mirror of
https://github.com/element-hq/synapse
synced 2024-06-28 05:43:30 +00:00
720 lines
26 KiB
Python
720 lines
26 KiB
Python
#
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# This file is licensed under the Affero General Public License (AGPL) version 3.
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#
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# Copyright 2020-2021 The Matrix.org Foundation C.I.C.
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# Copyright 2014-2016 OpenMarket Ltd
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# Copyright (C) 2023 New Vector, Ltd
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Affero General Public License as
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# published by the Free Software Foundation, either version 3 of the
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# License, or (at your option) any later version.
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#
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# See the GNU Affero General Public License for more details:
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# <https://www.gnu.org/licenses/agpl-3.0.html>.
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#
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# Originally licensed under the Apache License, Version 2.0:
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# <http://www.apache.org/licenses/LICENSE-2.0>.
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#
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# [This file includes modifications made by New Vector Limited]
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#
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#
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import logging
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from io import BytesIO
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from types import TracebackType
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from typing import TYPE_CHECKING, List, Optional, Tuple, Type
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from PIL import Image
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from synapse.api.errors import Codes, SynapseError, cs_error
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from synapse.config.repository import THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP
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from synapse.http.server import respond_with_json
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from synapse.http.site import SynapseRequest
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from synapse.logging.opentracing import trace
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from synapse.media._base import (
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FileInfo,
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ThumbnailInfo,
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respond_404,
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respond_with_file,
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respond_with_responder,
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)
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from synapse.media.media_storage import MediaStorage
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if TYPE_CHECKING:
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from synapse.media.media_repository import MediaRepository
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from synapse.server import HomeServer
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logger = logging.getLogger(__name__)
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EXIF_ORIENTATION_TAG = 0x0112
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EXIF_TRANSPOSE_MAPPINGS = {
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2: Image.FLIP_LEFT_RIGHT,
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3: Image.ROTATE_180,
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4: Image.FLIP_TOP_BOTTOM,
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5: Image.TRANSPOSE,
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6: Image.ROTATE_270,
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7: Image.TRANSVERSE,
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8: Image.ROTATE_90,
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}
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class ThumbnailError(Exception):
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"""An error occurred generating a thumbnail."""
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class Thumbnailer:
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FORMATS = {"image/jpeg": "JPEG", "image/png": "PNG"}
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@staticmethod
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def set_limits(max_image_pixels: int) -> None:
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Image.MAX_IMAGE_PIXELS = max_image_pixels
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def __init__(self, input_path: str):
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# Have we closed the image?
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self._closed = False
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try:
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self.image = Image.open(input_path)
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except OSError as e:
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# If an error occurs opening the image, a thumbnail won't be able to
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# be generated.
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raise ThumbnailError from e
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except Image.DecompressionBombError as e:
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# If an image decompression bomb error occurs opening the image,
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# then the image exceeds the pixel limit and a thumbnail won't
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# be able to be generated.
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raise ThumbnailError from e
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self.width, self.height = self.image.size
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self.transpose_method = None
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try:
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# We don't use ImageOps.exif_transpose since it crashes with big EXIF
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#
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# Ignore safety: Pillow seems to acknowledge that this method is
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# "private, experimental, but generally widely used". Pillow 6
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# includes a public getexif() method (no underscore) that we might
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# consider using instead when we can bump that dependency.
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#
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# At the time of writing, Debian buster (currently oldstable)
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# provides version 5.4.1. It's expected to EOL in mid-2022, see
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# https://wiki.debian.org/DebianReleases#Production_Releases
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image_exif = self.image._getexif() # type: ignore
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if image_exif is not None:
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image_orientation = image_exif.get(EXIF_ORIENTATION_TAG)
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assert type(image_orientation) is int # noqa: E721
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self.transpose_method = EXIF_TRANSPOSE_MAPPINGS.get(image_orientation)
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except Exception as e:
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# A lot of parsing errors can happen when parsing EXIF
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logger.info("Error parsing image EXIF information: %s", e)
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@trace
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def transpose(self) -> Tuple[int, int]:
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"""Transpose the image using its EXIF Orientation tag
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Returns:
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A tuple containing the new image size in pixels as (width, height).
