Commit Graph

23 Commits

Author SHA1 Message Date
Joe Tsai
2f68590cf0 reflect/prototype: use proto2 syntax for standalone extension fields
Without resolving the question of whether an extension field is always proto2
or sometimes proto3, just make it impossible to construct a standalone extension
field of the proto3 syntax.

By dropping the syntax field from the constructor, we can just assume that the
syntax is always proto2. There is no benefit for creating a proto3 standalone
extension, so there is no loss of functionality.

In the unlikely future where there needs to be distinction, we can add the field
back into the descriptor. The zero value of protoreflect.Syntax is invalid,
so we can determine if the user did not set that field.

Change-Id: Ie93fa55de96f29553fb04ff6649bbea79a144407
Reviewed-on: https://go-review.googlesource.com/c/144279
Reviewed-by: Damien Neil <dneil@google.com>
2018-10-24 17:35:49 +00:00
Damien Neil
204f1c0ad8 reflect/protoreflect: add Descriptor.Options method
Add a method to fetch descriptor options. Since options are proto
messages (e.g., google.protobuf.FieldOptions), and proto message
packages depend on the protoreflect package, returning the actual option
type would cause a dependency cycle. Instead, we return an interface
value which can be type asserted to the appropriate concrete type.

Add options support to the prototype package.

Some of the prototype constructors included fields (such as
Field.IsPacked) which represent information from the options
(such as google.protobuf.FieldOptions.packed). To avoid confusion about
the canonical source of information, drop these fields in favor of the
options.

Drop the unimplemented Descriptor.DescriptorOptionsProto.

Change-Id: I66579b6a7d10d99eb6977402a247306a78913e74
Reviewed-on: https://go-review.googlesource.com/c/144277
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-10-23 23:44:11 +00:00
Joe Tsai
90fe996bd1 internal/impl: derive descriptors for legacy enums and messages
In order for the v2 rollout to be as seamless as possible, we need to support
the situation where a v2 message depends on some other generated v1 message that
may be stale and does not support the v2 API. In such a situation, there needs
to be some way to wrap a legacy message or enum in such a way that it satisfies
the v2 API.

This wrapping is comprised of two parts:
1) Deriving an enum or message descriptor
2) Providing an reflection implementation for messages

This CL addresses part 1 (while part 2 has already been partially implemented,
since the implementation applies to both v1 and v2).

To derive the enum and message descriptor we rely on a mixture of parsing the
raw descriptor proto and also introspection on the fields in the message.
Methods for obtaining the raw descriptor protos were added in February, 2016,
and so has not always been available. For that reason, we attempt to derive
as much information from the Go type as possible.

As part of this change, we modify prototype to be able to create multiple
standalone messages as a set. This is needed since cyclic dependencies is allowed
between messages within a single proto file.

Change-Id: I71aaf5f977faf9fba03c370b1ee17b3758ce60a6
Reviewed-on: https://go-review.googlesource.com/c/143539
Reviewed-by: Damien Neil <dneil@google.com>
2018-10-22 17:18:39 +00:00
Joe Tsai
3903b218df reflect/protoreflect: remove List method
Remove List from KnownFields, UnknownFields, ExtensionFieldTypes, and Map.

Rationale:
* Each of those interfaces already have a Range method, which provides
a superset of the functionality of List. Furthermore, Range is more expressive
as it allows you to terminate iteration and provides both keys and values.
* List must always allocate a slice and populates it.
* Range is allocation free in some cases. For example, if you simply wanted to
iterate over all the populated fields to clear them, there is no need for a
closure, so a static version of the function can be directly referenced
(i.e., there is no need to create a stub function header that references the
closed-over variables).
* In the cases where a closure is needed, the allocation cost is O(1) since
there are a finite number of variables being closed over.
* In highly performance sensitive cases, the closured function could close over
a struct, such that the function and struct are stored in a sync.Pool when not
in use. For example:

	type MapLister struct {
		Entries []struct{K MapKey; V Value}
		f       func(MapKey, Value) true
	}
	func (m *MapLister) Ranger() func(MapKey, Value) bool {
		if m.f != nil {
			m.f = func(k MapKey, v Value) bool {
				m.Entries = append(m.Entries, ...)
				return true
			}
		}
		m.Entries = m.Entries[:0]
		return m.f
	}

The main benefit of List is the ease of use:

	for _, num := range knownFields.List() {
		...
	}

as opposed to:

	knownFields.Range(func(n FieldNumber, v Value) bool {
		...
		return true
	})

However, this is a marginal benefit.
Thus, remove List as it mostly inferior to Range.

