| // Copyright (C) MongoDB, Inc. 2017-present. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); you may |
| // not use this file except in compliance with the License. You may obtain |
| // a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 |
| |
| package bsonx |
| |
| import ( |
| "bytes" |
| "errors" |
| "fmt" |
| |
| "github.com/mongodb/mongo-go-driver/bson/bsontype" |
| "github.com/mongodb/mongo-go-driver/x/bsonx/bsoncore" |
| ) |
| |
| // ErrNilDocument indicates that an operation was attempted on a nil *bson.Document. |
| var ErrNilDocument = errors.New("document is nil") |
| |
| // KeyNotFound is an error type returned from the Lookup methods on Document. This type contains |
| // information about which key was not found and if it was actually not found or if a component of |
| // the key except the last was not a document nor array. |
| type KeyNotFound struct { |
| Key []string // The keys that were searched for. |
| Depth uint // Which key either was not found or was an incorrect type. |
| Type bsontype.Type // The type of the key that was found but was an incorrect type. |
| } |
| |
| func (knf KeyNotFound) Error() string { |
| depth := knf.Depth |
| if depth >= uint(len(knf.Key)) { |
| depth = uint(len(knf.Key)) - 1 |
| } |
| |
| if len(knf.Key) == 0 { |
| return "no keys were provided for lookup" |
| } |
| |
| if knf.Type != bsontype.Type(0) { |
| return fmt.Sprintf(`key "%s" was found but was not valid to traverse BSON type %s`, knf.Key[depth], knf.Type) |
| } |
| |
| return fmt.Sprintf(`key "%s" was not found`, knf.Key[depth]) |
| } |
| |
| // Doc is a type safe, concise BSON document representation. |
| type Doc []Elem |
| |
| // ReadDoc will create a Document using the provided slice of bytes. If the |
| // slice of bytes is not a valid BSON document, this method will return an error. |
| func ReadDoc(b []byte) (Doc, error) { |
| doc := make(Doc, 0) |
| err := doc.UnmarshalBSON(b) |
| if err != nil { |
| return nil, err |
| } |
| return doc, nil |
| } |
| |
| // Copy makes a shallow copy of this document. |
| func (d Doc) Copy() Doc { |
| d2 := make(Doc, len(d)) |
| copy(d2, d) |
| return d2 |
| } |
| |
| // Append adds an element to the end of the document, creating it from the key and value provided. |
| func (d Doc) Append(key string, val Val) Doc { |
| return append(d, Elem{Key: key, Value: val}) |
| } |
| |
| // Prepend adds an element to the beginning of the document, creating it from the key and value provided. |
| func (d Doc) Prepend(key string, val Val) Doc { |
| // TODO: should we just modify d itself instead of doing an alloc here? |
| return append(Doc{{Key: key, Value: val}}, d...) |
| } |
| |
| // Set replaces an element of a document. If an element with a matching key is |
| // found, the element will be replaced with the one provided. If the document |
| // does not have an element with that key, the element is appended to the |
| // document instead. |
| func (d Doc) Set(key string, val Val) Doc { |
| idx := d.IndexOf(key) |
| if idx == -1 { |
| return append(d, Elem{Key: key, Value: val}) |
| } |
| d[idx] = Elem{Key: key, Value: val} |
| return d |
| } |
| |
| // IndexOf returns the index of the first element with a key of key, or -1 if no element with a key |
| // was found. |
| func (d Doc) IndexOf(key string) int { |
| for i, e := range d { |
| if e.Key == key { |
| return i |
| } |
| } |
| return -1 |
| } |
| |
| // Delete removes the element with key if it exists and returns the updated Doc. |
| func (d Doc) Delete(key string) Doc { |
| idx := d.IndexOf(key) |
| if idx == -1 { |
| return d |
| } |
| return append(d[:idx], d[idx+1:]...) |
| } |
| |
| // Lookup searches the document and potentially subdocuments or arrays for the |
| // provided key. Each key provided to this method represents a layer of depth. |
| // |
| // This method will return an empty Value if they key does not exist. To know if they key actually |
| // exists, use LookupErr. |
| func (d Doc) Lookup(key ...string) Val { |
| val, _ := d.LookupErr(key...) |
| return val |
| } |
| |
| // LookupErr searches the document and potentially subdocuments or arrays for the |
| // provided key. Each key provided to this method represents a layer of depth. |
| func (d Doc) LookupErr(key ...string) (Val, error) { |
| elem, err := d.LookupElementErr(key...) |
| return elem.Value, err |
| } |
| |
| // LookupElement searches the document and potentially subdocuments or arrays for the |
| // provided key. Each key provided to this method represents a layer of depth. |
| // |
| // This method will return an empty Element if they key does not exist. To know if they key actually |