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"""
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if self.transpose_method is not None:
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# Safety: `transpose` takes an int rather than e.g. an IntEnum.
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# self.transpose_method is set above to be a value in
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# EXIF_TRANSPOSE_MAPPINGS, and that only contains correct values.
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with self.image:
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self.image = self.image.transpose(self.transpose_method) # type: ignore[arg-type]
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self.width, self.height = self.image.size
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self.transpose_method = None
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# We don't need EXIF any more
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self.image.info["exif"] = None
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return self.image.size
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def aspect(self, max_width: int, max_height: int) -> Tuple[int, int]:
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"""Calculate the largest size that preserves aspect ratio which
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fits within the given rectangle::
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(w_in / h_in) = (w_out / h_out)
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w_out = max(min(w_max, h_max * (w_in / h_in)), 1)
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h_out = max(min(h_max, w_max * (h_in / w_in)), 1)
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Args:
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max_width: The largest possible width.
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max_height: The largest possible height.
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"""
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if max_width * self.height < max_height * self.width:
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return max_width, max((max_width * self.height) // self.width, 1)
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else:
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return max((max_height * self.width) // self.height, 1), max_height
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def _resize(self, width: int, height: int) -> Image.Image:
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# 1-bit or 8-bit color palette images need converting to RGB
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# otherwise they will be scaled using nearest neighbour which
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# looks awful.
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#
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# If the image has transparency, use RGBA instead.
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if self.image.mode in ["1", "L", "P"]:
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if self.image.info.get("transparency", None) is not None:
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with self.image:
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self.image = self.image.convert("RGBA")
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else:
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with self.image:
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self.image = self.image.convert("RGB")
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return self.image.resize((width, height), Image.LANCZOS)
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@trace
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def scale(self, width: int, height: int, output_type: str) -> BytesIO:
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"""Rescales the image to the given dimensions.
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Returns:
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The bytes of the encoded image ready to be written to disk
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"""
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with self._resize(width, height) as scaled:
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return self._encode_image(scaled, output_type)
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@trace
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def crop(self, width: int, height: int, output_type: str) -> BytesIO:
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"""Rescales and crops the image to the given dimensions preserving
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aspect::
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(w_in / h_in) = (w_scaled / h_scaled)
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w_scaled = max(w_out, h_out * (w_in / h_in))
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h_scaled = max(h_out, w_out * (h_in / w_in))
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Args:
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max_width: The largest possible width.
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max_height: The largest possible height.
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Returns:
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The bytes of the encoded image ready to be written to disk
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"""
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if width * self.height > height * self.width:
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scaled_width = width
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scaled_height = (width * self.height) // self.width
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crop_top = (scaled_height - height) // 2
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crop_bottom = height + crop_top
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crop = (0, crop_top, width, crop_bottom)
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else:
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scaled_width = (height * self.width) // self.height
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scaled_height = height
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crop_left = (scaled_width - width) // 2
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crop_right = width + crop_left
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crop = (crop_left, 0, crop_right, height)
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with self._resize(scaled_width, scaled_height) as scaled_image:
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with scaled_image.crop(crop) as cropped:
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return self._encode_image(cropped, output_type)
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def _encode_image(self, output_image: Image.Image, output_type: str) -> BytesIO:
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output_bytes_io = BytesIO()
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fmt = self.FORMATS[output_type]
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if fmt == "JPEG":
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output_image = output_image.convert("RGB")
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output_image.save(output_bytes_io, fmt, quality=80)
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return output_bytes_io
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def close(self) -> None:
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"""Closes the underlying image file.
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Once closed no other functions can be called.
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Can be called multiple times.
