feat: Unify Driveのコピー処理を実装

vendor/exifread/core/find_exif.py

@@ -0,0 +1,118 @@
+"""Utilities to find the EXIF offset and endian."""
+
+import struct
+from typing import BinaryIO, Dict, Tuple
+
+from exifread.core.exceptions import ExifNotFound, InvalidExif
+from exifread.core.heic import HEICExifFinder, find_heic_tiff
+from exifread.core.jpeg import find_jpeg_exif
+from exifread.core.jxl import JXLExifFinder
+from exifread.core.utils import ord_
+from exifread.exif_log import get_logger
+
+logger = get_logger()
+
+
+ENDIAN_TYPES: Dict[str, str] = {
+    "I": "Intel",
+    "M": "Motorola",
+    "\x01": "Adobe Ducky",
+    "b": "XMP/Adobe unknown",
+}
+
+
+def get_endian_str(endian_bytes) -> Tuple[str, str]:
+    endian_str = chr(ord_(endian_bytes[0]))
+    return endian_str, ENDIAN_TYPES.get(endian_str, "Unknown")
+
+
+def find_tiff_exif(fh: BinaryIO) -> Tuple[int, bytes]:
+    logger.debug("TIFF format recognized in data[0:2]")
+    fh.seek(0)
+    endian = fh.read(1)
+    fh.read(1)
+    offset = 0
+    return offset, endian
+
+
+def find_webp_exif(fh: BinaryIO) -> Tuple[int, bytes]:
+    logger.debug("WebP format recognized in data[0:4], data[8:12]")
+    # file specification: https://developers.google.com/speed/webp/docs/riff_container
+    data = fh.read(5)
+    if data[0:4] == b"VP8X" and data[4] & 8:
+        # https://developers.google.com/speed/webp/docs/riff_container#extended_file_format
+        fh.seek(13, 1)
+        while True:
+            data = fh.read(8)  # Chunk FourCC (32 bits) and Chunk Size (32 bits)
+            if len(data) != 8:
+                raise InvalidExif("Invalid webp file chunk header.")
+            if data[0:4] == b"EXIF":
+                fh.seek(6, 1)
+                offset = fh.tell()
+                endian = fh.read(1)
+                return offset, endian
+            size = struct.unpack("<L", data[4:8])[0]
+            fh.seek(size, 1)
+    raise ExifNotFound("Webp file does not have exif data.")
+
+
+def find_png_exif(fh: BinaryIO, data: bytes) -> Tuple[int, bytes]:
+    logger.debug("PNG format recognized in data[0:8]=%s", data[:8].hex())
+    fh.seek(8)
+
+    while True:
+        data = fh.read(8)
+        chunk = data[4:8]
+        logger.debug("PNG found chunk %s", chunk.decode("ascii"))
+
+        if chunk in (b"", b"IEND"):
+            break
+        if chunk == b"eXIf":
+            offset = fh.tell()
+            return offset, fh.read(1)
+
+        chunk_size = int.from_bytes(data[:4], "big")
+        fh.seek(fh.tell() + chunk_size + 4)
+
+    raise ExifNotFound("PNG file does not have exif data.")
+
+
+def find_jxl_exif(fh: BinaryIO) -> Tuple[int, bytes]:
+    logger.debug("JPEG XL format recognized in data[0:12]")
+
+    fh.seek(0)
+    jxl = JXLExifFinder(fh)
+    offset, endian = jxl.find_exif()
+    if offset > 0:
+        return offset, endian
+
+    raise ExifNotFound("JPEG XL file does not have exif data.")
+
+
+def determine_type(fh: BinaryIO) -> Tuple[int, bytes, int]:
+    # by default do not fake an EXIF beginning
+    fake_exif = 0
+
+    data = fh.read(12)
+    if data[0:2] in [b"II", b"MM"]:
+        # it's a TIFF file
+        offset, endian = find_tiff_exif(fh)
+    elif data[4:12] in [b"ftypheic", b"ftypavif", b"ftypmif1"]:
+        fh.seek(0)
+        heic = HEICExifFinder(fh)
+        offset, endian = heic.find_exif()
+        if offset == 0:
+            offset, endian = find_heic_tiff(fh)
+            # It's a HEIC file with a TIFF header
+    elif data[0:4] == b"RIFF" and data[8:12] == b"WEBP":
+        offset, endian = find_webp_exif(fh)
+    elif data[0:2] == b"\xff\xd8":
+        # it's a JPEG file
+        offset, endian, fake_exif = find_jpeg_exif(fh, data, fake_exif)
+    elif data[0:8] == b"\x89PNG\r\n\x1a\n":
+        offset, endian = find_png_exif(fh, data)
+    elif data == b"\0\0\0\x0cJXL\x20\x0d\x0a\x87\x0a":
+        offset, endian = find_jxl_exif(fh)
+    else:
+        raise ExifNotFound("File format not recognized.")
+    return offset, endian, fake_exif