Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Make ppt_record_parser.IterStream.readinto() always return desired length #715

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Make ppt_record_parser.IterStream.readinto() always return desired length #715

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
36 changes: 20 additions & 16 deletions oletools/ppt_record_parser.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -491,7 +491,7 @@ def __init__(self, iterable_creator, size=None):
def reset(self):
""" re-set array to state right after creation """
self.iterable = None
self.leftover = None
self.leftover = ""
self.at_end = False
self.curr_pos = 0

Expand All @@ -515,22 +515,26 @@ def readinto(self, target):
# logging.debug('IterStream: created iterable {0}'
# .format(self.iterable))
self.curr_pos = 0
try:
target_len = len(target) # we should return at most this much
chunk = self.leftover or next(self.iterable)
# logging.debug('IterStream: chunk is size {0}'.format(len(chunk)))
output, self.leftover = chunk[:target_len], chunk[target_len:]
# logging.debug('IterStream: output is size {0}, leftover is {1}'
# .format(len(output), len(self.leftover)))
target[:len(output)] = output
self.curr_pos += len(output)
# logging.debug('IterStream: pos updated to {0}'
# .format(self.curr_pos))
return len(output)
except StopIteration:
target_len = len(target)
# aim to always return the desired length, if possible
while len(self.leftover) < target_len:
try:
self.leftover += next(self.iterable)
except StopIteration:
break
# logging.debug('IterStream: leftover size is {0}'
# .format(len(self.leftover)))
if len(self.leftover) == 0:
# logging.debug('IterStream: source iterable exhausted')
self.at_end = True
return 0 # indicate EOF
output, self.leftover = self.leftover[:target_len], self.leftover[target_len:]
# logging.debug('IterStream: output size is {0}, leftover size is {1}'
# .format(len(output), len(self.leftover)))
target[:len(output)] = output
self.curr_pos += len(output)
# logging.debug('IterStream: pos updated to {0}'.format(self.curr_pos))
return len(output)

def seek(self, offset, whence=io.SEEK_SET):
""" can seek to start, possibly end """
Expand All @@ -557,7 +561,7 @@ def seek(self, offset, whence=io.SEEK_SET):
raise IOError('size unknown, cannot seek to end')
self.at_end = True # fake jumping to the end
self.iterable = None # cannot safely be used any more
self.leftover = None
self.leftover = ""
return self.size
elif whence == io.SEEK_SET: # seek to start
# logging.debug('IterStream: seek to start')
Expand All @@ -580,7 +584,7 @@ def seek(self, offset, whence=io.SEEK_SET):

def close(self):
self.iterable = None
self.leftover = None
self.leftover = ""
self.at_end = False
self.curr_pos = 0

Expand Down