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"""
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if self._closed:
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return
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self._closed = True
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# Since we run this on the finalizer then we need to handle `__init__`
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# raising an exception before it can define `self.image`.
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image = getattr(self, "image", None)
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if image is None:
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return
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image.close()
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def __enter__(self) -> "Thumbnailer":
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"""Make `Thumbnailer` a context manager that calls `close` on
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`__exit__`.
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"""
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return self
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def __exit__(
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self,
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type: Optional[Type[BaseException]],
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value: Optional[BaseException],
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traceback: Optional[TracebackType],
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) -> None:
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self.close()
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def __del__(self) -> None:
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# Make sure we actually do close the image, rather than leak data.
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self.close()
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class ThumbnailProvider:
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def __init__(
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self,
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hs: "HomeServer",
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media_repo: "MediaRepository",
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media_storage: MediaStorage,
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):
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self.hs = hs
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self.media_repo = media_repo
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self.media_storage = media_storage
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self.store = hs.get_datastores().main
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self.dynamic_thumbnails = hs.config.media.dynamic_thumbnails
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async def respond_local_thumbnail(
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self,
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request: SynapseRequest,
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media_id: str,
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width: int,
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height: int,
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method: str,
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m_type: str,
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max_timeout_ms: int,
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) -> None:
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media_info = await self.media_repo.get_local_media_info(
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request, media_id, max_timeout_ms
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)
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if not media_info:
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return
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thumbnail_infos = await self.store.get_local_media_thumbnails(media_id)
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await self._select_and_respond_with_thumbnail(
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request,
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width,
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height,
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method,
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m_type,
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thumbnail_infos,
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media_id,
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media_id,
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url_cache=bool(media_info.url_cache),
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server_name=None,
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)
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async def select_or_generate_local_thumbnail(
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self,
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request: SynapseRequest,
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media_id: str,
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desired_width: int,
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desired_height: int,
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desired_method: str,
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desired_type: str,
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max_timeout_ms: int,
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) -> None:
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media_info = await self.media_repo.get_local_media_info(
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request, media_id, max_timeout_ms
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)
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if not media_info:
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return
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thumbnail_infos = await self.store.get_local_media_thumbnails(media_id)
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for info in thumbnail_infos:
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t_w = info.width == desired_width
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t_h = info.height == desired_height
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t_method = info.method == desired_method
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t_type = info.type == desired_type
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if t_w and t_h and t_method and t_type:
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file_info = FileInfo(
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server_name=None,
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file_id=media_id,
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url_cache=bool(media_info.url_cache),
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thumbnail=info,
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)
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responder = await self.media_storage.fetch_media(file_info)
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if responder:
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await respond_with_responder(
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request, responder, info.type, info.length
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)
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return
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logger.debug("We don't have a thumbnail of that size. Generating")
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# Okay, so we generate one.
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file_path = await self.media_repo.generate_local_exact_thumbnail(
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media_id,
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desired_width,
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desired_height,
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desired_method,
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desired_type,
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url_cache=bool(media_info.url_cache),
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)
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if file_path:
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await respond_with_file(request, desired_type, file_path)
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else:
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logger.warning("Failed to generate thumbnail")
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raise SynapseError(400, "Failed to generate thumbnail.")
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async def select_or_generate_remote_thumbnail(
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self,
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request: SynapseRequest,
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server_name: str,
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media_id: str,
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desired_width: int,
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desired_height: int,
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desired_method: str,
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desired_type: str,
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max_timeout_ms: int,
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ip_address: str,
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) -> None:
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media_info = await self.media_repo.get_remote_media_info(
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server_name, media_id, max_timeout_ms, ip_address
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)
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if not media_info:
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respond_404(request)
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return
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thumbnail_infos = await self.store.get_remote_media_thumbnails(
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server_name, media_id
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)
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file_id = media_info.filesystem_id
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for info in thumbnail_infos:
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t_w = info.width == desired_width
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t_h = info.height == desired_height
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t_method = info.method == desired_method
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t_type = info.type == desired_type
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if t_w and t_h and t_method and t_type:
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file_info = FileInfo(
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server_name=server_name,
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file_id=file_id,
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thumbnail=info,
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)
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responder = await self.media_storage.fetch_media(file_info)
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if responder:
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await respond_with_responder(
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request, responder, info.type, info.length
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)
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return
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logger.debug("We don't have a thumbnail of that size. Generating")
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# Okay, so we generate one.
