Added efficient data structure for maps indexed by file lines (fixes #347) (#348)

* implemented draft FileLineMap

* updated CHANGELOG

* updated attrs version

* added deprecated as a dependency

* added deprecation notices

* bug fix: missing imports

* use comment-style type annotations to support 3.5

* updated imports in core/__init__.py

* added pytest to setup.py

Author: ChrisTimperley

CHANGELOG.md

@@ -1,4 +1,10 @@
-## 2.1.29 (2019-09-05)
+## 2.1.29 (????-??-??)
+
+### Features
+
+* Added an efficient data structure for representing maps that are indexed
+  by FileLine objects: FileLineMap.
+
 
 ### Changes
 

bugzoo/core/__init__.py

@@ -2,7 +2,7 @@
 from .container import Container
 from .language import Language
 from .patch import Patch
-from .fileline import FileLine, FileLineSet
+from .fileline import FileLine, FileLineSet, FileLineMap
 from .filechar import FileChar, FileCharRange
 from .test import TestCase, TestOutcome, TestSuite
 from .coverage import CoverageInstructions, TestCoverage, TestSuiteCoverage

bugzoo/core/fileline.py

@@ -1,13 +1,17 @@
 # -*- coding: utf-8 -*-
-__all__ = ('FileLine', 'FileLineSet')
+__all__ = ('FileLine', 'FileLineSet', 'FileLineMap')
 
 import typing
 import collections.abc
 from typing import (Dict, List, Set, Iterator, Iterable, Any, FrozenSet,
-                    Callable, Optional, Tuple)
+                    Callable, Optional, Tuple, TypeVar, MutableMapping,
+                    Mapping)
 
+from deprecated import deprecated
 import attr
 
+T = TypeVar('T')
+
 
 @attr.s(frozen=True, slots=True)
 class FileLine:
@@ -22,6 +26,7 @@ def from_string(s: str) -> 'FileLine':
         return FileLine(fn, num)
 
     @staticmethod
+    @deprecated(version='2.1.29', reason='Replaced by FileLineMap.')
     def compactify(d: Dict['FileLine', Any]) -> Dict[str, Dict[int, Any]]:
         """
         Converts a dictionary that is indexed by FileLine objects into a
@@ -39,6 +44,7 @@ def compactify(d: Dict['FileLine', Any]) -> Dict[str, Dict[int, Any]]:
         return out
 
     @staticmethod
+    @deprecated(version='2.1.29', reason='Replaced by FileLineMap.')
     def decompactify(d: Dict[str, Dict[int, Any]]) -> 'Dict[FileLine, Any]':
         lines = {} # type: Dict['FileLine', Any]
         for fn in d:
@@ -53,8 +59,46 @@ def __str__(self) -> str:
 # see: https://github.com/python/mypy/issues/5446
 if typing.TYPE_CHECKING:
     BaseSet = Set[FileLine]
+    BaseMap = MutableMapping[FileLine, T]
 else:
     BaseSet = collections.abc.Set
+    BaseMap = collections.abc.MutableMapping
+
+
+class FileLineMap(BaseMap):
+    """
+    An efficient implementation of maps indexed by file lines.
+    Note that operations on instances of this class are NOT thread safe.
+    """
+    def __init__(self, contents: Mapping[FileLine, T]) -> None:
+        self.__contents = {}  # type: Dict[str, Dict[int, T]]
+        self.__length = 0
+        for line, val in contents.items():
+            self[line] = val
+
+    def __iter__(self) -> Iterator[FileLine]:
+        for fn in self.__contents:
+            for lineno in self.__contents[fn]:
+                yield FileLine(fn, lineno)
+
+    def __len__(self) -> int:
+        return self.__length
+
+    def __getitem__(self, line: FileLine) -> T:
+        return self.__contents[line.filename][line.num]
+
+    def __setitem__(self, line: FileLine, val: T) -> None:
+        if line.filename not in self.__contents:
+            self.__contents[line.filename] = {}
+        if line.num not in self.__contents[line.filename]:
+            self.__length += 1
+        self.__contents[line.filename][line.num] = val
+
+    def __delitem__(self, line: FileLine) -> None:
+        del self.__contents[line.filename][line.num]
+        if not self.__contents[line.filename]:
+            del self.__contents[line.filename]
+        self.__length -= 1
 
 
 class FileLineSet(BaseSet):

setup.py

@@ -24,11 +24,14 @@
         'tabulate',
         'flask',
         'cement>=2.10.12',
-        'attrs>=17.2.0',
+        'attrs~=19.1.0',
+        'deprecated~=1.2.6',
         'mypy-extensions>=0.3.0',
         'psutil>=5.0.0',
         'chardet>=3.0.4'
     ],
+    setup_requires=['pytest-runner'],
+    tests_require=['pytest'],
     packages=[
         'bugzoo',
         'bugzoo.client',