Remove outdated mentions of runtime support of Python 3.7 (#3896)

[etc/vim.git] / src / black / cache.py

diff --git a/src/black/cache.py b/src/black/cache.py
index bca7279f990bd222259fa9d362c1c18a60b38075..77f66cc34a9132dff8fc0a898d1c3246fa00d4c4 100644 (file)
--- a/src/black/cache.py
+++ b/src/black/cache.py
@@ -1,83 +1,141 @@
 """Caching of formatted files with feature-based invalidation."""
 """Caching of formatted files with feature-based invalidation."""

-
+import hashlib

 import os
 import pickle
 import os
 import pickle

-from pathlib import Path
+import sys

 import tempfile
 import tempfile

-from typing import Dict, Iterable, Set, Tuple
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Dict, Iterable, NamedTuple, Set, Tuple

 
 from platformdirs import user_cache_dir
 
 
 from platformdirs import user_cache_dir
 

-from black.mode import Mode
-

 from _black_version import version as __version__
 from _black_version import version as __version__

+from black.mode import Mode

 
 

+if sys.version_info >= (3, 11):
+    from typing import Self
+else:
+    from typing_extensions import Self

 
 

-# types
-Timestamp = float
-FileSize = int
-CacheInfo = Tuple[Timestamp, FileSize]
-Cache = Dict[str, CacheInfo]

 
 

+class FileData(NamedTuple):
+    st_mtime: float
+    st_size: int
+    hash: str

 
 

-CACHE_DIR = Path(user_cache_dir("black", version=__version__))

 
 

+def get_cache_dir() -> Path:
+    """Get the cache directory used by black.

 
 

-def read_cache(mode: Mode) -> Cache:
-    """Read the cache if it exists and is well formed.
+    Users can customize this directory on all systems using `BLACK_CACHE_DIR`
+    environment variable. By default, the cache directory is the user cache directory
+    under the black application.

 
 

-    If it is not well formed, the call to write_cache later should resolve the issue.
+    This result is immediately set to a constant `black.cache.CACHE_DIR` as to avoid
+    repeated calls.

     """
     """

-    cache_file = get_cache_file(mode)
-    if not cache_file.exists():
-        return {}
+    # NOTE: Function mostly exists as a clean way to test getting the cache directory.
+    default_cache_dir = user_cache_dir("black", version=__version__)
+    cache_dir = Path(os.environ.get("BLACK_CACHE_DIR", default_cache_dir))
+    return cache_dir

 
 

-    with cache_file.open("rb") as fobj:
-        try:
-            cache: Cache = pickle.load(fobj)
-        except (pickle.UnpicklingError, ValueError, IndexError):
-            return {}

 
 

-    return cache
+CACHE_DIR = get_cache_dir()

 
 
 def get_cache_file(mode: Mode) -> Path:
     return CACHE_DIR / f"cache.{mode.get_cache_key()}.pickle"
 
 
 
 
 def get_cache_file(mode: Mode) -> Path:
     return CACHE_DIR / f"cache.{mode.get_cache_key()}.pickle"
 
 

-def get_cache_info(path: Path) -> CacheInfo:
-    """Return the information used to check if a file is already formatted or not."""
-    stat = path.stat()
-    return stat.st_mtime, stat.st_size
-
-
-def filter_cached(cache: Cache, sources: Iterable[Path]) -> Tuple[Set[Path], Set[Path]]:
-    """Split an iterable of paths in `sources` into two sets.
-
-    The first contains paths of files that modified on disk or are not in the
-    cache. The other contains paths to non-modified files.
-    """
-    todo, done = set(), set()
-    for src in sources:
-        res_src = src.resolve()
-        if cache.get(str(res_src)) != get_cache_info(res_src):
-            todo.add(src)
-        else:
-            done.add(src)
-    return todo, done
-
-
-def write_cache(cache: Cache, sources: Iterable[Path], mode: Mode) -> None:
-    """Update the cache file."""
-    cache_file = get_cache_file(mode)
-    try:
-        CACHE_DIR.mkdir(parents=True, exist_ok=True)
-        new_cache = {
-            **cache,
-            **{str(src.resolve()): get_cache_info(src) for src in sources},
-        }
-        with tempfile.NamedTemporaryFile(dir=str(cache_file.parent), delete=False) as f:
-            pickle.dump(new_cache, f, protocol=4)
-        os.replace(f.name, cache_file)
-    except OSError:
-        pass
+@dataclass
+class Cache:
+    mode: Mode
+    cache_file: Path
+    file_data: Dict[str, FileData] = field(default_factory=dict)
+
+    @classmethod
+    def read(cls, mode: Mode) -> Self:
+        """Read the cache if it exists and is well formed.
+
+        If it is not well formed, the call to write later should
+        resolve the issue.
+        """
+        cache_file = get_cache_file(mode)
+        if not cache_file.exists():
+            return cls(mode, cache_file)
+
+        with cache_file.open("rb") as fobj:
+            try:
+                data: Dict[str, Tuple[float, int, str]] = pickle.load(fobj)
+                file_data = {k: FileData(*v) for k, v in data.items()}
+            except (pickle.UnpicklingError, ValueError, IndexError):
+                return cls(mode, cache_file)
+
+        return cls(mode, cache_file, file_data)
+
+    @staticmethod
+    def hash_digest(path: Path) -> str:
+        """Return hash digest for path."""
+
+        data = path.read_bytes()
+        return hashlib.sha256(data).hexdigest()
+
+    @staticmethod
+    def get_file_data(path: Path) -> FileData:
+        """Return file data for path."""
+
+        stat = path.stat()
+        hash = Cache.hash_digest(path)
+        return FileData(stat.st_mtime, stat.st_size, hash)
+
+    def is_changed(self, source: Path) -> bool:
+        """Check if source has changed compared to cached version."""
+        res_src = source.resolve()
+        old = self.file_data.get(str(res_src))
+        if old is None:
+            return True
+
+        st = res_src.stat()
+        if st.st_size != old.st_size:
+            return True
+        if int(st.st_mtime) != int(old.st_mtime):
+            new_hash = Cache.hash_digest(res_src)
+            if new_hash != old.hash:
+                return True
+        return False
+
+    def filtered_cached(self, sources: Iterable[Path]) -> Tuple[Set[Path], Set[Path]]:
+        """Split an iterable of paths in `sources` into two sets.
+
+        The first contains paths of files that modified on disk or are not in the
+        cache. The other contains paths to non-modified files.
+        """
+        changed: Set[Path] = set()
+        done: Set[Path] = set()
+        for src in sources:
+            if self.is_changed(src):
+                changed.add(src)
+            else:
+                done.add(src)
+        return changed, done
+
+    def write(self, sources: Iterable[Path]) -> None:
+        """Update the cache file data and write a new cache file."""
+        self.file_data.update(
+            **{str(src.resolve()): Cache.get_file_data(src) for src in sources}
+        )
+        try:
+            CACHE_DIR.mkdir(parents=True, exist_ok=True)
+            with tempfile.NamedTemporaryFile(
+                dir=str(self.cache_file.parent), delete=False
+            ) as f:
+                # We store raw tuples in the cache because pickling NamedTuples
+                # doesn't work with mypyc on Python 3.8, and because it's faster.
+                data: Dict[str, Tuple[float, int, str]] = {
+                    k: (*v,) for k, v in self.file_data.items()
+                }
+                pickle.dump(data, f, protocol=4)
+            os.replace(f.name, self.cache_file)
+        except OSError:
+            pass