Change-Id: I25586c6ea07a4706072ba06b1cf25cb6efb5e8a7
Reviewed-on: https://go-review.googlesource.com/c/142888
Reviewed-by: Damien Neil <dneil@google.com>
2018-10-17 19:30:39 +00:00
Damien Neil
21f62f4d53 reflect/prototype: fix name resolution when file has no package name
A .proto source file with no 'package' statement may still contain
references to descriptors within the file.

Change-Id: I86e942c9c06e5a2915e9722162e0455ffa9ba2ab
Reviewed-on: https://go-review.googlesource.com/c/140899
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-10-16 16:16:46 +00:00
Joe Tsai
1dab2cb0ad reflect/prototype: avoid unescaping string defaults
According to google.protobuf.FieldDescriptorProto.default_value documentation:
>>>
For strings, contains the default text contents (not escaped in any way).
For bytes, contains the C escaped value.  All bytes >= 128 are escaped.
<<<

Thus, use the default value ad-verbatim if the kind is a string.
For the bytes kind, we use the text format hack to unescape the string,
since the text format uses the same unescape syntax as C due to its heritage.

Change-Id: I79e6d4d7e8f0d1ebedccecb9424a49384485589d
Reviewed-on: https://go-review.googlesource.com/138515
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-28 20:50:27 +00:00
Joe Tsai
01ab29648e go.mod: rename google.golang.org/proto as github.com/golang/protobuf/v2
This change was created by running:
	git ls-files | xargs sed -i "s|google.golang.org/proto|github.com/golang/protobuf/v2|g"

This change is *not* an endorsement of "github.com/golang/protobuf/v2" as the
final import path when the v2 API is eventually released as stable.
We continue to reserve the right to make breaking changes as we see fit.

This change enables us to host the v2 API on a repository that is go-gettable
(since go.googlesource.com is not a known host by the "go get" tool;
and google.golang.org/proto was just a stub URL that is not currently served).
Thus, we can start work on a forked version of the v1 API that explores
what it would take to implement v1 in terms of v2 in a backwards compatible way.

Change-Id: Ia3ebc41ac4238af62ee140200d3158b53ac9ec48
Reviewed-on: https://go-review.googlesource.com/136736
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-24 16:11:50 +00:00
Joe Tsai
ded92f8033 reflect/prototype: lower minimum support to Go1.9
The minimum supported version is currently Go1.10 since we use strings.Builder
for a fairly significant optimization when constructing all of the descriptor
full names.

The strings.Builder implementation is not particularly complicated,
so just fork it into our code. The golang/protobuf and the golang/go
projects share the same authors and copyright license.

Change-Id: Ibb9519dbe756327a07369f10f80c15761002b5e7
Reviewed-on: https://go-review.googlesource.com/136735
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-21 19:30:05 +00:00
Damien Neil
d4803f5a4f cmd/protoc-gen-go: add "packed" encoding tag to fields
Change-Id: I423039d6c9edb50a07781a6e76336ed364f21866
Reviewed-on: https://go-review.googlesource.com/136359
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-20 17:08:44 +00:00
Joe Tsai
dd00a27837 reflect/prototype: simplify Format test
Derive the compact string from the multi string output.
This makes is such that we don't have to update two sets of golden data.

Change-Id: I94b94f1094b448539f8bee234be83ac7186fdd30
Reviewed-on: https://go-review.googlesource.com/135335
Reviewed-by: Herbie Ong <herbie@google.com>
2018-09-13 23:01:44 +00:00
Joe Tsai
d0f8aa294e reflect/prototype: add NewGoEnum and NewGoMessage constructors
Add constructors for creating protoreflect.{Enum,Message}Type,
which extend the protobuf descriptor with Go type information.

Rationale for API:
* NewGoEnum and NewGoMessage take in a struct instead of multiple
function parameters to provide future flexibility in adding more parameters.
* NewGoEnum and NewGoMessage take in a pointer to a struct so that generated
code can batch allocate these structs and convert them to them to EnumTypes
or MessageTypes efficiently. In other words, allocations are entirely in the
control of the caller.
* The user provides a New function as opposed to a reflect.Type or pointer to
the concrete type to support dynamic protobufs, where a single Go type may be
used to represent multiple protobuf types.
* The New functions take in an EnumType or MessageType since an implementation
for dynamic protobufs would need to close over these types. All statically
generated messages can ignore that argument.

There are no tests added since these are just wrappers;
they will be heavily exercised by other code.