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file_path = await self.media_repo.generate_remote_exact_thumbnail(
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server_name,
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file_id,
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media_id,
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desired_width,
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desired_height,
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desired_method,
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desired_type,
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)
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if file_path:
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await respond_with_file(request, desired_type, file_path)
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else:
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logger.warning("Failed to generate thumbnail")
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raise SynapseError(400, "Failed to generate thumbnail.")
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async def respond_remote_thumbnail(
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self,
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request: SynapseRequest,
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server_name: str,
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media_id: str,
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width: int,
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height: int,
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method: str,
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m_type: str,
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max_timeout_ms: int,
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ip_address: str,
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) -> None:
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# TODO: Don't download the whole remote file
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# We should proxy the thumbnail from the remote server instead of
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# downloading the remote file and generating our own thumbnails.
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media_info = await self.media_repo.get_remote_media_info(
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server_name, media_id, max_timeout_ms, ip_address
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)
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if not media_info:
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return
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thumbnail_infos = await self.store.get_remote_media_thumbnails(
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server_name, media_id
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)
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await self._select_and_respond_with_thumbnail(
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request,
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width,
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height,
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method,
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m_type,
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thumbnail_infos,
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media_id,
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media_info.filesystem_id,
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url_cache=False,
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server_name=server_name,
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)
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async def _select_and_respond_with_thumbnail(
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self,
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request: SynapseRequest,
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desired_width: int,
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desired_height: int,
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desired_method: str,
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desired_type: str,
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thumbnail_infos: List[ThumbnailInfo],
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media_id: str,
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file_id: str,
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url_cache: bool,
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server_name: Optional[str] = None,
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) -> None:
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"""
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Respond to a request with an appropriate thumbnail from the previously generated thumbnails.
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Args:
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request: The incoming request.
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desired_width: The desired width, the returned thumbnail may be larger than this.
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desired_height: The desired height, the returned thumbnail may be larger than this.
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desired_method: The desired method used to generate the thumbnail.
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desired_type: The desired content-type of the thumbnail.
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thumbnail_infos: A list of thumbnail info of candidate thumbnails.
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file_id: The ID of the media that a thumbnail is being requested for.
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url_cache: True if this is from a URL cache.
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server_name: The server name, if this is a remote thumbnail.
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"""
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logger.debug(
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"_select_and_respond_with_thumbnail: media_id=%s desired=%sx%s (%s) thumbnail_infos=%s",
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media_id,
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desired_width,
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desired_height,
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desired_method,
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thumbnail_infos,
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)
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# If `dynamic_thumbnails` is enabled, we expect Synapse to go down a
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# different code path to handle it.
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assert not self.dynamic_thumbnails
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if thumbnail_infos:
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file_info = self._select_thumbnail(
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desired_width,
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desired_height,
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desired_method,
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desired_type,
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thumbnail_infos,
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file_id,
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url_cache,
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server_name,
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)
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if not file_info:
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logger.info("Couldn't find a thumbnail matching the desired inputs")
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respond_404(request)
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return
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# The thumbnail property must exist.
