app/django/db/backends/util.py
author Todd Larsen <tlarsen@google.com>
Wed, 21 Jan 2009 00:27:39 +0000
changeset 858 e79e7a22326f
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Add an export() view, and implement it as text/text for Document. For every Model except Document, the public() view is displayed for any attempts to access the export() view. Currently, the permissions for export() are the same as for public(). This seems reasonable for Document, since anyone could extract the raw HTML from the page source anyway. The permissions should probably be different for other types of exports, such as vCard or iCard exports of profiles, CSV exports of lists, etc. Patch by: Todd Larsen Review by: to-be-reviewed

import datetime
from time import time

from django.utils.hashcompat import md5_constructor

try:
    import decimal
except ImportError:
    from django.utils import _decimal as decimal    # for Python 2.3

class CursorDebugWrapper(object):
    def __init__(self, cursor, db):
        self.cursor = cursor
        self.db = db # Instance of a BaseDatabaseWrapper subclass

    def execute(self, sql, params=()):
        start = time()
        try:
            return self.cursor.execute(sql, params)
        finally:
            stop = time()
            sql = self.db.ops.last_executed_query(self.cursor, sql, params)
            self.db.queries.append({
                'sql': sql,
                'time': "%.3f" % (stop - start),
            })

    def executemany(self, sql, param_list):
        start = time()
        try:
            return self.cursor.executemany(sql, param_list)
        finally:
            stop = time()
            self.db.queries.append({
                'sql': '%s times: %s' % (len(param_list), sql),
                'time': "%.3f" % (stop - start),
            })

    def __getattr__(self, attr):
        if attr in self.__dict__:
            return self.__dict__[attr]
        else:
            return getattr(self.cursor, attr)

    def __iter__(self):
        return iter(self.cursor)

###############################################
# Converters from database (string) to Python #
###############################################

def typecast_date(s):
    return s and datetime.date(*map(int, s.split('-'))) or None # returns None if s is null

def typecast_time(s): # does NOT store time zone information
    if not s: return None
    hour, minutes, seconds = s.split(':')
    if '.' in seconds: # check whether seconds have a fractional part
        seconds, microseconds = seconds.split('.')
    else:
        microseconds = '0'
    return datetime.time(int(hour), int(minutes), int(seconds), int(float('.'+microseconds) * 1000000))

def typecast_timestamp(s): # does NOT store time zone information
    # "2005-07-29 15:48:00.590358-05"
    # "2005-07-29 09:56:00-05"
    if not s: return None
    if not ' ' in s: return typecast_date(s)
    d, t = s.split()
    # Extract timezone information, if it exists. Currently we just throw
    # it away, but in the future we may make use of it.
    if '-' in t:
        t, tz = t.split('-', 1)
        tz = '-' + tz
    elif '+' in t:
        t, tz = t.split('+', 1)
        tz = '+' + tz
    else:
        tz = ''
    dates = d.split('-')
    times = t.split(':')
    seconds = times[2]
    if '.' in seconds: # check whether seconds have a fractional part
        seconds, microseconds = seconds.split('.')
    else:
        microseconds = '0'
    return datetime.datetime(int(dates[0]), int(dates[1]), int(dates[2]),
        int(times[0]), int(times[1]), int(seconds), int(float('.'+microseconds) * 1000000))

def typecast_boolean(s):
    if s is None: return None
    if not s: return False
    return str(s)[0].lower() == 't'

def typecast_decimal(s):
    if s is None or s == '':
        return None
    return decimal.Decimal(s)

###############################################
# Converters from Python to database (string) #
###############################################

def rev_typecast_boolean(obj, d):
    return obj and '1' or '0'

def rev_typecast_decimal(d):
    if d is None:
        return None
    return str(d)

def truncate_name(name, length=None):
    """Shortens a string to a repeatable mangled version with the given length.
    """
    if length is None or len(name) <= length:
        return name

    hash = md5_constructor(name).hexdigest()[:4]

    return '%s%s' % (name[:length-4], hash)

def format_number(value, max_digits, decimal_places):
    """
    Formats a number into a string with the requisite number of digits and
    decimal places.
    """
    return u"%.*f" % (decimal_places, value)