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ergo/irc/datastore/datastore.go
2023-01-04 05:06:21 -05:00

46 lines
1.2 KiB
Go

// Copyright (c) 2022 Shivaram Lingamneni <slingamn@cs.stanford.edu>
// released under the MIT license
package datastore
import (
"time"
"github.com/ergochat/ergo/irc/utils"
)
type Table uint16
// XXX these are persisted and must remain stable;
// do not reorder, when deleting use _ to ensure that the deleted value is skipped
const (
TableMetadata Table = iota
TableChannels
TableChannelPurges
)
type KV struct {
UUID utils.UUID
Value []byte
}
// A Datastore provides the following abstraction:
// 1. Tables, each keyed on a UUID (the implementation is free to merge
// the table name and the UUID into a single key as long as the rest of
// the contract can be satisfied). Table names are [a-z0-9_]+
// 2. The ability to efficiently enumerate all uuid-value pairs in a table
// 3. Gets, sets, and deletes for individual (table, uuid) keys
type Datastore interface {
Backoff() time.Duration
GetAll(table Table) ([]KV, error)
// This is rarely used because it would typically lead to TOCTOU races
Get(table Table, key utils.UUID) (value []byte, err error)
Set(table Table, key utils.UUID, value []byte, expiration time.Time) error
// Note that deleting a nonexistent key is not considered an error
Delete(table Table, key utils.UUID) error
}