mirror of
https://github.com/luxfi/database.git
synced 2026-10-30 15:01:18 +00:00
zeekay
62258f7260
Adds three new public types: - Txn: read/write transaction with Get/Put/Delete/PutWithTTL/iterators - Transactional: optional interface for callback-style Update/View - TTLWriter: optional interface for per-key TTL outside a transaction zapdb wrapper implements both Transactional and TTLWriter. Iterators created against a caller-owned txn (via Update/View) skip Discard on Release so the outer txn lifetime is preserved. Enables migrations of direct zapdb v4 importers (playground, kms, pubsub, mpc/e2e) off of badger-native APIs onto the canonical luxfi/database surface. Existing v1.x callers compile unchanged (the new methods live on a separate optional interface). Adds ErrReadOnlyTxn for View() write attempts. Tests cover commit/rollback, View read-only enforcement, standalone TTL expiry, and TTL inside a transaction.
68 lines
2.4 KiB
Go
68 lines
2.4 KiB
Go
// Copyright (C) 2020-2026, Lux Industries Inc. All rights reserved.
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// See the file LICENSE for licensing terms.
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package database
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import "time"
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// Txn is a single read/write transaction over a Transactional database.
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// Operations within a Txn are atomic: either all are committed on nil
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// return from the callback, or all are rolled back if the callback
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// returns an error.
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//
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// A Txn is not safe for concurrent use across goroutines.
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type Txn interface {
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// Has reports whether key is present in the transaction's view.
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Has(key []byte) (bool, error)
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// Get returns the value for key in the transaction's view.
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// Returns ErrNotFound if the key is not present.
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Get(key []byte) ([]byte, error)
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// Put writes (key, value) within the transaction. Visible only after
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// the enclosing Update commits.
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Put(key, value []byte) error
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// PutWithTTL writes (key, value) with an expiration. A ttl <= 0 means
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// no TTL (equivalent to Put). The exact eviction semantics depend on
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// the backend; readers may see the key briefly after expiry.
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PutWithTTL(key, value []byte, ttl time.Duration) error
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// Delete removes key from the transaction's view.
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Delete(key []byte) error
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// NewIterator returns an iterator over the transaction's view.
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NewIterator() Iterator
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// NewIteratorWithPrefix returns an iterator over keys with the given prefix.
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NewIteratorWithPrefix(prefix []byte) Iterator
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// NewIteratorWithStart returns an iterator starting at start.
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NewIteratorWithStart(start []byte) Iterator
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}
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// Transactional is an optional interface implemented by databases that
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// support callback-style atomic transactions. Callers detect support via
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// type assertion or UnwrapTo[Transactional].
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//
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// Update runs fn in a writable transaction. If fn returns nil, the
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// transaction is committed; if fn returns an error, the transaction is
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// rolled back and the error is returned. Implementations may retry fn on
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// transient conflicts, so fn MUST be idempotent.
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//
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// View runs fn in a read-only transaction. Writes inside fn return
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// ErrReadOnlyTxn.
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type Transactional interface {
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Update(fn func(txn Txn) error) error
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View(fn func(txn Txn) error) error
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}
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// TTLWriter is an optional interface for databases that support per-key
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// TTL outside of a transaction. Callers detect support via type assertion
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// or UnwrapTo[TTLWriter].
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//
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// A ttl <= 0 is equivalent to Put (no expiration).
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type TTLWriter interface {
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PutWithTTL(key, value []byte, ttl time.Duration) error
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}
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