udr/client/FBTransaction.pas

(*
 *  Firebird Interface (fbintf). The fbintf components provide a set of
 *  Pascal language bindings for the Firebird API. Although predominantly
 *  a new development they include source code taken from IBX and may be
 *  considered a derived product. This software thus also includes the copyright
 *  notice and license conditions from IBX.
 *
 *  Except for those parts dervied from IBX, contents of this file are subject
 *  to the Initial Developer's Public License Version 1.0 (the "License"); you
 *  may not use this file except in compliance with the License. You may obtain a
 *  copy of the License here:
 *
 *    http://www.firebirdsql.org/index.php?op=doc&id=idpl
 *
 *  Software distributed under the License is distributed on an "AS
 *  IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 *  implied. See the License for the specific language governing rights
 *  and limitations under the License.
 *
 *  The Initial Developer of the Original Code is Tony Whyman.
 *
 *  The Original Code is (C) 2016 Tony Whyman, MWA Software
 *  (http://www.mwasoftware.co.uk).
 *
 *  All Rights Reserved.
 *
 *  Contributor(s): ______________________________________.
 *
*)
{************************************************************************}
{                                                                        }
{       Borland Delphi Visual Component Library                          }
{       InterBase Express core components                                }
{                                                                        }
{       Copyright (c) 1998-2000 Inprise Corporation                      }
{                                                                        }
{    InterBase Express is based in part on the product                   }
{    Free IB Components, written by Gregory H. Deatz for                 }
{    Hoagland, Longo, Moran, Dunst & Doukas Company.                     }
{    Free IB Components is used under license.                           }
{                                                                        }
{    The contents of this file are subject to the InterBase              }
{    Public License Version 1.0 (the "License"); you may not             }
{    use this file except in compliance with the License. You            }
{    may obtain a copy of the License at http://www.Inprise.com/IPL.html }
{    Software distributed under the License is distributed on            }
{    an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either              }
{    express or implied. See the License for the specific language       }
{    governing rights and limitations under the License.                 }
{    The Original Code was created by InterBase Software Corporation     }
{       and its successors.                                              }
{    Portions created by Inprise Corporation are Copyright (C) Inprise   }
{       Corporation. All Rights Reserved.                                }
{    Contributor(s): Jeff Overcash                                       }
{                                                                        }
{    IBX For Lazarus (Firebird Express)                                  }
{    Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
{    Portions created by MWA Software are copyright McCallum Whyman      }
{    Associates Ltd 2011 - 2015                                                }
{                                                                        }
{************************************************************************}
unit FBTransaction;
{$IFDEF MSWINDOWS} 
{$DEFINE WINDOWS} 
{$ENDIF}

{$IFDEF FPC}
{$mode delphi}
{$interfaces COM}
{$ENDIF}

interface

uses
  Classes, SysUtils, IB, FBParamBlock, FBActivityMonitor, FBClientAPI, FBOutputBlock;

type
  { TFBTransaction }

  TFBTransaction = class(TActivityReporter, IActivityMonitor,ITransaction)
  private
    FFirebirdAPI: TFBClientAPI;
    function GenerateTPB(sl: array of byte): ITPB;
  protected
    FTPB: ITPB;
    FSeqNo: integer;
    FDefaultCompletion: TTransactionCompletion;
    FAttachments: array of IAttachment; {Keep reference to attachment - ensures
                                          attachment cannot be freed before transaction}
    FTransactionName: AnsiString;
    procedure CheckHandle;
    function GetActivityIntf(att: IAttachment): IActivityMonitor; virtual; abstract;
    function GetJournalIntf(Attachment: IAttachment): IJournallingHook;
    procedure SetInterface(api: TFBClientAPI); virtual;
    function GetTrInfo(ReqBuffer: PByte; ReqBufLen: integer): ITrInformation; virtual; abstract;
    procedure InternalStartSingle(attachment: IAttachment); virtual; abstract;
    procedure InternalStartMultiple; virtual; abstract;
    procedure InternalCommit(Force: boolean); virtual; abstract;
    procedure InternalCommitRetaining; virtual; abstract;
    procedure InternalRollback(Force: boolean); virtual; abstract;
    procedure InternalRollbackRetaining; virtual; abstract;
  public
    constructor Create(api: TFBClientAPI; Attachments: array of IAttachment; Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
    constructor Create(api: TFBClientAPI; Attachments: array of IAttachment; TPB: ITPB; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
    constructor Create(api: TFBClientAPI; Attachment: IAttachment; Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
    constructor Create(api: TFBClientAPI; Attachment: IAttachment; TPB: ITPB; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
    destructor Destroy; override;
    procedure DoDefaultTransactionEnd(Force: boolean);
    property FirebirdAPI: TFBClientAPI read FFirebirdAPI;

