Don Newton | 379ae25 | 2019-04-01 12:17:06 -0400 | [diff] [blame^] | 1 | // Copyright (C) MongoDB, Inc. 2017-present. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); you may |
| 4 | // not use this file except in compliance with the License. You may obtain |
| 5 | // a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| 6 | |
| 7 | package bsonx |
| 8 | |
| 9 | import ( |
| 10 | "bytes" |
| 11 | "fmt" |
| 12 | |
| 13 | "github.com/mongodb/mongo-go-driver/bson/bsontype" |
| 14 | "github.com/mongodb/mongo-go-driver/x/bsonx/bsoncore" |
| 15 | ) |
| 16 | |
| 17 | // MDoc is an unordered, type safe, concise BSON document representation. This type should not be |
| 18 | // used if you require ordering of values or duplicate keys. |
| 19 | type MDoc map[string]Val |
| 20 | |
| 21 | // ReadMDoc will create a Doc using the provided slice of bytes. If the |
| 22 | // slice of bytes is not a valid BSON document, this method will return an error. |
| 23 | func ReadMDoc(b []byte) (MDoc, error) { |
| 24 | doc := make(MDoc, 0) |
| 25 | err := doc.UnmarshalBSON(b) |
| 26 | if err != nil { |
| 27 | return nil, err |
| 28 | } |
| 29 | return doc, nil |
| 30 | } |
| 31 | |
| 32 | // Copy makes a shallow copy of this document. |
| 33 | func (d MDoc) Copy() MDoc { |
| 34 | d2 := make(MDoc, len(d)) |
| 35 | for k, v := range d { |
| 36 | d2[k] = v |
| 37 | } |
| 38 | return d2 |
| 39 | } |
| 40 | |
| 41 | // Lookup searches the document and potentially subdocuments or arrays for the |
| 42 | // provided key. Each key provided to this method represents a layer of depth. |
| 43 | // |
| 44 | // This method will return an empty Value if they key does not exist. To know if they key actually |
| 45 | // exists, use LookupErr. |
| 46 | func (d MDoc) Lookup(key ...string) Val { |
| 47 | val, _ := d.LookupErr(key...) |
| 48 | return val |
| 49 | } |
| 50 | |
| 51 | // LookupErr searches the document and potentially subdocuments or arrays for the |
| 52 | // provided key. Each key provided to this method represents a layer of depth. |
| 53 | func (d MDoc) LookupErr(key ...string) (Val, error) { |
| 54 | elem, err := d.LookupElementErr(key...) |
| 55 | return elem.Value, err |
| 56 | } |
| 57 | |
| 58 | // LookupElement searches the document and potentially subdocuments or arrays for the |
| 59 | // provided key. Each key provided to this method represents a layer of depth. |
| 60 | // |
| 61 | // This method will return an empty Element if they key does not exist. To know if they key actually |
| 62 | // exists, use LookupElementErr. |
| 63 | func (d MDoc) LookupElement(key ...string) Elem { |
| 64 | elem, _ := d.LookupElementErr(key...) |
| 65 | return elem |
| 66 | } |
| 67 | |
| 68 | // LookupElementErr searches the document and potentially subdocuments for the |
| 69 | // provided key. Each key provided to this method represents a layer of depth. |
| 70 | func (d MDoc) LookupElementErr(key ...string) (Elem, error) { |
| 71 | // KeyNotFound operates by being created where the error happens and then the depth is |
| 72 | // incremented by 1 as each function unwinds. Whenever this function returns, it also assigns |
| 73 | // the Key slice to the key slice it has. This ensures that the proper depth is identified and |
| 74 | // the proper keys. |
| 75 | if len(key) == 0 { |
| 76 | return Elem{}, KeyNotFound{Key: key} |
| 77 | } |
| 78 | |
| 79 | var elem Elem |
| 80 | var err error |
| 81 | val, ok := d[key[0]] |
| 82 | if !ok { |
| 83 | return Elem{}, KeyNotFound{Key: key} |
| 84 | } |
| 85 | |
| 86 | if len(key) == 1 { |
| 87 | return Elem{Key: key[0], Value: val}, nil |
| 88 | } |
| 89 | |
| 90 | switch val.Type() { |
| 91 | case bsontype.EmbeddedDocument: |
| 92 | switch tt := val.primitive.(type) { |
| 93 | case Doc: |
| 94 | elem, err = tt.LookupElementErr(key[1:]...) |
| 95 | case MDoc: |
| 96 | elem, err = tt.LookupElementErr(key[1:]...) |
| 97 | } |
| 98 | default: |
| 99 | return Elem{}, KeyNotFound{Type: val.Type()} |
