fc808ac538
In this commit, we create a new package `kvdb`, which is meant to serve as the basis for any future database abstractions within `lnd`. Rather than directly use the `walletdb` package (which we base off of), we instead use a series of type-aliases to re-type the fundamental types/interfaces of the `walletdb` package. This lets us type `kvdb.RwTx` instead of `walletdb.ReadWriteTransaction` everywhere. Additionally, our usage of type-aliases is also intended to create an easy pathway in the future wherein we can gradually re-defined or re-implement these types to wean off of the `walletdb` package.
91 lines
3.6 KiB
Go
91 lines
3.6 KiB
Go
package kvdb
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import (
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"github.com/btcsuite/btcwallet/walletdb"
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_ "github.com/btcsuite/btcwallet/walletdb/bdb" // Import to register backend.
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)
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// Update opens a database read/write transaction and executes the function f
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// with the transaction passed as a parameter. After f exits, if f did not
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// error, the transaction is committed. Otherwise, if f did error, the
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// transaction is rolled back. If the rollback fails, the original error
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// returned by f is still returned. If the commit fails, the commit error is
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// returned.
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var Update = walletdb.Update
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// View opens a database read transaction and executes the function f with the
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// transaction passed as a parameter. After f exits, the transaction is rolled
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// back. If f errors, its error is returned, not a rollback error (if any
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// occur).
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var View = walletdb.View
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// Batch is identical to the Update call, but it attempts to combine several
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// individual Update transactions into a single write database transaction on
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// an optimistic basis. This only has benefits if multiple goroutines call
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// Batch.
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var Batch = walletdb.Batch
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// Create initializes and opens a database for the specified type. The
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// arguments are specific to the database type driver. See the documentation
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// for the database driver for further details.
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//
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// ErrDbUnknownType will be returned if the database type is not registered.
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var Create = walletdb.Create
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// Backend represents an ACID database. All database access is performed
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// through read or read+write transactions.
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type Backend = walletdb.DB
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// Open opens an existing database for the specified type. The arguments are
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// specific to the database type driver. See the documentation for the database
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// driver for further details.
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//
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// ErrDbUnknownType will be returned if the database type is not registered.
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var Open = walletdb.Open
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// Driver defines a structure for backend drivers to use when they registered
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// themselves as a backend which implements the Backend interface.
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type Driver = walletdb.Driver
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// ReadBucket represents a bucket (a hierarchical structure within the
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// database) that is only allowed to perform read operations.
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type ReadBucket = walletdb.ReadBucket
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// ReadCursor represents a bucket cursor that can be positioned at the start or
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// end of the bucket's key/value pairs and iterate over pairs in the bucket.
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// This type is only allowed to perform database read operations.
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type ReadCursor = walletdb.ReadCursor
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// ReadTx represents a database transaction that can only be used for reads. If
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// a database update must occur, use a RwTx.
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type ReadTx = walletdb.ReadTx
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// RwBucket represents a bucket (a hierarchical structure within the database)
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// that is allowed to perform both read and write operations.
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type RwBucket = walletdb.ReadWriteBucket
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// RwCursor represents a bucket cursor that can be positioned at the start or
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// end of the bucket's key/value pairs and iterate over pairs in the bucket.
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// This abstraction is allowed to perform both database read and write
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// operations.
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type RwCursor = walletdb.ReadWriteCursor
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// ReadWriteTx represents a database transaction that can be used for both
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// reads and writes. When only reads are necessary, consider using a ReadTx
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// instead.
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type RwTx = walletdb.ReadWriteTx
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var (
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// ErrBucketNotFound is returned when trying to access a bucket that
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// has not been created yet.
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ErrBucketNotFound = walletdb.ErrBucketNotFound
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// ErrBucketExists is returned when creating a bucket that already
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// exists.
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ErrBucketExists = walletdb.ErrBucketExists
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// ErrDatabaseNotOpen is returned when a database instance is accessed
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// before it is opened or after it is closed.
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ErrDatabaseNotOpen = walletdb.ErrDbNotOpen
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)
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