Module codec 

OTLP/HTTP payloads: decoding an export request into the summary the model sees, and encoding every response the receiver sends.

Pure functions, shared by the server, the tests and nothing else. The model never sees a payload: it gets counts, the service name, a few resource attributes and the first few span names, metric names or log bodies, each truncated. It never writes one either: every response body — the empty full-success message, a partial success, a google.rpc.Status — is encoded here, in the encoding the request used.

Protobuf is decoded with the OpenTelemetry project’s own generated types (opentelemetry-proto, prost). prost stops at 100 levels of nesting, so a depth bomb in an AnyValue is a decode error, not a stack overflow. JSON is parsed as a serde_json::Value (recursion limit 128) and walked by hand rather than through the crate’s serde types, because OTLP/JSON senders differ in ways a strict typed decode would refuse (64-bit integers as numbers or strings, enum values as numbers or names); keys are accepted in lowerCamelCase, as the specification writes them, and in the proto’s own snake_case. Neither walk recurses into attribute values: an array or map is summarised by its length.

Structs

RpcStatus

google.rpc.Status, the body of every OTLP/HTTP failure response.

Summary

What the model is told about one export.

Enums

BodyError

Why a body could not be read.

Encoding

The two encodings OTLP/HTTP defines.

Signal

The three signals and their paths.

Constants

MAX_ATTRIBUTES

MAX_BODY_BYTES

The largest request body the receiver reads, after decompression: 4 MiB, the default message limit of the gRPC servers OTLP receivers are built on and what SDK exporters batch under. A gzip body is held to the same number once inflated, so a small compressed body cannot expand past it.

MAX_LOG_BODIES

MAX_NAMES

How much of an export the model is shown.

MAX_SERVICES

REJECT_STATUSES

The statuses a model may refuse with. 429, 502, 503 and 504 are the ones OTLP clients retry.

Functions

export_response

The export response: full success when partial is None, else a partial success naming how many items were rejected and why.

grpc_code

The gRPC code an HTTP failure status corresponds to, per the OTLP specification’s mapping.

gunzip_bounded

Inflate a gzip body, refusing it as soon as it passes limit bytes. Never allocates more than limit + 1 bytes of output.

retryable

Whether an OTLP client retries after this status.

status_body

A failure body in the request’s encoding.

summarize

Decode a request in either encoding.

summarize_json

Decode an OTLP/JSON export request.

summarize_protobuf

Decode a protobuf export request.