We modify protoc-gen-go to stop generating exported XXX fields.
The unsafe implementation is unaffected by this change since unsafe
can access fields regardless of visibility. However, for the purego
implementation, we need to respect Go visibility rules as enforced
by the reflect package.
We work around this by generating a exporter function that given
a reference to the message and the field to export, returns a reference
to the unexported field value. This exporter function is protected by
a constant such that it is not linked into the final binary in non-purego
build environment.
Updates golang/protobuf#276
Change-Id: Idf5c1f158973fa1c61187ff41440acb21c5dac94
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/185141
Reviewed-by: Damien Neil <dneil@google.com>
Move data used by the fast-path implementations into a substructure of
MessageInfo and initialize it separately.
Change-Id: Ib855ee8ea5cb0379528b52ba0e191319aa5e2dff
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/184077
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
This currently returns uninformative errors from the fast path and then
consults the slow, reflection-based path only when an error is detected.
Perhaps it's worth going through the effort of producing better errors
directly on the fast path.
Change-Id: I68536e9438010dbd97dbaff4f47b78430221d94b
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/171462
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Added API:
Message.Len
Message.Range
Message.Has
Message.Clear
Message.Get
Message.Set
Message.Mutable
Message.NewMessage
Message.WhichOneof
Message.GetUnknown
Message.SetUnknown
Deprecated API (to be removed in subsequent CL):
Message.KnownFields
Message.UnknownFields
The primary difference with the new API is that the top-level
Message methods are keyed by FieldDescriptor rather than FieldNumber
with the following semantics:
* For known fields, the FieldDescriptor must exactly match the
field descriptor known by the message.
* For extension fields, the FieldDescriptor must implement ExtensionType,
where ContainingMessage.FullName matches the message name, and
the field number is within the message's extension range.
When setting an extension field, it automatically stores
the extension type information.
* Extension fields are always considered nullable,
implying that repeated extension fields are nullable.
That is, you can distinguish between a unpopulated list and an empty list.
* Message.Get always returns a valid Value even if unpopulated.
The behavior is already well-defined for scalars, but for unpopulated
composite types, it now returns an empty read-only version of it.
Change-Id: Ia120630b4db221aeaaf743d0f64160e1a61a0f61
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175458
Reviewed-by: Damien Neil <dneil@google.com>
The internal/legacy package was originally separated out from internal/impl
to avoid a cyclic dependency on descriptor proto. However, the dependency
that legacy has on descriptor has long been dropped such that we can
now merge the two packages together again.
All legacy related logic are in a file with a legacy prefix.
Change-Id: I2424fc0f50721696ad06fa7cebb9bdd0babea13c
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178542
Reviewed-by: Damien Neil <dneil@google.com>
Add the prototype package which provides constructors for
protoreflect.{Enum,Message,Extension}Type.
Switch all usages of the internal/prototype equivalent to the new package.
Switch all custom implementions of {Enum,Message}Type to the new package.
Change-Id: Ia9dae6fed4f2b90e55c123627044a7faf098c4b1
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178438
Reviewed-by: Damien Neil <dneil@google.com>
Temporarily remove go.mod, since we can't generate an accurate one until
the corresponding v1 change is submitted.
Change-Id: I1e1ad97f2b455e33f61ffaeb8676289795e47e72
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177000
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Added API:
FieldDescriptor.IsExtension
FieldDescriptor.IsList
FieldDescriptor.MapKey
FieldDescriptor.MapValue
FieldDescriptor.ContainingOneof
FieldDescriptor.ContainingMessage
Deprecated API (to be removed in subsequent CL):
FieldDescriptor.Oneof
FieldDescriptor.Extendee
These methods help cleanup several common usage patterns.
Change-Id: I9a3ffabc2edb2173c536509b22f330f98bba7cf3
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/176977
Reviewed-by: Damien Neil <dneil@google.com>
Weak fields are an obsolete proto1 feature. They have been superseded
by extensions. However, some vestigial support for weak fields does
remain, mostly as Google-internal patches. (They aren't exciting;
extensions really do everything weak fields do in a cleaner and
more portable fashion.)
At the moment, the only visible impact of marking a field [weak=true]
is to exclude it from "internal/fileinit".FileBuilder.DependencyIndexes.
We want to preserve that behavior just in case we ever do add full weak
field support here.
Extend fileinit to look up message descriptors for weak fields in the
global registry. If the descriptor cannot be found, use a placeholder
instead.
Remove special-case handling of weak fields in the impl package. The
code generator doesn't do anything special for them, so they can be
treated as any other field.
