// Copyright 2016 PingCAP, 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, // See the License for the specific language governing permissions and // limitations under the License. package table import ( "context" "github.com/pingcap/parser/model" "github.com/pingcap/tidb/kv" "github.com/pingcap/tidb/sessionctx" "github.com/pingcap/tidb/sessionctx/stmtctx" "github.com/pingcap/tidb/types" ) // IndexIterator is the interface for iterator of index data on KV store. type IndexIterator interface { Next() (k []types.Datum, h int64, err error) Close() } // CreateIdxOpt contains the options will be used when creating an index. type CreateIdxOpt struct { Ctx context.Context SkipHandleCheck bool // If true, skip the handle constraint check. SkipCheck bool // If true, skip all the unique indices constraint check. Untouched bool // If true, the index key/value is no need to commit. } // CreateIdxOptFunc is defined for the Create() method of Index interface. // Here is a blog post about how to use this pattern: // https://dave.cheney.net/2014/10/17/functional-options-for-friendly-apis type CreateIdxOptFunc func(*CreateIdxOpt) // SkipHandleCheck is a defined value of CreateIdxFunc. var SkipHandleCheck CreateIdxOptFunc = func(opt *CreateIdxOpt) { opt.SkipHandleCheck = true } // SkipCheck is a defined value of CreateIdxFunc. var SkipCheck CreateIdxOptFunc = func(opt *CreateIdxOpt) { opt.SkipCheck = true } // IndexIsUntouched uses to indicate the index kv is untouched. var IndexIsUntouched CreateIdxOptFunc = func(opt *CreateIdxOpt) { opt.Untouched = true } // WithCtx returns a CreateIdxFunc. // This option is used to pass context.Context. func WithCtx(ctx context.Context) CreateIdxOptFunc { return func(opt *CreateIdxOpt) { opt.Ctx = ctx } } // Index is the interface for index data on KV store. type Index interface { // Meta returns IndexInfo. Meta() *model.IndexInfo // Create supports insert into statement. Create(ctx sessionctx.Context, rm kv.RetrieverMutator, indexedValues []types.Datum, h int64, opts ...CreateIdxOptFunc) (int64, error) // Delete supports delete from statement. Delete(sc *stmtctx.StatementContext, m kv.MemBuffer, indexedValues []types.Datum, h int64) error // Drop supports drop table, drop index statements. Drop(rm kv.RetrieverMutator) error // Exist supports check index exists or not. Exist(sc *stmtctx.StatementContext, rm kv.RetrieverMutator, indexedValues []types.Datum, h int64) (bool, int64, error) // GenIndexKey generates an index key. GenIndexKey(sc *stmtctx.StatementContext, indexedValues []types.Datum, h int64, buf []byte) (key []byte, distinct bool, err error) // Seek supports where clause. Seek(sc *stmtctx.StatementContext, r kv.Retriever, indexedValues []types.Datum) (iter IndexIterator, hit bool, err error) // SeekFirst supports aggregate min and ascend order by. SeekFirst(r kv.Retriever) (iter IndexIterator, err error) // FetchValues fetched index column values in a row. // Param columns is a reused buffer, if it is not nil, FetchValues will fill the index values in it, // and return the buffer, if it is nil, FetchValues will allocate the buffer instead. FetchValues(row []types.Datum, columns []types.Datum) ([]types.Datum, error) }