github.com/matrixorigin/matrixone@v1.2.0/pkg/sql/colexec/table_function/meta_scan.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 table_function
    16  
    17  import (
    18  	"github.com/matrixorigin/matrixone/pkg/catalog"
    19  	"github.com/matrixorigin/matrixone/pkg/container/batch"
    20  	"github.com/matrixorigin/matrixone/pkg/container/types"
    21  	"github.com/matrixorigin/matrixone/pkg/container/vector"
    22  	"github.com/matrixorigin/matrixone/pkg/sql/colexec"
    23  	"github.com/matrixorigin/matrixone/pkg/vm"
    24  	"github.com/matrixorigin/matrixone/pkg/vm/engine/tae/blockio"
    25  	"github.com/matrixorigin/matrixone/pkg/vm/engine/tae/common"
    26  	"github.com/matrixorigin/matrixone/pkg/vm/process"
    27  )
    28  
    29  func metaScanPrepare(proc *process.Process, arg *Argument) (err error) {
    30  	arg.ctr = new(container)
    31  	arg.ctr.executorsForArgs, err = colexec.NewExpressionExecutorsFromPlanExpressions(proc, arg.Args)
    32  	return err
    33  }
    34  
    35  func metaScanCall(_ int, proc *process.Process, arg *Argument, result *vm.CallResult) (bool, error) {
    36  	var (
    37  		err  error
    38  		rbat *batch.Batch
    39  	)
    40  	bat := result.Batch
    41  	defer func() {
    42  		if err != nil && rbat != nil {
    43  			rbat.Clean(proc.Mp())
    44  		}
    45  	}()
    46  	if bat == nil {
    47  		return true, nil
    48  	}
    49  
    50  	v, err := arg.ctr.executorsForArgs[0].Eval(proc, []*batch.Batch{bat})
    51  	if err != nil {
    52  		return false, err
    53  	}
    54  	uuid := vector.MustFixedCol[types.Uuid](v)[0]
    55  	// get file size
    56  	path := catalog.BuildQueryResultMetaPath(proc.SessionInfo.Account, uuid.ToString())
    57  	// read meta's meta
    58  	reader, err := blockio.NewFileReader(proc.FileService, path)
    59  	if err != nil {
    60  		return false, err
    61  	}
    62  	var idxs []uint16
    63  	for i, name := range catalog.MetaColNames {
    64  		for _, attr := range arg.Attrs {
    65  			if name == attr {
    66  				idxs = append(idxs, uint16(i))
    67  			}
    68  		}
    69  	}
    70  	// read meta's data
    71  	bats, closeCB, err := reader.LoadAllColumns(proc.Ctx, idxs, common.DefaultAllocator)
    72  	if err != nil {
    73  		return false, err
    74  	}
    75  	defer func() {
    76  		if closeCB != nil {
    77  			closeCB()
    78  		}
    79  	}()
    80  	rbat = batch.NewWithSize(len(bats[0].Vecs))
    81  	metaVecs := rbat.Vecs
    82  	for i, vec := range bats[0].Vecs {
    83  		metaVecs[i], err = vec.Dup(proc.Mp())
    84  		if err != nil {
    85  			rbat.Clean(proc.Mp())
    86  			return false, err
    87  		}
    88  	}
    89  	rbat.SetAttributes(catalog.MetaColNames)
    90  	rbat.SetRowCount(1)
    91  	result.Batch = rbat
    92  	return false, nil
    93  }