Source Code for Module tlib.base.HttpFileRequestor

 1 -class HttpFileRequestor(object): 
 2      """ 
 3      Helper class for retrieving http files from url  
 4      """ 
 5   
 6      _url = None 
 7      _size = None 
 8       
 9 -    def __init__(self, url=None): 
10          """ 
11          Constructor for class  
12          """ 
13          self._url = url 
14          self._size = self.get_file_size() 
15           
16 -    def get_file_size(self): 
17          """ 
18          Get the size of file from the url 
19          """ 
20          with urllib2.urlopen(self._url) as fd: 
21              info = fd.info() 
22          return int(info.getheader('Content-Length')) 
23   
24   
25 -    def tail(self, url=None, length=0): 
26          """ 
27          Tail the file from the url 
28          """ 
29          if url: 
30              self._url = url 
31          self._size = self.get_file_size() 
32          #we assume that each line may contains MAX_CHARS_IN_ONE_LINE characters at max 
33          start = max(0, self._size - (MAX_CHARS_IN_ONE_LINE * length)) 
34          #send the request asking for the last n bytes of the file content from the url 
35          myHeaders = {'Range': 'bytes=%i-' % start} 
36          req = urllib2.Request(url=self._url, headers=myHeaders) 
37          partialFile = urllib2.urlopen(req) 
38           
39          lines = partialFile.read().strip().split('\n') 
40           
41          return lines[-length:] if len(lines) > length else lines[1:] 
42