Inheritance diagram for ztail.Decoder:

Public Member Functions
def	__init__ (self, fname, last_n_lines)

def	decode (self, bytes, if_start=False)

def	follow (self)

def	initial (self)

def	initial_synchronize (self)

def	output_line (self, line)

def	reset (self)

Public Attributes
	f

	known_size

	last_n_lines

	sync

	zstream

Detailed Description

Definition at line 42 of file ztail.py.

Constructor & Destructor Documentation

◆ init()

def ztail.Decoder.__init__	(	self,
		fname,
		last_n_lines
	)

Definition at line 43 of file ztail.py.

     def __init__(self, fname, last_n_lines):
         self.f = open(fname, "rb")
         self.last_n_lines = last_n_lines
         self.reset()
  

Member Function Documentation

◆ decode()

def ztail.Decoder.decode	(	self,
		bytes,
		if_start = `False`
	)

Definition at line 55 of file ztail.py.

     def decode(self, bytes, if_start=False):
         if not bytes:
             return ""
  
         if if_start:
             self.sync = True
             #self.zstream = zlib.decompressobj(zlib.MAX_WBITS | 32)
             bytes = strip_gzip_header(bytes)
         elif not self.sync:
             x = bytes.find(BLOCK_MAGIC)
             if x != -1:
                 bytes = bytes[x + len(BLOCK_MAGIC):]
                 self.sync = True
  
         if not self.sync:
             # not in sync, can't decode
             return ""
         
         text = self.zstream.decompress(bytes)
         #print "decoded:", len(text), len(self.zstream.unused_data)
         if len(self.zstream.unused_data) == 8:
             # this usually means checksum and len is left
             # but we don't care about any of those!
             self.zstream.flush()
             self.zstream = None
  
         return text
  

References ztail.strip_gzip_header(), ztail.Decoder.sync, and ztail.Decoder.zstream.

Referenced by ztail.Decoder.follow(), and ztail.Decoder.initial_synchronize().

◆ follow()

def ztail.Decoder.follow ( self )

Definition at line 111 of file ztail.py.

     def follow(self):
         if self.known_size is None:
             raise Exception("Call initial() first.")
  
         while self.zstream:
             size = os.fstat(self.f.fileno()).st_size
  
             if self.known_size > size:
                 sys.stderr.write("%s: file truncated\n" % sys.argv[0])
                 sys.stderr.write("%s: waiting for the next write\n" % sys.argv[0])
                 sys.stderr.flush()
  
                 if self.sync:
                     self.sync = False
                     self.zstream.flush()
                     self.zstream = zlib.decompressobj(-zlib.MAX_WBITS)
  
                 text = self.initial_synchronize()
                 continue
             elif self.known_size == size:
                 time.sleep(1)
                 continue
  
             assert self.f.tell() == self.known_size
             body = self.f.read(size - self.known_size)
         
             text = self.decode(body, self.known_size == 0)
             self.output_line(text)
  
             self.known_size = size
  

References mySiStripNoises.decode(), ztail.Decoder.decode(), DTPosNeg.decode(), SiStripBadStrip.decode(), SiStripPedestals.decode(), SiStripNoises.decode(), l1t::HGCFETriggerDigi.decode(), CondFormats_BTauObjects::dictionary.f, FunctionMinSelector< F >.f, approx_math::binary32.f, DQMIO2histo.DQMIO.f, DTMuonLocalAlignment.f, ztail.Decoder.f, PixelToFEDAssociateFromAscii::Bdu.f, electronCompare.flushfile.f, electronStore.flushfile.f, DTMuonMillepede.f, TSFit.f, hippyaddtobaddatafiles.KeepWhileOpenFile.f, l1t::emtf::AMC13Trailer.f, cond::SmallWORMDict::IterHelp.f, SiPixelGenErrorDBObject::char2float.f, HcalGainsCheck.f, SiPixel2DTemplateDBObject::char2float.f, SiStripHotStripAlgorithmFromClusterOccupancy.f, ElectronCalibration.f, SiPixelTemplateDBObject::char2float.f, ElectronCalibrationUniv.f, SiStripBadAPVAlgorithmFromClusterOccupancy.f, SiStripBadAPVandHotStripAlgorithmFromClusterOccupancy.f, svgfig.Curve.f, svgfig.Line.f, svgfig.Rect.f, svgfig.Ellipse.f, svgfig.Ticks.f, svgfig.LineAxis.f, ztail.Decoder.initial_synchronize(), ztail.Decoder.known_size, ztail.Decoder.output_line(), readEcalDQMStatus.read, ztail.Decoder.sync, and ztail.Decoder.zstream.