Change-Id: Ifa2ee3d30d63680a0eeb59c66ebc9521f38fd660
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/175997
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
According to IEEE-754, equality on floats reports true for both +0 and -0.
However, this definition causes us to lose information. Instead, we want
a definition that checks for exact equality with +0.
Otherwise, we would lose the ability to serialize -0.
Change-Id: I36450c24258fc4f856bfd4bc4c53a90199b216b9
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172970
Reviewed-by: Herbie Ong <herbie@google.com>
The protobuf type system uses the word "descriptor" instead of "type".
We should avoid the "type" verbage when we aren't talking about Go types.
The old names are temporarily kept around for compatibility reasons.
Change-Id: Icc99c913528ead011f7a74aa8399d9c5ec6dc56e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/172238
Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Add a method that provides efficiently querying for which member field
in a oneof is actually set. This is useful when dealing with oneofs
with many member fields.
Change-Id: I918b566c432f8bdd24dcecbb5501d231ffefef29
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/170580
Reviewed-by: Damien Neil <dneil@google.com>
Most usages of New actually prefer to interact with the reflective view
rather than the native Go type. Thus, change New to return that instead.
This parallels reflect.New, which returns the reflective view
(i.e., reflect.Value) instead of native type (i.e., interface{}).
We make the equivalent change to KnownFields.NewMessage, List.NewMessage,
and Map.NewMessage for consistency.
Since this is a subtle change where the type system will not always
catch the changed type, this change was made by both changing the type
and renaming the function to NewXXX and manually looking at every usage
of the the function to ensure that the usage correctly operates
on either the native Go type or the reflective view of the type.
After the entire codebase was cleaned up, a rename was performed to convert
NewXXX back to New.
Change-Id: I153fef627b4bf0a427e4039ce0aaec52e20c7950
Reviewed-on: https://go-review.googlesource.com/c/157077
Reviewed-by: Damien Neil <dneil@google.com>
Remove the Mutable methods from KnownFields, List, and Map, replacing
them with methods which return a new, empty message value without adding
that value to the collection.
The new API is simpler, since it clearly applies only to message values,
and more orthogonal, since it provides a way to create a value without
mutating the collection. This latter point is particularly useful in
map deserialization, where the key may be unknown at the time the value
is deserialized.
Drop the Mutable interface, since it is no longer necessary.
Change-Id: Ic5f3d06a2aa331a5d5cd2b4e670a3dba4a74f77c
Reviewed-on: https://go-review.googlesource.com/c/153278
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Similar to how generated messages allow you to call Get methods on a
nil pointer, we permit similar functionality when protobuf reflection
is used on a nil pointer.
Change-Id: Ie2f596d39105c191073b42d7d689525c3b715240
Reviewed-on: https://go-review.googlesource.com/c/152021
Reviewed-by: Damien Neil <dneil@google.com>
The impl package currently supports wrapping legacy v1 enums and messages
so that they implement the v2 reflective APIs. This functionality is necessary
for v1 and v2 to interoperate. However, the existence of this functionality
presents several problems:
* A significant portion of the complexity in impl is for legacy wrapping.
* This complexity is linked into a Go binary even if all the other messages
in the binary natively support v2 reflection.
* It presents a cyclic dependency when trying to generate descriptor proto.
Suppose you are generating descriptor.proto. The generated code would want to
depend on the impl package because impl is the runtime implementation for
protobuf messages. However, impl currently depends depends on descriptor in
order to wrap legacy enum and messages since it needs the ability to dynamically
create new protobuf descriptor types. In the case of descriptor.proto, it would
presumably be generated with native reflection support, so the legacy wrapping
logic is unneccessary.
To break the dependency of impl on descriptor, we move the legacy support logic
to a different package and instead add hooks in impl so that legacy support could
be dynamically registered at runtime. This is dependency injection.
Change-Id: I01a582908ed5629993f6699e9bf2f4bee93857a4
Reviewed-on: https://go-review.googlesource.com/c/151877
Reviewed-by: Herbie Ong <herbie@google.com>
Add a Proto prefix before the Unwrap method to reduce the probability that
it would ever conflict with a method of the same name that a
custom implementation of Enum, Message, List, or Map may have.
Change-Id: I628bf8335583f2747ab4589f3e6ff82e4501ce98
Reviewed-on: https://go-review.googlesource.com/c/151817
Reviewed-by: Herbie Ong <herbie@google.com>
Clearly specify that Get on an unpopulated field:
* returns the default value for scalars
* returns a mutable (but empty) List for repeated fields
* returns a mutable (but empty) Map for map fields
* returns an invalid value for message fields
The difference in semantics between List+Maps and Messages is because
protobuf semantics provide no distinction between an unpopulated and empty list
or map. On the other hand, there is a semantic difference between an unpopulated
message and an empty message.
