queuelib-1.1.1/0000755000015400001640000000000012237677073014770 5ustar buildbotbuildbot00000000000000queuelib-1.1.1/LICENSE0000644000015400001640000000277312237677055016006 0ustar buildbotbuildbot00000000000000Copyright (c) w3lib and Scrapy developers. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. 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. 3. Neither the name of Scrapy 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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. queuelib-1.1.1/setup.py0000644000015400001640000000165612237677055016512 0ustar buildbotbuildbot00000000000000from distutils.core import setup setup( name='queuelib', version='1.1.1', license='BSD', description='Collection of persistent (disk-based) queues', long_description=open('README.rst').read(), author='Scrapy project', author_email='info@scrapy.org', url='http://github.com/scrapy/queuelib', packages=['queuelib', 'queuelib.tests'], platforms=['Any'], classifiers=[ 'Development Status :: 5 - Production/Stable', 'License :: OSI Approved :: BSD License', 'Operating System :: OS Independent', 'Programming Language :: Python', 'Programming Language :: Python :: 2', 'Programming Language :: Python :: 2.7', 'Programming Language :: Python :: 3', 'Programming Language :: Python :: 3.3', 'Programming Language :: Python :: Implementation :: CPython', 'Programming Language :: Python :: Implementation :: PyPy', ] ) queuelib-1.1.1/README.rst0000644000015400001640000000615212237677055016463 0ustar buildbotbuildbot00000000000000======== queuelib ======== Queuelib is a collection of persistent (disk-based) queues for Python. Queuelib goals are speed and simplicity. It was originally part of the `Scrapy framework`_ and stripped out on its own library. Requirements ============ * Python 2.7 or Python 3.3 * no external library requirements Installation Installation ============ You can install Queuelib either via the Python Package Index (PyPI) or from source. To install using pip:: $ pip install queuelib To install using easy_install:: $ easy_install queuelib If you have downloaded a source tarball you can install it by running the following (as root):: # python setup.py install FIFO/LIFO disk queues ===================== Queuelib provides FIFO and LIFO queue implementations. Here is an example usage of the FIFO queue:: >>> from queuelib import FifoDiskQueue >>> q = FifoDiskQueue("queuefile") >>> q.push('a') >>> q.push('b') >>> q.push('c') >>> q.pop() 'c' >>> q.close() >>> q = FifoDiskQueue("queuefile") >>> q.pop() 'b' >>> q.pop() 'a' >>> q.pop() >>> The LIFO queue is identical (API-wise), but importing ``LifoDiskQueue`` instead. PriorityQueue ============= A discrete-priority queue implemented by combining multiple FIFO/LIFO queues (one per priority). First, select the type of QUEUE (FIFO or LIFO):: >>> from queuelib import FifoDiskQueue >>> q = FifoDiskQueue("somedir") Then instantiate the Priority Queue with it:: >>> from queuelib import PriorityQueue >>> pq = PriorityQueue(q) And use it:: >>> pq.push('a', 3) >>> pq.push('b', 1) >>> pq.push('c', 2) >>> pq.push('d', 2) >>> pq.pop() 'b' >>> pq.pop() 'c' >>> pq.pop() 'd' >>> pq.pop() 'a' Mailing list ============ Use the `scrapy-users`_ mailing list for questions about Queuelib. Bug tracker =========== If you have any suggestions, bug reports or annoyances please report them to our issue tracker at: http://github.com/scrapy/queuelib/issues/ Contributing ============ Development of Queuelib happens at GitHub: http://github.com/scrapy/queuelib You