  public
    {ITransaction}
    function getTPB: ITPB;
    procedure PrepareForCommit;virtual; abstract;
    procedure Commit(Force: boolean=false);
    procedure CommitRetaining;
    function GetInTransaction: boolean; virtual; abstract;
    function GetIsReadOnly: boolean;
    function GetTransactionID: integer;
    function GetAttachmentCount: integer;
    function GetAttachment(index: integer): IAttachment;
    function GetJournalingActive(attachment: IAttachment): boolean;
    function GetDefaultCompletion: TTransactionCompletion;
    procedure Rollback(Force: boolean=false);
    procedure RollbackRetaining;
    procedure Start(DefaultCompletion: TTransactionCompletion=taCommit); overload;
    procedure Start(TPB: ITPB; DefaultCompletion: TTransactionCompletion=taCommit); overload;
    function GetTrInformation(Requests: array of byte): ITrInformation; overload;
    function GetTrInformation(Request: byte): ITrInformation; overload;
    function GetTransactionName: AnsiString;
    procedure SetTransactionName(aValue: AnsiString);

    property InTransaction: boolean read GetInTransaction;
    property TransactionSeqNo: integer read FSeqNo;
  end;

  {The transaction user interface is used to force an action on the end of the
   transaction.}

  ITransactionUser = interface
    ['{156fcdc9-a326-44b3-a82d-f23c6fb9f97c}']
    procedure TransactionEnding(aTransaction: ITransaction; Force: boolean);
  end;

  { TTPBItem }

  TTPBItem = class(TParamBlockItem,ITPBItem)
  public
    function getParamTypeName: AnsiString; override;
  end;

  { TTPB }

  TTPB = class (TCustomParamBlock<TTPBItem,ITPBItem>, ITPB)
  protected
    function LookupItemType(ParamTypeName: AnsiString): byte; override;
  public
    constructor Create(api: TFBClientAPI);
    function GetParamTypeName(ParamType: byte): Ansistring;
    {$IFDEF FPC}
    function ITPB.GetDPBParamTypeName = GetParamTypeName;
    {$ELSE}
    function GetDPBParamTypeName(ParamType: byte): Ansistring;
    {$ENDIF}
    function AsText: AnsiString;
end;

  {$IFDEF FPC}
  TTrInfoItem = class;

  { TTrInfoItem }

  TTrInfoItem = class(TOutputBlockItemGroup<TTrInfoItem,ITrInfoItem>,ITrInfoItem)
  {$ELSE}
    TTrInfoItem = class(TOutputBlockItemGroup<TOutputBlockItem,ITrInfoItem>,ITrInfoItem)
  {$ENDIF}
    public
      procedure DecodeTraIsolation(var IsolationType, RecVersion: byte);
  end;

  { TTrInformation }

  TTrInformation = class(TCustomOutputBlock<TTrInfoItem,ITrInfoItem>, ITrInformation)
  protected
    procedure DoParseBuffer; override;
  public
    constructor Create(api: TFBClientAPI; aSize: integer = DefaultBufferSize);
    {$IFNDEF FPC}
    function Find(ItemType: byte): ITrInfoItem;
    {$ENDIF}
  end;


implementation

uses FBMessages;

const
  isc_tpb_last_tpb_constant = isc_tpb_at_snapshot_number;

  TPBConstantNames: array[1..isc_tpb_last_tpb_constant] of string = (
    'consistency',
    'concurrency',
    'shared',
    'protected',
    'exclusive',
    'wait',
    'nowait',
    'read',
    'write',
    'lock_read',
    'lock_write',
    'verb_time',
    'commit_time',
    'ignore_limbo',
    'read_committed',
    'autocommit',
    'rec_version',
    'no_rec_version',
    'restart_requests',
    'no_auto_undo',
    'lock_timeout',
    'read_consistency',
    'at_snapshot_number'
  );

