The failover runbook's Windows switch scope returns to the native Windows jobs:
remove the Python runtime eligibility sentences, the pool Python prerequisite,
and the proposal links. The #3629 self-hosted Python runtime proposal is
retired (deleted as obsolete after its unmeasured-throughput run), and a new
implemented note records that the Windows x64 runtime lane stays on
GitHub-hosted Windows with the evidence and alternatives. Bilingual sidecars
re-recorded.
The failover runbook's Windows switch scope returns to the native Windows jobs:
remove the Python runtime eligibility sentences, the pool Python prerequisite,
and the links to the proposal. The self-hosted Python runtime proposal is
moved to rejected with its unmeasured-throughput verdict, and a new
implemented note records that the Windows x64 runtime lane stays on
GitHub-hosted Windows with the reasons. Bilingual sidecars re-recorded.
Windows x64 runtime builds resolve their hosted matrix.runner unconditionally
again (windows-2025 for pull-request CI). Remove the DSH_CI_FAILOVER_WINDOWS
selector, job-private Python toolchain, self-hosted dependency install and
post-step cleanup, the private setup script, and the routing spec introduced
in #3629. The Windows failover switch again covers only the native Windows
jobs in ci.yml.
Consolidate the existing notes-only PR into one review baseline. Preserve the exact reviewed tree; subsequent corrections remain separate commits with their own rationale and regression evidence.
Reflect the review feedback on the reader list: assistantStreamFirstTokenTime and the has-visible readers stop at the first qualifying member, while lastAssistantStreamChunk, assistantStreamChunks, and joinAssistantStreamText scan the whole stream; assembleAssistantStream feeds a BlockAssembler one joined delta per run. Record-level readers trust the static record type; expandAssistantStream is the validating path.
Session format v2 embeds each attempt's compact stream in
assistant/message and assistant/attempt, but Host and client consumers
still expanded it into per-member TimedStreamChunk arrays and did
per-member work; expandAssistantStream materializes the full array before
find/toReversed/break can answer. Session Stats (the projection phase of
every Session open), the token meter's usage and provider-assembly folds,
the subagent output fold, and the Session Controller image lookup still
paid O(members) allocation and time per settlement.
The Chat and Trajectory definitions were already settled from
message.content on master; the remaining per-member folds stay.
dsh-llm now exports record-level readers (first token, visible content,
visible text, last raw chunk of a type, raw chunks of a type, joined
text, run-aware assembly, per-run first-token/first-visible times) that
scan the compact records once with early exit. Session Stats reads
assistantStreamFirstTokenTime, the token meter reads
lastAssistantStreamChunk(stream, 'usage') and assembles through
assembleAssistantStream, the subagent output fold appends
joinAssistantStreamText, and the Session Controller scans
assistantStreamChunks(stream, 'block-end').
expandAssistantStream is deliberately not memoized: retaining expansions
costs roughly ten times the compact stream for the Session's lifetime.
It remains the validating path at durable boundaries.
Synthetic 200-turn v0 migration benchmark, median of five: first-open
projection 28.0 ms -> 5.4 ms, first-open total 76.9 -> 50.0 ms, peak RSS
137.2 -> 94.9 MB; reopen projection 17.8 -> 5.6 ms; all phase budgets and
the 128 MB heap constraint keep passing.
Yichen Jiang