github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/storage/resolver/resolver.go (about)

     1  // Copyright 2022 zGraph Authors. All rights reserved.
     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 resolver
    16  
    17  import (
    18  	"context"
    19  	"sync/atomic"
    20  
    21  	"github.com/cockroachdb/pebble"
    22  	"github.com/vescale/zgraph/internal/logutil"
    23  )
    24  
    25  type resolver struct {
    26  	db     *pebble.DB
    27  	ch     chan Task
    28  	closed atomic.Bool
    29  }
    30  
    31  func newResolver(db *pebble.DB) *resolver {
    32  	return &resolver{
    33  		db: db,
    34  		ch: make(chan Task, 512),
    35  	}
    36  }
    37  
    38  func (r *resolver) run(ctx context.Context) {
    39  	for {
    40  		select {
    41  		case task, ok := <-r.ch:
    42  			if !ok {
    43  				return
    44  			}
    45  			c := len(r.ch)
    46  			tasks := make([]Task, 0, c+1)
    47  			tasks = append(tasks, task)
    48  			if c > 0 {
    49  				for i := 0; i < c; i++ {
    50  					tasks = append(tasks, <-r.ch)
    51  				}
    52  			}
    53  			r.resolve(tasks)
    54  
    55  		case <-ctx.Done():
    56  			return
    57  		}
    58  	}
    59  }
    60  
    61  func (r *resolver) resolve(tasks []Task) {
    62  	batch := r.db.NewBatch()
    63  	for _, task := range tasks {
    64  		var err error
    65  		if task.CommitVer > 0 {
    66  			err = Resolve(r.db, batch, task.Key, task.StartVer, task.CommitVer)
    67  		} else {
    68  			err = Rollback(r.db, batch, task.Key, task.StartVer)
    69  		}
    70  		if err != nil {
    71  			logutil.Errorf("Resolve key failed, key:%v, startVer:%d, commitVer:%d, caused by:%+v",
    72  				task.Key, task.StartVer, task.CommitVer, err)
    73  		}
    74  		if task.Notifier != nil {
    75  			task.Notifier.Notify(err)
    76  		}
    77  	}
    78  	err := batch.Commit(nil)
    79  	if err != nil {
    80  		logutil.Errorf("Commit batch failed: %+v", err)
    81  	}
    82  }
    83  
    84  func (r *resolver) push(tasks ...Task) {
    85  	for _, t := range tasks {
    86  		r.ch <- t
    87  	}
    88  }
    89  
    90  func (r *resolver) close() {
    91  	if r.closed.Swap(true) {
    92  		return
    93  	}
    94  	close(r.ch)
    95  }