{ TFBTransaction }

function TFBTransaction.GenerateTPB(sl: array of byte): ITPB;
var
  i: Integer;
begin
  Result := TTPB.Create(FFirebirdAPI);
  for i := 0 to Length(sl) - 1 do
    Result.Add(sl[i]);
end;

procedure TFBTransaction.CheckHandle;
begin
  if not InTransaction then
    IBError(ibxeNotInTransaction,[]);
end;

function TFBTransaction.GetJournalIntf(Attachment: IAttachment): IJournallingHook;
begin
  Attachment.QueryInterface(IJournallingHook,Result)
end;

procedure TFBTransaction.SetInterface(api: TFBClientAPI);
begin
  FFirebirdAPI := api;
end;

constructor TFBTransaction.Create(api: TFBClientAPI; Attachments: array of IAttachment;
  Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString);
begin
  Create(api, Attachments,GenerateTPB(Params), DefaultCompletion, aName);
end;

constructor TFBTransaction.Create(api: TFBClientAPI; Attachments: array of IAttachment; TPB: ITPB;
  DefaultCompletion: TTransactionAction; aName: AnsiString);
var
  i: Integer;
begin
  inherited Create(nil);
  FTransactionName := aName;
  SetInterface(api);
  if Length(Attachments) = 0 then
    IBError(ibxeEmptyAttachmentsList,[nil]);

  {make sure all attachments use same Firebird API}
  for i := 0 to Length(Attachments) - 1 do
    if Attachments[i].getFirebirdAPI.GetFBLibrary.GetHandle <> FFirebirdAPI.GetFBLibrary.GetHandle then
      IBError(ibxeDifferentAPIs,[nil]);

  SetLength(FAttachments,Length(Attachments));
  for i := 0 to Length(Attachments) - 1 do
  begin
    AddMonitor(GetActivityIntf(Attachments[i]));
    FAttachments[i] := Attachments[i];
  end;
  FTPB := TPB;
  Start(DefaultCompletion);
end;

constructor TFBTransaction.Create(api: TFBClientAPI; Attachment: IAttachment;
  Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString);
begin
  Create(api,Attachment,GenerateTPB(Params),DefaultCompletion,aName);
end;

constructor TFBTransaction.Create(api: TFBClientAPI; Attachment: IAttachment; TPB: ITPB;
  DefaultCompletion: TTransactionAction; aName: AnsiString);
begin
  inherited Create(nil);
  SetInterface(api);
  AddMonitor(GetActivityIntf(Attachment));
  SetLength(FAttachments,1);
  FAttachments[0] := Attachment;
  FTPB := TPB;
  FTransactionName := aName;
  Start(DefaultCompletion);
end;

destructor TFBTransaction.Destroy;
begin
  DoDefaultTransactionEnd(false);
  inherited Destroy;
end;

procedure TFBTransaction.DoDefaultTransactionEnd(Force: boolean);
var i: integer;
    intf: IUnknown;
    user: ITransactionUser;
begin
  if InTransaction then
  begin
    for i := 0 to InterfaceCount - 1 do
    begin
      intf := GetInterface(i);
      if (intf <> nil) and  (intf.QueryInterface(ITransactionUser,user) = S_OK) then
        user.TransactionEnding(self,Force);
    end;
    case FDefaultCompletion of
    taRollback:
      Rollback(Force);
    taCommit:
      Commit(Force);
    end;
  end;
end;

function TFBTransaction.getTPB: ITPB;
begin
  Result := FTPB;
end;

procedure TFBTransaction.Commit(Force: boolean);
var i: integer;
    TransactionID: integer;
    TransactionEndNeeded: array of boolean;
begin
  if not GetInTransaction then Exit;

  SetLength(TransactionEndNeeded,Length(FAttachments));
  TransactionID := GetTransactionID;
  for i := 0 to Length(FAttachments) - 1 do
    if (FAttachments[i] <> nil)  then
      TransactionEndNeeded[i] := GetJournalingActive(FAttachments[i])
    else
      TransactionEndNeeded[i] := false;
  InternalCommit(Force);
  for i := 0 to Length(FAttachments) - 1 do
    if TransactionEndNeeded[i] then
       GetJournalIntf(FAttachments[i]).TransactionEnd(TransactionID, TACommit);
end;

procedure TFBTransaction.CommitRetaining;
var i: integer;
    TransactionID: integer;
begin
  if not GetInTransaction then Exit;

