Move cache code to its own file

morss/cache.py

@@ -0,0 +1,163 @@
+# This file is part of morss
+#
+# Copyright (C) 2013-2020 pictuga <contact@pictuga.com>
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <https://www.gnu.org/licenses/>.
+
+import os
+import pickle
+import time
+import threading
+from collections import OrderedDict
+
+CACHE_SIZE = int(os.getenv('CACHE_SIZE', 1000)) # max number of items in cache (default: 1k items)
+CACHE_LIFESPAN = int(os.getenv('CACHE_LIFESPAN', 60)) # how often to auto-clear the cache (default: 1min)
+
+
+class BaseCache:
+    """ Subclasses must behave like a dict """
+
+    def trim(self):
+        pass
+
+    def autotrim(self, delay=CACHE_LIFESPAN):
+        # trim the cache every so often
+
+        self.trim()
+
+        t = threading.Timer(delay, self.autotrim)
+        t.daemon = True
+        t.start()
+
+    def __contains__(self, url):
+        try:
+            self[url]
+
+        except KeyError:
+            return False
+
+        else:
+            return True
+
+
+try:
+    import sqlite3 # isort:skip
+except ImportError:
+    pass
+
+
+class SQLiteCache(BaseCache):
+    def __init__(self, filename=':memory:'):
+        self.con = sqlite3.connect(filename, detect_types=sqlite3.PARSE_DECLTYPES, check_same_thread=False)
+
+        with self.con:
+            self.con.execute('CREATE TABLE IF NOT EXISTS data (ky UNICODE PRIMARY KEY, data BLOB, timestamp INT)')
+            self.con.execute('pragma journal_mode=WAL')
+
+        self.trim()
+
+    def __del__(self):
+        self.con.close()
+
+    def trim(self):
+        with self.con:
+            self.con.execute('DELETE FROM data WHERE timestamp <= ( SELECT timestamp FROM ( SELECT timestamp FROM data ORDER BY timestamp DESC LIMIT 1 OFFSET ? ) foo )', (CACHE_SIZE,))
+
+    def __getitem__(self, key):
+        row = self.con.execute('SELECT * FROM data WHERE ky=?', (key,)).fetchone()
+
+        if not row:
+            raise KeyError
+
+        return row[1]
+
+    def __setitem__(self, key, data):
+        with self.con:
+            self.con.execute('INSERT INTO data VALUES (?,?,?) ON CONFLICT(ky) DO UPDATE SET data=?, timestamp=?', (key, data, time.time(), data, time.time()))
+
+
+try:
+    import pymysql.cursors # isort:skip
+except ImportError:
+    pass
+
+
+class MySQLCacheHandler(BaseCache):
+    def __init__(self, user, password, database, host='localhost'):
+        self.user = user
+        self.password = password
+        self.database = database
+        self.host = host
+
+        with self.cursor() as cursor:
+            cursor.execute('CREATE TABLE IF NOT EXISTS data (ky VARCHAR(255) NOT NULL PRIMARY KEY, data MEDIUMBLOB, timestamp INT)')
+
+        self.trim()
+
+    def cursor(self):
+        return pymysql.connect(host=self.host, user=self.user, password=self.password, database=self.database, charset='utf8', autocommit=True).cursor()
+
+    def trim(self):
+        with self.cursor() as cursor:
+            cursor.execute('DELETE FROM data WHERE timestamp <= ( SELECT timestamp FROM ( SELECT timestamp FROM data ORDER BY timestamp DESC LIMIT 1 OFFSET %s ) foo )', (CACHE_SIZE,))
+
+    def __getitem__(self, key):
+        cursor = self.cursor()
+        cursor.execute('SELECT * FROM data WHERE ky=%s', (key,))
+        row = cursor.fetchone()
+
+        if not row:
+            raise KeyError
+
+        return row[1]
+
+    def __setitem__(self, key, data):
+        with self.cursor() as cursor:
+            cursor.execute('INSERT INTO data VALUES (%s,%s,%s) ON DUPLICATE KEY UPDATE data=%s, timestamp=%s',
+                (key, data, time.time(), data, time.time()))
+
+
+class CappedDict(OrderedDict, BaseCache):
+    def trim(self):
+        if CACHE_SIZE >= 0:
+            for i in range( max( len(self) - CACHE_SIZE , 0 )):
+                self.popitem(False)
+
+    def __setitem__(self, key, data):
+        # https://docs.python.org/2/library/collections.html#ordereddict-examples-and-recipes
+        if key in self:
+            del self[key]
+        OrderedDict.__setitem__(self, key, data)
+
+
+if 'CACHE' in os.environ:
+    if os.environ['CACHE'] == 'mysql':
+        default_cache = MySQLCacheHandler(
+            user = os.getenv('MYSQL_USER'),
+            password = os.getenv('MYSQL_PWD'),
+            database = os.getenv('MYSQL_DB'),
+            host = os.getenv('MYSQL_HOST', 'localhost')
+        )
+
+    elif os.environ['CACHE'] == 'sqlite':
+        if 'SQLITE_PATH' in os.environ:
+            path = os.getenv('SQLITE_PATH')
+
+        else:
+            path = ':memory:'
+
+        default_cache = SQLiteCache(path)
+
+else:
+        default_cache = CappedDict()

