We want to make sure that every database backend has their own
implementation of the View() and Update() methods to make sure any
custom retry/commit/rollback strategies are used even when invoked
through the package-provided View() and Update() functions.
This commit extends the ReadTx (and ReadWriteTx) interface with
ForEachBucket which can be used to iterate through all top level
buckets. This is a missing piece from the walletdb abstraction which
will allow us to iterate all keys in a walletdb opening the possibility
to build generic tools to browse and edit walletdb files regardless of
the underlying driver.
In this commit, we add a new package-level function to emulate the
existing Batch interface for bbolt. We do this via a new super-set
interface which is then checked against in the main implementation of
the Batch method.
In this commit, we add the trio of sequence based methods that bbolt
ships with to the main bucket interface. We do this in order to easily
allow walletdb as is to be slotted into place where bbolt is currently
used, without sacrificing any functionality.
This commit adds the method OnCommit to the ReadWriteTx interface,
making it possible to add closures to be executed once the transaction
is commitited. The method Tx is added to the ReadWriteBucket interface,
for getting the bucket's underlying tx.
The bdb implementation is updated to satisfy the interface change.
Recently the Bucket and Tx interfaces were split into Read and ReadWrite
versions. This commit updates the godoc for the bdb interface
implementation to be consistent with this change.
This changes the database access APIs and each of the "manager"
packages (waddrmgr/wstakemgr) so that transactions are opened (only)
by the wallet package and the namespace buckets that each manager
expects to operate on are passed in as parameters.
This helps improve the atomicity situation as it means that many
calls to these APIs can be grouped together into a single
database transaction.
This change does not attempt to completely fix the "half-processed"
block problem. Mined transactions are still added to the wallet
database under their own database transaction as this is how they are
notified by the consensus JSON-RPC server (as loose transactions,
without the rest of the block that contains them). It will make
updating to a fixed notification model significantly easier, as the
same "manager" APIs can still be used, but grouped into a single
atomic transaction.
This fixes a deadlock where failed transactions due to the namespaces'
bucket being missing would cause deadlocks due to bolt's mmap rwmutex
still being read or write locked (and no way to unlock it, since the
underlying bolt tx was not returned on failure).
This commit implements a new namespaced db package which is intended to
be used be wallet and any sub-packages as its data storage mechanism.
- Key/value store
- Namespace support
- Allows multiple packages to have their own area in the database without
worrying about conflicts
- Read-only and read-write transactions with both manual and managed modes
- Nested buckets
- Supports registration of backend databases
- Comprehensive test coverage