  TransactionID := GetTransactionID;
  InternalCommitRetaining;
  for i := 0 to Length(FAttachments) - 1 do
    if (FAttachments[i] <> nil) and GetJournalingActive(FAttachments[i]) then
       GetJournalIntf(FAttachments[i]).TransactionRetained(self,TransactionID, TACommitRetaining);
end;

function TFBTransaction.GetIsReadOnly: boolean;
var Info: ITrInformation;
begin
  Info := GetTrInformation(isc_info_tra_access);
  if (Info.Count > 0) and (Info[0].getItemType = isc_info_tra_access) then
    Result := Info[0].getAsInteger = isc_info_tra_readonly
  else
    Result := false;
end;

function TFBTransaction.GetTransactionID: integer;
var Info: ITrInformation;
begin
  Result := -1;
  Info := GetTrInformation(isc_info_tra_id);
  if (Info.Count > 0) and (Info[0].getItemType = isc_info_tra_id) then
    Result := Info[0].getAsInteger;
end;

function TFBTransaction.GetAttachmentCount: integer;
begin
  Result := Length(FAttachments);
end;

function TFBTransaction.GetAttachment(index: integer): IAttachment;
begin
  if (index >= 0) and (index < Length(FAttachments)) then
    Result := FAttachments[index]
  else
    IBError(ibxeAttachmentListIndexError,[index]);
end;

function TFBTransaction.GetJournalingActive(attachment: IAttachment): boolean;
begin
  Result := false;
  if (attachment = nil) and (length(FAttachments) > 0) then
    attachment := FAttachments[0];
  if attachment <> nil then
  with attachment do
  Result := self.GetInTransaction and JournalingActive and
     ((((joReadOnlyTransactions in GetJournalOptions) and self.GetIsReadOnly)) or
     ((joReadWriteTransactions in GetJournalOptions) and not self.GetIsReadOnly));
end;

function TFBTransaction.GetDefaultCompletion: TTransactionCompletion;
begin
  Result := FDefaultCompletion;
end;

procedure TFBTransaction.Rollback(Force: boolean);
var i: integer;
    TransactionID: integer;
    TransactionEndNeeded: array of boolean;
begin
  if not GetInTransaction then Exit;

  SetLength(TransactionEndNeeded,Length(FAttachments));
  TransactionID := GetTransactionID;
  for i := 0 to Length(FAttachments) - 1 do
    if (FAttachments[i] <> nil)  then
      TransactionEndNeeded[i] := GetJournalingActive(FAttachments[i])
    else
      TransactionEndNeeded[i] := false;
  InternalRollback(Force);
  for i := 0 to Length(FAttachments) - 1 do
    if TransactionEndNeeded[i] then
       GetJournalIntf(FAttachments[i]).TransactionEnd(TransactionID, TARollback);
end;

procedure TFBTransaction.RollbackRetaining;
var i: integer;
    TransactionID: integer;
begin
  if not GetInTransaction then Exit;

  TransactionID := GetTransactionID;
  InternalRollbackRetaining;
  for i := 0 to Length(FAttachments) - 1 do
    if (FAttachments[i] <> nil) and GetJournalingActive(FAttachments[i]) then
       GetJournalIntf(FAttachments[i]).TransactionRetained(self,TransactionID,TARollbackRetaining);
end;

procedure TFBTransaction.Start(DefaultCompletion: TTransactionCompletion);
var i: integer;
begin
  if GetInTransaction then
    Exit;

