`merge_chains` now returns a tuple of the resultant checkpoint AND
changeset. This is arguably a more readable/understandable setup.
To do this, we had to create `CheckPoint::apply_changeset` which is kept
as a private method.
Thank you @ValuedMammal for the suggestion.
Co-authored-by: valuedvalued mammal <valuedmammal@protonmail.com>
The intention is to remove the `Update::introduce_older_blocks`
parameter and update the local chain directly with `CheckPoint`.
This simplifies the API and there is a way to do this efficiently.
I don't think this was ever used. The only possible usecase I can think
of is for tests, but I don't think that is a strong enough incentive for
us to keep this.
These methods allow us to query for checkpoints contained within the
linked list by height and height range. This is useful to determine
checkpoints to fetch for chain sources without having to refer back to
the `LocalChain`.
Currently this is not implemented efficiently, but in the future, we
will change `CheckPoint` to use a skip list structure.
* `CheckPoint::from_header` allows us to construct a checkpoint from
block header.
* `CheckPoint::into_update` transforms the cp into a
`local_chain::Update`.
Thank you @vladimirfomene for these suggestions.
* Rename `LocalUpdate::keychain` to `LocalUpdate::last_active_indices`.
* Change docs for `CheckPoint` to be more descriptive.
* Fix incorrect logic in `update_local_chain` for `EsploraExt` and
`EsploraAsyncExt`.
Shout out to @LLFourn for these suggestions.
* Improve/fix `LocalChain` documentation
* Refactor `TxGraph::missing_blocks` to make it more explicit that
`last_block` has state.
* `update_local_chain` method of `EsploraExt` and `EsploraAsyncExt` now
returns a `local_chain::Update` instead of just a `CheckPoint`.
This commit changes the `LocalChain` implementation to have blocks
stored as a linked-list. This allows the data-src thread to hold a
shared ref to a single checkpoint and have access to the whole history
of checkpoints without cloning or keeping a lock on `LocalChain`.
The APIs of `bdk::Wallet`, `esplora` and `electrum` are also updated to
reflect these changes. Note that the `esplora` crate is rewritten to
anchor txs in the confirmation block (using the esplora API's tx status
block_hash). This guarantees 100% consistency between anchor blocks and
their transactions (instead of anchoring txs to the latest tip).
`ExploraExt` now has separate methods for updating the `TxGraph` and
`LocalChain`.
A new method `TxGraph::missing_blocks` is introduced for finding
"floating anchors" of a `TxGraph` update (given a chain).
Additional changes:
* `test_local_chain.rs` is refactored to make test cases easier to
write. Additional tests are also added.
* Examples are updated.
* Fix `tempfile` dev dependency of `bdk_file_store` to work with MSRV
Co-authored-by: LLFourn <lloyd.fourn@gmail.com>
* Introduce `LocalChain::inner` method to get the inner map of block
height to hash.
* Replace `LocalChain::get_block` (which outputted `BlockId`, thus able
to return invalid representation) with `get_blockhash` that just
returns a `BlockHash`.
* Remove `TODO` comments that should be github tickets.
* Remove `chain_oracle::CacheBackend` for now as it is not used.
* `SparseChain` does not need to implement `ChainOracle`.
* Remove filter predicate for `list..` methods of `TxGraph` and
`IndexedTxGraph` as this is premature optimisation.
* `Append` can be implemented for all `BTreeMap`s and `BTreeSet`s,
instead of only `local_chain::ChangeSet`.
This is mostly copying over the relevant tests from `SparseChain`.
Changes are made to `local_chain::ChangeSet` to re-add the ability to
remove blocks.
The problem with the previous `ChainOracle` interface is that it had no
guarantee for consistency. For example, a block deemed to be part of the
"best chain" can be reorged out. So when `ChainOracle` is called
multiple times for an operation (such as getting the UTXO set), the
returned result may be inconsistent.
This PR changes `ChainOracle::is_block_in_chain` to take in another
input `static_block`, ensuring `block` is an ancestor of `static_block`.
Thus, if `static_block` is consistent across the operation, the result
will be consistent also.
`is_block_in_chain` now returns `Option<bool>`. The `None` case means
that the oracle implementation cannot determine whether block is an
ancestor of static block. `IndexedTxGraph::list_chain_txouts` handles
this case by checking child spends that are in chain, and if so, the
parent tx must be in chain too.
* Instead of implementing `ChainPosition` for `ObservedIn<BlockId>` to
use `FullTxOut` methods (`is_spendable_at` and `is_mature`), we create
alternative versions of those methods that require bounds with `Anchor`.
This removes all `ObservedIn<A>: ChainPosition` bounds for methods of
`IndexedTxGraph`.
* Various improvements to comments and names.
Introduce `chain_oracle::Cache` which is a cache for requests to the
chain oracle. `ChainOracle` has also been moved to the `chain_oracle`
module.
Introduce `get_tip_in_best_chain` method to the `ChainOracle` trait.
This allows for guaranteeing that chain state can be consistent across
operations with `IndexedTxGraph`.