are highly encouraged to participate in the development. If you don't like GitHub (for some reason) you're welcome to send regular patches. All changes require tests to be merged. Tests ===== Tests are located in `queuelib/tests` directory. They can be run using `nosetests`_ with the following command:: nosetests The output should be something like the following:: $ nosetests ............................................................................. ---------------------------------------------------------------------- Ran 77 tests in 0.145s OK License ======= This software is licensed under the BSD License. See the LICENSE file in the top distribution directory for the full license text. Versioning ========== This software follows `Semantic Versioning`_ .. _Scrapy framework: http://scrapy.org .. _scrapy-users: http://groups.google.com/group/scrapy-users .. _Semantic Versioning: http://semver.org/ .. _nosetests: https://nose.readthedocs.org/en/latest/ queuelib-1.1.1/NEWS0000644000015400001640000000020212237677055015461 0ustar buildbotbuildbot00000000000000Queuelib release notes ====================== Version 1.0 ----------- (released on April 23rd, 2013) First release of Queuelib. queuelib-1.1.1/queuelib/0000755000015400001640000000000012237677073016603 5ustar buildbotbuildbot00000000000000queuelib-1.1.1/queuelib/pqueue.py0000644000015400001640000000373612237677055020472 0ustar buildbotbuildbot00000000000000class PriorityQueue(object): """A priority queue implemented using multiple internal queues (typically, FIFO queues). The internal queue must implement the following methods: * push(obj) * pop() * close() * __len__() The constructor receives a qfactory argument, which is a callable used to instantiate a new (internal) queue when a new priority is allocated. The qfactory function is called with the priority number as first and only argument. Only integer priorities should be used. Lower numbers are higher priorities. startprios is a sequence of priorities to start with. If the queue was previously closed leaving some priority buckets non-empty, those priorities should be passed in startprios. """ def __init__(self, qfactory, startprios=()): self.queues = {} self.qfactory = qfactory for p in startprios: self.queues[p] = self.qfactory(p) self.curprio = min(startprios) if startprios else None def push(self, obj, priority=0): if priority not in self.queues: self.queues[priority] = self.qfactory(priority) q = self.queues[priority] q.push(obj) # this may fail (eg. serialization error) if self.curprio is None or priority < self.curprio: self.curprio = priority def pop(self): if self.curprio is None: return q = self.queues[self.curprio] m = q.pop() if len(q) == 0: del self.queues[self.curprio] q.close() prios = [p for p, q in self.queues.items() if len(q) > 0] self.curprio = min(prios) if prios else None return m def close(self): active = [] for p, q in self.queues.items(): if len(q): active.append(p) q.close() return active def __len__(self): return sum(len(x) for x in self.queues.values()) if self.queues else 0 queuelib-1.1.1/queuelib/__init__.py0000644000015400001640000000014212237677055020711 0ustar buildbotbuildbot00000000000000from queuelib.queue import FifoDiskQueue, LifoDiskQueue from queuelib.pqueue import PriorityQueue queuelib-1.1.1/queuelib/tests/0000755000015400001640000000000012237677073017745 5ustar buildbotbuildbot00000000000000queuelib-1.1.1/queuelib/tests/test_pqueue.py0000644000015400001640000001335012237677055022664 0ustar buildbotbuildbot00000000000000from queuelib.pqueue import PriorityQueue from queuelib.queue import FifoMemoryQueue, LifoMemoryQueue, FifoDiskQueue, LifoDiskQueue from queuelib.tests import QueuelibTestCase def track_closed(cls): """Wraps a queue class to track down if close() method was called""" class TrackingClosed(cls): def __init__(self, *a, **kw): super(TrackingClosed, self).