eric: comparison src/eric7/DebugClients/Python/coverage/numbits.py

-:3fc8dfeb6ebe
+:b99e7fd55fd3
+# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0
+# For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt
+"""
+Functions to manipulate packed binary representations of number sets.
+To save space, coverage stores sets of line numbers in SQLite using a packed
+binary representation called a numbits.  A numbits is a set of positive
+integers.
+A numbits is stored as a blob in the database.  The exact meaning of the bytes
+in the blobs should be considered an implementation detail that might change in
+the future.  Use these functions to work with those binary blobs of data.
+"""
+import json
+from itertools import zip_longest
+from coverage.misc import contract, new_contract
+def _to_blob(b):
+"""Convert a bytestring into a type SQLite will accept for a blob."""
+return b
+new_contract('blob', lambda v: isinstance(v, bytes))
+@contract(nums='Iterable', returns='blob')
+def nums_to_numbits(nums):
+"""Convert `nums` into a numbits.
+Arguments:
+nums: a reusable iterable of integers, the line numbers to store.
+Returns:
+A binary blob.
+"""
+try:
+nbytes = max(nums) // 8 + 1
+except ValueError:
+# nums was empty.
+return _to_blob(b'')
+b = bytearray(nbytes)
+for num in nums:
+b[num//8] |= 1 << num % 8
+return _to_blob(bytes(b))
+@contract(numbits='blob', returns='list[int]')
+def numbits_to_nums(numbits):
+"""Convert a numbits into a list of numbers.
+Arguments:
+numbits: a binary blob, the packed number set.
+Returns:
+A list of ints.
+When registered as a SQLite function by :func:`register_sqlite_functions`,
+this returns a string, a JSON-encoded list of ints.
+"""
+nums = []
+for byte_i, byte in enumerate(numbits):
+for bit_i in range(8):
+if (byte & (1 << bit_i)):
+nums.append(byte_i * 8 + bit_i)
+return nums
+@contract(numbits1='blob', numbits2='blob', returns='blob')
+def numbits_union(numbits1, numbits2):
+"""Compute the union of two numbits.
+Returns:
+A new numbits, the union of `numbits1` and `numbits2`.
+"""
+byte_pairs = zip_longest(numbits1, numbits2, fillvalue=0)
+return _to_blob(bytes(b1 | b2 for b1, b2 in byte_pairs))
+@contract(numbits1='blob', numbits2='blob', returns='blob')
+def numbits_intersection(numbits1, numbits2):
+"""Compute the intersection of two numbits.
+Returns:
+A new numbits, the intersection `numbits1` and `numbits2`.
+"""
+byte_pairs = zip_longest(numbits1, numbits2, fillvalue=0)
+intersection_bytes = bytes(b1 & b2 for b1, b2 in byte_pairs)
+return _to_blob(intersection_bytes.rstrip(b'\0'))
+@contract(numbits1='blob', numbits2='blob', returns='bool')
+def numbits_any_intersection(numbits1, numbits2):
+"""Is there any number that appears in both numbits?
+Determine whether two number sets have a non-empty intersection. This is
+faster than computing the intersection.
+Returns:
+A bool, True if there is any number in both `numbits1` and `numbits2`.
+"""
+byte_pairs = zip_longest(numbits1, numbits2, fillvalue=0)
+return any(b1 & b2 for b1, b2 in byte_pairs)
+@contract(num='int', numbits='blob', returns='bool')
+def num_in_numbits(num, numbits):
+"""Does the integer `num` appear in `numbits`?
+Returns:
+A bool, True if `num` is a member of `numbits`.
+"""
+nbyte, nbit = divmod(num, 8)
+if nbyte >= len(numbits):
+return False
+return bool(numbits[nbyte] & (1 << nbit))
+def register_sqlite_functions(connection):
+"""
+Define numbits functions in a SQLite connection.
+This defines these functions for use in SQLite statements:
+* :func:`numbits_union`
+* :func:`numbits_intersection`
+* :func:`numbits_any_intersection`
+* :func:`num_in_numbits`
+* :func:`numbits_to_nums`
+`connection` is a :class:`sqlite3.Connection <python:sqlite3.Connection>`
+object.  After creating the connection, pass it to this function to
+register the numbits functions.  Then you can use numbits functions in your
+queries::
+import sqlite3
+from coverage.numbits import register_sqlite_functions
+conn = sqlite3.connect('example.db')
+register_sqlite_functions(conn)
+c = conn.cursor()
+# Kind of a nonsense query: find all the files and contexts that
+# executed line 47 in any file:
+c.execute(
+"select file_id, context_id from line_bits where num_in_numbits(?, numbits)",
+(47,)
+)
+"""
+connection.create_function("numbits_union", 2, numbits_union)
+connection.create_function("numbits_intersection", 2, numbits_intersection)
+connection.create_function("numbits_any_intersection", 2, numbits_any_intersection)
+connection.create_function("num_in_numbits", 2, num_in_numbits)
+connection.create_function("numbits_to_nums", 1, lambda b: json.dumps(numbits_to_nums(b)))

Mercurial Repositories > eric / file comparison

comparison: src/eric7/DebugClients/Python/coverage/numbits.py

src/eric7/DebugClients/Python/coverage/numbits.py