RawRootFile.Key Class Reference

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

Public Attributes
	large = large
	are file location pointers 4 or 8 bits?
int	wordlen = 8 if self.large else 4
	size of file location pointers
	nbytes
	length of compressed object (in bytes)
	version = self.get_int(keydata, pos)
	TKey version identifier.
	objlen = self.get_int(keydata, pos, 2)
	length of uncompressed object
str	datime = self.get_int(keydata, pos)
	date and time when object was written to file
	keylen = keydata[pos:pos+4], pos+4
	length of the key structure (in bytes)
	cycle = self.get_int(keydata, pos, 2)
	cycle of key
	seekkey = self.get_int(keydata, pos, 2)
	pointer to record itself (consistency check)
	seekpdir = self.get_int(keydata, pos, self.wordlen)
	pointer to directory header
	classname = self.get_int(keydata, pos, self.wordlen)
	object Class Name
	name = self.get_string(keydata, pos)
	name of the object
	title = self.get_string(keydata, pos)
	title of the object
str	header = keydata[:pos]
	binary header
	data = keydata[pos:]
	data bytes associated to the object
	showname = self.classname
	name to show in the list of keys

Detailed Description

Root file key

Definition at line 119 of file b2root.py.

Constructor & Destructor Documentation

__init__()

__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()

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()

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()

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()

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

classname

classname = self.get_int(keydata, pos, self.wordlen)

object Class Name

Definition at line 151 of file b2root.py.

cycle

cycle = self.get_int(keydata, pos, 2)

cycle of key

Definition at line 145 of file b2root.py.

data

data = keydata[pos:]

data bytes associated to the object

Definition at line 159 of file b2root.py.

datime

str datime = self.get_int(keydata, pos)

date and time when object was written to file

Definition at line 141 of file b2root.py.

header

str header = keydata[:pos]

binary header

Definition at line 157 of file b2root.py.

keylen

keylen = keydata[pos:pos+4], pos+4

length of the key structure (in bytes)

Definition at line 143 of file b2root.py.

large

large = large

are file location pointers 4 or 8 bits?

Definition at line 130 of file b2root.py.

name

name = self.get_string(keydata, pos)

name of the object

Definition at line 153 of file b2root.py.

nbytes

nbytes

length of compressed object (in bytes)

Definition at line 135 of file b2root.py.

objlen

objlen = self.get_int(keydata, pos, 2)

length of uncompressed object

Definition at line 139 of file b2root.py.

seekkey

seekkey = self.get_int(keydata, pos, 2)

pointer to record itself (consistency check)

pointer to record itself (consistency check)

Definition at line 147 of file b2root.py.

seekpdir

seekpdir = self.get_int(keydata, pos, self.wordlen)

pointer to directory header

Definition at line 149 of file b2root.py.

showname

showname = self.classname

name to show in the list of keys

Definition at line 161 of file b2root.py.

title

title = self.get_string(keydata, pos)

title of the object

Definition at line 155 of file b2root.py.

version

version = self.get_int(keydata, pos)

TKey version identifier.

Definition at line 137 of file b2root.py.

wordlen

int wordlen = 8 if self.large else 4

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