Change-Id: I9fca44e06f3388375be7eaca94f8fd75c17233a3
Reviewed-on: https://go-review.googlesource.com/135356
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-13 23:01:27 +00:00
Joe Tsai
757806cdda reflect/prototype: fix build due to protoreflect.Value method change
protoreflect.Value.IsNull was inverted to become IsValid in CL 134998.
However, that CL was submitted without a rebase,
which broke the build since CL 135255 added a few more usages of IsNull.

Change-Id: I5e52fb880ffc92e9d8f6cab30848e65b2d6dcbdc
Reviewed-on: https://go-review.googlesource.com/135337
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-13 20:00:42 +00:00
Joe Tsai
812d9137df reflect/protoreflect: add Has and Clear to KnownFields and Map
Change the API to use explicit Has/Clear methods instead of relying on the
"invalid" form of Value to represent nullability.

There are several reasons for this change:

* Much of the ecosystem around protobufs do not care about nullability alone.
For example, for the encoder to determine whether to emit a field:
it needs to first check if a field is nulled, and if not, it still needs to go
through a series of type-assertion to check whether the value is the zero value.
It is much easier to be able to just call Has.

* It enables representing the default value as part of the value API, rather
than only as part of the descriptor API.

* The C++ API also uses explicit has and clear methods. However, we differ from
them by defining Has for proto3 scalars (while C++ panics instead).

For internal consistency, we also use a Has/Clear API for Maps.

Change-Id: I30eda482c959d3e1454d72d9fc761c761ace27a6
Reviewed-on: https://go-review.googlesource.com/134998
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-13 19:52:11 +00:00
Damien Neil
e6fa22ab33 reflect/prototype: add HasDefault to FieldDescriptor
Provide a way to distinguish between a field with a zero-value
default and one with no default.

Change-Id: I4b1231de2d1bb141099cb1a415b35184dd198f93
Reviewed-on: https://go-review.googlesource.com/135255
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-13 18:13:20 +00:00
Damien Neil
2c8b670c6c reflect/protoreflect: put Value and MapKey types next to their methods
The Value and MayKey types are defined in value.go, but the methods on
these types are defined in value_union.go. It's not immediately clear
to the reader of the code that these types have methods, or where they
are defined.

Move the type definitions to value_union.go to keep the entire type in a
single place.

Change-Id: I7b3f3fc219a24a3b0236c2c3335e5d46f9086d25
Reviewed-on: https://go-review.googlesource.com/134997
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-12 22:16:46 +00:00
Joe Tsai
17764983d4 reflect/prototype: implement Format methods
Implement Format methods to provide the ability to pretty-print the descriptor
in a humanly readable fashion. While this functionality is not strictly necessary
for the operation of Go protobuf, it is a useful aid for humans.

Change-Id: I88807b38b5be713867f2f2aab5a0843fc147dc35
Reviewed-on: https://go-review.googlesource.com/131255
Reviewed-by: Herbie Ong <herbie@google.com>
2018-09-11 23:25:30 +00:00
Damien Neil
3de06c0868 reflect: add Index method to descriptor
Useful for dealing with SourceCodeInfo location paths, which identify
entities by their index.

Change-Id: I2034fc06b14c9b29b26e356fad21e106f63fbd14
Reviewed-on: https://go-review.googlesource.com/134115
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-07 17:57:37 +00:00
Damien Neil
ef18063941 reflect/prototype: default proto file syntax is "proto2"
protoc leaves FileDescriptorProto.Syntax unset when the syntax is
"proto2".

Change-Id: Id1370145fc9c5c67344f5a998d118fd0f9f65f24
Reviewed-on: https://go-review.googlesource.com/133636
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
2018-09-06 15:52:05 +00:00
Joe Tsai
23ddbd1430 reflect/prototype: add NewFileFromDescriptorProto constructor
Implement NewFileFromDescriptorProto, which constructs a
protoreflect.FileDescriptor from a provided descriptor.FileDescriptorProto.

Some other minor changes:
* Allow calling Find and Range methods on nil *protoregistry.Files to match
the behavior of maps where index operations are permitted, but store panics.
* Switch protoregistry test to be protoregistry_test to avoid cyclic dependency.

Change-Id: I5536901ef5096014a3421e63bc4a9dfcad335ea4
Reviewed-on: https://go-review.googlesource.com/132455
Reviewed-by: Damien Neil <dneil@google.com>
2018-09-05 21:25:53 +00:00
Joe Tsai
095e462e1c reflect/protoregistry: initial commit
Package protoregistry provides data structures to register and lookup
protobuf descriptor types.

