github.com/matrixorigin/matrixone@v0.7.0/pkg/vm/engine/tae/tables/evictable/deltameta.go (about) 1 // Copyright 2022 Matrix Origin 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package evictable 16 17 import ( 18 "context" 19 "github.com/matrixorigin/matrixone/pkg/objectio" 20 "github.com/matrixorigin/matrixone/pkg/vm/engine/tae/buffer" 21 "github.com/matrixorigin/matrixone/pkg/vm/engine/tae/buffer/base" 22 "github.com/matrixorigin/matrixone/pkg/vm/engine/tae/dataio/blockio" 23 ) 24 25 type DeltaMetaNode struct { 26 *buffer.Node 27 // data 28 objectio.BlockObject 29 // used to load data 30 fs *objectio.ObjectFS 31 deltaloc string 32 } 33 34 func NewDeltaMetaNode(mgr base.INodeManager, metaKey string, fs *objectio.ObjectFS, deltaloc string) *DeltaMetaNode { 35 node := &DeltaMetaNode{ 36 fs: fs, 37 deltaloc: deltaloc, 38 } 39 _, ext, _ := blockio.DecodeMetaLoc(deltaloc) 40 baseNode := buffer.NewNode(node, mgr, metaKey, uint64(ext.OriginSize())) 41 node.Node = baseNode 42 node.LoadFunc = node.onLoad 43 node.UnloadFunc = node.onUnLoad 44 node.HardEvictableFunc = func() bool { return true } 45 return node 46 } 47 48 func (n *DeltaMetaNode) onLoad() { 49 if n.BlockObject != nil { 50 return 51 } 52 // Do IO, fetch columnData 53 reader, err := blockio.NewReader(context.Background(), n.fs, n.deltaloc) 54 if err != nil { 55 panic(err) 56 } 57 meta, err := reader.ReadMeta(nil) 58 if err != nil { 59 panic(err) 60 } 61 n.BlockObject = meta 62 } 63 64 func (n *DeltaMetaNode) onUnLoad() { 65 n.BlockObject = nil 66 }