53 lines
1.6 KiB
Go
53 lines
1.6 KiB
Go
package kv
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import (
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"context"
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"errors"
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)
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var (
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// ErrKeyNotFound is the error returned when the key requested is not found.
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ErrKeyNotFound = errors.New("key not found")
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// ErrTxNotWritable is the error returned when an mutable operation is called during
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// a non-writable transaction.
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ErrTxNotWritable = errors.New("transaction is not writable")
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)
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// Store is an interface for a generic key value store. It is modeled after
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// the boltdb database struct.
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type Store interface {
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// View opens up a transaction that will not write to any data. Implementing interfaces
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// should take care to ensure that all view transactions do not mutate any data.
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View(func(Tx) error) error
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// Update opens up a transaction that will mutate data.
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Update(func(Tx) error) error
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}
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// Tx is a transaction in the store.
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type Tx interface {
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Bucket(b []byte) (Bucket, error)
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Context() context.Context
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WithContext(ctx context.Context)
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}
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// Bucket is the abstraction used to perform get/put/delete/get-many operations
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// in a key value store.
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type Bucket interface {
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Get(key []byte) ([]byte, error)
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Cursor() (Cursor, error)
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// Put should error if the transaction it was called in is not writable.
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Put(key, value []byte) error
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// Delete should error if the transaction it was called in is not writable.
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Delete(key []byte) error
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}
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// Cursor is an abstraction for iterating/ranging through data. A concrete implementation
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// of a cursor can be found in cursor.go.
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type Cursor interface {
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Seek(prefix []byte) (k []byte, v []byte)
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First() (k []byte, v []byte)
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Last() (k []byte, v []byte)
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Next() (k []byte, v []byte)
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Prev() (k []byte, v []byte)
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}
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