mirror of
https://mau.dev/maunium/synapse.git
synced 2024-11-12 13:01:34 +01:00
81 lines
3 KiB
Markdown
81 lines
3 KiB
Markdown
# Media Repository
|
|
|
|
*Synapse implementation-specific details for the media repository*
|
|
|
|
The media repository
|
|
* stores avatars, attachments and their thumbnails for media uploaded by local
|
|
users.
|
|
* caches avatars, attachments and their thumbnails for media uploaded by remote
|
|
users.
|
|
* caches resources and thumbnails used for
|
|
[URL previews](development/url_previews.md).
|
|
|
|
All media in Matrix can be identified by a unique
|
|
[MXC URI](https://spec.matrix.org/latest/client-server-api/#matrix-content-mxc-uris),
|
|
consisting of a server name and media ID:
|
|
```
|
|
mxc://<server-name>/<media-id>
|
|
```
|
|
|
|
## Local Media
|
|
Synapse generates 24 character media IDs for content uploaded by local users.
|
|
These media IDs consist of upper and lowercase letters and are case-sensitive.
|
|
Other homeserver implementations may generate media IDs differently.
|
|
|
|
Local media is recorded in the `local_media_repository` table, which includes
|
|
metadata such as MIME types, upload times and file sizes.
|
|
Note that this table is shared by the URL cache, which has a different media ID
|
|
scheme.
|
|
|
|
### Paths
|
|
A file with media ID `aabbcccccccccccccccccccc` and its `128x96` `image/jpeg`
|
|
thumbnail, created by scaling, would be stored at:
|
|
```
|
|
local_content/aa/bb/cccccccccccccccccccc
|
|
local_thumbnails/aa/bb/cccccccccccccccccccc/128-96-image-jpeg-scale
|
|
```
|
|
|
|
## Remote Media
|
|
When media from a remote homeserver is requested from Synapse, it is assigned
|
|
a local `filesystem_id`, with the same format as locally-generated media IDs,
|
|
as described above.
|
|
|
|
A record of remote media is stored in the `remote_media_cache` table, which
|
|
can be used to map remote MXC URIs (server names and media IDs) to local
|
|
`filesystem_id`s.
|
|
|
|
### Paths
|
|
A file from `matrix.org` with `filesystem_id` `aabbcccccccccccccccccccc` and its
|
|
`128x96` `image/jpeg` thumbnail, created by scaling, would be stored at:
|
|
```
|
|
remote_content/matrix.org/aa/bb/cccccccccccccccccccc
|
|
remote_thumbnail/matrix.org/aa/bb/cccccccccccccccccccc/128-96-image-jpeg-scale
|
|
```
|
|
Older thumbnails may omit the thumbnailing method:
|
|
```
|
|
remote_thumbnail/matrix.org/aa/bb/cccccccccccccccccccc/128-96-image-jpeg
|
|
```
|
|
|
|
Note that `remote_thumbnail/` does not have an `s`.
|
|
|
|
## URL Previews
|
|
See [URL Previews](development/url_previews.md) for documentation on the URL preview
|
|
process.
|
|
|
|
When generating previews for URLs, Synapse may download and cache various
|
|
resources, including images. These resources are assigned temporary media IDs
|
|
of the form `yyyy-mm-dd_aaaaaaaaaaaaaaaa`, where `yyyy-mm-dd` is the current
|
|
date and `aaaaaaaaaaaaaaaa` is a random sequence of 16 case-sensitive letters.
|
|
|
|
The metadata for these cached resources is stored in the
|
|
`local_media_repository` and `local_media_repository_url_cache` tables.
|
|
|
|
Resources for URL previews are deleted after a few days.
|
|
|
|
### Paths
|
|
The file with media ID `yyyy-mm-dd_aaaaaaaaaaaaaaaa` and its `128x96`
|
|
`image/jpeg` thumbnail, created by scaling, would be stored at:
|
|
```
|
|
url_cache/yyyy-mm-dd/aaaaaaaaaaaaaaaa
|
|
url_cache_thumbnails/yyyy-mm-dd/aaaaaaaaaaaaaaaa/128-96-image-jpeg-scale
|
|
```
|