| // exists, use LookupElementErr. |
| func (d Doc) LookupElement(key ...string) Elem { |
| elem, _ := d.LookupElementErr(key...) |
| return elem |
| } |
| |
| // LookupElementErr searches the document and potentially subdocuments for the |
| // provided key. Each key provided to this method represents a layer of depth. |
| func (d Doc) LookupElementErr(key ...string) (Elem, error) { |
| // KeyNotFound operates by being created where the error happens and then the depth is |
| // incremented by 1 as each function unwinds. Whenever this function returns, it also assigns |
| // the Key slice to the key slice it has. This ensures that the proper depth is identified and |
| // the proper keys. |
| if len(key) == 0 { |
| return Elem{}, KeyNotFound{Key: key} |
| } |
| |
| var elem Elem |
| var err error |
| idx := d.IndexOf(key[0]) |
| if idx == -1 { |
| return Elem{}, KeyNotFound{Key: key} |
| } |
| |
| elem = d[idx] |
| if len(key) == 1 { |
| return elem, nil |
| } |
| |
| switch elem.Value.Type() { |
| case bsontype.EmbeddedDocument: |
| switch tt := elem.Value.primitive.(type) { |
| case Doc: |
| elem, err = tt.LookupElementErr(key[1:]...) |
| case MDoc: |
| elem, err = tt.LookupElementErr(key[1:]...) |
| } |
| default: |
| return Elem{}, KeyNotFound{Type: elem.Value.Type()} |
| } |
| switch tt := err.(type) { |
| case KeyNotFound: |
| tt.Depth++ |
| tt.Key = key |
| return Elem{}, tt |
| case nil: |
| return elem, nil |
| default: |
| return Elem{}, err // We can't actually hit this. |
| } |
| } |
| |
| // MarshalBSONValue implements the bsoncodec.ValueMarshaler interface. |
| // |
| // This method will never return an error. |
| func (d Doc) MarshalBSONValue() (bsontype.Type, []byte, error) { |
| if d == nil { |
| // TODO: Should we do this? |
| return bsontype.Null, nil, nil |
| } |
| data, _ := d.MarshalBSON() |
| return bsontype.EmbeddedDocument, data, nil |
| } |
| |
| // MarshalBSON implements the Marshaler interface. |
| // |
| // This method will never return an error. |
| func (d Doc) MarshalBSON() ([]byte, error) { return d.AppendMarshalBSON(nil) } |
| |
| // AppendMarshalBSON marshals Doc to BSON bytes, appending to dst. |
| // |
| // This method will never return an error. |
| func (d Doc) AppendMarshalBSON(dst []byte) ([]byte, error) { |
| idx, dst := bsoncore.ReserveLength(dst) |
| for _, elem := range d { |
| t, data, _ := elem.Value.MarshalBSONValue() // Value.MarshalBSONValue never returns an error. |
| dst = append(dst, byte(t)) |
| dst = append(dst, elem.Key...) |
| dst = append(dst, 0x00) |
| dst = append(dst, data...) |
| } |
| dst = append(dst, 0x00) |
| dst = bsoncore.UpdateLength(dst, idx, int32(len(dst[idx:]))) |
| return dst, nil |
| } |
| |
| // UnmarshalBSON implements the Unmarshaler interface. |
| func (d *Doc) UnmarshalBSON(b []byte) error { |
| if d == nil { |
| return ErrNilDocument |
| } |
| |
| if err := bsoncore.Document(b).Validate(); err != nil { |
| return err |
| } |
| |
| elems, err := bsoncore.Document(b).Elements() |
| if err != nil { |
| return err |
| } |
| var val Val |
| for _, elem := range elems { |
| rawv := elem.Value() |
| err = val.UnmarshalBSONValue(rawv.Type, rawv.Data) |
| if err != nil { |
| return err |
| } |
| *d = d.Append(elem.Key(), val) |
| } |
| return nil |
| } |
| |
| // UnmarshalBSONValue implements the bson.ValueUnmarshaler interface. |
| func (d *Doc) UnmarshalBSONValue(t bsontype.Type, data []byte) error { |
| if t != bsontype.EmbeddedDocument { |
| return fmt.Errorf("cannot unmarshal %s into a bsonx.Doc", t) |
| } |
| return d.UnmarshalBSON(data) |
| } |
| |
| // Equal compares this document to another, returning true if they are equal. |
| func (d Doc) Equal(id IDoc) bool { |
| switch tt := id.(type) { |
| case Doc: |
| d2 := tt |
| if len(d) != len(d2) { |
| return false |
| } |
| for idx := range d { |
| if !d[idx].Equal(d2[idx]) { |
| return false |
| } |
| } |
| case MDoc: |
| unique := make(map[string]struct{}, 0) |
| for _, elem := range d { |
| unique[elem.Key] = struct{}{} |
| val, ok := tt[elem.Key] |
| if !ok { |
| return false |
| } |
| if !val.Equal(elem.Value) { |
| return false |
| } |
| } |
| if len(unique) != len(tt) { |
| return false |
| } |
| case nil: |
| return d == nil |
| default: |
| return false |
| } |
| |
| return true |
| } |
| |
| // String implements the fmt.Stringer interface. |
| func (d Doc) String() string { |
| var buf bytes.Buffer |
| buf.Write([]byte("bson.Document{")) |
| for idx, elem := range d { |
| if idx > 0 { |
| buf.Write([]byte(", ")) |
| } |
| fmt.Fprintf(&buf, "%v", elem) |
| } |
| buf.WriteByte('}') |
| |
| return buf.String() |
| } |
| |
| func (Doc) idoc() {} |