Changes between Version 2 and Version 3 of FDORfc61
- Timestamp:
- May 12, 2011, 11:31:18 PM (13 years ago)
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FDORfc61
v2 v3 1 = FDO RFC 60 - Extend FDO API to add support forsave point =1 = FDO RFC 60 - Extend FDO transaction API to support save point = 2 2 3 3 This page contains a request for comments document (RFC) for the FDO Open Source project. … … 21 21 22 22 == Overview == 23 23 This RFC proposes an extended FDO transaction capability to support save point. 24 24 25 25 26 26 == Motivation == 27 27 FDO currently does not support starting another transaction (i.e. a sub transaction) inside a transaction that has already been started, or divide a transaction into smaller parts that can be independently submit or rolled back. The consequence of this is that for a complicated transaction (may be time consuming), the overall effort will be rolled back if a little error occurs at some point. Thus we need to extend the FDO transaction API to support save point. The purpose of this RFC is to provide a solution for such extension. 28 28 29 29 == Proposed Solution == 30 30 31 Since most FDO data providers which natively support save point mark save points by name, I propose we can add the following interface method to “FdoITransaction” interface. 32 {{{ 33 class FdoITransaction : public FdoIDisposable 34 { 35 ...... 36 /// \brief 37 /// Creates a save point in this transaction. 38 /// 39 /// \param savePointName 40 /// Save point name. 41 /// 42 FDO_API virtual void AddSavePoint(FdoString* savePointName) = 0; 43 44 /// \brief 45 /// Rollbacks the transaction to the specified save point. 46 /// 47 /// \param savePointName 48 /// Save point name. 49 /// 50 FDO_API virtual void Rollback(FdoString* savePointName) = 0; 51 ...... 52 } 53 }}} 54 55 “AddSavePoint” method is used to add a save point with a specific name which can later be rolled back to without affecting the work done prior to the save point. “Rollback” method rolls back to a named save point. 56 57 The “FdoIConnectionCapabilities” interface also has to be extended to enable query for this capability: 58 59 {{{ 60 class FdoIConnectionCapabilities : public FdoIDisposable 61 { 62 ...... 63 /// \brief 64 /// Returns the current transaction of the connection. 65 /// 66 /// \return 67 /// Returns the current transaction, NULL if no active transaction exists. 68 /// 69 FDO_API virtual bool SupportsSavePoint() = 0; 70 ...... 71 } 72 }}} 31 73 32 74 33 == Implications==75 == Managed FDO API == 34 76 35 TBD 77 The FDO Managed Interfaces will be updated in a similar manner to reflect the proposed changes. 78 79 == Provider Implementation == 80 81 All providers that natively support save point should return true in FdoIConnectionCapabilities::SupportsSavePoint and implement new methods in “FdoITransaction” interface to support save point. 36 82 37 83 == Test Plan == 38 84 39 TBD 85 Existing FDO core unit tests will be expanded to test the proposed enhancements defined above. 86 Provider specific unit tests will be added to test the proposed enhancements defined above. 40 87 41 88 == !Funding/Resources == 42 89 43 TBD 90 Autodesk to provide funding/resources. 44 91
