/usr/share/pyshared/scrapy/utils/queue.py is in python-scrapy 0.14.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 | from __future__ import with_statement
import os
import struct
import glob
from collections import deque
from scrapy.utils.py26 import json
class FifoMemoryQueue(object):
"""Memory FIFO queue."""
def __init__(self):
self.q = deque()
def push(self, obj):
self.q.appendleft(obj)
def pop(self):
if self.q:
return self.q.pop()
def close(self):
pass
def __len__(self):
return len(self.q)
class LifoMemoryQueue(FifoMemoryQueue):
"""Memory LIFO queue."""
def push(self, obj):
self.q.append(obj)
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])
self.tailf.seek(self.info['tail'][2])
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
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