Encoding as a pure JVM value + native publisher default + pinned per-put override#484
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An encoding IS its (id, schema) pair — Zenoh's own representation; the textual form is derived from a fixed table. With the id<->name table already JVM-side (the generated ENCODING_* constants) and the companion zenoh-flat-jni change crossing Encoding by value in both directions, the SDK Encoding becomes a plain immutable value: no native handle, no native calls, no lazy caches, no locking, nothing to close. This also removes a native memory leak: received Sample/Query/ReplyError previously retained a cloned Encoding handle with no close path. - Encoding.kt: immutable (id, schema); from()/toString()/withSchema() implement Zenoh's exact conversion rules (incl. the custom-encoding name-preserving withSchema and the render-only CUSTOM<->"" table row); equality on (id, schema), matching Zenoh core. - ZenohId.toString: the little-endian lowercase-hex rule in pure Kotlin. - Callback/fromParts leaves follow the new (encId, encSchema) decomposition; outbound sites pass .id/.schema directly. - Correspondence tests (EncodingCorrespondenceTest, ZenohIdCorrespondenceTest) verify the pure implementations against the native ones across the whole predefined id range, parse/render edge shapes, and random ids — the contract for any JVM-side reimplementation of zenoh-flat API. One test caught and fixed a real divergence (custom-encoding withSchema). Pairs with ZettaScaleLabs/zenoh-flat-jni#4 (CI pin bumped). jvmTest: 105 tests, 0 failures.
Two encoding fast paths over the dual-arm expansion (prebindgen#80, zenoh-flat#3, zenoh-flat-jni#4): - The publisher's default encoding is set NATIVELY once at declare time (PublisherOptions.encoding -> declarePublisher's encoding arm); plain put(payload) passes absent (sel -1), so no encoding data crosses per call. Previously the JVM tier re-sent (id, schema) on every put. - PinnedEncoding (Encoding.pinned()) preallocates the native form; passing it in PutOptions/ReplyOptions/GetOptions crosses only a borrowed handle (native clone = Arc bump) — no schema-string traffic in hot publish loops. close() releases the handle (falls back to the plain (id, schema) arm); a finalizer backstops leaks. A PinnedEncoding equals its plain counterpart. - All outbound sites route through one Encoding?.forWire() helper emitting the selector tuple (-1 absent / 0 value / 1 pinned handle). Tests: PinnedEncodingTest (publisher-default applies natively end-to-end; pinned override reused across puts; post-close fallback), correspondence tests updated to the dual-arm newWithSchema. jvmTest: 107 tests, 0 failures. CI pins: zenoh-flat-jni cbbca40, zenoh-flat d792547.
This was referenced Jul 16, 2026
zenoh-flat-jni is the shared tier reused by both zenoh-java and zenoh-kotlin, so the pure-JVM conversion logic moves there (EncodingCodec, ZenohId.zidString — next to the generated constants they are built from). io.zenoh.bytes.Encoding shrinks to a thin facade: the established constants and API delegating to the shared codec, zero logic. Drop PinnedEncoding and the selector-tuple wire helper: with the publisher's default encoding set natively at declare time, the hot publish loop crosses no encoding data at all, and per-call overrides crossing (id, schema) cost only a short string decode — not worth a resource class in the public API. Encoding params revert to the plain (present, id, schema) crossing. jvmTest: 106 tests, 0 failures (correspondence suites now exercise the shared codec; PublisherEncodingTest verifies the native declare-time default + per-put override end-to-end). CI pins: zenoh-flat-jni 9bc155b, zenoh-flat main (6d22091, #3 merged).
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Constituent of the zenoh-flat transition (#482). Reworks the Encoding story on the shared-tier principle: all logic lives in zenoh-flat-jni (reused by zenoh-java and zenoh-kotlin); this repo keeps only the established API facade.
1.
Encodingis a pure JVM value, logic in the shared tierAn encoding is its
(id, schema)pair — Zenoh's own representation. The conversion logic (id↔name table + Zenoh's exact parse/render/with_schemarules) lives in zenoh-flat-jni's sharedEncodingCodec(zenoh-flat-jni#4);io.zenoh.bytes.Encodinghere is a thin facade — the established constants and methods, pure delegation, zero logic. Same forZenohId.toString()(sharedzidString()).Encodinghandle with no close path.EncodingCorrespondenceTest,ZenohIdCorrespondenceTest) verify the shared codecs against the native oracle across the whole predefined id range, parse/render edges, and random ids — one caught a real divergence (custom-encodingwithSchemapreserves the name inside the schema slot).2. Publisher default encoding — set natively at declare, zero crossing per put
PublisherOptions.encodingwas emulated JVM-side by re-sending(id, schema)on every put. Now it's passed once to the generateddeclarePublisher(zenoh-flat#3, merged — exposes zenoh'sPublisherBuilder::encoding), and plainput(payload)passes absent — the native default applies, no encoding data crosses at all. Per-callPutOptions.encodingoverrides still work (crossing the cheap(id, schema)pair).Design note:
PinnedEncodingwas implemented, then deliberately droppedThe branch history contains a
PinnedEncoding(a preallocated native encoding handle crossing per call via a dual-arm expansion), later removed by design decision. Rationale:(id, schema)crossing costs only a short schema-string decode (~tens of ns for schema-bearing encodings, zero for predefined ones) against a put path of ≈1µs — noise in practice.Encodingvalue would hide a native handle in a value class — reintroducing exactly the lifecycle machinery (close/finalize, locking, leak hazard) this PR deletes; a separate resource class earned its ~30 lines only for a narrow niche (schema-bearing per-call overrides in non-publisher hot loops).The enabling generator feature (prebindgen #80: Optional selector-dispatched expansion, selector
-1= absent) is merged and covertest-covered, so the pinned-handle arm can be reintroduced wire-compatibly if a real workload ever demands it. Encoding params meanwhile keep the simple(present, id, schema)crossing.Verification
jvmTest: 106 tests, 0 failures — incl. the correspondence suites andPublisherEncodingTest(native declare-time default + per-put override, end-to-end pub/sub).9bc155b(PR Addressed issue #1 #4 head), zenoh-flatmain(6d22091, Update build for cross-platform builds and add github workflow. Close #2 #3 merged), prebindgenmain(SyncCargo.lockwith Zenoh45e05f0from2024-05-13#80 merged).Merge order: zenoh-flat-jni#4 → this.