morss/crawler.py

@@ -16,10 +16,10 @@
 # with this program. If not, see <https://www.gnu.org/licenses/>.
 
 import os
+import pickle
 import random
 import re
 import sys
-import threading
 import time
 import zlib
 from cgi import parse_header
@@ -28,6 +28,8 @@ from io import BytesIO, StringIO
 
 import chardet
 
+from .cache import default_cache
+
 try:
     # python 2
     from urllib import quote
@@ -53,10 +55,6 @@ except NameError:
     basestring = unicode = str
 
 
-CACHE_SIZE = int(os.getenv('CACHE_SIZE', 1000)) # max number of items in cache (default: 1k items)
-CACHE_LIFESPAN = int(os.getenv('CACHE_LIFESPAN', 60)) # how often to auto-clear the cache (default: 1min)
-
-
 MIMETYPE = {
     'xml': ['text/xml', 'application/xml', 'application/rss+xml', 'application/rdf+xml', 'application/atom+xml', 'application/xhtml+xml'],
     'rss': ['application/rss+xml', 'application/rdf+xml', 'application/atom+xml'],
@@ -457,37 +455,46 @@ class CacheHandler(BaseHandler):
 
     def load(self, url):
         try:
-            out = list(self.cache[url])
+            data = pickle.loads(self.cache[url])
+
         except KeyError:
-            out = [None, None, unicode(), bytes(), 0]
+            data = None
 
-        if sys.version_info[0] >= 3:
-            out[2] = email.message_from_string(out[2] or unicode()) # headers
         else:
-            out[2] = mimetools.Message(StringIO(out[2] or unicode()))
+            if sys.version_info[0] >= 3:
+                data['headers'] = email.message_from_string(data['headers'] or unicode()) # headers
+            else:
+                data['headers'] = mimetools.Message(StringIO(data['headers'] or unicode()))
 
-        return out
+        return data
 
-    def save(self, url, code, msg, headers, data, timestamp):
-        self.cache[url] = (code, msg, unicode(headers), data, timestamp)
+    def save(self, key, data):
+        data['headers'] = unicode(data['headers'])
+        self.cache[key] = pickle.dumps(data, 0)
 
-    def is_cached(self, url):
-        return self.load(url)[0] is not None
+    def is_cached(self, key):
+        return self.load(key) is not None
 
     def cached_response(self, req):
         # this does NOT check whether it's already cached, use with care
-        (code, msg, headers, data, timestamp) = self.load(req.get_full_url())
+        data = self.load(req.get_full_url())
 
         # return the cache as a response
-        resp = addinfourl(BytesIO(data), headers, req.get_full_url(), code)
-        resp.msg = msg
+        resp = addinfourl(BytesIO(data['data']), data['headers'], req.get_full_url(), data['code'])
+        resp.msg = data['msg']
 
         return resp
 
     def save_response(self, req, resp):
         data = resp.read()
 
-        self.save(req.get_full_url(), resp.code, resp.msg, resp.headers, data, time.time())
+        self.save(req.get_full_url(), {
+            'code': resp.code,
+            'msg': resp.msg,
+            'headers': resp.headers,
+            'data': data,
+            'timestamp': time.time()
+            })
 
         fp = BytesIO(data)
         old_resp = resp
@@ -497,13 +504,14 @@ class CacheHandler(BaseHandler):
         return resp
 
     def http_request(self, req):
-        (code, msg, headers, data, timestamp) = self.load(req.get_full_url())
+        data = self.load(req.get_full_url())
 
