Can mmap and gzip collaborate?

Question

I\'m trying to figure how to use mmap with a gzip compressed file. Is that even possible ?

import mmap
import os
import gzip

filename = r\'C:\\temp\\data.gz\'

file          


        

Answer 1

You can do easilly. Indeed the gzip module gets as optional argument a file-like object.

import mmap
import gzip

filename = "a.gz"
handle = open(filename, "rb")
mapped = mmap.mmap(handle.fileno(), 0, access=mmap.ACCESS_READ)
gzfile = gzip.GzipFile(mode="r", fileobj=mapped)

print gzfile.read()

The same applies to tarfile module:

import sys
import mmap
import tarfile

f = open(sys.argv[1], 'rb')
fo = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
tf = tarfile.open(mode='r:gz', fileobj=fo)

print tf.getnames()