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Diffstat (limited to 'vendor/go.mongodb.org/mongo-driver/bson/doc.go')
| -rw-r--r-- | vendor/go.mongodb.org/mongo-driver/bson/doc.go | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/doc.go b/vendor/go.mongodb.org/mongo-driver/bson/doc.go new file mode 100644 index 000000000..0134006d8 --- /dev/null +++ b/vendor/go.mongodb.org/mongo-driver/bson/doc.go @@ -0,0 +1,141 @@ +// 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 bson is a library for reading, writing, and manipulating BSON. BSON is a binary serialization format used to +// store documents and make remote procedure calls in MongoDB. The BSON specification is located at https://bsonspec.org. +// The BSON library handles marshalling and unmarshalling of values through a configurable codec system. For a description +// of the codec system and examples of registering custom codecs, see the bsoncodec package. +// +// # Raw BSON +// +// The Raw family of types is used to validate and retrieve elements from a slice of bytes. This +// type is most useful when you want do lookups on BSON bytes without unmarshaling it into another +// type. +// +// Example: +// +// var raw bson.Raw = ... // bytes from somewhere +// err := raw.Validate() +// if err != nil { return err } +// val := raw.Lookup("foo") +// i32, ok := val.Int32OK() +// // do something with i32... +// +// # Native Go Types +// +// The D and M types defined in this package can be used to build representations of BSON using native Go types. D is a +// slice and M is a map. For more information about the use cases for these types, see the documentation on the type +// definitions. +// +// Note that a D should not be constructed with duplicate key names, as that can cause undefined server behavior. +// +// Example: +// +// bson.D{{"foo", "bar"}, {"hello", "world"}, {"pi", 3.14159}} +// bson.M{"foo": "bar", "hello": "world", "pi": 3.14159} +// +// When decoding BSON to a D or M, the following type mappings apply when unmarshalling: +// +// 1. BSON int32 unmarshals to an int32. +// 2. BSON int64 unmarshals to an int64. +// 3. BSON double unmarshals to a float64. +// 4. BSON string unmarshals to a string. +// 5. BSON boolean unmarshals to a bool. +// 6. BSON embedded document unmarshals to the parent type (i.e. D for a D, M for an M). +// 7. BSON array unmarshals to a bson.A. +// 8. BSON ObjectId unmarshals to a primitive.ObjectID. +// 9. BSON datetime unmarshals to a primitive.DateTime. +// 10. BSON binary unmarshals to a primitive.Binary. +// 11. BSON regular expression unmarshals to a primitive.Regex. +// 12. BSON JavaScript unmarshals to a primitive.JavaScript. +// 13. BSON code with scope unmarshals to a primitive.CodeWithScope. +// 14. BSON timestamp unmarshals to an primitive.Timestamp. +// 15. BSON 128-bit decimal unmarshals to an primitive.Decimal128. +// 16. BSON min key unmarshals to an primitive.MinKey. +// 17. BSON max key unmarshals to an primitive.MaxKey. +// 18. BSON undefined unmarshals to a primitive.Undefined. +// 19. BSON null unmarshals to nil. +// 20. BSON DBPointer unmarshals to a primitive.DBPointer. +// 21. BSON symbol unmarshals to a primitive.Symbol. +// +// The above mappings also apply when marshalling a D or M to BSON. Some other useful marshalling mappings are: +// +// 1. time.Time marshals to a BSON datetime. +// 2. int8, int16, and int32 marshal to a BSON int32. +// 3. int marshals to a BSON int32 if the value is between math.MinInt32 and math.MaxInt32, inclusive, and a BSON int64 +// otherwise. +// 4. int64 marshals to BSON int64. +// 5. uint8 and uint16 marshal to a BSON int32. +// 6. uint, uint32, and uint64 marshal to a BSON int32 if the value is between math.MinInt32 and math.MaxInt32, +// inclusive, and BSON int64 otherwise. +// 7. BSON null and undefined values will unmarshal into the zero value of a field (e.g. unmarshalling a BSON null or +// undefined value into a string will yield the empty string.). +// +// # Structs +// +// Structs can be marshalled/unmarshalled to/from BSON or Extended JSON. When transforming structs to/from BSON or Extended +// JSON, the following rules apply: +// +// 1. Only exported fields in structs will be marshalled or unmarshalled. +// +// 2. When marshalling a struct, each field will be lowercased to generate the