__init__(*a, **kw) self.closed = False def close(self): super(TrackingClosed, self).close() self.closed = True return TrackingClosed class FifoMemoryPriorityQueueTest(QueuelibTestCase): def setUp(self): QueuelibTestCase.setUp(self) self.q = PriorityQueue(self.qfactory) def qfactory(self, prio): return track_closed(FifoMemoryQueue)() def test_push_pop_noprio(self): self.q.push(b'a') self.q.push(b'b') self.q.push(b'c') self.assertEqual(self.q.pop(), b'a') self.assertEqual(self.q.pop(), b'b') self.assertEqual(self.q.pop(), b'c') self.assertEqual(self.q.pop(), None) def test_push_pop_prio(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.q.push(b'c', 2) self.q.push(b'd', 1) self.assertEqual(self.q.pop(), b'b') self.assertEqual(self.q.pop(), b'd') self.assertEqual(self.q.pop(), b'c') self.assertEqual(self.q.pop(), b'a') self.assertEqual(self.q.pop(), None) def test_len_nonzero(self): assert not self.q self.assertEqual(len(self.q), 0) self.q.push(b'a', 3) assert self.q self.q.push(b'b', 1) self.q.push(b'c', 2) self.q.push(b'd', 1) self.assertEqual(len(self.q), 4) self.q.pop() self.q.pop() self.q.pop() self.q.pop() assert not self.q self.assertEqual(len(self.q), 0) def test_close(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.q.push(b'c', 2) self.q.push(b'd', 1) iqueues = self.q.queues.values() self.assertEqual(sorted(self.q.close()), [1, 2, 3]) assert all(q.closed for q in iqueues) def test_close_return_active(self): self.q.push(b'b', 1) self.q.push(b'c', 2) self.q.push(b'a', 3) self.q.pop() self.assertEqual(sorted(self.q.close()), [2, 3]) def test_popped_internal_queues_closed(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.q.push(b'c', 2) p1queue = self.q.queues[1] self.assertEqual(self.q.pop(), b'b') self.q.close() assert p1queue.closed class LifoMemoryPriorityQueueTest(FifoMemoryPriorityQueueTest): def qfactory(self, prio): return track_closed(LifoMemoryQueue)() def test_push_pop_noprio(self): self.q.push(b'a') self.q.push(b'b') self.q.push(b'c') self.assertEqual(self.q.pop(), b'c') self.assertEqual(self.q.pop(), b'b') self.assertEqual(self.q.pop(), b'a') self.assertEqual(self.q.pop(), None) def test_push_pop_prio(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.q.push(b'c', 2) self.q.push(b'd', 1) self.assertEqual(self.q.pop(), b'd') self.assertEqual(self.q.pop(), b'b') self.assertEqual(self.q.pop(), b'c') self.assertEqual(self.q.pop(), b'a') self.assertEqual(self.q.pop(), None) class FifoDiskPriorityQueueTest(FifoMemoryPriorityQueueTest): def setUp(self): FifoMemoryPriorityQueueTest.setUp(self) self.q = PriorityQueue(self.qfactory) def qfactory(self, prio): return track_closed(FifoDiskQueue)(self.mktemp()) def test_nonserializable_object_one(self): self.assertRaises(TypeError, self.q.push, lambda x: x, 0) self.assertEqual(self.q.close(), []) def test_nonserializable_object_many_close(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.assertRaises(TypeError, self.q.push, lambda x: x, 0) self.q.push(b'c', 2) self.assertEqual(self.q.pop(), b'b') self.assertEqual(sorted(self.q.close()), [2, 3]) def test_nonserializable_object_many_pop(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.assertRaises(TypeError, self.q.push, lambda