""" 
 * ====================================================================
 * Copyright (c) 2001 Jon Travis.  All rights reserved.
 * See the file COPYING for information on usage and redistribution.
 * ====================================================================
"""

try:
    from cStringIO import StringIO
except:
    from StringIO import StringIO
    
class RequestFile:
    """RequestFile:  An object that acts like a standard file, and wraps
    around a request_rec's IO routines.  It supports only a few of the
    file methods, as needed by cgi.py"""
    CHUNKSIZE = 1024

    def __init__(self, request):
        self.__req = request
        self.__sio = StringIO()

    def __sio_length(self):
        sio = self.__sio
        cur_pos = sio.tell()
        sio.seek(0,2)
        res = sio.tell()
        sio.seek(cur_pos)
        
    def __readmore(self, once):
        """Read all the data from the req into the sio"""
        cur_pos = self.__sio.tell()
        self.__sio.seek(0, 2)
        eofres = 0
        while 1:
            data, dataerr = self.__req.get_client_block(self.CHUNKSIZE)
            if dataerr <= 0:
                eofres = -1
                break
            self.__sio.write(data)
            if once: break
        self.__sio.seek(cur_pos)
        return eofres
            
    def readline(self):
        res = ''
        sio = self.__sio
        while 1:  # Keep reading in until we have a line, or end of file
            res = res + sio.readline()
            if res[-1:] == '\n':
                cur_pos = sio.tell()
                sio_len = self.__sio_length()

                if cur_pos == sio_len:  # The end was read
                    self.__sio = StringIO()
                return res
            else:
                # Otherwise, try to read more data
                readres = self.__readmore(1)
                if readres < 0:  # End of input
                    return res
            
    def read(self, *bytes):
        if not len(bytes): # Read until we can read no more
            self.__readmore(0)
            data = self.__sio.read()
            self.__sio = StringIO()
            return data

        return self.__sio.read(bytes[0])

    def write(self, str):
        nwrote = 0
        while nwrote != len(str):
            just_wrote = self.__req.rwrite(str[nwrote:])
            if just_wrote < 0:
                return  # XXX -- Client closed connexxion!
            
            nwrote = nwrote + just_wrote