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assert file_info.thumbnail is not None
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responder = await self.media_storage.fetch_media(file_info)
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if responder:
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await respond_with_responder(
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request,
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responder,
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file_info.thumbnail.type,
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file_info.thumbnail.length,
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)
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return
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|
|
# If we can't find the thumbnail we regenerate it. This can happen
|
|
# if e.g. we've deleted the thumbnails but still have the original
|
|
# image somewhere.
|
|
#
|
|
# Since we have an entry for the thumbnail in the DB we a) know we
|
|
# have have successfully generated the thumbnail in the past (so we
|
|
# don't need to worry about repeatedly failing to generate
|
|
# thumbnails), and b) have already calculated that appropriate
|
|
# width/height/method so we can just call the "generate exact"
|
|
# methods.
|
|
|
|
# First let's check that we do actually have the original image
|
|
# still. This will throw a 404 if we don't.
|
|
# TODO: We should refetch the thumbnails for remote media.
|
|
await self.media_storage.ensure_media_is_in_local_cache(
|
|
FileInfo(server_name, file_id, url_cache=url_cache)
|
|
)
|
|
|
|
if server_name:
|
|
await self.media_repo.generate_remote_exact_thumbnail(
|
|
server_name,
|
|
file_id=file_id,
|
|
media_id=media_id,
|
|
t_width=file_info.thumbnail.width,
|
|
t_height=file_info.thumbnail.height,
|
|
t_method=file_info.thumbnail.method,
|
|
t_type=file_info.thumbnail.type,
|
|
)
|
|
else:
|
|
await self.media_repo.generate_local_exact_thumbnail(
|
|
media_id=media_id,
|
|
t_width=file_info.thumbnail.width,
|
|
t_height=file_info.thumbnail.height,
|
|
t_method=file_info.thumbnail.method,
|
|
t_type=file_info.thumbnail.type,
|
|
url_cache=url_cache,
|
|
)
|
|
|
|
responder = await self.media_storage.fetch_media(file_info)
|
|
await respond_with_responder(
|
|
request,
|
|
responder,
|
|
file_info.thumbnail.type,
|
|
file_info.thumbnail.length,
|
|
)
|
|
else:
|
|
# This might be because:
|
|
# 1. We can't create thumbnails for the given media (corrupted or
|
|
# unsupported file type), or
|
|
# 2. The thumbnailing process never ran or errored out initially
|
|
# when the media was first uploaded (these bugs should be
|
|
# reported and fixed).
|
|
# Note that we don't attempt to generate a thumbnail now because
|
|
# `dynamic_thumbnails` is disabled.
|
|
logger.info("Failed to find any generated thumbnails")
|
|
|
|
assert request.path is not None
|
|
respond_with_json(
|
|
request,
|
|
400,
|
|
cs_error(
|
|
"Cannot find any thumbnails for the requested media ('%s'). This might mean the media is not a supported_media_format=(%s) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)"
|
|
% (
|
|
request.path.decode(),
|
|
", ".join(THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP.keys()),
|
|
),
|
|
code=Codes.UNKNOWN,
|
|
),
|
|
send_cors=True,
|
|
)
|
|
|
|
def _select_thumbnail(
|
|
self,
|
|
desired_width: int,
|
|
desired_height: int,
|
|
desired_method: str,
|
|
desired_type: str,
|
|
thumbnail_infos: List[ThumbnailInfo],
|
|
file_id: str,
|
|
url_cache: bool,
|
|
server_name: Optional[str],
|
|
) -> Optional[FileInfo]:
|
|
"""
|
|
Choose an appropriate thumbnail from the previously generated thumbnails.
|
|
|
|
Args:
|
|
desired_width: The desired width, the returned thumbnail may be larger than this.
|
|
desired_height: The desired height, the returned thumbnail may be larger than this.
|
|
desired_method: The desired method used to generate the thumbnail.
|
|
desired_type: The desired content-type of the thumbnail.
|
|
thumbnail_infos: A list of thumbnail infos of candidate thumbnails.
|
|
file_id: The ID of the media that a thumbnail is being requested for.
|
|
url_cache: True if this is from a URL cache.
|
|
server_name: The server name, if this is a remote thumbnail.
|
|
|
|
Returns:
|
|
The thumbnail which best matches the desired parameters.
