Модули для обработки http-запросов, базовый обработчик url-путей. Обертка для работы с shelve базами данных, html-шаблонизатор.

11 files changed, 469 insertions, 0 deletions

diff --git a/day7/__init__.py b/day7/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/day7/__init__.py
diff --git a/day7/backend.py b/day7/backend.py
new file mode 100644
index 0000000..9f9b118
--- /dev/null
+++ b/day7/backend.py
@@ -0,0 +1,180 @@
+import re
+
+from templater import render_template
+from utils import parse_cookies, add_headers, SUCCESS, BAD_REQUEST, NOT_FOUND
+from config import TEXT_TEMPLATE_NAME
+import db
+
+
+_router_tree = {}
+
+
+# url_format - регулярное выражение
+def route(url_format, methods=None):
+    if methods is None:
+        methods = ['GET']
+
+    def wrapper(func):
+        def inner(url, query, *args, **kwargs):
+            pattern = re.compile(url_format)
+            match = re.match(pattern, url)
+
+            if match is None or len(match.groups()) != pattern.groups:
+                return BAD_REQUEST, '400 BAD REQUEST'
+
+            return func(query, *match.groups(), *args, **kwargs)
+
+        _router_tree[url_format] = _router_tree.get(url_format, {})
+        for method in methods:
+            _router_tree[url_format][method] = inner
+
+        return inner
+
+    return wrapper
+
+
+def run(method, url: str, cookies: dict, query):
+    res = NOT_FOUND, NOT_FOUND + 'KAVO'
+    for key, value in cookies.items():
+        db.set_cookie(key, value)
+
+    for url_pattern in _router_tree:
+        if re.fullmatch(url_pattern, url) and method in _router_tree[url_pattern]:
+            res = _router_tree[url_pattern][method](url, query)
+
+    return add_headers(*res)
+
+
+@route('/')
+def index_get(query, *args):
+    return SUCCESS, render_template('form', color=get_color())
+
+
+@route('/', ['POST'])
+def index_post(query, *args):
+    return SUCCESS, str(query)
+
+# Хотелось попробовать сделать что-то высокоуровневое с декораторами.
+# Если в этом коде есть какие-то серьезные проблемы, то скажите сразу.
+@route(r'/div/(\d+)/to/(\d+)/?')
+def divide_get(query, *args):
+    color = get_color()
+
+    try:
+        text = str(int(args[0]) / int(args[1]))
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, text=text, color=color)
+
+    except ZeroDivisionError as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+@route(r'/div/?', ['POST'])
+def divide_post(query, *args):
+    color = get_color()
+
+    try:
+        text = str(int(query['numerator']) / int(query['denominator']))
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, text=text, color=color)
+
+    except KeyError:
+        field = 'числитель' if 'numerator' not in query else 'знаменатель'
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + f'Указан неверный {field}')
+        )
+
+    except (ValueError, ZeroDivisionError) as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+@route(r'/show_errors/(\d{1})/?')
+def show_errors_get(query, *args):
+    color = get_color()
+
+    if args[0] == '1':
+        db.set_config_entry('show_errors', 1)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors включена')
+
+    elif args[0] == '0':
+        db.set_config_entry('show_errors', 0)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors выключена')
+
+    else:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text='Опция show_errors не может принимать такое значение'
+        )
+
+
+@route(r'/show_errors/?', ['POST'])
+def show_errors_post(query, *args):
+    color = get_color()
+
+    if 'show_errors' not in query:
+        db.set_config_entry('show_errors', 0)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors выключена')
+
+    elif query['show_errors'] == '1':
+        db.set_config_entry('show_errors', 1)
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Опция show_errors включена')
+
+    else:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text='Опция show_errors не может принимать такое значение'
+        )
+
+
+@route(r'/set_cookie/=/(.*)/?')
