search Namespace Reference

Classes
class	ResourceLimitExceededError

Functions
def	_all_bytestrings ()
def	_bytestrings_of_length (length)
def	_get_hamming_distance (a, b)
def	_get_hash (secret)
def	_get_substring_hamming_distance (candidate, target)
def	search (target, ideal_distance, stop_event, maximum_hashes, interesting_hamming_distance=None)

Variables
int	_BYTE_MAX = 255
	_LOGGER = logging.getLogger(__name__)

Function Documentation

_all_bytestrings()

def search._all_bytestrings ( )

private

Generates a stream containing all possible bytestrings.

This generator does not terminate.

Yields:
  All bytestrings in ascending order of length.

Definition at line 86 of file search.py.

_bytestrings_of_length()

def search._bytestrings_of_length (   length )

private

Generates a stream containing all bytestrings of a given length.

Args:
  length: A positive integer length.

Yields:
  All bytestrings of length `length`.

Definition at line 73 of file search.py.

_get_hamming_distance()

def search._get_hamming_distance (   a,   b  )

private

Calculates hamming distance between strings of equal length.

Definition at line 32 of file search.py.

_get_hash()

def search._get_hash (   secret )

private

Definition at line 63 of file search.py.

_get_substring_hamming_distance()

def search._get_substring_hamming_distance (   candidate,   target  )

private

Calculates the minimum hamming distance between between the target
    and any substring of the candidate.

Args:
  candidate: The string whose substrings will be tested.
  target: The target string.

Returns:
  The minimum Hamming distance between candidate and target.

Definition at line 41 of file search.py.

search()

def search.search	(		target,
			ideal_distance,
			stop_event,
			maximum_hashes,
			interesting_hamming_distance = None
	)

Find candidate strings.

Search through the space of all bytestrings, in order of increasing length,
indefinitely, until a hash with a Hamming distance of `maximum_distance` or
less has been found.

Args:
  target: The search string.
  ideal_distance: The desired Hamming distance.
  stop_event: An event indicating whether the RPC should terminate.
  maximum_hashes: The maximum number of hashes to check before stopping.
  interesting_hamming_distance: If specified, strings with a Hamming
    distance from the target below this value will be yielded.

Yields:
  Instances  of HashNameResponse. The final entry in the stream will be of
    `maximum_distance` Hamming distance or less from the target string,
    while all others will be of less than `interesting_hamming_distance`.

Raises:
  ResourceLimitExceededError: If the computation exceeds `maximum_hashes`
    iterations.

Definition at line 99 of file search.py.

Variable Documentation

_BYTE_MAX

int search._BYTE_MAX = 255

private

Definition at line 29 of file search.py.

_LOGGER

search._LOGGER = logging.getLogger(__name__)

private

Definition at line 28 of file search.py.