[1].[代碼] [Python]代碼

# -*- coding: GBK -*-

import urlparse

import datetime

import os

from multiprocessing import Process,Queue,Array,RLock

"""

多進程分塊讀取文件

"""

WORKERS = 4

BLOCKSIZE = 100000000

FILE_SIZE = 0

def getFilesize(file):

"""

獲取要讀取文件的大小

"""

global FILE_SIZE

fstream = open(file,'r')

fstream.seek(0,os.SEEK_END)

FILE_SIZE = fstream.tell()

fstream.close()

def process_found(pid,array,file,rlock):

global FILE_SIZE

global JOB

global PREFIX

"""

進程處理

Args:

pid:進程編號

array:進程間共享隊列，用于標記各進程所讀的文件塊結束位置

file:所讀文件名稱

各個進程先從array中獲取當前最大的值為起始位置startpossition

結束的位置endpossition (startpossition+BLOCKSIZE) if (startpossition+BLOCKSIZE)

if startpossition==FILE_SIZE則進程結束

if startpossition==0則從0開始讀取

if startpossition!=0為防止行被block截斷的情況，先讀一行不處理，從下一行開始正式處理

if 當前位置 <=endpossition 就readline

否則越過邊界，就從新查找array中的最大值

"""

fstream = open(file,'r')

while True:

rlock.acquire()

print 'pid%s'%pid,','.join([str(v) for v in array])

startpossition = max(array)

endpossition = array[pid] = (startpossition+BLOCKSIZE) if (startpossition+BLOCKSIZE)

rlock.release()

if startpossition == FILE_SIZE:#end of the file

print 'pid%s end'%(pid)

break

elif startpossition !=0:

fstream.seek(startpossition)

fstream.readline()

pos = ss = fstream.tell()

ostream = open('/data/download/tmp_pid'+str(pid)+'_jobs'+str(endpossition),'w')

while pos

#處理line

line = fstream.readline()

ostream.write(line)

pos = fstream.tell()

print 'pid:%s,startposition:%s,endposition:%s,pos:%s'%(pid,ss,pos,pos)

ostream.flush()

ostream.close()

ee = fstream.tell()

fstream.close()

def main():

global FILE_SIZE

print datetime.datetime.now().strftime("%Y/%d/%m %H:%M:%S")

file = "/data/pds/download/scmcc_log/tmp_format_2011004.log"

getFilesize(file)

print FILE_SIZE

rlock = RLock()

array = Array('l',WORKERS,lock=rlock)

threads=[]

for i in range(WORKERS):

p=Process(target=process_found, args=[i,array,file,rlock])

threads.append(p)

for i in range(WORKERS):

threads[i].start()

for i in range(WORKERS):

threads[i].join()

print datetime.datetime.now().strftime("%Y/%d/%m %H:%M:%S")

if __name__ == '__main__':

main()

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