needed for seeking
in a Key open for reading.
"""
import os
from boto.exception import StorageResponseError
class KeyFile():
def __init__(self, key):
self.key = key
self.key.open_read()
self.location = 0
self.closed = False
self.softspace = -1 # Not implemented.
self.mode = 'r'
self.encoding = 'Undefined in KeyFile'
self.errors = 'Undefined in KeyFile'
self.newlines = 'Undefined in KeyFile'
self.name = key.name
def tell(self):
if self.location is None:
raise ValueError("I/O operation on closed file")
return self.location
def seek(self, pos, whence=os.SEEK_SET):
self.key.close(fast=True)
if whence == os.SEEK_END:
# We need special handling for this case because sending an HTTP range GET
# with EOF for the range start would cause an invalid range error. Instead
# we position to one before EOF (plus pos) and then read one byte to
# position at EOF.
if self.key.size == 0:
# Don't try to seek with an empty key.
return
pos = self.key.size + pos - 1
if pos < 0:
raise IOError("Invalid argument")
self.key.open_read(headers={"Range": "bytes=%d-" % pos})
self.key.read(1)
self.location = pos + 1
return
if whence == os.SEEK_SET:
if pos < 0:
raise IOError("Invalid argument")
elif whence == os.SEEK_CUR:
pos += self.location
else:
raise IOError('Invalid whence param (%d) passed to seek' % whence)
try:
self.key.open_read(headers={"Range": "bytes=%d-" % pos})
except StorageResponseError as e:
# 416 Invalid Range means that the given starting byte was past the end
# of file. We catch this because the Python file interface allows silently
# seeking past the end of the file.
if e.status != 416:
raise
self.location = pos
def read(self, size):
self.location += size
return self.key.read(size)
def close(self):
self.key.close()
self.location = None
self.closed = True
def isatty(self):
return False
# Non-file interface, useful for code that wants to dig into underlying Key
# state.
def getkey(self):
return self.key
# Unimplemented interfaces below here.
def write(self, buf):
raise NotImplementedError('write not implemented in KeyFile')
def fileno(self):
raise NotImplementedError('fileno not implemented in KeyFile')
def flush(self):
raise NotImplementedError('flush not implemented in KeyFile')
def next(self):
raise NotImplementedError('next not implemented in KeyFile')
def readinto(self):
raise NotImplementedError('readinto not implemented in KeyFile')
def readline(self):
raise NotImplementedError('readline not implemented in KeyFile')
def readlines(self):
raise NotImplementedError('readlines not implemented in KeyFile')
def truncate(self):
raise NotImplementedError('truncate not implemented in KeyFile')
def writelines(self):
raise NotImplementedError('writelines not implemented in KeyFile')
def xreadlines(self):
raise NotImplementedError('xreadlines not implemented in KeyFile')