◆ initial()

def ztail.Decoder.initial ( self )

Definition at line 101 of file ztail.py.

     def initial(self):
         text = self.initial_synchronize()
  
         n_lines = self.last_n_lines
         lines = text.rsplit(ENDLINE_MAGIC, n_lines + 1)
         if len(lines) > n_lines:
             lines = lines[1:]
  
         self.output_line(ENDLINE_MAGIC.join(lines))
  

References ztail.Decoder.initial_synchronize(), ztail.Decoder.last_n_lines, and ztail.Decoder.output_line().

◆ initial_synchronize()

def ztail.Decoder.initial_synchronize ( self )

Definition at line 87 of file ztail.py.

     def initial_synchronize(self):
         f = self.f
  
         f.seek(0, 2)
         end = f.tell()
         start = max(0, end - DECOMPRESS_BUF_SIZE)
         f.seek(start, 0)
  
         body = f.read(end - start)
         text = self.decode(body, start == 0)
         
         self.known_size = end
         return text
  

References mySiStripNoises.decode(), ztail.Decoder.decode(), DTPosNeg.decode(), SiStripBadStrip.decode(), SiStripPedestals.decode(), SiStripNoises.decode(), l1t::HGCFETriggerDigi.decode(), CondFormats_BTauObjects::dictionary.f, FunctionMinSelector< F >.f, approx_math::binary32.f, DQMIO2histo.DQMIO.f, DTMuonLocalAlignment.f, ztail.Decoder.f, PixelToFEDAssociateFromAscii::Bdu.f, electronCompare.flushfile.f, electronStore.flushfile.f, DTMuonMillepede.f, TSFit.f, hippyaddtobaddatafiles.KeepWhileOpenFile.f, l1t::emtf::AMC13Trailer.f, cond::SmallWORMDict::IterHelp.f, SiPixelGenErrorDBObject::char2float.f, HcalGainsCheck.f, SiPixel2DTemplateDBObject::char2float.f, SiStripHotStripAlgorithmFromClusterOccupancy.f, ElectronCalibration.f, SiPixelTemplateDBObject::char2float.f, ElectronCalibrationUniv.f, SiStripBadAPVAlgorithmFromClusterOccupancy.f, SiStripBadAPVandHotStripAlgorithmFromClusterOccupancy.f, svgfig.Curve.f, svgfig.Line.f, svgfig.Rect.f, svgfig.Ellipse.f, svgfig.Ticks.f, svgfig.LineAxis.f, and SiStripPI.max.

Referenced by ztail.Decoder.follow(), and ztail.Decoder.initial().

◆ output_line()

def ztail.Decoder.output_line	(	self,
		line
	)

Definition at line 83 of file ztail.py.

     def output_line(self, line):
         sys.stdout.write(line)
         sys.stdout.flush()
  

Referenced by ztail.Decoder.follow(), and ztail.Decoder.initial().

◆ reset()

def ztail.Decoder.reset ( self )

Definition at line 48 of file ztail.py.

     def reset(self):
         self.sync = False
         if hasattr(self, 'zstream'):
             self.zstream.flush()
  
         self.zstream = zlib.decompressobj(-zlib.MAX_WBITS)
  