  FDefaultCompletion := DefaultCompletion;

  if Length(FAttachments) = 1 then
    InternalStartSingle(FAttachments[0])
  else
    InternalStartMultiple;
  for i := 0 to Length(FAttachments) - 1 do
    if (FAttachments[i] <> nil) and GetJournalingActive(FAttachments[i]) then
      GetJournalIntf(FAttachments[i]).TransactionStart(self);
  Inc(FSeqNo);
end;

procedure TFBTransaction.Start(TPB: ITPB; DefaultCompletion: TTransactionCompletion
  );
begin
  FTPB := TPB;
  Start(DefaultCompletion);
end;

function TFBTransaction.GetTrInformation(Requests: array of byte
  ): ITrInformation;
var ReqBuffer: PByte;
    i: integer;
begin
  CheckHandle;
  if Length(Requests) = 1 then
    Result := GetTrInformation(Requests[0])
  else
  begin
    GetMem(ReqBuffer,Length(Requests));
    try
      for i := 0 to Length(Requests) - 1 do
        ReqBuffer[i] := Requests[i];

      Result := GetTrInfo(ReqBuffer,Length(Requests));

    finally
      FreeMem(ReqBuffer);
    end;
  end;
end;

function TFBTransaction.GetTrInformation(Request: byte): ITrInformation;
begin
  CheckHandle;
  Result := GetTrInfo(@Request,1);
end;

function TFBTransaction.GetTransactionName: AnsiString;
begin
  Result := FTransactionName;
end;

procedure TFBTransaction.SetTransactionName(aValue: AnsiString);
begin
  FTransactionName := aValue;
end;

{ TTPBItem }

function TTPBItem.getParamTypeName: AnsiString;
begin
  Result :=  TPBPrefix + TPBConstantNames[getParamType];
end;


{TTPB}

constructor TTPB.Create(api: TFBClientAPI);
begin
  inherited Create(api);
  FDataLength := 1;
  FBuffer^ := isc_tpb_version3;
end;

function TTPB.GetParamTypeName(ParamType: byte): Ansistring;
begin
  if ParamType <= isc_tpb_last_tpb_constant then
    Result := TPBPrefix + TPBConstantNames[ParamType]
  else
    Result := '';
end;

function TTPB.AsText: AnsiString;
var i: integer;
begin
  Result := '[';
  for i := 0 to getCount - 1 do
  begin
    Result := Result + GetParamTypeName(getItems(i).getParamType);
    if i < getCount - 1 then
      Result := Result + ',';
  end;
  Result := Result + ']';
end;

{$IFNDEF FPC}
function TTPB.GetDPBParamTypeName(ParamType: byte): Ansistring;
begin
  Result := GetParamTypeName(ParamType);
end;
{$ENDIF}


function TTPB.LookupItemType(ParamTypeName: AnsiString): byte;
var i: byte;
begin
  Result := 0;
  ParamTypeName := LowerCase(ParamTypeName);
  if (Pos(TPBPrefix, ParamTypeName) = 1) then
    Delete(ParamTypeName, 1, Length(TPBPrefix));

  for i := 1 to isc_tpb_last_tpb_constant do
    if (ParamTypeName = TPBConstantNames[i]) then
    begin
      Result := i;
      break;
    end;
end;

{ TTrInfoItem }

procedure TTrInfoItem.DecodeTraIsolation(var IsolationType, RecVersion: byte);
begin
  with FFirebirdClientAPI, ItemData^ do
  if getItemType = isc_info_tra_isolation then
  begin
    if FDataLength = 1 then
    begin
      IsolationType := getAsInteger;
      RecVersion := 0;
    end
    else
    begin
      IsolationType := (FBufPtr + 3)^;
      RecVersion := (FBufPtr + 4)^;
    end
  end
  else
    IBError(ibxeInfoBufferTypeError,[integer(FBufPtr^)]);
end;

{ TTrInformation }

procedure TTrInformation.DoParseBuffer;
var P: PByte;
    index: integer;
begin
  P := Buffer;
  index := 0;
  SetLength(FItems,0);
  while (P^ <> isc_info_end) and (P < Buffer + getBufSize) do
  begin
    SetLength(FItems,index+1);
    case byte(P^) of
    isc_info_tra_id,
    isc_info_tra_oldest_interesting,
    isc_info_tra_oldest_active,
    isc_info_tra_oldest_snapshot,
    fb_info_tra_snapshot_number,
    isc_info_tra_lock_timeout:
      FItems[index] := AddIntegerItem(P);

    isc_info_tra_isolation,
      {return transaction isolation mode of current transaction.
        format of returned clumplets is following:

        isc_info_tra_isolation,
                1, isc_info_tra_consistency | isc_info_tra_concurrency
        |
                2, isc_info_tra_read_committed,
                         isc_info_tra_no_rec_version | isc_info_tra_rec_version

        i.e. for read committed transactions returned 2 items while for
        other transactions returned 1 item}

    isc_info_tra_access:
      FItems[index] := AddIntegerItem(P);
    fb_info_tra_dbpath:
      FItems[index] := AddStringItem(P);
    else
      FItems[index] := AddItem(P);
    end;
    P := P + FItems[index]^.FSize;
    Inc(index);
  end;
end;

constructor TTrInformation.Create(api: TFBClientAPI; aSize: integer);
begin
  inherited Create(api,aSize);
  FIntegerType := dtInteger;
end;

{$IFNDEF FPC}
function TTrInformation.Find(ItemType: byte): ITrInfoItem;
begin
  Result := inherited Find(ItemType);
  if Result.GetSize = 0 then
    Result := nil;
end;
{$ENDIF}

end.

Revision:	363
Committed:	Tue Dec 7 13:30:05 2021 UTC (2 years, 11 months ago) by tony
Content type:	text/x-pascal
Original Path:	*ibx/branches/journaling/fbintf/client/FBTransaction.pas*
File size:	20484 byte(s)
Log Message:	add fbintf
#	Content
1	(*
2	* Firebird Interface (fbintf). The fbintf components provide a set of
3	* Pascal language bindings for the Firebird API. Although predominantly
4	* a new development they include source code taken from IBX and may be
5	* considered a derived product. This software thus also includes the copyright
6	* notice and license conditions from IBX.
7	*
8	* Except for those parts dervied from IBX, contents of this file are subject
9	* to the Initial Developer's Public License Version 1.0 (the "License"); you
10	* may not use this file except in compliance with the License. You may obtain a
11	* copy of the License here:
12	*
13	* http://www.firebirdsql.org/index.php?op=doc&id=idpl
14	*
15	* Software distributed under the License is distributed on an "AS
16	* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
17	* implied. See the License for the specific language governing rights
18	* and limitations under the License.
19	*
20	* The Initial Developer of the Original Code is Tony Whyman.
21	*
22	* The Original Code is (C) 2016 Tony Whyman, MWA Software
23	* (http://www.mwasoftware.co.uk).
24	*
25	* All Rights Reserved.
26	*
27	* Contributor(s): ______________________________________.
28	*
29	*)
30	{************************************************************************}
31	{ }
32	{ Borland Delphi Visual Component Library }
33	{ InterBase Express core components }
34	{ }
35	{ Copyright (c) 1998-2000 Inprise Corporation }
36	{ }
37	{ InterBase Express is based in part on the product }
38	{ Free IB Components, written by Gregory H. Deatz for }
39	{ Hoagland, Longo, Moran, Dunst & Doukas Company. }
40	{ Free IB Components is used under license. }
41	{ }
42	{ The contents of this file are subject to the InterBase }
43	{ Public License Version 1.0 (the "License"); you may not }
44	{ use this file except in compliance with the License. You }
45	{ may obtain a copy of the License at http://www.Inprise.com/IPL.html }
46	{ Software distributed under the License is distributed on }
47	{ an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either }
48	{ express or implied. See the License for the specific language }
49	{ governing rights and limitations under the License. }
50	{ The Original Code was created by InterBase Software Corporation }
51	{ and its successors. }
52	{ Portions created by Inprise Corporation are Copyright (C) Inprise }
53	{ Corporation. All Rights Reserved. }
54	{ Contributor(s): Jeff Overcash }
55	{ }
56	{ IBX For Lazarus (Firebird Express) }
57	{ Contributor: Tony Whyman, MWA Software http://www.mwasoftware.co.uk }