x: x, 0) self.q.push(b'c', 2) self.assertEqual(self.q.pop(), b'b') self.assertEqual(self.q.pop(), b'c') self.assertEqual(self.q.pop(), b'a') self.assertEqual(self.q.pop(), None) self.assertEqual(self.q.close(), []) class FifoDiskPriorityQueueTest(FifoMemoryPriorityQueueTest): def qfactory(self, prio): return track_closed(FifoDiskQueue)(self.mktemp()) def test_nonserializable_object_one(self): self.assertRaises(TypeError, self.q.push, lambda x: x, 0) self.assertEqual(self.q.close(), []) def test_nonserializable_object_many_close(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.assertRaises(TypeError, self.q.push, lambda x: x, 0) self.q.push(b'c', 2) self.assertEqual(self.q.pop(), b'b') self.assertEqual(sorted(self.q.close()), [2, 3]) def test_nonserializable_object_many_pop(self): self.q.push(b'a', 3) self.q.push(b'b', 1) self.assertRaises(TypeError, self.q.push, lambda x: x, 0) self.q.push(b'c', 2) self.assertEqual(self.q.pop(), b'b') self.assertEqual(self.q.pop(), b'c') self.assertEqual(self.q.pop(), b'a') self.assertEqual(self.q.pop(), None) self.assertEqual(self.q.close(), []) class LifoDiskPriorityQueueTest(LifoMemoryPriorityQueueTest): def qfactory(self, prio): return track_closed(LifoDiskQueue)(self.mktemp()) queuelib-1.1.1/queuelib/tests/test_queue.py0000644000015400001640000001375212237677055022512 0ustar buildbotbuildbot00000000000000import os, glob, tempfile from queuelib.queue import FifoMemoryQueue, LifoMemoryQueue, FifoDiskQueue, LifoDiskQueue from queuelib.tests import QueuelibTestCase class FifoMemoryQueueTest(QueuelibTestCase): def queue(self): return FifoMemoryQueue() def test_empty(self): """Empty queue test""" q = self.queue() assert q.pop() is None def test_push_pop1(self): """Basic push/pop test""" q = self.queue() q.push(b'a') q.push(b'b') q.push(b'c') self.assertEqual(q.pop(), b'a') self.assertEqual(q.pop(), b'b') self.assertEqual(q.pop(), b'c') self.assertEqual(q.pop(), None) def test_push_pop2(self): """Test interleaved push and pops""" q = self.queue() q.push(b'a') q.push(b'b') q.push(b'c') q.push(b'd') self.assertEqual(q.pop(), b'a') self.assertEqual(q.pop(), b'b') q.push(b'e') self.assertEqual(q.pop(), b'c') self.assertEqual(q.pop(), b'd') self.assertEqual(q.pop(), b'e') def test_len(self): q = self.queue() self.assertEqual(len(q), 0) q.push(b'a') self.assertEqual(len(q), 1) q.push(b'b') q.push(b'c') self.assertEqual(len(q), 3) q.pop() q.pop() q.pop() self.assertEqual(len(q), 0) class LifoMemoryQueueTest(QueuelibTestCase): def queue(self): return LifoMemoryQueue() def test_empty(self): """Empty queue test""" q = self.queue() assert q.pop() is None def test_push_pop1(self): """Basic push/pop test""" q = self.queue() q.push(b'a') q.push(b'b') q.push(b'c') self.assertEqual(q.pop(), b'c') self.assertEqual(q.pop(), b'b') self.assertEqual(q.pop(), b'a') self.assertEqual(q.pop(), None) def test_push_pop2(self): """Test interleaved push and pops""" q = self.queue() q.push(b'a') q.push(b'b') q.push(b'c') q.push(b'd') self.assertEqual(q.pop(), b'd') self.assertEqual(q.pop(), b'c') q.push(b'e') self.assertEqual(q.pop(), b'e') self.assertEqual(q.pop(), b'b') self.assertEqual(q.pop(), b'a') def test_len(self): q = self.queue() self.assertEqual(len(q), 0) q.push(b'a') self.assertEqual(len(q), 1) q.push(b'b') q.push(b'c') self.assertEqual(len(q), 3) q.pop() q.pop() q.pop() self.assertEqual(len(q), 0) class FifoDiskQueueTest(FifoMemoryQueueTest): chunksize = 100000 def setUp(self): FifoMemoryQueueTest.setUp(self) self.qdir = self.mktemp() def