sync changes with master

dist/ba_data/python/bacommon/transfer.py

@@ -0,0 +1,80 @@
+# Released under the MIT License. See LICENSE for details.
+#
+"""Functionality related to transferring files/data."""
+
+from __future__ import annotations
+
+import os
+from dataclasses import dataclass
+from typing import TYPE_CHECKING, Annotated
+
+from efro.dataclassio import ioprepped, IOAttrs
+
+if TYPE_CHECKING:
+    from pathlib import Path
+
+
+@ioprepped
+@dataclass
+class DirectoryManifestFile:
+    """Describes metadata and hashes for a file in a manifest."""
+    filehash: Annotated[str, IOAttrs('h')]
+    filesize: Annotated[int, IOAttrs('s')]
+
+
+@ioprepped
+@dataclass
+class DirectoryManifest:
+    """Contains a summary of files in a directory."""
+    files: Annotated[dict[str, DirectoryManifestFile], IOAttrs('f')]
+
+    _empty_hash: str | None = None
+
+    @classmethod
+    def create_from_disk(cls, path: Path) -> DirectoryManifest:
+        """Create a manifest from a directory on disk."""
+        import hashlib
+        from concurrent.futures import ThreadPoolExecutor
+
+        pathstr = str(path)
+        paths: list[str] = []
+
+        if path.is_dir():
+            # Build the full list of package-relative paths.
+            for basename, _dirnames, filenames in os.walk(path):
+                for filename in filenames:
+                    fullname = os.path.join(basename, filename)
+                    assert fullname.startswith(pathstr)
+                    paths.append(fullname[len(pathstr) + 1:])
+        elif path.exists():
+            # Just return a single file entry if path is not a dir.
+            paths.append(pathstr)
+
+        def _get_file_info(filepath: str) -> tuple[str, DirectoryManifestFile]:
+            sha = hashlib.sha256()
+            fullfilepath = os.path.join(pathstr, filepath)
+            if not os.path.isfile(fullfilepath):
+                raise Exception(f'File not found: "{fullfilepath}"')
+            with open(fullfilepath, 'rb') as infile:
+                filebytes = infile.read()
+                filesize = len(filebytes)
+                sha.update(filebytes)
+            return (filepath,
+                    DirectoryManifestFile(filehash=sha.hexdigest(),
+                                          filesize=filesize))
+
+        # Now use all procs to hash the files efficiently.
+        cpus = os.cpu_count()
+        if cpus is None:
+            cpus = 4
+        with ThreadPoolExecutor(max_workers=cpus) as executor:
+            return cls(files=dict(executor.map(_get_file_info, paths)))
+
+    @classmethod
+    def get_empty_hash(cls) -> str:
+        """Return the hash for an empty file."""
+        if cls._empty_hash is None:
+            import hashlib
+            sha = hashlib.sha256()
+            cls._empty_hash = sha.hexdigest()
+        return cls._empty_hash