+def set_cookie_get(query, *args):
+    cookie_line = args[0]
+    color = get_color()
+    try:
+        cookies = parse_cookies(cookie_line)
+        for key, value in cookies.items():
+            db.set_cookie(key, value)
+
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Cookie-файл обновлен')
+
+    except ValueError as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+@route(r'/set_cookie/=/?', ['POST'])
+def set_cookie_post(query, *args):
+    color = get_color()
+    try:
+        cookie_line = query['cookie_line']
+        cookies = parse_cookies(cookie_line)
+        for key, value in cookies.items():
+            db.set_cookie(key, value)
+
+        return SUCCESS, render_template(TEXT_TEMPLATE_NAME, color=color, text='Cookie-файл обновлен')
+
+    except KeyError:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + f'Не указана строка с cookie')
+        )
+
+    except ValueError as e:
+        return BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=color,
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        )
+
+
+def get_color():
+    color = db.get_cookie('bg_color', 'white')
+    if color not in ['green', 'white']:
+        color = 'white'
+    return color
diff --git a/day7/config.py b/day7/config.py
new file mode 100644
index 0000000..b5d596a
--- /dev/null
+++ b/day7/config.py
@@ -0,0 +1,2 @@
+CHUNK = 1024
+TEXT_TEMPLATE_NAME = 'index'
diff --git a/day7/db.py b/day7/db.py
new file mode 100644
index 0000000..11d2a45
--- /dev/null
+++ b/day7/db.py
@@ -0,0 +1,21 @@
+import shelve
+
+
+def set_cookie(key, value):
+    _db[key] = value
+
+
+def get_cookie(key, default=None):
+    return _db.get(key, default)
+
+
+def set_config_entry(key, value):
+    _config[key] = value
+
+
+def get_config_entry(key, default=None):
+    return _config.get(key, default)
+
+
+_db = shelve.open('db/cookies.db')
+_config = shelve.open('db/config.db')
diff --git a/day7/db/config.db b/day7/db/config.db
new file mode 100644
index 0000000..5c7d9e2
--- /dev/null
+++ b/day7/db/config.db
diff --git a/day7/db/cookies.db b/day7/db/cookies.db
new file mode 100644
index 0000000..649e4a6
--- /dev/null
+++ b/day7/db/cookies.db
diff --git a/day7/http_handler.py b/day7/http_handler.py
new file mode 100644
index 0000000..e5a551b
--- /dev/null
+++ b/day7/http_handler.py
@@ -0,0 +1,137 @@
+from socket import socket, AF_INET, SOCK_STREAM, SHUT_RDWR
+from time import strftime, gmtime
+
+from backend import run
+from utils import validate_url, parse_cookies, parse_query, parse_headers, add_headers, NOT_FOUND, BAD_REQUEST
+from templater import render_template
+from config import *
+import db
+
+
+def log_func(func):
+    def wrapper(*args, **kwargs):
+        address = kwargs['address'] if 'address' in kwargs else args[0]
+        method = kwargs['method'] if 'method' in kwargs else args[1]
+        url = kwargs['url'] if 'url' in kwargs else args[2]
+        http_ver = kwargs['http_ver'] if 'http_ver' in kwargs else args[3]
+
+        response = func(*args, **kwargs)
+        status = response.split('\n').pop(0).split()[1]
+
+        log_line = f'{address[0]}: {strftime("[%d %b %Y %H:%M:%S]", gmtime())} "{method} {url} {http_ver}" Status: {status}'
+        print(log_line)
+
+        return response
+
+    return wrapper
+
+
+@log_func
+def process_request(address, method, url, http_ver, headers: dict, query):
+    if validate_url(url):
+        try:
+            cookies = parse_cookies(headers['Cookie'])
+        except (ValueError, KeyError):
+            cookies = {}
+
+        response = run(method, url, cookies, query)
+    else:
+        response = add_headers(NOT_FOUND, '404 NOT FOUND')
+
+    return response
+
+
+def get_request(connection):
+    buffer = b''
+    request = b''
+    while not request.endswith(b'\r\n\r\n'):
+        data = connection.recv(1024).split(b'\r\n\r\n')
+        if len(data) == 1:
+            if not data[0]:
+                return None
+            request += data[0]
+        else:
+            request += data[0] + b'\r\n\r\n'
+            buffer += data[1]
+
+    method, url, http_ver, headers = parse_headers(request.strip().decode())
+    if 'Content-Type' in headers and headers['Content-Type'] == 'application/x-www-form-urlencoded':
+        length = int(headers['Content-Length']) - len(buffer)
+        while length > 0:
+            if length < CHUNK:
+                data = connection.recv(length)
+                length = 0
+            else:
+                data = connection.recv(CHUNK)
+                length -= CHUNK
+
+            buffer += data[0]
+
+    query = parse_query(buffer.strip().decode()) if buffer else {}
+
+    return method, url, http_ver, headers, query
+
+
+def get_color():
+    color = db.get_cookie('bg_color', 'white')
+    if color not in ['green', 'white']:
+        color = 'white'
+    return color
+
+
+def handle_connection(connection, address):
+    try:
+        request = get_request(connection)
+    except ValueError as e:
+        response = add_headers(BAD_REQUEST, render_template(
+            TEXT_TEMPLATE_NAME, color=get_color(),
+            text=BAD_REQUEST + ('<br>' + str(e) if db.get_config_entry('show_errors') else '')
+        ))
+        connection.sendall(response.encode())
+        return
+
+    if request is None:
+        return
+
+    method, url, http_ver, headers, query = request
+
+    response = process_request(address, method, url, http_ver, headers, query)
+    connection.sendall(response.encode())
+
+
+def main(host, port):
+    sock = socket(AF_INET, SOCK_STREAM)
+    sock.bind((host, port))
+    sock.listen(5)
+    print(f'* Server started on http://{host}:{port}/')
+    print('* Listening to new connections...')
+
+    while True:
+        try:
+            connection, address = sock.accept()
+
+            handle_connection(connection, address)
+
+            connection.shutdown(SHUT_RDWR)
+            connection.close()
+            del connection
+
+        except KeyboardInterrupt:
+            print('Stopping server...')