queue(self): return FifoDiskQueue(self.qdir, chunksize=self.chunksize) def test_close_open(self): """Test closing and re-opening keeps state""" q = self.queue() q.push(b'a') q.push(b'b') q.push(b'c') q.push(b'd') self.assertEqual(q.pop(), b'a') self.assertEqual(q.pop(), b'b') q.close() del q q = self.queue() self.assertEqual(len(q), 2) q.push(b'e') self.assertEqual(q.pop(), b'c') self.assertEqual(q.pop(), b'd') q.close() del q q = self.queue() self.assertEqual(q.pop(), b'e') self.assertEqual(len(q), 0) def test_chunks(self): """Test chunks are created and removed""" values = [b'0', b'1', b'2', b'3', b'4'] q = self.queue() for x in values: q.push(x) chunks = glob.glob(os.path.join(self.qdir, 'q*')) self.assertEqual(len(chunks), 5 // self.chunksize + 1) for x in values: q.pop() chunks = glob.glob(os.path.join(self.qdir, 'q*')) self.assertEqual(len(chunks), 1) def test_cleanup(self): """Test queue dir is removed if queue is empty""" q = self.queue() values = [b'0', b'1', b'2', b'3', b'4'] assert os.path.exists(self.qdir) for x in values: q.push(x) for x in values: q.pop() q.close() assert not os.path.exists(self.qdir) class ChunkSize1FifoDiskQueueTest(FifoDiskQueueTest): chunksize = 1 class ChunkSize2FifoDiskQueueTest(FifoDiskQueueTest): chunksize = 2 class ChunkSize3FifoDiskQueueTest(FifoDiskQueueTest): chunksize = 3 class ChunkSize4FifoDiskQueueTest(FifoDiskQueueTest): chunksize = 4 class LifoDiskQueueTest(LifoMemoryQueueTest): def setUp(self): LifoMemoryQueueTest.setUp(self) self.path = tempfile.mktemp() def queue(self): return LifoDiskQueue(self.path) def test_close_open(self): """Test closing and re-opening keeps state""" q = self.queue() q.push(b'a') q.push(b'b') q.push(b'c') q.push(b'd') self.assertEqual(q.pop(), b'd') self.assertEqual(q.pop(), b'c') q.close() del q q = self.queue() self.assertEqual(len(q), 2) q.push(b'e') self.assertEqual(q.pop(), b'e') self.assertEqual(q.pop(), b'b') q.close() del q q = self.queue() self.assertEqual(q.pop(), b'a') self.assertEqual(len(q), 0) def test_cleanup(self): """Test queue file is removed if queue is empty""" q = self.queue() values = [b'0', b'1', b'2', b'3', b'4'] assert os.path.exists(self.path) for x in values: q.push(x) for x in values: q.pop() q.close() assert not os.path.exists(self.path) def test_file_size_shrinks(self): """Test size of queue file shrinks when popping items""" q = self.queue() q.push(b'a') q.push(b'b') q.close() size = os.path.getsize(self.path) q = self.queue() q.pop() q.close() assert os.path.getsize(self.path), size queuelib-1.1.1/queuelib/tests/__init__.py0000644000015400001640000000045012237677055022055 0ustar buildbotbuildbot00000000000000import unittest, tempfile, shutil class QueuelibTestCase(unittest.TestCase): def setUp(self): self.tmpdir = tempfile.mkdtemp(prefix="queuelib-tests-") def tearDown(self): shutil.rmtree(self.tmpdir) def mktemp(self): return tempfile.mktemp(dir=self.tmpdir) queuelib-1.1.1/queuelib/queue.py0000644000015400001640000001140612237677055020303 0ustar buildbotbuildbot00000000000000import os import struct import glob import json from collections import deque class FifoMemoryQueue(object): """In-memory FIFO queue, API compliant with FifoDiskQueue.""" def __init__(self): self.q = deque() self.push = self.q.append def pop(self): q = self.q return q.popleft() if q else None def close(self): pass def __len__(self): return len(self.q) class LifoMemoryQueue(FifoMemoryQueue): """In-memory LIFO queue, API compliant with LifoDiskQueue.""" def pop(self): q = self.q return q.pop() if q else