Default values for scalars is trivial to implement with FieldDescriptor.Default.
A mutable, but empty List and Map is easy to implement for known fields since
known fields are generated as a slice or map field in a struct.
Since struct fields are addressable, the implementation can just return a
reference to the slice or map.
Repeated, extension fields are a little more tricky since extension fields
are implemented under the hood as a map[FieldNumber]Extension.
Rather than allocating an empty list in KnownFields.Get upon first retrieval
(which presents a race), delegate the work to ExtensionFieldTypes.Register,
which must occur before any Get operation. Register is not a concurrent-safe
operation, so that is an excellent time to initilize empty lists.
The implementation of extensions will need to be careful that Clear on a repeated
field simply truncates it zero instead of deleting the object.
For unpopulated messages, we return an invalid value, instead of the prior
behavior of returning a typed nil-pointer to the Go type for the message.
The approach is problematic because it assumes that
1) all messages are always implemented on a pointer reciever
2) a typed nil-pointer is an appropriate "read-only, but empty" message
These assumptions are not true of all message types (e.g., dynamic messages).
Change-Id: Ie96e6744c890308d9de738b6cf01d3b19e7e7c6a
Reviewed-on: https://go-review.googlesource.com/c/150319
Reviewed-by: Damien Neil <dneil@google.com>
The definition of Has for proto3 scalars is whether the value is non-zero.
Change-Id: I6aee92dd518d63a66515ad35da84b2be7aa22527
Reviewed-on: https://go-review.googlesource.com/c/150320
Reviewed-by: Herbie Ong <herbie@google.com>
Reviewed-by: Joe Tsai <joetsai@google.com>
The terminology Vector does not occur in protobuf documentation at all,
so we should rename the Go use of the term to something more recognizable.
As such, all instances that match the regexp "[Vv]ect(or)?" were replaced.
The C++ documentation uses the term "Repeated", which is a reasonable name.
However, the term became overloaded in 2014, when maps were added as a feature
and implementated under the hood as repeated fields. This is confusing as it
means "repeated" could either refer to repeated fields proper (i.e., explicitly
marked with the "repeated" label in the proto file) or map fields. In the case
of the C++ reflective API, this is not a problem since repeated fields proper
and map fields are interacted with through the same RepeatedField type.
In Go, we do not use a single type to handle both types of repeated fields:
1) We are coming up with the Go protobuf reflection API for the first time
and so do not need to piggy-back on the repeated fields API to remain backwards
compatible since no former usages of Go protobuf reflection exists.
2) Map fields are commonly represented in Go as the Go map type, which do not
preserve ordering information. As such it is fundamentally impossible to present
an unordered map as a consistently ordered list. Thus, Go needs two different
interfaces for lists and maps.
Given the above situation, "Repeated" is not a great term to use since it
refers to two different things (when we only want one of the meanings).
To distinguish between the two, we'll use the terms "List" and "Map" instead.
There is some precedence for the term "List" in the protobuf codebase
(e.g., "getRepeatedInt32List").
Change-Id: Iddcdb6b78e1e60c14fa4ca213c15f45e214b967b
Reviewed-on: https://go-review.googlesource.com/c/149657
Reviewed-by: Damien Neil <dneil@google.com>
Implement support for extension fields for messages that use the v1
data structures for extensions. The legacyExtensionFields type wraps a
v1 map to implement the v2 protoreflect.KnownFields interface.
Working on this change revealed a bug in the dynamic construction of
message types for protobuf messages that had cyclic dependencies (e.g.,
message Foo has a sub-field of message Bar, and Bar has a sub-field of Foo).
In such a situation, a deadlock occurs because initialization code depends on
the very initialization code that is currently running. To break these cycles,
we make some systematic changes listed in the following paragraphs.
Generally speaking, we separate the logic for construction and wrapping,
where constuction does not recursively rely on dependencies,
while wrapping may recursively inspect dependencies.
Promote the MessageType.MessageOf method as a standalone MessageOf function
that dynamically finds the proper *MessageType to use. We make it such that
MessageType only supports two forms of messages types:
* Those that fully implement the v2 API.
* Those that do not implement the v2 API at all.