key for the corresponding BSON element. +// For example, a struct field named "Foo" will generate key "foo". This can be overridden via a struct tag (e.g. +// `bson:"fooField"` to generate key "fooField" instead). +// +// 3. An embedded struct field is marshalled as a subdocument. The key will be the lowercased name of the field's type. +// +// 4. A pointer field is marshalled as the underlying type if the pointer is non-nil. If the pointer is nil, it is +// marshalled as a BSON null value. +// +// 5. When unmarshalling, a field of type interface{} will follow the D/M type mappings listed above. BSON documents +// unmarshalled into an interface{} field will be unmarshalled as a D. +// +// The encoding of each struct field can be customized by the "bson" struct tag. +// +// This tag behavior is configurable, and different struct tag behavior can be configured by initializing a new +// bsoncodec.StructCodec with the desired tag parser and registering that StructCodec onto the Registry. By default, JSON tags +// are not honored, but that can be enabled by creating a StructCodec with JSONFallbackStructTagParser, like below: +// +// Example: +// +// structcodec, _ := bsoncodec.NewStructCodec(bsoncodec.JSONFallbackStructTagParser) +// +// The bson tag gives the name of the field, possibly followed by a comma-separated list of options. +// The name may be empty in order to specify options without overriding the default field name. The following options can be used +// to configure behavior: +// +// 1. omitempty: If the omitempty struct tag is specified on a field, the field will not be marshalled if it is set to +// the zero value. Fields with language primitive types such as integers, booleans, and strings are considered empty if +// their value is equal to the zero value for the type (i.e. 0 for integers, false for booleans, and "" for strings). +// Slices, maps, and arrays are considered empty if they are of length zero. Interfaces and pointers are considered +// empty if their value is nil. By default, structs are only considered empty if the struct type implements the +// bsoncodec.Zeroer interface and the IsZero method returns true. Struct fields whose types do not implement Zeroer are +// never considered empty and will be marshalled as embedded documents. +// NOTE: It is recommended that this tag be used for all slice and map fields. +// +// 2. minsize: If the minsize struct tag is specified on a field of type int64, uint, uint32, or uint64 and the value of +// the field can fit in a signed int32, the field will be serialized as a BSON int32 rather than a BSON int64. For other +// types, this tag is ignored. +// +// 3. truncate: If the truncate struct tag is specified on a field with a non-float numeric type, BSON doubles unmarshalled +// into that field will be truncated at the decimal point. For example, if 3.14 is unmarshalled into a field of type int, +// it will be unmarshalled as 3. If this tag is not specified, the decoder will throw an error if the value cannot be +// decoded without losing precision. For float64 or non-numeric types, this tag is ignored. +// +// 4. inline: If the inline struct tag is specified for a struct or map field, the field will be "flattened" when +// marshalling and "un-flattened" when unmarshalling. This means that all of the fields in that struct/map will be +// pulled up one level and will become top-level fields rather than being fields in a nested document. For example, if a +// map field named "Map" with value map[string]interface{}{"foo": "bar"} is inlined, the resulting document will be +// {"foo": "bar"} instead of {"map": {"foo": "bar"}}. There can only be one inlined map field in a struct. If there are +// duplicated fields in the resulting document when an inlined struct is marshalled, the inlined field will be overwritten. +// If there are duplicated fields in the resulting document when an inlined map is marshalled, an error will be returned. +// This tag can be used with fields that are pointers to structs. If an inlined pointer field is nil, it will not be +// marshalled. For fields that are not maps or structs, this tag is ignored. +// +// # Marshalling and Unmarshalling +// +// Manually marshalling and unmarshalling can be done with the Marshal and Unmarshal family of functions. +package bson |