None class FifoDiskQueue(object): """Persistent FIFO queue.""" szhdr_format = ">L" szhdr_size = struct.calcsize(szhdr_format) def __init__(self, path, chunksize=100000): self.path = path if not os.path.exists(path): os.makedirs(path) self.info = self._loadinfo(chunksize) self.chunksize = self.info['chunksize'] self.headf = self._openchunk(self.info['head'][0], 'ab+') self.tailf = self._openchunk(self.info['tail'][0]) os.lseek(self.tailf.fileno(), self.info['tail'][2], os.SEEK_SET) def push(self, string): hnum, hpos = self.info['head'] hpos += 1 szhdr = struct.pack(self.szhdr_format, len(string)) os.write(self.headf.fileno(), szhdr + string) if hpos == self.chunksize: hpos = 0 hnum += 1 self.headf.close() self.headf = self._openchunk(hnum, 'ab+') self.info['size'] += 1 self.info['head'] = [hnum, hpos] def _openchunk(self, number, mode='r'): return open(os.path.join(self.path, 'q%05d' % number), mode) def pop(self): tnum, tcnt, toffset = self.info['tail'] if [tnum, tcnt] >= self.info['head']: return tfd = self.tailf.fileno() szhdr = os.read(tfd, self.szhdr_size) if not szhdr: return size, = struct.unpack(self.szhdr_format, szhdr) data = os.read(tfd, size) tcnt += 1 toffset += self.szhdr_size + size if tcnt == self.chunksize and tnum <= self.info['head'][0]: tcnt = toffset = 0 tnum += 1 self.tailf.close() os.remove(self.tailf.name) self.tailf = self._openchunk(tnum) self.info['size'] -= 1 self.info['tail'] = [tnum, tcnt, toffset] return data def close(self): self.headf.close() self.tailf.close() self._saveinfo(self.info) if len(self) == 0: self._cleanup() def __len__(self): return self.info['size'] def _loadinfo(self, chunksize): infopath = self._infopath() if os.path.exists(infopath): with open(infopath) as f: info = json.load(f) else: info = { 'chunksize': chunksize, 'size': 0, 'tail': [0, 0, 0], 'head': [0, 0], } return info def _saveinfo(self, info): with open(self._infopath(), 'w') as f: json.dump(info, f) def _infopath(self): return os.path.join(self.path, 'info.json') def _cleanup(self): for x in glob.glob(os.path.join(self.path, 'q*')): os.remove(x) os.remove(os.path.join(self.path, 'info.json')) if not os.listdir(self.path): os.rmdir(self.path) class LifoDiskQueue(object): """Persistent LIFO queue.""" SIZE_FORMAT = ">L" SIZE_SIZE = struct.calcsize(SIZE_FORMAT) def __init__(self, path): self.path = path if os.path.exists(path): self.f = open(path, 'rb+') qsize = self.f.read(self.SIZE_SIZE) self.size, = struct.unpack(self.SIZE_FORMAT, qsize) self.f.seek(0, os.SEEK_END) else: self.f = open(path, 'wb+') self.f.write(struct.pack(self.SIZE_FORMAT, 0)) self.size = 0 def push(self, string): self.f.write(string) ssize = struct.pack(self.SIZE_FORMAT, len(string)) self.f.write(ssize) self.size += 1 def pop(self): if not self.size: return self.f.seek(-self.SIZE_SIZE, os.SEEK_END) size, = struct.unpack(self.SIZE_FORMAT, self.f.read()) self.f.seek(-size-self.SIZE_SIZE, os.SEEK_END) data = self.f.read(size) self.f.seek(-size, os.SEEK_CUR) self.f.truncate() self.size -= 1 return data def close(self): if self.size: self.f.seek(0) self.f.write(struct.pack(self.SIZE_FORMAT, self.size)) self.f.close() if not self.size: os.remove(self.path) def __len__(self): return self.size queuelib-1.1.1/PKG-INFO0000644000015400001640000001200512237677073016063 0ustar buildbotbuildbot00000000000000Metadata-Version: 1.1 Name: queuelib Version: 1.1.1 Summary: Collection of persistent (disk-based) queues Home-page: http://github.com/scrapy/queuelib Author: Scrapy project Author-email: info@scrapy.org License: BSD Description: ======== queuelib ======== Queuelib is a collection of persistent (disk-based) queues for Python. Queuelib goals are speed and simplicity. It was originally part of the `Scrapy framework`_ and stripped out on its own library. Requirements ============ * Python 2.7 or Python 3.3 * no external library requirements Installation Installation ============ You can install Queuelib either via the Python Package Index (PyPI) or from source. To install using pip:: $ pip install queuelib To install using easy_install:: $ easy_install queuelib If you have downloaded a source tarball you can install it by running the following (as root):: # python setup.py install FIFO/LIFO disk queues ===================== Queuelib provides FIFO and LIFO queue implementations. Here is an example usage of the FIFO queue:: >>> from queuelib import FifoDiskQueue >>> q = FifoDiskQueue("queuefile") >>> q.push('a') >>> q.push('b') >>> q.push('c') >>> q.pop() 'c' >>> q.close() >>> q = FifoDiskQueue("queuefile") >>> q.pop() 'b' >>> q.pop() 'a' >>> q.pop() >>> The LIFO queue is identical (API-wise), but importing ``LifoDiskQueue`` instead. PriorityQueue ============= A discrete-priority queue implemented by combining multiple FIFO/LIFO queues (one per priority). First, select the type of QUEUE (FIFO or LIFO):: >>> from queuelib import FifoDiskQueue >>> q = FifoDiskQueue("somedir") Then instantiate the Priority Queue with it:: >>> from queuelib import PriorityQueue >>> pq = PriorityQueue(q) And use it:: >>> pq.push('a', 3) >>> pq.push('b', 1) >>> pq.push('c', 2) >>> pq.push('d', 2) >>> pq.pop() 'b' >>> pq.pop() 'c' >>> pq.pop() 'd' >>> pq.pop() 'a' Mailing list ============ Use the `scrapy-users`_ mailing list for questions about Queuelib. Bug tracker =========== If you have any suggestions, bug reports or annoyances please report them to our issue tracker at: http://github.com/scrapy/queuelib/issues/ Contributing ============ Development of Queuelib happens at GitHub: http://github.com/scrapy/queuelib You are highly encouraged to participate in the development. If you don't like GitHub (for some reason) you're welcome to send regular patches. All changes require tests to be merged. Tests ===== Tests are located in `queuelib/tests` directory. They can be run using `nosetests`_ with the following command:: nosetests The output should be something like the following:: $ nosetests ............................................................................. ---------------------------------------------------------------------- Ran 77 tests in 0.145s OK License ======= This software is licensed under the BSD License. See the LICENSE file in the top distribution directory for the full license text. Versioning ========== This software follows `Semantic Versioning`_ .. _Scrapy framework: http://scrapy.org .. _scrapy-users: http://groups.google.com/group/scrapy-users .. _Semantic Versioning: http://semver.org/ .. _nosetests: https://nose.readthedocs.org/en/latest/ Platform: Any Classifier: Development Status :: 5 - Production/Stable Classifier: License :: OSI Approved :: BSD License Classifier: Operating System :: OS Independent Classifier: Programming Language :: Python Classifier: Programming Language :: Python :: 2 Classifier: Programming Language :: Python :: 2.7 Classifier: Programming Language :: Python :: 3 Classifier: Programming Language :: Python :: 3.3 Classifier: Programming Language :: Python :: Implementation :: CPython Classifier: Programming Language :: Python :: Implementation :: PyPy