|
|
"""
|
|
desired_method = desired_method.lower()
|
|
|
|
# The chosen thumbnail.
|
|
thumbnail_info = None
|
|
|
|
d_w = desired_width
|
|
d_h = desired_height
|
|
|
|
if desired_method == "crop":
|
|
# Thumbnails that match equal or larger sizes of desired width/height.
|
|
crop_info_list: List[
|
|
Tuple[int, int, int, bool, Optional[int], ThumbnailInfo]
|
|
] = []
|
|
# Other thumbnails.
|
|
crop_info_list2: List[
|
|
Tuple[int, int, int, bool, Optional[int], ThumbnailInfo]
|
|
] = []
|
|
for info in thumbnail_infos:
|
|
# Skip thumbnails generated with different methods.
|
|
if info.method != "crop":
|
|
continue
|
|
|
|
t_w = info.width
|
|
t_h = info.height
|
|
aspect_quality = abs(d_w * t_h - d_h * t_w)
|
|
min_quality = 0 if d_w <= t_w and d_h <= t_h else 1
|
|
size_quality = abs((d_w - t_w) * (d_h - t_h))
|
|
type_quality = desired_type != info.type
|
|
length_quality = info.length
|
|
if t_w >= d_w or t_h >= d_h:
|
|
crop_info_list.append(
|
|
(
|
|
aspect_quality,
|
|
min_quality,
|
|
size_quality,
|
|
type_quality,
|
|
length_quality,
|
|
info,
|
|
)
|
|
)
|
|
else:
|
|
crop_info_list2.append(
|
|
(
|
|
aspect_quality,
|
|
min_quality,
|
|
size_quality,
|
|
type_quality,
|
|
length_quality,
|
|
info,
|
|
)
|
|
)
|
|
# Pick the most appropriate thumbnail. Some values of `desired_width` and
|
|
# `desired_height` may result in a tie, in which case we avoid comparing on
|
|
# the thumbnail info and pick the thumbnail that appears earlier
|
|
# in the list of candidates.
|
|
if crop_info_list:
|
|
thumbnail_info = min(crop_info_list, key=lambda t: t[:-1])[-1]
|
|
elif crop_info_list2:
|
|
thumbnail_info = min(crop_info_list2, key=lambda t: t[:-1])[-1]
|
|
elif desired_method == "scale":
|
|
# Thumbnails that match equal or larger sizes of desired width/height.
|
|
info_list: List[Tuple[int, bool, int, ThumbnailInfo]] = []
|
|
# Other thumbnails.
|
|
info_list2: List[Tuple[int, bool, int, ThumbnailInfo]] = []
|
|
|
|
for info in thumbnail_infos:
|
|
# Skip thumbnails generated with different methods.
|
|
if info.method != "scale":
|
|
continue
|
|
|
|
t_w = info.width
|
|
t_h = info.height
|
|
size_quality = abs((d_w - t_w) * (d_h - t_h))
|
|
type_quality = desired_type != info.type
|
|
length_quality = info.length
|
|
if t_w >= d_w or t_h >= d_h:
|
|
info_list.append((size_quality, type_quality, length_quality, info))
|
|
else:
|
|
info_list2.append(
|
|
(size_quality, type_quality, length_quality, info)
|
|
)
|
|
# Pick the most appropriate thumbnail. Some values of `desired_width` and
|
|
# `desired_height` may result in a tie, in which case we avoid comparing on
|
|
# the thumbnail info and pick the thumbnail that appears earlier
|
|
# in the list of candidates.
|
|
if info_list:
|
|
thumbnail_info = min(info_list, key=lambda t: t[:-1])[-1]
|
|
elif info_list2:
|
|
thumbnail_info = min(info_list2, key=lambda t: t[:-1])[-1]
|
|
|
|
if thumbnail_info:
|
|
return FileInfo(
|
|
file_id=file_id,
|
|
url_cache=url_cache,
|
|
server_name=server_name,
|
|
thumbnail=thumbnail_info,
|
|
)
|
|
|
|
# No matching thumbnail was found.
|
|
return None
|