-        if 'etag' in headers:
-            req.add_unredirected_header('If-None-Match', headers['etag'])
+        if data is not None:
+            if 'etag' in data['headers']:
+                req.add_unredirected_header('If-None-Match', data['headers']['etag'])
 
-        if 'last-modified' in headers:
-            req.add_unredirected_header('If-Modified-Since', headers.get('last-modified'))
+            if 'last-modified' in data['headers']:
+                req.add_unredirected_header('If-Modified-Since', data['headers']['last-modified'])
 
         return req
 
@@ -512,33 +520,33 @@ class CacheHandler(BaseHandler):
         # If 'None' is returned, try your chance with the next-available handler
         # If a 'resp' is returned, stop there, and proceed with 'http_response'
 
-        (code, msg, headers, data, timestamp) = self.load(req.get_full_url())
+        data = self.load(req.get_full_url())
+
+        if data is None:
+            # cache empty, refresh
+            return None
 
         # some info needed to process everything
-        cache_control = parse_http_list(headers.get('cache-control', ()))
-        cache_control += parse_http_list(headers.get('pragma', ()))
+        cache_control = parse_http_list(data['headers'].get('cache-control', ()))
+        cache_control += parse_http_list(data['headers'].get('pragma', ()))
 
         cc_list = [x for x in cache_control if '=' not in x]
         cc_values = parse_keqv_list([x for x in cache_control if '=' in x])
 
-        cache_age = time.time() - timestamp
+        cache_age = time.time() - data['timestamp']
 
         # list in a simple way what to do when
         if self.force_min == -2:
-            if code is not None:
+            if data['code'] is not None:
                 # already in cache, perfect, use cache
                 return self.cached_response(req)
 
             else:
                 # raise an error, via urllib handlers
-                resp = addinfourl(BytesIO(), headers, req.get_full_url(), 409)
+                resp = addinfourl(BytesIO(), data['headers'], req.get_full_url(), 409)
                 resp.msg = 'Conflict'
                 return resp
 
-        elif code is None:
-            # cache empty, refresh
-            return None
-
         elif self.force_min == -1:
             # force use cache
             return self.cached_response(req)
@@ -547,7 +555,7 @@ class CacheHandler(BaseHandler):
             # force refresh
             return None
 
-        elif code == 301 and cache_age < 7*24*3600:
+        elif data['code'] == 301 and cache_age < 7*24*3600:
             # "301 Moved Permanently" has to be cached...as long as we want
             # (awesome HTTP specs), let's say a week (why not?). Use force_min=0
             # if you want to bypass this (needed for a proper refresh)
@@ -604,142 +612,6 @@ class CacheHandler(BaseHandler):
     https_response = http_response
 