+
+            try:
+                connection.shutdown(SHUT_RDWR)
+                connection.close()
+            except UnboundLocalError:
+                pass
+
+            sock.shutdown(SHUT_RDWR)
+            sock.close()
+
+            print('Server stopped')
+            break
+
+
+if __name__ == '__main__':
+    HOST, PORT = ADDR = '0.0.0.0', 4002
+    main(HOST, PORT)
diff --git a/day7/templater.py b/day7/templater.py
new file mode 100644
index 0000000..92fb87f
--- /dev/null
+++ b/day7/templater.py
@@ -0,0 +1,5 @@
+def render_template(template_name, **kwargs):
+    with open(f'templates/{template_name}.html') as f:
+        data = f.read()
+
+    return data.format(**kwargs)
diff --git a/day7/templates/form.html b/day7/templates/form.html
new file mode 100644
index 0000000..e1edb96
--- /dev/null
+++ b/day7/templates/form.html
@@ -0,0 +1,26 @@
+<html style="background-color: {color};">
+    <body>
+        <form action="/show_errors" method="POST">
+            <input type="checkbox" name="show_errors" value="1">Show errors<br/>
+            <input type="submit" value="Send"><br/>
+        </form>
+
+        <form action="/div" method="POST">
+            Разделить
+            <input type="text" name="numerator"> на
+            <input type="text" name="denominator"><br/>
+            <input type="submit" value="Send"><br/>
+        </form>
+
+        <form action="/set_cookie/=" method="POST">
+            Изменить Cookies
+            <input type="text" name="cookie_line"><br/>
+            <input type="submit" value="Send"><br/>
+        </form>
+
+        <form action="/" method="POST">
+            <input type="checkbox" name="short_log" value="1">Short log<br/>
+            <input type="submit" value="Send"><br/>
+        </form>
+    </body>
+</html>
diff --git a/day7/templates/index.html b/day7/templates/index.html
new file mode 100644
index 0000000..b5fae3a
--- /dev/null
+++ b/day7/templates/index.html
@@ -0,0 +1,7 @@
+<html style="background-color: {color};">
+
+<body>
+{text}
+</body>
+
+</html>
\ No newline at end of file
diff --git a/day7/utils.py b/day7/utils.py
new file mode 100644
index 0000000..0aa0709
--- /dev/null
+++ b/day7/utils.py
@@ -0,0 +1,91 @@
+import re
+from time import strftime, gmtime
+
+_URI_RESERVED = {
+    '21': '!', '23': '#', '24': '$', '26': '&',
+    '27': '\'', '28': '(', '29': ')', '2A': '*',
+    '2B': '+', '2C': ',', '2F': '/', '3A': ':',
+    '3B': ';', '3D': '=', '3F': '?', '40': '@',
+    '5B': '[', '5D': ']'
+}
+
+BAD_REQUEST = 'HTTP/1.1 400 Bad Request'
+NOT_FOUND = 'HTTP/1.1 404 Not Found'
+SUCCESS = 'HTTP/1.1 200 OK'
+METHOD_NOT_ALLOWED = 'HTTP/1.1 405 Method Not Allowed'
+
+
+def add_headers(status, html: str):
+    return '\r\n'.join([
+        status,
+        f'Date: {strftime("%a, %d %b %Y %H:%M:%S GMT", gmtime())}',
+        'Server: BrandNewServer',
+        'Content-Type: text/html; charset=utf-8',
+        'Connection: keep-alive',
+        '', html
+    ])
+
+
+def validate_url(url):
+    url_pattern = re.compile(r'/((.*?/?)+)?')
+    return bool(url_pattern.fullmatch(url))
+
+
+def parse_cookies(cookies_line: str):
+    cookies_line = cookies_line.strip().strip(';')
+    pairs = cookies_line.split(';')
+    d = {}
+    for pair in pairs:
+        try:
+            key, value = pair.split('=', maxsplit=1)
+            d[key] = value
+        except ValueError:
+            raise ValueError('Wrong format of cookies')
+
+    return d
+
+
+def parse_headers(request_line: str):
+    request = request_line.split('\r\n')
+    method, url, http_ver = request.pop(0).split()
+    headers = {}
+    for line in request:
+        field, value = line.split(': ', maxsplit=1)
+        headers[field] = value
+
+    return method, url, http_ver, headers
+
+
+def parse_query(query_line: str):
+    pairs = query_line.strip().split('&')
+    d = {}
+    for pair in pairs:
+        try:
+            key, value = pair.split('=', maxsplit=1)
+            d[url_decoder(key)] = url_decoder(value)
+        except ValueError:
+            raise ValueError('Wrong format of query')
+
+    return d
+
+
+def url_decoder(url_line: str):
+    url_line = url_line.replace('+', ' ')
+    encoded = b''
+    i = 0
+    while i < len(url_line):
+        if url_line[i] == '%':
+            hex_value = url_line[i + 1: i + 3]
+            if hex_value in _URI_RESERVED:
+                integer = ord(_URI_RESERVED[hex_value])
+            else:
+                integer = int(hex_value, 16)
+
+            encoded += bytes([integer])
+            i += 3
+            continue
+        else:
+            encoded += bytes([ord(url_line[i])])
+            i += 1
+
+    return encoded.decode()