civetweb/bindings/python/mongoose.py

#  Copyright (c) 2004-2009 Sergey Lyubka
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#  The above copyright notice and this permission notice shall be included in
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#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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#  $Id: mongoose.py 471 2009-08-30 14:30:21Z valenok $

"""
This module provides python binding for the Mongoose web server.

There are two classes defined:

  Connection: - wraps all functions that accept struct mg_connection pointer
    as first argument.

  Mongoose: wraps all functions that accept struct mg_context pointer as
    first argument.

  Creating Mongoose object automatically starts server, deleting object
  automatically stops it. There is no need to call mg_start() or mg_stop().
"""


import ctypes
import os


NEW_REQUEST = 0
HTTP_ERROR = 1
EVENT_LOG = 2
INIT_SSL = 3


class mg_header(ctypes.Structure):
    """A wrapper for struct mg_header."""
    _fields_ = [
        ('name', ctypes.c_char_p),
        ('value', ctypes.c_char_p),
    ]


class mg_request_info(ctypes.Structure):
    """A wrapper for struct mg_request_info."""
    _fields_ = [
        ('request_method', ctypes.c_char_p),
        ('uri', ctypes.c_char_p),
        ('http_version', ctypes.c_char_p),
        ('query_string', ctypes.c_char_p),
        ('remote_user', ctypes.c_char_p),
        ('log_message', ctypes.c_char_p),
        ('remote_ip', ctypes.c_long),
        ('remote_port', ctypes.c_int),
        ('status_code', ctypes.c_int),
        ('is_ssl', ctypes.c_int),
        ('num_headers', ctypes.c_int),
        ('http_headers', mg_header * 64),
    ]


mg_callback_t = ctypes.CFUNCTYPE(ctypes.c_void_p,
                                 ctypes.c_int,
                                 ctypes.c_void_p,
                                 ctypes.POINTER(mg_request_info))


class Connection(object):
    """A wrapper class for all functions that take
    struct mg_connection * as the first argument."""

    def __init__(self, mongoose, connection):
        self.m = mongoose
        self.conn = ctypes.c_void_p(connection)

    def get_header(self, name):
        val = self.m.dll.mg_get_header(self.conn, name)
        return ctypes.c_char_p(val).value

    def get_var(self, data, name):
        size = len(data)
        buf = ctypes.create_string_buffer(size)
        n = self.m.dll.mg_get_var(data, size, name, buf, size)
        return n >= 0 and buf or None
    
    def printf(self, fmt, *args):
        val = self.m.dll.mg_printf(self.conn, fmt, *args)
        return ctypes.c_int(val).value

    def write(self, data):
        val = self.m.dll.mg_write(self.conn, data, len(data))
        return ctypes.c_int(val).value

    def read(self, size):
        buf = ctypes.create_string_buffer(size)
        n = self.m.dll.mg_read(self.conn, buf, size)
        return n <= 0 and None or buf[:n]


class Mongoose(object):
    """A wrapper class for Mongoose shared library."""

    def __init__(self, callback, **kwargs):
        dll_extension = os.name == 'nt' and 'dll' or 'so'
        self.dll = ctypes.CDLL('_mongoose.%s' % dll_extension)

        self.dll.mg_start.restype = ctypes.c_void_p
        self.dll.mg_modify_passwords_file.restype = ctypes.c_int
        self.dll.mg_read.restype = ctypes.c_int
        self.dll.mg_write.restype = ctypes.c_int
        self.dll.mg_printf.restype = ctypes.c_int
        self.dll.mg_get_header.restype = ctypes.c_char_p
        self.dll.mg_get_var.restype = ctypes.c_int
        self.dll.mg_get_cookie.restype = ctypes.c_int
        self.dll.mg_get_option.restype = ctypes.c_char_p

        if callback:
            # Create a closure that will be called by the  shared library.
            def func(event, connection, request_info):
                # Wrap connection pointer into the connection
                # object and call Python callback
                conn = Connection(self, connection)
                return callback(event, conn, request_info.contents) and 1 or 0

            # Convert the closure into C callable object
            self.callback = mg_callback_t(func)
            self.callback.restype = ctypes.c_char_p
        else:
            self.callback = ctypes.c_void_p(0)

        args = [y for x in kwargs.items() for y in x] + [None]
        options = (ctypes.c_char_p * len(args))(*args)

        ret = self.dll.mg_start(self.callback, options)
        self.ctx = ctypes.c_void_p(ret)

    def __del__(self):
        """Destructor, stop Mongoose instance."""
        self.dll.mg_stop(self.ctx)

    def get_option(self, name):
        return self.dll.mg_get_option(self.ctx, name)