mirror of https://github.com/python/cpython
Add the option to pass an open file object to GzipFile. This obviates
the need for the StringIO subclass.
This commit is contained in:
Guido van Rossum
parent
6576dd6ad6
commit
68de37973f
97
Lib/gzip.py
97
Lib/gzip.py
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@ -2,6 +2,7 @@ import time
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import string
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import zlib
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import StringIO
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import __builtin__
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# implements a python function that reads and writes a gzipped file
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# the user of the file doesn't have to worry about the compression,
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@ -38,23 +39,31 @@ def read32(input):
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v = v + (ord(buf[3]) << 24)
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return v
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written = []
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_py_open = open
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def open(filename, mode, compresslevel=9):
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def open(filename, mode="r", compresslevel=9):
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return GzipFile(filename, mode, compresslevel)
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class GzipFile:
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def __init__(self, filename, mode='r', compresslevel=9):
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if mode == 'r' or mode == 'rb':
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myfileobj = None
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def __init__(self, filename=None, mode=None,
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compresslevel=9, fileobj=None):
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if fileobj is None:
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fileobj = self.myfileobj = __builtin__.open(filename, mode or 'r')
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if filename is None:
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if hasattr(fileobj, 'name'): filename = fileobj.name
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else: filename = 'GzippedFile'
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if mode is None:
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if hasattr(fileobj, 'mode'): mode = fileobj.mode
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else: mode = 'r'
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if mode[0:1] == 'r':
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self.mode = READ
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self._init_read()
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self.filename = filename
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self.decompress = zlib.decompressobj(-zlib.MAX_WBITS)
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elif mode == 'w' or mode == 'wb':
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elif mode[0:1] == 'w':
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self.mode = WRITE
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self._init_write(filename)
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self.compress = zlib.compressobj(compresslevel,
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@ -65,7 +74,7 @@ class GzipFile:
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else:
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raise ValueError, "Mode " + mode + " not supported"
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self.fileobj = _py_open(self.filename,mode)
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self.fileobj = fileobj
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if self.mode == WRITE:
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self._write_gzip_header()
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@ -134,6 +143,8 @@ class GzipFile:
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def write(self,data):
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if self.fileobj is None:
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raise ValueError, "write() on closed GzipFile object"
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if len(data) > 0:
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self.size = self.size + len(data)
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self.crc = zlib.crc32(data, self.crc)
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@ -143,7 +154,7 @@ class GzipFile:
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self.write(string.join(lines))
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def read(self,size=None):
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if self.extrasize <= 0 and self.fileobj.closed:
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if self.extrasize <= 0 and self.fileobj is None:
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return ''
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if not size:
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@ -173,7 +184,7 @@ class GzipFile:
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uncompress = self.decompress.flush()
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if uncompress == "":
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self._read_eof()
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self.fileobj.close()
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self.fileobj = None
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raise EOFError, 'Reached EOF'
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else:
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uncompress = self.decompress.decompress(buf)
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@ -201,9 +212,12 @@ class GzipFile:
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self.fileobj.write(self.compress.flush())
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write32(self.fileobj, self.crc)
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write32(self.fileobj, self.size)
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self.fileobj.close()
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self.fileobj = None
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elif self.mode == READ:
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self.fileobj.close()
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self.fileobj = None
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if self.myfileobj:
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self.myfileobj.close()
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self.myfileobj = None
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def flush(self):
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self.fileobj.flush()
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@ -218,47 +232,22 @@ class GzipFile:
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return 0
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def readline(self):
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# should I bother with this
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raise RuntimeError, "not implemented"
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# XXX This function isn't implemented in a very efficient way
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line=""
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while 1:
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c = self.read(1)
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line = line + c
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if c=='\n' or c=="": break
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return line
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def readlines(self):
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# should I bother with this
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raise RuntimeError, "not implemented"
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class StringIOgz(GzipFile):
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"""A StringIO substitute that reads/writes gzipped buffers."""
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def __init__(self, buf=None, filename="StringIOgz"):
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"""Read/write mode depends on first argument.
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If __init__ is passed a buffer, it will treat that as the
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gzipped data and set up the StringIO for reading. Without the
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initial argument, it will assume a new file for writing.
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The filename argument is written in the header of buffers
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opened for writing. Not sure that this is useful, but the
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GzipFile code expects *some* filename."""
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if buf:
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self.mode = READ
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self._init_read()
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self.filename = filename
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self.decompress = zlib.decompressobj(-zlib.MAX_WBITS)
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self.fileobj = StringIO.StringIO(buf)
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else:
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self.mode = WRITE
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self._init_write(filename)
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self.compress = zlib.compressobj(compresslevel,
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zlib.DEFLATED,
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-zlib.MAX_WBITS,
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zlib.DEF_MEM_LEVEL,
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0)
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self.fileobj = StringIO.StringIO()
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if self.mode == WRITE:
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self._write_gzip_header()
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elif self.mode == READ:
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self._read_gzip_header()
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L=[]
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line = self.readline()
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while line!="":
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L.append(line)
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line = self.readline()
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return L
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def writelines(self, L):
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for line in L:
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self.write(line)
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