This removes support for the hybrid form that was exploited by message_test.go
In impl/message_test.go, switch each message to look more like how future
generated messages will look like. This is done in reaction to the fact that
MessageType.MessageOf no longer exists.
In value/{map,vector}.go, fix Unwrap to return a pointer since the underlying
reflect.Value is addressable reference value, not a pointer value.
In value/convert.go, split the logic apart so that obtaining a v2 type and
wrapping a type as v2 are distinct operations. Wrapping requires further
initialization than simply creating the initial message type, and calling it
during initial construction would lead to a deadlock.
In protoreflect/go_type.go, we switch back to a lazy initialization of GoType
to avoid a deadlock since the user-provided fn may rely on the fact that
prototype.GoMessage returned.
Change-Id: I5dea00e36fe1a9899bd2ac0aed2c8e51d5d87420
Reviewed-on: https://go-review.googlesource.com/c/148826
Reviewed-by: Herbie Ong <herbie@google.com>
Rather than having the Converter carry a NewMessage method, have the struct
simply expose the MessageType or EnumType since they carry more information
and are retrieved anyways as part of the functionality of NewConverter.
While changing Converter, export the fields and remove all the methods.
Also, add an IsLegacy boolean, which is useful for the later implementation
of the extension fields.
Add a wrapLegacyEnum function which is used to wrap v1 enums as v2 enums.
We use this functionality in NewLegacyConverter to detrive the EnumType.
Additionally, modify wrapLegacyMessage to return a protoreflect.ProtoMessage
to be consistent with wrapLegacyEnum which must return a protoreflect.ProtoEnum.
Change-Id: Idc8989d07e4895d30de4ebc22c9ffa7357815cad
Reviewed-on: https://go-review.googlesource.com/c/148827
Reviewed-by: Herbie Ong <herbie@google.com>
The implementation of reflect/protoreflect.NewGoExtension needs to be able to
provide a constructor for wrapping *[]T as a protoreflect.Vector.
However, it cannot depend on internal/impl since impl also depends on prototype.
Extract the common logic of Vector creation into a separate package that
has no dependencies on either impl or prototype.
Change-Id: I9295fde9b8861de11af085c91d9dfa56047d1b1e
Reviewed-on: https://go-review.googlesource.com/c/147446
Reviewed-by: Herbie Ong <herbie@google.com>
Dynamically generate functions for handling message and enum fields,
regardless of whether they are of the v1 or v2 forms.
If a v1 message is encountered, it is automatically wrapped such that it
implements the v2 interface.
Change-Id: I457bc5286892e8fc00a61da7062dd33058daafd5
Reviewed-on: https://go-review.googlesource.com/c/143837
Reviewed-by: Damien Neil <dneil@google.com>
Dynamically generate functions for handling individual fields within an oneof.
This implementation uses Go reflection to interact with the currently generated
approach, which uses an interface that can only be set by a limited set of
wrapper structs.
Change-Id: Ic848df922d6547411a15c4a20bfbbcae362da5c0
Reviewed-on: https://go-review.googlesource.com/c/142895
Reviewed-by: Damien Neil <dneil@google.com>
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>
Generate functions for wrapping map[K]V to implement protoreflect.Map.
This implementation uses Go reflection instead to provide a single implementation
that can handle all Go map types.
Change-Id: Idcb8069ef836614a88e5df12ef7c5044e8aa3dea
Reviewed-on: https://go-review.googlesource.com/c/142778
Reviewed-by: Damien Neil <dneil@google.com>
Generate functions for wrapping []T to implement protoreflect.Vector.
This implementation uses Go reflection instead to provide a single implementation
that can handle all Go slice types.
The test harness was greatly expanded to be able to test vectors (in addition
to messages and maps in the near future).
Change-Id: I0106c175f84a1e7e0a0a5b0e02e2489b70b0d177
Reviewed-on: https://go-review.googlesource.com/c/135339
Reviewed-by: Damien Neil <dneil@google.com>
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>
This provides an implementation of the has, get, set, clear methods for each
field in a message. The approach taken here is similar to the table-driven
implementation in the current v1 proto package.
The pointer_reflect.go and pointer_unsafe.go files are a simplified version of
the same files in the v1 implementation. They provide a pointer abstraction
that enables a high-efficiency approach in a non-purego environment.
The unsafe fast-path is not implemented in this commit.
This commit only implements the accessor methods for scalars using pure
Go reflection.
Change-Id: Icdf707e9d4e3385e55434f93b30a341a7680ae11
Reviewed-on: https://go-review.googlesource.com/135136
Reviewed-by: Damien Neil <dneil@google.com>
