RawRootFile.Key Class Reference

Public Member Functions
def	__init__ (self, keydata, large=False)
def	normalize (self, pos=None, offset=None)
def	recreate_header (self)
def	get_int (self, data, pos, wordlen=4)
def	get_string (self, data, pos)

Public Attributes
	large
	are file location pointers 4 or 8 bits?
	wordlen
	size of file location pointers
	header
	length of compressed object (in bytes)
	data
	data bytes associated to the object
	showname
	name to show in the list of keys
	datime
	date and time when object was written to file
	seekkey
	pointer to record itself (consistency check)

Detailed Description

Root file key

Definition at line 119 of file b2root.py.

Constructor & Destructor Documentation

__init__()

def __init__	(		self,
			keydata,
			large = False
	)

Obtain key header and data payload from given data and extract header information

Definition at line 124 of file b2root.py.

        def __init__(self, keydata, large=False):
            """
            Obtain key header and data payload from given data and extract header information
            """
 
            
            self.large = large
            
            self.wordlen = 8 if self.large else 4
            pos = 0
            
            self.nbytes, pos = self.get_int(keydata, pos)
            
            self.version, pos = self.get_int(keydata, pos, 2)
            
            self.objlen, pos = self.get_int(keydata, pos)
            
            self.datime, pos = keydata[pos:pos+4], pos+4
            
            self.keylen, pos = self.get_int(keydata, pos, 2)
            
            self.cycle, pos = self.get_int(keydata, pos, 2)
            
            self.seekkey, pos = self.get_int(keydata, pos, self.wordlen)
            
            self.seekpdir, pos = self.get_int(keydata, pos, self.wordlen)
            
            self.classname, pos = self.get_string(keydata, pos)
            
            self.name, pos = self.get_string(keydata, pos)
            
            self.title, pos = self.get_string(keydata, pos)
            
            self.header = keydata[:pos]
            
            self.data = keydata[pos:]
            
            self.showname = self.classname
 

Member Function Documentation

get_int()

def get_int	(		self,
			data,
			pos,
			wordlen = 4
	)

Helper function to read an int from binary data

Definition at line 195 of file b2root.py.

        def get_int(self, data, pos, wordlen=4):
            """
            Helper function to read an int from binary data
            """
 
            return (int.from_bytes(data[pos:pos+wordlen], byteorder), pos+wordlen)
 

get_string()

def get_string	(		self,
			data,
			pos
	)

Helper function to read a string from binary data

Definition at line 202 of file b2root.py.

        def get_string(self, data, pos):
            """
            Helper function to read a string from binary data
            """
 
            strlen = data[pos]
            return (data[pos+1:pos+1+strlen], pos+1+strlen)
 
    def __next__(self):

normalize()

def normalize	(		self,
			pos = None,
			offset = None
	)

Set the key datime to zero adjust the pointer to itself if given as argument

Definition at line 163 of file b2root.py.

        def normalize(self, pos=None, offset=None):
            """
            Set the key datime to zero adjust the pointer to itself if given as argument
            """
 
            
            self.datime = b'\x00' * 4
            if self.seekkey > 0:
                if pos:
                    
                    self.seekkey = pos
                elif offset:
                    self.seekkey += offset
            self.recreate_header()
 

recreate_header()

def recreate_header

(

self

)

Build the binary header information from the data members

Definition at line 178 of file b2root.py.

        def recreate_header(self):
            """
            Build the binary header information from the data members
            """
 
            self.header = self.nbytes.to_bytes(4, byteorder) \
                + self.version.to_bytes(2, byteorder) \
                + self.objlen.to_bytes(4, byteorder) \
                + self.datime \
                + self.keylen.to_bytes(2, byteorder) \
                + self.cycle.to_bytes(2, byteorder) \
                + self.seekkey.to_bytes(self.wordlen, byteorder) \
                + self.seekpdir.to_bytes(self.wordlen, byteorder) \
                + len(self.classname).to_bytes(1, byteorder) + self.classname \
                + len(self.name).to_bytes(1, byteorder) + self.name \
                + len(self.title).to_bytes(1, byteorder) + self.title
 

Member Data Documentation

data

data

data bytes associated to the object

Definition at line 159 of file b2root.py.

datime

datime

date and time when object was written to file

Definition at line 169 of file b2root.py.

header

header

length of compressed object (in bytes)

TKey version identifier

length of uncompressed object

date and time when object was written to file

length of the key structure (in bytes)

cycle of key

pointer to record itself (consistency check)

pointer to directory header

object Class Name

name of the object

title of the object

binary header

Definition at line 157 of file b2root.py.

large

large

are file location pointers 4 or 8 bits?

Definition at line 130 of file b2root.py.

seekkey

seekkey

pointer to record itself (consistency check)

Definition at line 173 of file b2root.py.

showname

showname

name to show in the list of keys

Definition at line 161 of file b2root.py.

wordlen

wordlen

size of file location pointers

Definition at line 132 of file b2root.py.

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The documentation for this class was generated from the following file:

• framework/scripts/B2Tools/b2root.py