github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/catalog/patch.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 catalog
    16  
    17  import (
    18  	"github.com/vescale/zgraph/internal/logutil"
    19  	"github.com/vescale/zgraph/parser/model"
    20  )
    21  
    22  // PatchType represents the type of patch.
    23  type PatchType byte
    24  
    25  const (
    26  	PatchTypeCreateGraph PatchType = iota
    27  	PatchTypeCreateLabel
    28  	PatchTypeCreateIndex
    29  	PatchTypeDropGraph
    30  	PatchTypeDropLabel
    31  	PatchTypeDropIndex
    32  	PatchTypeCreateProperties
    33  )
    34  
    35  type (
    36  	// Patch represents patch which contains a DDL change.
    37  	Patch struct {
    38  		Type PatchType
    39  		Data interface{}
    40  	}
    41  
    42  	// PatchLabel represents the payload of patching create/drop label DDL.
    43  	PatchLabel struct {
    44  		GraphID   int64
    45  		LabelInfo *model.LabelInfo
    46  	}
    47  
    48  	// PatchProperties represents the payload of patching create properties
    49  	PatchProperties struct {
    50  		MaxPropID  uint16
    51  		GraphID    int64
    52  		Properties []*model.PropertyInfo
    53  	}
    54  )
    55  
    56  // Apply applies the patch to catalog.
    57  // Note: we need to ensure the DDL changes have applied to persistent storage first.
    58  func (c *Catalog) Apply(patch *Patch) {
    59  	switch patch.Type {
    60  	case PatchTypeCreateGraph:
    61  		data := patch.Data.(*model.GraphInfo)
    62  		graph := NewGraph(data)
    63  		c.mu.Lock()
    64  		c.byName[data.Name.L] = graph
    65  		c.byID[data.ID] = graph
    66  		c.mu.Unlock()
    67  
    68  	case PatchTypeDropGraph:
    69  		data := patch.Data.(*model.GraphInfo)
    70  		c.mu.Lock()
    71  		delete(c.byName, data.Name.L)
    72  		delete(c.byID, data.ID)
    73  		c.mu.Unlock()
    74  
    75  	case PatchTypeCreateLabel:
    76  		data := patch.Data.(*PatchLabel)
    77  		graph := c.GraphByID(data.GraphID)
    78  		if graph == nil {
    79  			logutil.Errorf("Create label on not exists graph. GraphID: %d", data.GraphID)
    80  			return
    81  		}
    82  		graph.CreateLabel(data.LabelInfo)
    83  
    84  	case PatchTypeDropLabel:
    85  		data := patch.Data.(*PatchLabel)
    86  		graph := c.GraphByID(data.GraphID)
    87  		if graph == nil {
    88  			logutil.Errorf("Drop label on not exists graph. GraphID: %d", data.GraphID)
    89  			return
    90  		}
    91  		graph.DropLabel(data.LabelInfo)
    92  
    93  	case PatchTypeCreateProperties:
    94  		data := patch.Data.(*PatchProperties)
    95  		graph := c.GraphByID(data.GraphID)
    96  		graph.SetNextPropID(data.MaxPropID)
    97  		for _, p := range data.Properties {
    98  			graph.CreateProperty(p)
    99  		}
   100  	}
   101  }