clj-protobuf.runtime — com.github.bpalermo/clj-protobuf 0.2.1

The runtime half of protoc-gen-clojure's generated-code contract.

Generated files call exactly four things here: file-descriptor to rebuild their embedded FileDescriptorProto, known-file for well-known-type deps, message for a prototype per message, and field for a handle per field. Everything protobuf decides per edition — presence, delimited encoding, utf8 validation, packedness — is resolved by protobuf-java when the descriptor is built, which is why generated code never mentions editions at all.

field returns a precomputed FieldHandle rather than a bare FieldDescriptor: the codec's hot path dispatches on a keyword and never touches the descriptor API per call. Handles are built against a specific prototype, so a message-typed field's nested prototype has the right concrete class in both the DynamicMessage and generated-class arms.

compiled-message clj

(compiled-message fd lookup)

A compiled-codec prototype, whatever the codec setting.

dynamic-message clj

(dynamic-message fd lookup)

A DynamicMessage prototype, whatever the codec setting: the reference arm, for tests and comparisons.

field clj

(field prototype field-name)

A precomputed handle for one field of a message prototype, looked up by its exact proto field name — the name is the authority; kebab-cased keys are derived from it, never the reverse (STYLE_LEGACY files can mix conventions).

file-descriptor clj

(file-descriptor descriptor-b64 deps)

Build a FileDescriptor from the base64 FileDescriptorProto a generated file embeds, linked against its dependencies (already-built FileDescriptors — sibling namespaces' file-descriptor vars or known-file results).

java-class-hint clj

(java-class-hint d)

The Java class protoc generates for this message, by the emitter's rule — the hint a generated namespace passes to message for it — or nil when the rule declines to guess. Only ever a hint: prototype verifies it.

known-file clj

(known-file path)

The FileDescriptor for a well-known type bundled in protobuf-java, e.g. "google/protobuf/timestamp.proto".

message clj

(message fd lookup)

(message fd lookup class-hint)

The prototype for a message type: a default instance whose .newBuilderForType the generated ->proto fns drive.

With a Java class hint (3-arity) the generated class's default instance is used when it is present and describes the same message — protoc's own serializer, and the fastest arm. Otherwise, and always in the 2-arity, the compiled codec's prototype: a Message over a slot array with the descriptor compiled once into reader and writer tables. DynamicMessage serves only for extendable types, which the compiled codec does not support, or when -Dclj-protobuf.codec=dynamic asks for it. Same codec, same field descriptors, same bytes on every arm.

prototype clj

(prototype x)

The prototype for a message type from its Descriptor, or from any Message of that type — the same arm message hands the generated namespace: the generated class when it is on the classpath (its name derived by the emitter's own rule), else the compiled codec, else DynamicMessage for extendable types or under -Dclj-protobuf.codec=dynamic.

For code that manufactures prototypes for types it did not generate — gRPC marshallers, say — and must land on the arm the generated proto->X fns read. A generated-class or compiled prototype passed in comes back as it is; a DynamicMessage is re-resolved, so a consumer that built one before 0.2.0 wraps that one call and needs no other change.