util.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

# Copyright (c) 2012, Dongsheng Cai
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#    * Redistributions of source code must retain the above copyright
#      notice, this list of conditions and the following disclaimer.
#    * Redistributions in binary form must reproduce the above copyright
#      notice, this list of conditions and the following disclaimer in the
#      documentation and/or other materials provided with the distribution.
#    * Neither the name of the Dongsheng Cai nor the names of its
#      contributors may be used to endorse or promote products derived
#      from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL DONGSHENG CAI BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

from HTMLParser import HTMLParser
import calendar
import datetime
import htmlentitydefs
import re
import sys
import unicodedata
import os
from tornado.options import options
from hashlib import sha1

from bson.dbref import DBRef
from bson.max_key import MaxKey
from bson.min_key import MinKey
from bson.objectid import ObjectId
from bson.son import RE_TYPE
from bson.timestamp import Timestamp

try:
    import uuid
    _use_uuid = True
except ImportError:
    _use_uuid = False

class HTMLTextExtractor(HTMLParser):
    def __init__(self):
        HTMLParser.__init__(self)
        self.result = [ ]

    def handle_data(self, d):
        self.result.append(d)

    def handle_charref(self, number):
        codepoint = int(number[1:], 16) if number[0] in (u'x', u'X') else int(number)
        self.result.append(unichr(codepoint))

    def handle_entityref(self, name):
        codepoint = htmlentitydefs.name2codepoint[name]
        self.result.append(unichr(codepoint))

    def get_text(self):
        return u''.join(self.result)

def strip_tags(html):
    s = HTMLTextExtractor()
    s.feed(html)
    return s.get_text()

def json_default(obj):
    """ adapted from bson.json_util.default """
    if isinstance(obj, ObjectId):
        """ _id field should be just string """
        return str(obj)
    if isinstance(obj, DBRef):
        return obj.as_doc()
    if isinstance(obj, datetime.datetime):
        # TODO share this code w/ bson.py?
        if obj.utcoffset() is not None:
            obj = obj - obj.utcoffset()
        millis = int(calendar.timegm(obj.timetuple()) * 1000 +
                     obj.microsecond / 1000)
        return {"$date": millis}
    if isinstance(obj, RE_TYPE):
        flags = ""
        if obj.flags & re.IGNORECASE:
            flags += "i"
        if obj.flags & re.MULTILINE:
            flags += "m"
        return {"$regex": obj.pattern,
                "$options": flags}
    if isinstance(obj, MinKey):
        return {"$minKey": 1}
    if isinstance(obj, MaxKey):
        return {"$maxKey": 1}
    if isinstance(obj, Timestamp):
        return {"t": obj.time, "i": obj.inc}
    if _use_uuid and isinstance(obj, uuid.UUID):
        return {"$uuid": obj.hex}
    raise TypeError("%r is not JSON serializable" % obj)

def filter_alphabetanum(string):
    # absolutely alphabeta and number only
    string = unicodedata.normalize("NFKD", string).encode("ascii", "ignore")
    string = re.sub(r"[^\w]+", " ", string)
    string = "".join(string.lower().strip().split())
    return string

def error_log(log):
    sys.stderr.write(log)

def get_filepath(filename):
    return os.path.join(os.path.abspath(options.pemdir), filename)

def save_file(req):
    filename = sha1(req['body']).hexdigest()
    filepath = get_filepath(filename)
    thefile = open(filepath, "w")
    thefile.write(req['body'])
    thefile.close()
    return filename

def file_exists(filename):
    if not filename:
        return False
    if os.path.exists(filename):
        return True
    fullpath = get_filepath(filename)
    if fullpath and os.path.exists(fullpath):
        return True
    return False

def rm_file(filename):
    if not filename:
        return
    fullpath = get_filepath(filename)
    if os.path.isfile(filename):
        os.remove(filename)
    elif os.path.isfile(fullpath):
        os.remove(fullpath)