M4 wave 1 prep — the design-pivotal small types per dependencies.md
("(b) is small but design-pivotal — agree the event shape before
consumers depend on it"). The actual Session implementation lands
next iteration as wave 1 main (the .NET MxNativeSession.cs is ~24 KB).
RecoveryPolicy
- Was a unit struct; now carries max_attempts: u32 + delay: Duration
(port of MxNativeRecoveryPolicy at MxNativeSession.cs:24-43).
- SINGLE_ATTEMPT associated const matches the .NET static at cs:26.
- validate() rejects max_attempts == 0 (cs:33-36); the negative-Delay
branch (cs:38-41) is unreachable in Rust because Duration is
unsigned, so it's elided with a doc note.
- Default impl now returns SINGLE_ATTEMPT (was derive Default which
zero-initialised).
SessionOptions (new — port of MxNativeClientOptions at cs:7-22)
- local_engine_id, engine_name, partner_version, galaxy_id,
source_platform_id, heartbeat_ticks_per_beat: Option<i32>,
heartbeat_max_missed_ticks.
- default_local_engine_id() constructor: 0x7000 + (process_id & 0x0FFF)
per GenerateDefaultLocalEngineId at cs:18-21.
- default_engine_name(): "mxaccess.<pid>" mirroring the .NET
"MxNativeClient.{ProcessId}" at cs:10.
- partner_version=6 default matches design/60-roadmap.md:54 DoD #1.
Test count delta: 468 -> 479 (+11). All four DoD gates green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty
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