58	{ Portions created by MWA Software are copyright McCallum Whyman }
59	{ Associates Ltd 2011 - 2015 }
60	{ }
61	{************************************************************************}
62	unit FBTransaction;
63	{$IFDEF MSWINDOWS}
64	{$DEFINE WINDOWS}
65	{$ENDIF}
66
67	{$IFDEF FPC}
68	{$mode delphi}
69	{$interfaces COM}
70	{$ENDIF}
71
72	interface
73
74	uses
75	Classes, SysUtils, IB, FBParamBlock, FBActivityMonitor, FBClientAPI, FBOutputBlock;
76
77	type
78	{ TFBTransaction }
79
80	TFBTransaction = class(TActivityReporter, IActivityMonitor,ITransaction)
81	private
82	FFirebirdAPI: TFBClientAPI;
83	function GenerateTPB(sl: array of byte): ITPB;
84	protected
85	FTPB: ITPB;
86	FSeqNo: integer;
87	FDefaultCompletion: TTransactionCompletion;
88	FAttachments: array of IAttachment; {Keep reference to attachment - ensures
89	attachment cannot be freed before transaction}
90	FTransactionName: AnsiString;
91	procedure CheckHandle;
92	function GetActivityIntf(att: IAttachment): IActivityMonitor; virtual; abstract;
93	function GetJournalIntf(Attachment: IAttachment): IJournallingHook;
94	procedure SetInterface(api: TFBClientAPI); virtual;
95	function GetTrInfo(ReqBuffer: PByte; ReqBufLen: integer): ITrInformation; virtual; abstract;
96	procedure InternalStartSingle(attachment: IAttachment); virtual; abstract;
97	procedure InternalStartMultiple; virtual; abstract;
98	procedure InternalCommit(Force: boolean); virtual; abstract;
99	procedure InternalCommitRetaining; virtual; abstract;
100	procedure InternalRollback(Force: boolean); virtual; abstract;
101	procedure InternalRollbackRetaining; virtual; abstract;
102	public
103	constructor Create(api: TFBClientAPI; Attachments: array of IAttachment; Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
104	constructor Create(api: TFBClientAPI; Attachments: array of IAttachment; TPB: ITPB; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
105	constructor Create(api: TFBClientAPI; Attachment: IAttachment; Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
106	constructor Create(api: TFBClientAPI; Attachment: IAttachment; TPB: ITPB; DefaultCompletion: TTransactionAction; aName: AnsiString); overload;
107	destructor Destroy; override;
108	procedure DoDefaultTransactionEnd(Force: boolean);
109	property FirebirdAPI: TFBClientAPI read FFirebirdAPI;
110
111	public
112	{ITransaction}
113	function getTPB: ITPB;
114	procedure PrepareForCommit;virtual; abstract;
115	procedure Commit(Force: boolean=false);
116	procedure CommitRetaining;
117	function GetInTransaction: boolean; virtual; abstract;
118	function GetIsReadOnly: boolean;
119	function GetTransactionID: integer;
120	function GetAttachmentCount: integer;
121	function GetAttachment(index: integer): IAttachment;
122	function GetJournalingActive(attachment: IAttachment): boolean;
123	function GetDefaultCompletion: TTransactionCompletion;
124	procedure Rollback(Force: boolean=false);
125	procedure RollbackRetaining;
126	procedure Start(DefaultCompletion: TTransactionCompletion=taCommit); overload;
127	procedure Start(TPB: ITPB; DefaultCompletion: TTransactionCompletion=taCommit); overload;
128	function GetTrInformation(Requests: array of byte): ITrInformation; overload;
129	function GetTrInformation(Request: byte): ITrInformation; overload;
130	function GetTransactionName: AnsiString;
131	procedure SetTransactionName(aValue: AnsiString);
132
133	property InTransaction: boolean read GetInTransaction;
134	property TransactionSeqNo: integer read FSeqNo;
135	end;
136
137	{The transaction user interface is used to force an action on the end of the
138	transaction.}
139
140	ITransactionUser = interface
141	['{156fcdc9-a326-44b3-a82d-f23c6fb9f97c}']
