Now that we require API key authentication - and therefore security is greatly improved - many users will want to bypass the whitelist in order for the UI to communicate with their remote node. This gives an easy way to do this, without having to override the default whitelist. This boolean can now optionally be added to the default settings.json that is published with new releases, without removing the code's ability to update default whitelist values.
This should fix issue where it would take up to 30 seconds to return for a recent block, and would consume masses of CPU due to having to base58 encode the online accounts signatures. Base58 is very slow and made this API endpoint almost unusable for recent blocks, due to them having untrimmed online accounts signatures.
The procedure outlined in commit f4b06fb is now incorrect. Updated procedure:
- A node can opt into relay mode via the "relayModeEnabled":true setting.
- From this time onwards, they will ask their peers if they ever receive a file list request that they cannot serve by themselves.
- Whenever a peer responds with a file list, it is forwarded on to the originally requesting peer, complete with the peer address of the node that responded. Currently, only the first response is forwarded, but we may later decide to forward all responses.
- As well as forwarding, the relay peer keeps track of the peers that report to be holding hashes (these mappings are held for 30 seconds).
- The originally requesting peer can then make a request to the relay peer for the data file(s).
- The relay peer uses the mapping to forward the request on to another peer, and then forwards the response (i.e. the data file) back to the peer that originally requested the file.
It's best that the source peer's address isn't exposed to the requesting peer. The relay peer can keep track of this mapping itself.
The only real issue with this approach is that we can't use data from ArbitraryDataFileListMessage to update our ArbitraryPeers data, because we can't distinguish between relay peers and hosting peers. But this isn't something we currently do anyway, as we have the ARBITRARY_SIGNATURES message type to take care of updating ArbitraryPeers mappings.
Setting this to false prevents new connections being made to peers that report to have the data that is needed. This is likely only useful for testing, as disabling it in production would reduce the success rate of data retrieval.
This reuses most of the code already in place in the core related to forwarding.
- A node can opt into relay mode via the "relayModeEnabled": true setting
- From this time onwards, they will ask their peers if they ever receive a file list request that they cannot serve by themselves
- Whenever a peer responds with a file list, it is forwarded on to the originally requesting peer, complete with the peer address of the node that responded
- The original peer can then make a request for the data file(s) themselves using a similar approach, specifying the IP address of the ultimate peer so that the relay node knows who to ask. This part is not implemented yet.
This makes them extremely generic, improves filenames, and makes it easier to create custom lists. It doesn't have backwards support, but the lists feature isn't working properly in core 2.1+ anyway.
It turns out that when you call SLEEP_UNTIL_MESSAGE, the AT resumes from that very same line on the next execution. The original code incorrectly assumed that it would execute from the restart position (SET_PCS).
So sleeping can be thought of as pausing one execution half way through, rather than ending it.
This caused a bug, because once the AT receives a transaction it wakes up and resumes from the SLEEP_UNTIL_MESSAGE line, which is after the refund check. Even when it loops back around again it lands on labelRedeemTxnLoop = codeByteBuffer.position(); which is again after the refund check.
For now, the simplest fix is to only sleep when listed. We could have alternatively moved the SLEEP_UNTIL_MESSAGE above GET_BLOCK_TIMESTAMP, but this would still require users to send a random transaction to the AT to trigger the refund. Given that the ATs are only "alive" for 30 minutes once the trade begins, it's simpler to just execute every block and therefore allow the refunds to happen automatically.
Also modified the directory structure of single file resources to make them consistent with multi file resources.
For multi file resources, the original folder is renamed to "data", resulting in a layout such as:
data/file1.txt
data/file2.txt
data/dir1/file3.txt
For single file resources, the file is now moved into a "data" folder, like so:
data/file.txt
This is slightly unconventional, but is appropriate within the context of QDN to keep everything consistent.
This adds support for "unconfirmable" data uploads, which will be useful for Q-Chat. It also handles cases where a transaction is orphaned and then subsequently becomes invalid.
A website must contain one of the following files in its root directory to be considered valid:
index.html
index.htm
default.html
default.htm
home.html
home.htm
This is the first page that is loaded when loading a Qortal-hosted website.
