Documentation
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Overview ¶
Package schema contains utility functions for relating Go types and Beam Schemas.
Not all Go types can be converted to schemas. This is Go is more expressive than Beam schemas. Just as not all Go types can be serialized, similarly, not all Beam Schemas will have a conversion to Go types, until the correct mechanism exists in the SDK to handle them.
While efforts will be made to have conversions be reversable, this will not be possible in all instances. Eg. Go arrays as fields will be converted to Beam Arrays, but a Beam Array type will map by default to a Go slice.
Index ¶
- func FromType(ot reflect.Type) (*pipepb.Schema, error)
- func Initialize()
- func RegisterLogicalType(lt LogicalType)
- func RegisterLogicalTypeProvider(rt reflect.Type, ltp LogicalTypeProvider)
- func RegisterType(ut reflect.Type)
- func Registered(ut reflect.Type) bool
- func ToType(s *pipepb.Schema) (reflect.Type, error)
- type LogicalType
- type LogicalTypeProvider
- type Registry
- func (r *Registry) FromType(ot reflect.Type) (*pipepb.Schema, error)
- func (r *Registry) RegisterLogicalType(lt LogicalType)
- func (r *Registry) RegisterLogicalTypeProvider(rt reflect.Type, ltp LogicalTypeProvider)
- func (r *Registry) RegisterType(ut reflect.Type)
- func (r *Registry) Registered(ut reflect.Type) bool
- func (r *Registry) ToType(s *pipepb.Schema) (reflect.Type, error)
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func FromType ¶
FromType returns a Beam Schema of the passed in type. Returns an error if the type cannot be converted to a Schema.
func Initialize ¶
func Initialize()
Initialize registered schemas. For use by the beam package at beam.Init time.
func RegisterLogicalType ¶
func RegisterLogicalType(lt LogicalType)
RegisterLogicalType registers a logical type with the beam schema system. A logical type is a type that has distinct representations and storage.
RegisterLogicalType will panic if the storage type of the LogicalType instance is not a valid storage type.
func RegisterLogicalTypeProvider ¶
func RegisterLogicalTypeProvider(rt reflect.Type, ltp LogicalTypeProvider)
RegisterLogicalTypeProvider allows registration of providers for interface types.
func RegisterType ¶
RegisterType converts the type to it's schema representation, and converts it back to a synthetic type so we can map from the synthetic type back to the user type. Recursively registers other named struct types in any component parts.
func Registered ¶
Registered returns whether the given type has been registered with the default schema registry.
Types ¶
type LogicalType ¶
type LogicalType struct {
// contains filtered or unexported fields
}
LogicalType is a mapping between custom Go types, and their schema equivalent storage types.
A LogicalType is a way to define a type that can be stored in a schema field using a known underlying type for storage. The storage type must be comprised of known schema field types, or pre-registered LogicalTypes.
LogicalTypes may not be mutually recursive at any level of indirection. LogicalTypes must map from a Go type to a single Schema Equivalent storage type.
func ToLogicalType ¶
func ToLogicalType(identifier string, goType, storageType reflect.Type) LogicalType
ToLogicalType creates a LogicalType, indicating that there's a conversion from one to the other.
func (*LogicalType) ArgumentType ¶
func (l *LogicalType) ArgumentType() reflect.Type
ArgumentType returns the Go type of the argument for parameterized types.
func (*LogicalType) ArgumentValue ¶
func (l *LogicalType) ArgumentValue() reflect.Value
ArgumentValue returns the Go value of the argument for parameterized types.
func (*LogicalType) GoType ¶
func (l *LogicalType) GoType() reflect.Type
GoType returns the Go type of the logical type. This is the type in a Go field.
func (*LogicalType) ID ¶
func (l *LogicalType) ID() string
ID is a unique identifier for the logical type.
func (*LogicalType) StorageType ¶
func (l *LogicalType) StorageType() reflect.Type
StorageType is the schema equivalent representation of this logical type. The storage type is how the logical type is encoded in bytes, and if the logical type is unknown, can be decoded into a value of this type instead.
type LogicalTypeProvider ¶
LogicalTypeProvider produces a logical type for a given Go type.
If unable to produce a logical type, it instead produces an error. Typically used to handle mapping LogicalTypes from interface types to a concrete implementation. The provider will be passed a type, and will produce an appropriate LogicalType for it.
type Registry ¶
type Registry struct {
// contains filtered or unexported fields
}
Registry retains mappings from go types to Schemas and LogicalTypes.
func NewRegistry ¶
func NewRegistry() *Registry
NewRegistry creates an initialized LogicalTypeRegistry.
func (*Registry) FromType ¶
FromType returns a Beam Schema of the passed in type. Returns an error if the type cannot be converted to a Schema.
func (*Registry) RegisterLogicalType ¶
func (r *Registry) RegisterLogicalType(lt LogicalType)
RegisterLogicalType a single logical type.
func (*Registry) RegisterLogicalTypeProvider ¶
func (r *Registry) RegisterLogicalTypeProvider(rt reflect.Type, ltp LogicalTypeProvider)
RegisterLogicalTypeProvider allows registration of providers for interface types.
func (*Registry) RegisterType ¶
RegisterType converts the type to it's schema representation, and converts it back to a synthetic type so we can map from the synthetic type back to the user type. Recursively registers other named struct types in any component parts.
func (*Registry) Registered ¶
Registered returns whether the given type has been registered with the schema package.
Source Files