High-level API:
	var GlobalFiles = new(Files)
	var NotFound = errors.New("not found")
	type Files struct{ ... }
		func NewFiles(...pref.FileDescriptor) *Files
		func (*Files) Register(...pref.FileDescriptor) error
		func (*Files) FindDescriptorByName(pref.FullName) (pref.Descriptor, error)
		func (*Files) RangeFiles(func(pref.FileDescriptor) bool)
		func (*Files) RangeFilesByPackage(pref.FullName, func(pref.FileDescriptor) bool)
		func (*Files) RangeFilesByPath(string, func(pref.FileDescriptor) bool)

To support the FindDescriptorByName method, we add a DescriptorByName to
protoreflect.FileDescriptor and associated logic to prototype.

Change-Id: I14d65f74d2bd9f4f48641da9dfa70190310e5878
Reviewed-on: https://go-review.googlesource.com/129499
Reviewed-by: Damien Neil <dneil@google.com>
2018-08-24 23:46:08 +00:00
Joe Tsai
bfda014ecd reflect/prototype: initial commit
The prototype package provides constructors to create protobuf types that
implement the interfaces defined in the protoreflect package.

High-level API:
	func NewFile(t *File) (protoreflect.FileDescriptor, error)
	type File struct{ ... }
	type Message struct{ ... }
	type Field struct{ ... }
	type Oneof struct{ ... }
	type Enum struct{ ... }
	type EnumValue struct{ ... }
	type Extension struct{ ... }
	type Service struct{ ... }
	type Method struct{ ... }

	func NewEnum(t *StandaloneEnum) (protoreflect.EnumDescriptor, error)
	func NewMessage(t *StandaloneMessage) (protoreflect.MessageDescriptor, error)
	func NewExtension(t *StandaloneExtension) (protoreflect.ExtensionDescriptor, error)
	type StandaloneEnum struct{ ... }
	type StandaloneMessage struct{ ... }
	type StandaloneExtension struct{ ... }

	func PlaceholderFile(path string, pkg protoreflect.FullName) protoreflect.FileDescriptor
	func PlaceholderEnum(name protoreflect.FullName) protoreflect.EnumDescriptor
	func PlaceholderMessage(name protoreflect.FullName) protoreflect.MessageDescriptor

This CL is missing some features that are to be added later:
* The stringer methods are not implemented, providing no way to print the
descriptors in a humanly readable manner.
* There is no support for proto options or retrieving the raw descriptor.
* There are constructors for Go specific types (e.g., protoreflect.MessageType).

We drop go1.9 support since we use strings.Builder.
We switch to go.11rc1 to obtain some bug fixes for modules.

Change-Id: Ieac9a2530afc81e5a5bb9ab5816804372f652b18
Reviewed-on: https://go-review.googlesource.com/129057
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Herbie Ong <herbie@google.com>
2018-08-15 18:44:04 +00:00
Joe Tsai
dbc9a12dbd reflect/protoreflect: initial commit
Package protoreflect provides APIs for programatically interacting with messages
according to the protobuf type system.

Change-Id: I11fa3874e4b3f94771514c69efb2ae8bb812d7fa
Reviewed-on: https://go-review.googlesource.com/127823
Reviewed-by: Damien Neil <dneil@google.com>
2018-08-10 19:59:50 +00:00
Joe Tsai
27c2a76c85 internal/encoding/text: initial commit of proto text format parser/serializer
Package text provides a parser and serializer for the proto text format.
This focuses on the grammar of the format and is agnostic towards specific
semantics of protobuf types.

High-level API:
	func Marshal(v Value, indent string, delims [2]byte, outputASCII bool) ([]byte, error)
	func Unmarshal(b []byte) (Value, error)
	type Type uint8
		const Bool Type ...
	type Value struct{ ... }
		func ValueOf(v interface{}) Value
		func (v Value) Type() Type
		func (v Value) Bool() (x bool, ok bool)
		func (v Value) Int(b64 bool) (x int64, ok bool)
		func (v Value) Uint(b64 bool) (x uint64, ok bool)
		func (v Value) Float(b64 bool) (x float64, ok bool)
		func (v Value) Name() (protoreflect.Name, bool)
		func (v Value) String() string
		func (v Value) List() []Value
		func (v Value) Message() [][2]Value
		func (v Value) Raw() []byte

Change-Id: I4a78ec4474c160d0de4d32120651edd931ea2c1e
Reviewed-on: https://go-review.googlesource.com/127455
Reviewed-by: Herbie Ong <herbie@google.com>
2018-08-07 22:44:06 +00:00