Module overnight_whitelist 

v1.4.113 US overnight order parity: CMD20874 dynamic overnight white list. 给 C++ AdjustTradeSession 的 Session_ALL → ALL_DAY/ETH 分支提供 broker+stock_id cache. CMD20874 QryNightWhitelistClient — dynamic overnight white list.

C++ source of truth:

• NNProtoCenter/Trade/NNProto_Trd_OvernightWhiteList.cpp
• NNDataCenter/Trade/NNData_Trd_OvernightWhiteList.cpp
• FTGateway/GTWCmdAndPushReply.cpp::Timer_PullOvernightWhiteList

OpenD startup loads cached overnight_white_list.dat, then periodically sends CMD20874 per broker. AdjustTradeSession uses the in-memory IsStockInWhiteList(enBroker, secInfo.nSecID) result: Session_ALL stays ALL_DAY only for broker+stock IDs in this list; otherwise it downgrades to ETH.

Hardcoded / Assumption Ledger

• CMD20874 is NN_ProtoCmd_Trd_OvernightWhiteList, from C++ NNBase_Define_ProtoCmd.h.
• Valid brokers {1001,1007,1008,1009} are copied from C++ NNData_Trd_OvernightWhiteList.cpp::IsValidBrokerID (Futu HK/US/SG/AU).
• stock_id_list is gzip-compressed bytes containing native uint64_t stock IDs. Official OpenD targets little-endian macOS/Windows in our test matrix, so Rust decodes explicit little-endian u64 chunks rather than host-native order.
• Current BackendConn::request does not expose C++ nExtErrCode == -1009 cache-match replies. A decode/fetch error leaves the last cache intact; normal response updates remain dynamic.

Structs

OvernightWhitelistCache

Shared per-broker overnight whitelist cache.

OvernightWhitelistSnapshot

Decoded CMD20874 response.

Constants

CMD_TRD_OVERNIGHT_WHITE_LIST

CMD20874 NN_ProtoCmd_Trd_OvernightWhiteList.

DEFAULT_UPDATE_INTERVAL_SECS

C++ fallback interval in OMEvProc_OvernightWhiteList when backend does not provide a usable update_interval.

MIN_UPDATE_INTERVAL_SECS

Minimum refresh interval guard for malformed backend values.

Functions

build_overnight_whitelist_request

is_valid_overnight_whitelist_broker

normalized_update_interval

parse_overnight_whitelist_rsp

refresh_overnight_whitelist

unpack_stock_id_list_gzip