forked-synapse/synapse/rest/media/v1/thumbnail_resource.py

# -*- coding: utf-8 -*-
# Copyright 2014 - 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


from ._base import parse_media_id, respond_404, respond_with_file
from twisted.web.resource import Resource
from synapse.http.servlet import parse_string, parse_integer
from synapse.http.server import request_handler, set_cors_headers

from twisted.web.server import NOT_DONE_YET
from twisted.internet import defer

import logging

logger = logging.getLogger(__name__)


class ThumbnailResource(Resource):
    isLeaf = True

    def __init__(self, hs, media_repo):
        Resource.__init__(self)

        self.store = hs.get_datastore()
        self.filepaths = media_repo.filepaths
        self.media_repo = media_repo
        self.dynamic_thumbnails = hs.config.dynamic_thumbnails
        self.server_name = hs.hostname
        self.version_string = hs.version_string
        self.clock = hs.get_clock()

    def render_GET(self, request):
        self._async_render_GET(request)
        return NOT_DONE_YET

    @request_handler()
    @defer.inlineCallbacks
    def _async_render_GET(self, request):
        set_cors_headers(request)
        server_name, media_id, _ = parse_media_id(request)
        width = parse_integer(request, "width")
        height = parse_integer(request, "height")
        method = parse_string(request, "method", "scale")
        m_type = parse_string(request, "type", "image/png")

        if server_name == self.server_name:
            if self.dynamic_thumbnails:
                yield self._select_or_generate_local_thumbnail(
                    request, media_id, width, height, method, m_type
                )
            else:
                yield self._respond_local_thumbnail(
                    request, media_id, width, height, method, m_type
                )
        else:
            if self.dynamic_thumbnails:
                yield self._select_or_generate_remote_thumbnail(
                    request, server_name, media_id,
                    width, height, method, m_type
                )
            else:
                yield self._respond_remote_thumbnail(
                    request, server_name, media_id,
                    width, height, method, m_type
                )

    @defer.inlineCallbacks
    def _respond_local_thumbnail(self, request, media_id, width, height,
                                 method, m_type):
        media_info = yield self.store.get_local_media(media_id)

        if not media_info or media_info["quarantined_by"]:
            respond_404(request)
            return

        thumbnail_infos = yield self.store.get_local_media_thumbnails(media_id)

        if thumbnail_infos:
            thumbnail_info = self._select_thumbnail(
                width, height, method, m_type, thumbnail_infos
            )
            t_width = thumbnail_info["thumbnail_width"]
            t_height = thumbnail_info["thumbnail_height"]
            t_type = thumbnail_info["thumbnail_type"]
            t_method = thumbnail_info["thumbnail_method"]

            if media_info["url_cache"]:
                # TODO: Check the file still exists, if it doesn't we can redownload
                # it from the url `media_info["url_cache"]`
                file_path = self.filepaths.url_cache_thumbnail(
                    media_id, t_width, t_height, t_type, t_method,
                )
            else:
                file_path = self.filepaths.local_media_thumbnail(
                    media_id, t_width, t_height, t_type, t_method,
                )
            yield respond_with_file(request, t_type, file_path)

        else:
            respond_404(request)

    @defer.inlineCallbacks
    def _select_or_generate_local_thumbnail(self, request, media_id, desired_width,
                                            desired_height, desired_method,
                                            desired_type):
        media_info = yield self.store.get_local_media(media_id)

        if not media_info or media_info["quarantined_by"]:
            respond_404(request)
            return

        thumbnail_infos = yield self.store.get_local_media_thumbnails(media_id)
        for info in thumbnail_infos:
            t_w = info["thumbnail_width"] == desired_width
            t_h = info["thumbnail_height"] == desired_height
            t_method = info["thumbnail_method"] == desired_method
            t_type = info["thumbnail_type"] == desired_type

            if t_w and t_h and t_method and t_type:
                if media_info["url_cache"]:
                    # TODO: Check the file still exists, if it doesn't we can redownload
                    # it from the url `media_info["url_cache"]`
                    file_path = self.filepaths.url_cache_thumbnail(
                        media_id, desired_width, desired_height, desired_type,
                        desired_method,
                    )
                else:
                    file_path = self.filepaths.local_media_thumbnail(
                        media_id, desired_width, desired_height, desired_type,
                        desired_method,
                    )
                yield respond_with_file(request, desired_type, file_path)
                return

        logger.debug("We don't have a local thumbnail of that size. Generating")

