tendermint/example/python/abci/reader.py

# Simple read() method around a bytearray


class BytesBuffer():

    def __init__(self, b):
        self.buf = b
        self.readCount = 0

    def count(self):
        return self.readCount

    def reset_count(self):
        self.readCount = 0

    def size(self):
        return len(self.buf)

    def peek(self):
        return self.buf[0]

    def write(self, b):
        # b should be castable to byte array
        self.buf += bytearray(b)

    def read(self, n):
        if len(self.buf) < n:
            print "reader err: buf less than n"
            # TODO: exception
            return
        self.readCount += n
        r = self.buf[:n]
        self.buf = self.buf[n:]
        return r

# Buffer bytes off a tcp connection and read them off in chunks


class ConnReader():

    def __init__(self, conn):
        self.conn = conn
        self.buf = bytearray()

    # blocking
    def read(self, n):
        while n > len(self.buf):
            moreBuf = self.conn.recv(1024)
            if not moreBuf:
                raise IOError("dead connection")
            self.buf = self.buf + bytearray(moreBuf)

        r = self.buf[:n]
        self.buf = self.buf[n:]
        return r