github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/libraries/doltcore/conflict/conflict.go (about)

     1  // Copyright 2019 Dolthub, Inc.
     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 conflict
    16  
    17  import (
    18  	"context"
    19  	"errors"
    20  
    21  	"github.com/dolthub/dolt/go/libraries/doltcore/schema"
    22  	"github.com/dolthub/dolt/go/libraries/doltcore/schema/encoding"
    23  	"github.com/dolthub/dolt/go/store/types"
    24  )
    25  
    26  type ConflictSchema struct {
    27  	Base        schema.Schema
    28  	Schema      schema.Schema
    29  	MergeSchema schema.Schema
    30  }
    31  
    32  func NewConflictSchema(base, sch, mergeSch schema.Schema) ConflictSchema {
    33  	return ConflictSchema{
    34  		Base:        base,
    35  		Schema:      sch,
    36  		MergeSchema: mergeSch,
    37  	}
    38  }
    39  
    40  func ValueFromConflictSchema(ctx context.Context, vrw types.ValueReadWriter, cs ConflictSchema) (types.Value, error) {
    41  	b, err := serializeSchema(ctx, vrw, cs.Base)
    42  	if err != nil {
    43  		return nil, err
    44  	}
    45  
    46  	s, err := serializeSchema(ctx, vrw, cs.Schema)
    47  	if err != nil {
    48  		return nil, err
    49  	}
    50  
    51  	m, err := serializeSchema(ctx, vrw, cs.MergeSchema)
    52  	if err != nil {
    53  		return nil, err
    54  	}
    55  
    56  	return types.NewTuple(vrw.Format(), b, s, m)
    57  }
    58  
    59  func ConflictSchemaFromValue(ctx context.Context, vrw types.ValueReadWriter, v types.Value) (cs ConflictSchema, err error) {
    60  	tup, ok := v.(types.Tuple)
    61  	if !ok {
    62  		err = errors.New("conflict schema value must be types.Struct")
    63  		return ConflictSchema{}, err
    64  	}
    65  
    66  	b, err := tup.Get(0)
    67  	if err != nil {
    68  		return ConflictSchema{}, err
    69  	}
    70  	cs.Base, err = deserializeSchema(ctx, vrw, b)
    71  	if err != nil {
    72  		return ConflictSchema{}, err
    73  	}
    74  
    75  	s, err := tup.Get(1)
    76  	if err != nil {
    77  		return ConflictSchema{}, err
    78  	}
    79  	cs.Schema, err = deserializeSchema(ctx, vrw, s)
    80  	if err != nil {
    81  		return ConflictSchema{}, err
    82  	}
    83  
    84  	m, err := tup.Get(2)
    85  	if err != nil {
    86  		return ConflictSchema{}, err
    87  	}
    88  	cs.MergeSchema, err = deserializeSchema(ctx, vrw, m)
    89  	if err != nil {
    90  		return ConflictSchema{}, err
    91  	}
    92  
    93  	return cs, nil
    94  }
    95  
    96  func serializeSchema(ctx context.Context, vrw types.ValueReadWriter, sch schema.Schema) (types.Ref, error) {
    97  	st, err := encoding.MarshalSchema(ctx, vrw, sch)
    98  	if err != nil {
    99  		return types.Ref{}, err
   100  	}
   101  
   102  	return vrw.WriteValue(ctx, st)
   103  }
   104  
   105  func deserializeSchema(ctx context.Context, vrw types.ValueReadWriter, v types.Value) (schema.Schema, error) {
   106  	r, ok := v.(types.Ref)
   107  	if !ok {
   108  		return nil, errors.New("conflict schemas field value is unexpected type")
   109  	}
   110  
   111  	return encoding.UnmarshalSchemaAtAddr(ctx, vrw, r.TargetHash())
   112  }
   113  
   114  type Conflict struct {
   115  	Base       types.Value
   116  	Value      types.Value
   117  	MergeValue types.Value
   118  }
   119  
   120  func NewConflict(base, value, mergeValue types.Value) Conflict {
   121  	if base == nil {
   122  		base = types.NullValue
   123  	}
   124  	if value == nil {
   125  		value = types.NullValue
   126  	}
   127  	if mergeValue == nil {
   128  		mergeValue = types.NullValue
   129  	}
   130  	return Conflict{base, value, mergeValue}
   131  }
   132  
   133  func ConflictFromTuple(tpl types.Tuple) (Conflict, error) {
   134  	base, err := tpl.Get(0)
   135  
   136  	if err != nil {
   137  		return Conflict{}, err
   138  	}
   139  
   140  	val, err := tpl.Get(1)
   141  
   142  	if err != nil {
   143  		return Conflict{}, err
   144  	}
   145  
   146  	mv, err := tpl.Get(2)
   147  
   148  	if err != nil {
   149  		return Conflict{}, err
   150  	}
   151  	return Conflict{base, val, mv}, nil
   152  }
   153  
   154  func (c Conflict) ToNomsList(vrw types.ValueReadWriter) (types.Tuple, error) {
   155  	return types.NewTuple(vrw.Format(), c.Base, c.Value, c.MergeValue)
   156  }