This would happen if a name fills their limit, and then additional names are followed. Alternatively it could happen if the total storage capacity reduces due to disk space being used by other apps. Chunks are deleted at random to reduce the chance of the same chunk being deleted everywhere. Data loss is possible here for transactions that don't have many peers. We'll have to see in practice how much of a problem this is, but it's better than the scenario where one content creator consumes all space on their followers' nodes, leaving no space for other names that are subsequently followed.
This is calculated by the total capacity divided by the number of names the node follows. The idea here is that a single content creator can't upload terabytes of data and consume all the space on their followers' nodes. They can only use a proportion, with equal space given to each followed name. And since the limit is dynamic, following more names reduces the allocation to existing names.
This discourages an incorrect file size being included with a transaction, as the system will reject it and won't even serve it to other peers.
FUTURE: we could introduce some kind of blacklist to track invalid files like this, and avoid repeated attempts to retrieve them. It is okay for now as the system will backoff after a few attempts.
This API call could get quite heavy when large amounts of files are hosted, but it's preferable to maintaining a list in the database. Ideally we need to keep the database generic so that it can be bootstrapped without interfering with the state. We can always add caching and rate limiting if needed.
Chunk hashes are now stored off chain in a metadata file. The metadata file's hash is then included in the transaction.
The main benefits of this approach are:
1. We no longer need to limit the total file size, because adding more chunks doesn't increase the transaction size.
2. This increases the chain capacity by a huge amount - a 512MB file would have previously increased the transaction size by 16kB, whereas it now requires only an additional 32 bytes.
3. We no longer need to use variable difficulty; every transaction is the same size and so the difficulty can be constant no matter how large the files are.
4. Additional metadata (such as title, description, and tags) can ultimately be stored in the metadata file, as apposed to using a separate transaction & resource.
5. There is also scope for adding hashes of individual files into the metadata file, if we ever wanted to allow single files to be requested without having to download and build the entire resource. Although this is unlikely to be available in the short term.
The only real negative is that we now how to fetch the metadata file before we know anything about the chunks for a transaction. This seems to be quite a small trade off by comparison.
Since we're not live yet, there is no backwards support for on-chain hashes, so a new data testchain will be required. This hasn't been tested outside of unit tests yet, so there will likely be several fixes needed before it is stable.
It's not good to be moving files around in a method that should really be read only. This also adds an intentional checkAndRelocateMiscFiles() call rather than relying on a call to isDataLocal() which may be removed at any time.
This would have been caught by the max differences check anyway, but it's a good check to have in place in case we recalibrate or remove the differences check in the future.
Could be improved in the future to return different codes depending on its status (e.g. doesn't exist = 404, 102 for loading, 500 for error, etc), but 404 makes the most sense until that has been developed
- If an identifier parameter is missing or empty, it will return an unfiltered list of all possible identifiers.
- If an identifier is specified, only resources with a matching identifier will be returned.
- If default is set to true, only resources without identifiers will be returned.
Files are now keyed by signature, in the format:
data/si/gn/signature/hash
For times when there is no signature available (i.e. at the time of initial upload), files are keyed by hash, in the format:
data/_misc/ha/sh/hash
Files in the _misc folder are subsequently relocated to a path that is keyed by the resulting signature.
The end result is that chunks are now grouped on the filesystem by signature. This allows more transparency as to what is being hosted, and will also help simplify the reporting and management of local files.
This should allow for a relatively even distribution of chunks, but there is a (currently unavoidable) risk of files with very few mirrors being deleted altogether.
Longer term this could be improved by checking that one of our peers has a file, before it's deleted locally
Nodes will stop proactively storing new data when they reach 90% capacity.
A new "maxStorageCapacity" setting has been added to allow the user to optionally limit the allocated space for this node. Limits are approximate only, not exact.
publicDataEnabled - whether to store decryptable data (default true)
privateDataEnabled - whether to store data without a decryption key (default false)
This doesn't affect minting rewards; it is simply a means of reducing block candidates. There should be no noticeable difference other than hopefully less re-orgs. We can ultimately do a hard fork and increase Blockchain.minAccountLevelToMint but this allows us to test the approach in a lower risk way.
