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Diffstat (limited to 'slime-0.11/StringIO2.py')
| -rw-r--r-- | slime-0.11/StringIO2.py | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/slime-0.11/StringIO2.py b/slime-0.11/StringIO2.py new file mode 100644 index 0000000..505f057 --- /dev/null +++ b/slime-0.11/StringIO2.py @@ -0,0 +1,159 @@ +# class StringIO implements file-like objects that read/write a +# string buffer (a.k.a. "memory files"). +# +# This implements (nearly) all stdio methods. +# +# f = StringIO() # ready for writing +# f = StringIO(buf) # ready for reading +# f.close() # explicitly release resources held +# flag = f.isatty() # always false +# pos = f.tell() # get current position +# f.seek(pos) # set current position +# f.seek(pos, mode) # mode 0: absolute; 1: relative; 2: relative to EOF +# buf = f.read() # read until EOF +# buf = f.read(n) # read up to n bytes +# buf = f.readline() # read until end of line ('\n') or EOF +# list = f.readlines()# list of f.readline() results until EOF +# f.write(buf) # write at current position +# f.writelines(list) # for line in list: f.write(line) +# f.getvalue() # return whole file's contents as a string +# +# Notes: +# - Using a real file is often faster (but less convenient). +# - fileno() is left unimplemented so that code which uses it triggers +# an exception early. +# - Seeking far beyond EOF and then writing will insert real null +# bytes that occupy space in the buffer. +# - There's a simple test set (see end of this file). + +import string + +class StringIO: + def __init__(self, buf = ''): + self.buf = buf + self.len = len(buf) + self.buflist = [] + self.pos = 0 + self.closed = 0 + self.softspace = 0 + def close(self): + if not self.closed: + self.closed = 1 + del self.buf, self.pos + def isatty(self): + return 0 + def seek(self, pos, mode = 0): + if self.buflist: + self.buf = self.buf + string.joinfields(self.buflist, '') + self.buflist = [] + if mode == 1: + pos = pos + self.pos + elif mode == 2: + pos = pos + self.len + self.pos = max(0, pos) + def tell(self): + return self.pos + def read(self, n = -1): + if self.buflist: + self.buf = self.buf + string.joinfields(self.buflist, '') + self.buflist = [] + if n < 0: + newpos = self.len + else: + newpos = min(self.pos+n, self.len) + r = self.buf[self.pos:newpos] + self.pos = newpos + return r + def readline(self, length = None): + if self.buflist: + self.buf = self.buf + string.joinfields(self.buflist, '') + self.buflist = [] + i = string.find(self.buf, '\n', self.pos) + if i < 0: + newpos = self.len + else: + newpos = i+1 + if not length is None: + if self.pos + length < newpos: + newpos = self.pos + length + r = self.buf[self.pos:newpos] + self.pos = newpos + return r + def readlines(self): + lines = [] + line = self.readline() + while line: + lines.append(line) + line = self.readline() + return lines + def write(self, s): + if not s: return + if self.pos > self.len: + self.buflist.append('\0'*(self.pos - self.len)) + self.len = self.pos + newpos = self.pos + len(s) + if self.pos < self.len: + if self.buflist: + self.buf = self.buf + string.joinfields(self.buflist, '') + self.buflist = [] + self.buflist = [self.buf[:self.pos], s, self.buf[newpos:]] + self.buf = '' + else: + self.buflist.append(s) + self.len = newpos + self.pos = newpos + def writelines(self, list): + self.write(string.joinfields(list, '')) + def flush(self): + pass + def getvalue(self): + if self.buflist: + self.buf = self.buf + string.joinfields(self.buflist, '') + self.buflist = [] + return self.buf + + +# A little test suite + +def test(): + import sys + if sys.argv[1:]: + file = sys.argv[1] + else: + file = '/etc/passwd' + lines = open(file, 'r').readlines() + text = open(file, 'r').read() + f = StringIO() + for line in lines[:-2]: + f.write(line) + f.writelines(lines[-2:]) + if f.getvalue() != text: + raise RuntimeError, 'write failed' + length = f.tell() + print 'File length =', length + f.seek(len(lines[0])) + f.write(lines[1]) + f.seek(0) + print 'First line =', `f.readline()` + here = f.tell() + line = f.readline() + print 'Second line =', `line` + f.seek(-len(line), 1) + line2 = f.read(len(line)) + if line != line2: + raise RuntimeError, 'bad result after seek back' + f.seek(len(line2), 1) + list = f.readlines() + line = list[-1] + f.seek(f.tell() - len(line)) + line2 = f.read() + if line != line2: + raise RuntimeError, 'bad result after seek back from EOF' + print 'Read', len(list), 'more lines' + print 'File length =', f.tell() + if f.tell() != length: + raise RuntimeError, 'bad length' + f.close() + +if __name__ == '__main__': + test() |