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Diffstat (limited to 'lib/Python/Lib/PIL/ContainerIO.py')
-rw-r--r-- | lib/Python/Lib/PIL/ContainerIO.py | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/lib/Python/Lib/PIL/ContainerIO.py b/lib/Python/Lib/PIL/ContainerIO.py new file mode 100644 index 000000000..dcedcd6dd --- /dev/null +++ b/lib/Python/Lib/PIL/ContainerIO.py @@ -0,0 +1,117 @@ +# +# The Python Imaging Library. +# $Id$ +# +# a class to read from a container file +# +# History: +# 1995-06-18 fl Created +# 1995-09-07 fl Added readline(), readlines() +# +# Copyright (c) 1997-2001 by Secret Labs AB +# Copyright (c) 1995 by Fredrik Lundh +# +# See the README file for information on usage and redistribution. +# + +## +# A file object that provides read access to a part of an existing +# file (for example a TAR file). + + +class ContainerIO: + + ## + # Create file object. + # + # @param file Existing file. + # @param offset Start of region, in bytes. + # @param length Size of region, in bytes. + + def __init__(self, file, offset, length): + self.fh = file + self.pos = 0 + self.offset = offset + self.length = length + self.fh.seek(offset) + + ## + # Always false. + + def isatty(self): + return 0 + + ## + # Move file pointer. + # + # @param offset Offset in bytes. + # @param mode Starting position. Use 0 for beginning of region, 1 + # for current offset, and 2 for end of region. You cannot move + # the pointer outside the defined region. + + def seek(self, offset, mode=0): + if mode == 1: + self.pos = self.pos + offset + elif mode == 2: + self.pos = self.length + offset + else: + self.pos = offset + # clamp + self.pos = max(0, min(self.pos, self.length)) + self.fh.seek(self.offset + self.pos) + + ## + # Get current file pointer. + # + # @return Offset from start of region, in bytes. + + def tell(self): + return self.pos + + ## + # Read data. + # + # @def read(bytes=0) + # @param bytes Number of bytes to read. If omitted or zero, + # read until end of region. + # @return An 8-bit string. + + def read(self, n=0): + if n: + n = min(n, self.length - self.pos) + else: + n = self.length - self.pos + if not n: # EOF + return "" + self.pos = self.pos + n + return self.fh.read(n) + + ## + # Read a line of text. + # + # @return An 8-bit string. + + def readline(self): + s = "" + while True: + c = self.read(1) + if not c: + break + s = s + c + if c == "\n": + break + return s + + ## + # Read multiple lines of text. + # + # @return A list of 8-bit strings. + + def readlines(self): + l = [] + while True: + s = self.readline() + if not s: + break + l.append(s) + return l |