Other versions on book detail page.

[wolnelektury.git] / apps / catalogue / utils.py

diff --git a/apps/catalogue/utils.py b/apps/catalogue/utils.py
index bda7e04..fd74c94 100644 (file)
--- a/apps/catalogue/utils.py
+++ b/apps/catalogue/utils.py
@@ -4,6 +4,7 @@
 #
 from __future__ import with_statement
 
+import hashlib
 import random
 import re
 import time
@@ -13,7 +14,7 @@ from django.http import HttpResponse
 from django.core.files.uploadedfile import UploadedFile
 from django.core.files.storage import DefaultStorage
 from django.utils.encoding import force_unicode
-from django.utils.hashcompat import sha_constructor
+from django.utils.translation import get_language
 from django.conf import settings
 from os import mkdir, path, unlink
 from errno import EEXIST, ENOENT
@@ -31,21 +32,25 @@ MAX_SESSION_KEY = 18446744073709551616L     # 2 << 63
 
 
 def get_random_hash(seed):
-    sha_digest = sha_constructor('%s%s%s%s' %
+    sha_digest = hashlib.sha1('%s%s%s%s' %
         (randrange(0, MAX_SESSION_KEY), time.time(), unicode(seed).encode('utf-8', 'replace'),
         settings.SECRET_KEY)).digest()
     return urlsafe_b64encode(sha_digest).replace('=', '').replace('_', '-').lower()
 
 
-def split_tags(tags):
-    result = {}
+def split_tags(tags, initial=None):
+    if initial is None:
+        result = {}
+    else:
+        result = initial
+    
     for tag in tags:
         result.setdefault(tag.category, []).append(tag)
     return result
 
 
 def get_dynamic_path(media, filename, ext=None, maxlen=100):
-    from slughifi import slughifi
+    from fnpdjango.utils.text.slughifi import slughifi
 
     # how to put related book's slug here?
     if not ext:
@@ -187,6 +192,52 @@ class MultiQuerySet(object):
                     stop = total_len - len(items)
                     continue
 
+class SortedMultiQuerySet(MultiQuerySet):
+    def __init__(self, *args, **kwargs):
+        self.order_by = kwargs.pop('order_by', None)
+        self.sortfn = kwargs.pop('sortfn', None)
+        if self.order_by is not None:
+            self.sortfn = lambda a, b: cmp(getattr(a, self.order_by), 
+                                           getattr(b, self.order_by))
+        super(SortedMultiQuerySet, self).__init__(*args, **kwargs)
+
+    def __getitem__(self, item):
+        sort_heads = [0] * len(self.querysets)
+        try:
+            indices = (offset, stop, step) = item.indices(self.count())
+        except AttributeError:
+            # it's not a slice - make it one
+            return self[item : item + 1][0]
+        items = []
+        total_len = stop - offset
+        skipped = 0
+        i_s = range(len(sort_heads))
+
+        while len(items) < total_len:
+            candidate = None
+            for i in i_s:
+                def get_next():
+                    return self.querysets[i][sort_heads[i]]
+                try:
+                    if candidate is None:
+                        candidate = get_next()
+                    else:
+                        competitor = get_next()
+                        if self.sortfn(candidate, competitor) > 0:
+                            candidate = competitor
+                except IndexError:
+                    continue # continue next sort_head
+                sort_heads[i] += 1
+            # we have no more elements:
+            if candidate is None:
+                break
+            if skipped < offset:
+                skipped += 1
+                continue # continue next item
+            items.append(candidate)
+        
+        return items
+
 
 def truncate_html_words(s, num, end_text='...'):
     """Truncates HTML to a certain number of words (not counting tags and
@@ -276,3 +327,48 @@ def clear_custom_pdf(book):
     """
     from waiter.utils import clear_cache
     clear_cache('book/%s' % book.slug)
+
+
+class AppSettings(object):
+    """Allows specyfying custom settings for an app, with default values.
+
+    Just subclass, set some properties and instantiate with a prefix.
+    Getting a SETTING from an instance will check for prefix_SETTING
+    in project settings if set, else take the default. The value will be
+    then filtered through _more_SETTING method, if there is one.
+
+    """
+    def __init__(self, prefix):
+        self._prefix = prefix
+
+    def __getattribute__(self, name):
+        if name.startswith('_'):
+            return object.__getattribute__(self, name)
+        value = getattr(settings,
+                         "%s_%s" % (self._prefix, name),
+                         object.__getattribute__(self, name))
+        more = "_more_%s" % name
+        if hasattr(self, more):
+            value = getattr(self, more)(value)
+        return value
+
+
+def trim_query_log(trim_to=25):
+    """
+connection.queries includes all SQL statements -- INSERTs, UPDATES, SELECTs, etc. Each time your app hits the database, the query will be recorded.
+This can sometimes occupy lots of memory, so trim it here a bit.
+    """
+    if settings.DEBUG:
+        from django.db import connection
+        connection.queries = trim_to > 0 \
+            and connection.queries[-trim_to:] \
+            or []
+
+
+def related_tag_name(tag_info, language=None):
+    return tag_info.get("name_%s" % (language or get_language()),
+        tag_info.get("name_%s" % settings.LANGUAGE_CODE, ""))
+
+
+def delete_from_cache_by_language(cache, key_template):
+    cache.delete_many([key_template % lc for lc, ln in settings.LANGUAGES])