Files
dolt/go/store/prolly/tree/mutable_map.go

121 lines
3.1 KiB
Go

// Copyright 2021 Dolthub, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package tree
import (
"context"
"github.com/dolthub/dolt/go/store/skip"
)
// MutableMap is a mutable prolly Static with ordered elements.
type MutableMap[K, V ~[]byte, O Ordering[K]] struct {
Edits *skip.List
Static StaticMap[K, V, O]
}
func (m MutableMap[K, V, O]) Put(_ context.Context, key K, value V) error {
m.Edits.Put(key, value)
return nil
}
func (m MutableMap[K, V, O]) Delete(_ context.Context, key K) error {
m.Edits.Put(key, nil)
return nil
}
func (m MutableMap[K, V, O]) Get(ctx context.Context, key K, cb KeyValueFn[K, V]) (err error) {
value, ok := m.Edits.Get(key)
if ok {
if value == nil {
key = nil // there is a pending delete of |key| in |m.Edits|.
}
return cb(key, value)
}
return m.Static.Get(ctx, key, cb)
}
func (m MutableMap[K, V, O]) GetPrefix(ctx context.Context, key K, prefixOrder O, cb KeyValueFn[K, V]) (err error) {
iter := m.Edits.GetIterFromSeekFn(func(k []byte) (advance bool) {
if k != nil { // seek until |k| >= |key|
advance = prefixOrder.Compare(k, key) < 0
}
return
})
k, v := iter.Current()
if k != nil && prefixOrder.Compare(k, key) == 0 {
if v == nil {
k = nil // there is a pending delete of |key| in |m.Edits|.
}
return cb(k, v)
}
return m.Static.GetPrefix(ctx, key, prefixOrder, cb)
}
func (m MutableMap[K, V, O]) Has(ctx context.Context, key K) (present bool, err error) {
value, ok := m.Edits.Get(key)
if ok {
present = value != nil
return
}
return m.Static.Has(ctx, key)
}
func (m MutableMap[K, V, O]) HasPrefix(ctx context.Context, key K, prefixOrder O) (present bool, err error) {
iter := m.Edits.GetIterFromSeekFn(func(k []byte) (advance bool) {
if k != nil { // seek until |k| >= |key|
advance = prefixOrder.Compare(k, key) < 0
}
return
})
k, v := iter.Current()
if k != nil && prefixOrder.Compare(k, key) == 0 {
present = v != nil
return
}
return m.Static.HasPrefix(ctx, key, prefixOrder)
}
func (m MutableMap[K, V, O]) Copy() MutableMap[K, V, O] {
return MutableMap[K, V, O]{
Edits: m.Edits.Copy(),
Static: m.Static,
}
}
func (m MutableMap[K, V, O]) Mutations() MutationIter {
return orderedListIter[K, V]{iter: m.Edits.IterAtStart()}
}
type orderedListIter[K, V ~[]byte] struct {
iter *skip.ListIter
}
var _ MutationIter = &orderedListIter[Item, Item]{}
func (it orderedListIter[K, V]) NextMutation(context.Context) (Item, Item) {
k, v := it.iter.Current()
if k == nil {
return nil, nil
}
it.iter.Advance()
return k, v
}
func (it orderedListIter[K, V]) Close() error {
return nil
}