We may choose to save on CPU by not compressing individual files, so this allows the network to support that. However it is still using compression by default, to reduce file sizes.
This process could potentially be simplified if we were to modify the structure of the actual zipped data (on the writer side), but this approach is more of a "catch-all" (on the reader side) to support multiple different zip structures, giving us more flexibility. We can still choose to modify the written zip structure if we choose to, which would then cause most of this new code to be skipped.
Note: the filename of a single file is not currently retained; it is renamed to "data" as part of the packaging process. Need to decide if this is okay before we go live.
Thumbnails will be used in order to show logos/screenshots in the list of websites or other resources. Playlists will allow for media apps to group videos/audio/images into collections, e.g. albums.
Until now we have been limited to one data resource per name/service combination. This meant that each name could only have a single website, git repo, image, video, etc, and adding another would overwrite the previous data. The identifier property now allows an optional string to be supplied with each resource, therefore allowing an unlimited amount of resources per name/service combination.
Some examples of what this will allow us to do:
- Create a video library app which holds multiple videos per name
- Same as above but for photos
- Store multiple images against each name, such as an avatar, website thumbnails, video thumbnails, etc. This will be necessary for many "system level" features.
- Attach multiple websites to each name. The default website (with blank/null identifier) would remain the entry point, but other websites could be hosted essentially as subdomains, and then linked from the default site. This also provides a means to go beyond the 500MB website size limit.
Not all of these features will exist initially, but having this identifier included in the protocol layer allows them to be added at any time.
This is generated whenever a data resource cannot be built because it is missing data for at least one layer. Using a custom exception type here enables a few new features:
1. A single build process is now able to request missing data from all the layers that need it. Previously it would only request from the first missing layer and would then give up. This resulted in the user/application having to issue the build command multiple times rather than just once, until all layers had been requested.
2. GET /arbitrary/{service}/{name} will now block the response and retry in the background until the data arrives. This allows it to be used synchronously. Note: we'll need to add a timeout.
3. Loading a website via GET /site/{name} will avoid adding to the failed builds queue when a MissingDataException is thrown, which allows it to be quickly retried. The interface already auto refreshes, allowing the site to load as soon as it's available.
We may need to temporarily hold files for the purpose of viewing, but restrictions need to be in place to avoid these being served to peers of stored for longer than they are needed.
- If storage policy includes "FOLLOWING", only process transactions relating to the followed names.
- If storage policy is "ALL", process all transactions.
- If storage policy is "NONE" or "VIEWED", don't process or prefetch any data.
This is will be used to coordinate all build processes and threads. This way it keeps it separate from the ArbitraryDataManager class, which was getting a bit cluttered.
This causes the build to fail on the first pass due to missing chunks, however it now fails with a message indicating that it should be retried shortly. The website loader is already set up in such a way that it will be automatically retried, during which time the loading screen is shown.
Also added code to remove the resource from the "failed builds list" once the chunks arrive, so that it is able to be rebuilt sooner than the FAILURE_TIMEOUT (currently 5 minutes).
- Don't attempt to fetch data for transactions which fall outside of the storage policy
- Delete files relating to transactions that are no longer within the scope of the storage policy
Note: some additional work needs to be done to ensure that viewed files are deleted when using a storage policy that excludes "VIEWED" content.
This means that no additional structural code is required to add new lists. The only non-generic aspect are the API endpoints - it's best to keep these specific until we have a need for user-created lists.
CalDescent