| 100 | } |
| 101 | switch tt := err.(type) { |
| 102 | case KeyNotFound: |
| 103 | tt.Depth++ |
| 104 | tt.Key = key |
| 105 | return Elem{}, tt |
| 106 | case nil: |
| 107 | return elem, nil |
| 108 | default: |
| 109 | return Elem{}, err // We can't actually hit this. |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | // MarshalBSONValue implements the bsoncodec.ValueMarshaler interface. |
| 114 | // |
| 115 | // This method will never return an error. |
| 116 | func (d MDoc) MarshalBSONValue() (bsontype.Type, []byte, error) { |
| 117 | if d == nil { |
| 118 | // TODO: Should we do this? |
| 119 | return bsontype.Null, nil, nil |
| 120 | } |
| 121 | data, _ := d.MarshalBSON() |
| 122 | return bsontype.EmbeddedDocument, data, nil |
| 123 | } |
| 124 | |
| 125 | // MarshalBSON implements the Marshaler interface. |
| 126 | // |
| 127 | // This method will never return an error. |
| 128 | func (d MDoc) MarshalBSON() ([]byte, error) { return d.AppendMarshalBSON(nil) } |
| 129 | |
| 130 | // AppendMarshalBSON marshals Doc to BSON bytes, appending to dst. |
| 131 | // |
| 132 | // This method will never return an error. |
| 133 | func (d MDoc) AppendMarshalBSON(dst []byte) ([]byte, error) { |
| 134 | idx, dst := bsoncore.ReserveLength(dst) |
| 135 | for k, v := range d { |
| 136 | t, data, _ := v.MarshalBSONValue() // Value.MarshalBSONValue never returns an error. |
| 137 | dst = append(dst, byte(t)) |
| 138 | dst = append(dst, k...) |
| 139 | dst = append(dst, 0x00) |
| 140 | dst = append(dst, data...) |
| 141 | } |
| 142 | dst = append(dst, 0x00) |
| 143 | dst = bsoncore.UpdateLength(dst, idx, int32(len(dst[idx:]))) |
| 144 | return dst, nil |
| 145 | } |
| 146 | |
| 147 | // UnmarshalBSON implements the Unmarshaler interface. |
| 148 | func (d *MDoc) UnmarshalBSON(b []byte) error { |
| 149 | if d == nil { |
| 150 | return ErrNilDocument |
| 151 | } |
| 152 | |
| 153 | if err := bsoncore.Document(b).Validate(); err != nil { |
| 154 | return err |
| 155 | } |
| 156 | |
| 157 | elems, err := bsoncore.Document(b).Elements() |
| 158 | if err != nil { |
| 159 | return err |
| 160 | } |
| 161 | var val Val |
| 162 | for _, elem := range elems { |
| 163 | rawv := elem.Value() |
| 164 | err = val.UnmarshalBSONValue(rawv.Type, rawv.Data) |
| 165 | if err != nil { |
| 166 | return err |
| 167 | } |
| 168 | (*d)[elem.Key()] = val |
| 169 | } |
| 170 | return nil |
| 171 | } |
| 172 | |
| 173 | // Equal compares this document to another, returning true if they are equal. |
| 174 | func (d MDoc) Equal(id IDoc) bool { |
| 175 | switch tt := id.(type) { |
| 176 | case MDoc: |
| 177 | d2 := tt |
| 178 | if len(d) != len(d2) { |
| 179 | return false |
| 180 | } |
| 181 | for key, value := range d { |
| 182 | value2, ok := d2[key] |
| 183 | if !ok { |
| 184 | return false |
| 185 | } |
| 186 | if !value.Equal(value2) { |
| 187 | return false |
| 188 | } |
| 189 | } |
| 190 | case Doc: |
| 191 | unique := make(map[string]struct{}, 0) |
| 192 | for _, elem := range tt { |
| 193 | unique[elem.Key] = struct{}{} |
| 194 | val, ok := d[elem.Key] |
| 195 | if !ok { |
| 196 | return false |
| 197 | } |
| 198 | if !val.Equal(elem.Value) { |
| 199 | return false |
| 200 | } |
| 201 | } |
| 202 | if len(unique) != len(d) { |
| 203 | return false |
| 204 | } |
| 205 | case nil: |
| 206 | return d == nil |
| 207 | default: |
| 208 | return false |
| 209 | } |
| 210 | |
| 211 | return true |
| 212 | } |
| 213 | |
| 214 | // String implements the fmt.Stringer interface. |
| 215 | func (d MDoc) String() string { |
| 216 | var buf bytes.Buffer |
| 217 | buf.Write([]byte("bson.Document{")) |
| 218 | first := true |
| 219 | for key, value := range d { |
| 220 | if !first { |
| 221 | buf.Write([]byte(", ")) |
| 222 | } |
| 223 | fmt.Fprintf(&buf, "%v", Elem{Key: key, Value: value}) |
| 224 | first = false |
| 225 | } |
| 226 | buf.WriteByte('}') |
| 227 | |
| 228 | return buf.String() |
| 229 | } |
| 230 | |
| 231 | func (MDoc) idoc() {} |