99 lines
2.5 KiB
Python
99 lines
2.5 KiB
Python
# SPDX-FileCopyrightText: 2014 MicroPython & CircuitPython contributors (https://github.com/adafruit/circuitpython/graphs/contributors)
|
|
#
|
|
# SPDX-License-Identifier: MIT
|
|
|
|
import uctypes
|
|
|
|
# http://www.gnu.org/software/tar/manual/html_node/Standard.html
|
|
TAR_HEADER = {
|
|
"name": (uctypes.ARRAY | 0, uctypes.UINT8 | 100),
|
|
"size": (uctypes.ARRAY | 124, uctypes.UINT8 | 11),
|
|
}
|
|
|
|
DIRTYPE = "dir"
|
|
REGTYPE = "file"
|
|
|
|
def roundup(val, align):
|
|
return (val + align - 1) & ~(align - 1)
|
|
|
|
class FileSection:
|
|
|
|
def __init__(self, f, content_len, aligned_len):
|
|
self.f = f
|
|
self.content_len = content_len
|
|
self.align = aligned_len - content_len
|
|
|
|
def read(self, sz=65536):
|
|
if self.content_len == 0:
|
|
return b""
|
|
if sz > self.content_len:
|
|
sz = self.content_len
|
|
data = self.f.read(sz)
|
|
sz = len(data)
|
|
self.content_len -= sz
|
|
return data
|
|
|
|
def readinto(self, buf):
|
|
if self.content_len == 0:
|
|
return 0
|
|
if len(buf) > self.content_len:
|
|
buf = memoryview(buf)[:self.content_len]
|
|
sz = self.f.readinto(buf)
|
|
self.content_len -= sz
|
|
return sz
|
|
|
|
def skip(self):
|
|
sz = self.content_len + self.align
|
|
if sz:
|
|
buf = bytearray(16)
|
|
while sz:
|
|
s = min(sz, 16)
|
|
self.f.readinto(buf, s)
|
|
sz -= s
|
|
|
|
class TarInfo:
|
|
|
|
def __str__(self):
|
|
return "TarInfo(%r, %s, %d)" % (self.name, self.type, self.size)
|
|
|
|
class TarFile:
|
|
|
|
def __init__(self, name=None, fileobj=None):
|
|
if fileobj:
|
|
self.f = fileobj
|
|
else:
|
|
self.f = open(name, "rb")
|
|
self.subf = None
|
|
|
|
def next(self):
|
|
if self.subf:
|
|
self.subf.skip()
|
|
buf = self.f.read(512)
|
|
if not buf:
|
|
return None
|
|
|
|
h = uctypes.struct(uctypes.addressof(buf), TAR_HEADER, uctypes.LITTLE_ENDIAN)
|
|
|
|
# Empty block means end of archive
|
|
if h.name[0] == 0:
|
|
return None
|
|
|
|
d = TarInfo()
|
|
d.name = str(h.name, "utf-8").rstrip("\0")
|
|
d.size = int(bytes(h.size), 8)
|
|
d.type = [REGTYPE, DIRTYPE][d.name[-1] == "/"]
|
|
self.subf = d.subf = FileSection(self.f, d.size, roundup(d.size, 512))
|
|
return d
|
|
|
|
def __iter__(self):
|
|
return self
|
|
|
|
def __next__(self):
|
|
v = self.next()
|
|
if v is None:
|
|
raise StopIteration
|
|
return v
|
|
|
|
def extractfile(self, tarinfo):
|
|
return tarinfo.subf
|