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>
Other changes:
* The `async-https` feature of `bdk_esplora` is no longer default.
* Rename `ObservedAs` to `ChainPosition`.
* Set temporary MSRV to 1.60.0 to compile all workspace members will all
features.
If `BlockId` implements `Anchor`, the meaning is ambiguous. We cannot
tell whether it means the tx is anchors at the block, or whether it also
means the tx is confirmed at that block.
Instead, `ConfirmationHeightAnchor` and `ConfirmationTimeAnchor` structs
are introduced as non-ambiguous `Anchor` implementations.
Additionally, `TxGraph::relevant_heights` is removed because it is also
ambiguous. What heights are deemed relevant? A simpler and more flexible
method `TxGraph::all_anchors` is introduced instead.
`TxGraph::try_get_chain_position` used to always exclude unconfirmed
transactions with last_seen value of 0. However, what is the point of
including a transaction in the graph if it cannot be part of the chain
history? Additionally, maybe sometimes we don't wish to use the
last_seen field at all.
The new behavior will consider unconfirmed transactions with last_seen
of 0.
* `Additions` now implements `Append` and uses `Append` to implement
`append()`.
* `append()` logic enforces that `last_seen` values should only
increase.
* Test written for `append()` with `last_seen` behaviour.
Previously, I have misunderstood the definition of anchor. If a tx is
anchored in a block, it does not necessarily mean it is confirmed in
that block. The tx can be confirmed in an ancestor block of the anchor
block.
With this new definition, we need a new trait `ConfirmationHeight` that
has one method `confirmation_height`. This trait can be used to extend
`Anchor` for those implementations that can give us the exact
conirmation height of a tx (which is useful in most cases).
Another change is to add another variant to the `ObservedAs` enum;
`ObservedAs::ConfirmedImplicit(A)`. If a tx does not have an anchor, but
another tx that spends it has an anchor that in in the best chain, we
can assume that tx is also in the best chain. The logic of
`TxGraph::try_get_chain_position` is also changed to reflect this.
Some methods from `IndexedTxGraph` have been moved to `TxGraph` as they
do not require the `Indexer`. Some `TxGraph` methods have been renamed
for clarity and consistency.
Also more docs are added.
Methods of old structures that return transaction(s) no longer return
`TxNode`, but `Transaction` as done previously.
`TxInGraph` is renamed to `TxNode`, while the internal `TxNode` is
renamed to `TxNodeInternal`.
* Introduce `GraphedTx` struct to access transaction data of graphed
transactions.
* Ability to insert/access anchors and "seen at" values for graphed
transactions.
* `Additions` now records changes to anchors and last_seen_at.
