pydllfile - double linked list in heap file storage

pydllfile implements a file persistent double linked list

What's new ?

Check CHANGELOG for latest ongoing, or upcoming news

memory / file layout

a double linked element node resides inside a heap node as data part. see also pyheapfile for layout.

general node layout

name	size / value	description
prev	xpos bytes	previous element
succ	xpos bytes	next element
data	x bytes	data area

limitation

xpos (default) == 8 bytes ==> 2**(8*8) == 18.446.744.073.709.551.616 bytes total file size (default)

binary prefix	size	unit
2**20	17.592.186.044.416	MB
2**30	17.179.869.184	GB
2**40	16.777.216	TB
2**50	16.384	PB
2**60	16	EB

the default can be changed by creating DoubleLinkedListFile with a different link_size
see other limits also here pyheapfile

remark on hexdump tool

hexdump tool raise error when configured not properly. use valid hex address for node and link. the internal hexdump tool for dumping single elements nodes from the dllfile can be called with:

usage: python3 -m pydllfile.hexdump [options]

dump heapfile double linked elements

optional arguments:
  -h, --help            show this help message and exit
  -v, --version         show version info and exit
  -V, --verbose         show more info
  -f FILE_NAME, --file FILE_NAME
                        input file
  -n NODE_NO, --node NODE_NO
                        hex address of node. blanks in a quoted string are ignored. address of 0x0 will read the 2nd heap node since a dll element node can not be
                        stored in first heap node. (default: 000000)
  -l LINK_NO, --link LINK_NO
                        hex address of dll element node. blanks in a quoted string are ignored. (default: 000000)
  -aw ADDESS_WIDTH, --addess_width ADDESS_WIDTH
                        hex address width. (default: 6)
  -ls LINK_SIZE, --link_size LINK_SIZE
                        link size. (default: 8)
  -r REL_NO, --relative REL_NO
                        relative position of dll element node. can be combined with -n or -l option. when negative it reads backwards starting from the -n/-l node.
                        keep in mind that -n is an address and -r is a position. (default: 0)
  -w WIDTH, --width WIDTH
                        with of data output (default: 16)
  -g GROUP, --group GROUP
                        group bytes in data output (default: 1)
  -ho, --header_only    prints only header, no data.

Related Projects

search for topic pyheapfile on github to explore related tools/ modules.

Platform

Tested on Python3, and Linux.

development status

alpha state. the API or logical call flow might change without prior notice.

read CHANGELOG for latest, or upcoming news.

installation

available on pypi. install with:

python3 -m pip install pydllfile

PavlosP1987/pydllfile