ENG-317: price wire float→double (Phase A, client)#333
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islandbitcoin wants to merge 1 commit intomainfrom
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ENG-317: price wire float→double (Phase A, client)#333islandbitcoin wants to merge 1 commit intomainfrom
islandbitcoin wants to merge 1 commit intomainfrom
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Adds `double price_v2 = 3` alongside the existing `float price = 1` (now deprecated) on PriceResponse and the equivalent on Tick. Servers populate both fields; clients prefer `price_v2` and fall back to `price` so the two repos can roll out independently. Float32 quantises non-USD/non-BTC rates (notably JMD-class rates) by ~6e-8 relative drift, which compounds to ~J$19 of uncertainty on a 1-BTC quote — the wire-level baseline behind ENG-316. Phase B (separate PR, after one prod release cycle on Phase A) removes `float price` entirely.
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ENG-317 — float→double on the price wire (Phase A, client side)
Pairs with lnflash/price#7. These two PRs MUST land in
either order but the server PR should hit prod first so this client has
something to read from.
What changes
price.protoandprice_history.proto: adddouble price_v2 = 3alongside the existing
float price(now[deprecated = true]).Wire-compatible: old servers and old clients keep working unchanged.
services/price/index.ts: newpreferDouble({ price, price_v2 })helper used at every read site (real-time get-price, USD-cross
conversion, and the
Tickmapping inlistHistory). Picksprice_v2when populated and non-zero, else falls back toprice.0continues to mean "no price" (existingPriceNotAvailableErrorsemantics).__tests__/wire-precision.test.ts: 10 cases. Demonstrates the float32drift on real-world JMD/USD/JPY intraday rates, and locks in the
fallback semantics for both new-server and pre-ENG-317-server cases.
Why dual-field instead of in-place float→double
Protobuf wire types differ between
float(5) anddouble(1) — anin-place change would silently corrupt all readers. The additive
deprecate-then-remove pattern is the only safe rollout. Phase B (a
follow-up PR after one full release cycle in prod) drops
float priceentirely.Drift baseline
For
9.45 JMD/sat(the ENG-316 rate):price_v2carries the float64 unchanged, so the drift drops to zeroonce both ends are upgraded.
Acceptance
price_v2, falls back toprice, surfacesPriceNotAvailableErroron0fallback path for pre-ENG-317 servers