mongo-based url shorten service engine

urlshortener.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# requirements: pip install mongoengine simplejson bottle
import mongoengine
import string
from bottle import (
    route, run, HTTPResponse, request
)
import simplejson


mongo_db_name = 't110me'
mongoengine.connect(mongo_db_name)
counter_name = 'count'


class Counter(mongoengine.Document):
    name = mongoengine.StringField()
    value = mongoengine.IntField()


class ShortenedUrl(mongoengine.Document):
    url = mongoengine.StringField()
    key = mongoengine.StringField()
    key_n = mongoengine.IntField()
    meta = {
        'indexes': ['key']
    }


class URLShortenManager(object):
    def shorten(self, url):
        count = self._get_current_count_and_count_up()
        key = self._num_to_key(count)

        shortened_url = ShortenedUrl()
        shortened_url.url = url
        shortened_url.key = key
        shortened_url.key_n = count
        shortened_url.save()

        return key

    def find(self, key):
        s_url = ShortenedUrl.objects(key=key).first()
        return s_url

    def _get_current_count_and_count_up(self):
        c = Counter.objects(name=counter_name).first()
        if c is None:
            c = Counter()
            c.name = counter_name
            c.value = -1  # will be zero
        ret = c.value
        c.value = c.value + 1
        c.save()
        return ret

    def _num_to_key(self, num):
        chars = string.ascii_letters + string.digits
        base_n = len(chars)

        n = num
        ret = ""
        while True:
            amari = n % base_n
            n = n / base_n
            ret = chars[amari] + ret
            if n == 0:
                break
        return ret


@route('/control/shorten', method=['GET', 'POST'])
def web_shorten():
    if request.method == 'GET':
        url = request.query.get('url')
    else:
        url = request.forms.get('url')
    m = URLShortenManager()
    key = m.shorten(url)
    result = {'status': 'ok', 'result': {'key': key, 'url': url}}
    r = HTTPResponse(status=200, body=simplejson.dumps(result))
    r.set_header('Content-Type', 'application/json')
    return r


@route('/control/info/<key>')
def web_info(key):
    m = URLShortenManager()
    info = m.find(key)
    status = 200
    if info:
        result = {'status': 'ok', 'result': {'key': key, 'url': info.url, 'key_n': info.key_n}}
    else:
        result = {'status': 'error', 'result': None, 'message': 'no such key'}
        status = 500
    r = HTTPResponse(status=status, body=simplejson.dumps(result))
    r.set_header('Content-Type', 'application/json')
    return r


@route('/<key>')
def web_jump(key):
    m = URLShortenManager()
    info = m.find(key)
    if info:
        r = HTTPResponse(status=302)
        r.set_header('Location', info.url)
        return r
    else:
        result = {'status': 'error', 'result': None, 'message': 'no such key'}
        r = HTTPResponse(status=500, body=simplejson.dumps(result))
        r.set_header('Content-Type', 'application/json')
        return r


if __name__ == '__main__':
    run(host='0.0.0.0', port=7780, debug=True)