        # Okay, so we generate one.
        file_path = yield self.media_repo.generate_local_exact_thumbnail(
            media_id, desired_width, desired_height, desired_method, desired_type
        )

        if file_path:
            yield respond_with_file(request, desired_type, file_path)
        else:
            respond_404(request)

    @defer.inlineCallbacks
    def _select_or_generate_remote_thumbnail(self, request, server_name, media_id,
                                             desired_width, desired_height,
                                             desired_method, desired_type):
        media_info = yield self.media_repo.get_remote_media(server_name, media_id)

        thumbnail_infos = yield self.store.get_remote_media_thumbnails(
            server_name, media_id,
        )

        file_id = media_info["filesystem_id"]

        for info in thumbnail_infos:
            t_w = info["thumbnail_width"] == desired_width
            t_h = info["thumbnail_height"] == desired_height
            t_method = info["thumbnail_method"] == desired_method
            t_type = info["thumbnail_type"] == desired_type

            if t_w and t_h and t_method and t_type:
                file_path = self.filepaths.remote_media_thumbnail(
                    server_name, file_id, desired_width, desired_height,
                    desired_type, desired_method,
                )
                yield respond_with_file(request, desired_type, file_path)
                return

        logger.debug("We don't have a local thumbnail of that size. Generating")

        # Okay, so we generate one.
        file_path = yield self.media_repo.generate_remote_exact_thumbnail(
            server_name, file_id, media_id, desired_width,
            desired_height, desired_method, desired_type
        )

        if file_path:
            yield respond_with_file(request, desired_type, file_path)
        else:
            respond_404(request)

    @defer.inlineCallbacks
    def _respond_remote_thumbnail(self, request, server_name, media_id, width,
                                  height, method, m_type):
        thumbnail_infos = yield self.store.get_remote_media_thumbnails(
            server_name, media_id,
        )

        if thumbnail_infos:
            thumbnail_info = self._select_thumbnail(
                width, height, method, m_type, thumbnail_infos
            )
            t_width = thumbnail_info["thumbnail_width"]
            t_height = thumbnail_info["thumbnail_height"]
            t_type = thumbnail_info["thumbnail_type"]
            t_method = thumbnail_info["thumbnail_method"]
            file_id = thumbnail_info["filesystem_id"]
            t_length = thumbnail_info["thumbnail_length"]

            file_path = self.filepaths.remote_media_thumbnail(
                server_name, file_id, t_width, t_height, t_type, t_method,
            )
            yield respond_with_file(request, t_type, file_path, t_length)
        else:
            respond_404(request)

    def _select_thumbnail(self, desired_width, desired_height, desired_method,
                          desired_type, thumbnail_infos):
        d_w = desired_width
        d_h = desired_height

        if desired_method.lower() == "crop":
            info_list = []
            info_list2 = []
            for info in thumbnail_infos:
                t_w = info["thumbnail_width"]
                t_h = info["thumbnail_height"]
                t_method = info["thumbnail_method"]
                if t_method == "crop":
                    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["thumbnail_type"]
                    length_quality = info["thumbnail_length"]
                    if t_w >= d_w or t_h >= d_h:
                        info_list.append((
                            aspect_quality, min_quality, size_quality, type_quality,
                            length_quality, info
                        ))
                    else:
                        info_list2.append((
                            aspect_quality, min_quality, size_quality, type_quality,
                            length_quality, info
                        ))
            if info_list:
                return min(info_list)[-1]
            else:
                return min(info_list2)[-1]
        else:
            info_list = []
            info_list2 = []
            for info in thumbnail_infos:
                t_w = info["thumbnail_width"]
                t_h = info["thumbnail_height"]
                t_method = info["thumbnail_method"]
                size_quality = abs((d_w - t_w) * (d_h - t_h))
                type_quality = desired_type != info["thumbnail_type"]
                length_quality = info["thumbnail_length"]
                if t_method == "scale" and (t_w >= d_w or t_h >= d_h):
                    info_list.append((
                        size_quality, type_quality, length_quality, info
                    ))
                elif t_method == "scale":
                    info_list2.append((
                        size_quality, type_quality, length_quality, info
                    ))
            if info_list:
                return min(info_list)[-1]
            else:
                return min(info_list2)[-1]