Unit ContractDBUnit

Description

Lightweight in-memory DB for Contracts and TradeRouteLegs.

• TContractDB manages:

  • Contracts (mapped by GroupId)

  • TradeRouteLegs (temporary "limbo" legs mapped by PanelID)

  • Panel subscriptions (panels register to receive notifications)

Design notes:

• Panels register with RegisterPanel and receive a unique PanelID.

• Panels provide two optional callbacks: one for leg/row updates (OnLegNotify) and one for contract-level updates (OnContractNotify).

• When a panel pushes an updated TTradeRouteLeg to the DB via PanelChanged, if Leg.GroupId = 0 the leg is kept in the TTradeRouteLeg mapping; if Leg.GroupId > 0 the DB will create or update a TContract for that GroupId, convert the leg into a TContractLeg and add/remove it from the contract.

• If a panel moves from a GroupId > 0 back to 0, the associated contract leg is removed from the contract and the route leg is returned to the limbo mapping.

• We assume that all changes to the status of the system stored in the database occur within limbo; to achieve this, we modify the GroupID of the calling panel by setting it to 0 and only operate in the instruction block with AItem = eGroupID. *

Overview

Classes, Interfaces, Objects and Records