 
-class BaseCache:
-    """ Subclasses must behave like a dict """
-
-    def trim(self):
-        pass
-
-    def autotrim(self, delay=CACHE_LIFESPAN):
-        # trim the cache every so often
-
-        self.trim()
-
-        t = threading.Timer(delay, self.autotrim)
-        t.daemon = True
-        t.start()
-
-    def __contains__(self, url):
-        try:
-            self[url]
-
-        except KeyError:
-            return False
-
-        else:
-            return True
-
-
-import sqlite3 # isort:skip
-
-
-class SQLiteCache(BaseCache):
-    def __init__(self, filename=':memory:'):
-        self.con = sqlite3.connect(filename, detect_types=sqlite3.PARSE_DECLTYPES, check_same_thread=False)
-
-        with self.con:
-            self.con.execute('CREATE TABLE IF NOT EXISTS data (url UNICODE PRIMARY KEY, code INT, msg UNICODE, headers UNICODE, data BLOB, timestamp INT)')
-            self.con.execute('pragma journal_mode=WAL')
-
-        self.trim()
-
-    def __del__(self):
-        self.con.close()
-
-    def trim(self):
-        with self.con:
-            self.con.execute('DELETE FROM data WHERE timestamp <= ( SELECT timestamp FROM ( SELECT timestamp FROM data ORDER BY timestamp DESC LIMIT 1 OFFSET ? ) foo )', (CACHE_SIZE,))
-
-    def __getitem__(self, url):
-        row = self.con.execute('SELECT * FROM data WHERE url=?', (url,)).fetchone()
-
-        if not row:
-            raise KeyError
-
-        return row[1:]
-
-    def __setitem__(self, url, value): # value = (code, msg, headers, data, timestamp)
-        value = list(value)
-        value[3] = sqlite3.Binary(value[3]) # data
-        value = tuple(value)
-
-        with self.con:
-            self.con.execute('INSERT INTO data VALUES (?,?,?,?,?,?) ON CONFLICT(url) DO UPDATE SET code=?, msg=?, headers=?, data=?, timestamp=?', (url,) + value + value)
-
-
-import pymysql.cursors # isort:skip
-
-
-class MySQLCacheHandler(BaseCache):
-    def __init__(self, user, password, database, host='localhost'):
-        self.user = user
-        self.password = password
-        self.database = database
-        self.host = host
-
-        with self.cursor() as cursor:
-            cursor.execute('CREATE TABLE IF NOT EXISTS data (url VARCHAR(255) NOT NULL PRIMARY KEY, code INT, msg TEXT, headers TEXT, data BLOB, timestamp INT)')
-
-        self.trim()
-
-    def cursor(self):
-        return pymysql.connect(host=self.host, user=self.user, password=self.password, database=self.database, charset='utf8', autocommit=True).cursor()
-
-    def trim(self):
-        with self.cursor() as cursor:
-            cursor.execute('DELETE FROM data WHERE timestamp <= ( SELECT timestamp FROM ( SELECT timestamp FROM data ORDER BY timestamp DESC LIMIT 1 OFFSET %s ) foo )', (CACHE_SIZE,))
-
-    def __getitem__(self, url):
-        cursor = self.cursor()
-        cursor.execute('SELECT * FROM data WHERE url=%s', (url,))
-        row = cursor.fetchone()
-
-        if not row:
-            raise KeyError
-
-        return row[1:]
-
-    def __setitem__(self, url, value): # (code, msg, headers, data, timestamp)
-        with self.cursor() as cursor:
-            cursor.execute('INSERT INTO data VALUES (%s,%s,%s,%s,%s,%s) ON DUPLICATE KEY UPDATE code=%s, msg=%s, headers=%s, data=%s, timestamp=%s',
-                (url,) + value + value)
-
-
-class CappedDict(OrderedDict, BaseCache):
-    def trim(self):
-        if CACHE_SIZE >= 0:
-            for i in range( max( len(self) - CACHE_SIZE , 0 )):
-                self.popitem(False)
-
-    def __setitem__(self, key, value):
-        # https://docs.python.org/2/library/collections.html#ordereddict-examples-and-recipes
-        if key in self:
-            del self[key]
-        OrderedDict.__setitem__(self, key, value)
-
-
-if 'CACHE' in os.environ:
-    if os.environ['CACHE'] == 'mysql':
-        default_cache = MySQLCacheHandler(
-            user = os.getenv('MYSQL_USER'),
-            password = os.getenv('MYSQL_PWD'),
-            database = os.getenv('MYSQL_DB'),
-            host = os.getenv('MYSQL_HOST', 'localhost')
-        )
-
-    elif os.environ['CACHE'] == 'sqlite':
-        if 'SQLITE_PATH' in os.environ:
-            path = os.getenv('SQLITE_PATH')
-
-        else:
-            path = ':memory:'
-
-        default_cache = SQLiteCache(path)
-
-else:
-        default_cache = CappedDict()
-
-
 if 'IGNORE_SSL' in os.environ:
     import ssl
     ssl._create_default_https_context = ssl._create_unverified_context

setup.py

@@ -13,7 +13,8 @@ setup(
     download_url = 'https://git.pictuga.com/pictuga/morss',
     license = 'AGPL v3',
     packages = [package_name],
-    install_requires = ['lxml', 'bs4', 'python-dateutil', 'chardet', 'pymysql'],
+    install_requires = ['lxml', 'bs4', 'python-dateutil', 'chardet'],
+    extras_require = {'full': ['pymysql']},
     package_data = {package_name: ['feedify.ini']},
     data_files = [
         ('share/' + package_name, ['README.md', 'LICENSE']),