142	procedure TransactionEnding(aTransaction: ITransaction; Force: boolean);
143	end;
144
145	{ TTPBItem }
146
147	TTPBItem = class(TParamBlockItem,ITPBItem)
148	public
149	function getParamTypeName: AnsiString; override;
150	end;
151
152	{ TTPB }
153
154	TTPB = class (TCustomParamBlock<TTPBItem,ITPBItem>, ITPB)
155	protected
156	function LookupItemType(ParamTypeName: AnsiString): byte; override;
157	public
158	constructor Create(api: TFBClientAPI);
159	function GetParamTypeName(ParamType: byte): Ansistring;
160	{$IFDEF FPC}
161	function ITPB.GetDPBParamTypeName = GetParamTypeName;
162	{$ELSE}
163	function GetDPBParamTypeName(ParamType: byte): Ansistring;
164	{$ENDIF}
165	function AsText: AnsiString;
166	end;
167
168	{$IFDEF FPC}
169	TTrInfoItem = class;
170
171	{ TTrInfoItem }
172
173	TTrInfoItem = class(TOutputBlockItemGroup<TTrInfoItem,ITrInfoItem>,ITrInfoItem)
174	{$ELSE}
175	TTrInfoItem = class(TOutputBlockItemGroup<TOutputBlockItem,ITrInfoItem>,ITrInfoItem)
176	{$ENDIF}
177	public
178	procedure DecodeTraIsolation(var IsolationType, RecVersion: byte);
179	end;
180
181	{ TTrInformation }
182
183	TTrInformation = class(TCustomOutputBlock<TTrInfoItem,ITrInfoItem>, ITrInformation)
184	protected
185	procedure DoParseBuffer; override;
186	public
187	constructor Create(api: TFBClientAPI; aSize: integer = DefaultBufferSize);
188	{$IFNDEF FPC}
189	function Find(ItemType: byte): ITrInfoItem;
190	{$ENDIF}
191	end;
192
193
194	implementation
195
196	uses FBMessages;
197
198	const
199	isc_tpb_last_tpb_constant = isc_tpb_at_snapshot_number;
200
201	TPBConstantNames: array[1..isc_tpb_last_tpb_constant] of string = (
202	'consistency',
203	'concurrency',
204	'shared',
205	'protected',
206	'exclusive',
207	'wait',
208	'nowait',
209	'read',
210	'write',
211	'lock_read',
212	'lock_write',
213	'verb_time',
214	'commit_time',
215	'ignore_limbo',
216	'read_committed',
217	'autocommit',
218	'rec_version',
219	'no_rec_version',
220	'restart_requests',
221	'no_auto_undo',
222	'lock_timeout',
223	'read_consistency',
224	'at_snapshot_number'
225	);
226
227	{ TFBTransaction }
228
229	function TFBTransaction.GenerateTPB(sl: array of byte): ITPB;
230	var
231	i: Integer;
232	begin
233	Result := TTPB.Create(FFirebirdAPI);
234	for i := 0 to Length(sl) - 1 do
235	Result.Add(sl[i]);
236	end;
237
238	procedure TFBTransaction.CheckHandle;
239	begin
240	if not InTransaction then
241	IBError(ibxeNotInTransaction,[]);
242	end;
243
244	function TFBTransaction.GetJournalIntf(Attachment: IAttachment): IJournallingHook;
245	begin
246	Attachment.QueryInterface(IJournallingHook,Result)
247	end;
248
249	procedure TFBTransaction.SetInterface(api: TFBClientAPI);
250	begin
251	FFirebirdAPI := api;
252	end;
253
254	constructor TFBTransaction.Create(api: TFBClientAPI; Attachments: array of IAttachment;
255	Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString);
256	begin
257	Create(api, Attachments,GenerateTPB(Params), DefaultCompletion, aName);
258	end;
259
260	constructor TFBTransaction.Create(api: TFBClientAPI; Attachments: array of IAttachment; TPB: ITPB;
261	DefaultCompletion: TTransactionAction; aName: AnsiString);
262	var
263	i: Integer;
264	begin
265	inherited Create(nil);
266	FTransactionName := aName;
267	SetInterface(api);
268	if Length(Attachments) = 0 then
269	IBError(ibxeEmptyAttachmentsList,[nil]);
270
271	{make sure all attachments use same Firebird API}
272	for i := 0 to Length(Attachments) - 1 do
273	if Attachments[i].getFirebirdAPI.GetFBLibrary.GetHandle <> FFirebirdAPI.GetFBLibrary.GetHandle then
274	IBError(ibxeDifferentAPIs,[nil]);
275
276	SetLength(FAttachments,Length(Attachments));
277	for i := 0 to Length(Attachments) - 1 do
278	begin
279	AddMonitor(GetActivityIntf(Attachments[i]));
280	FAttachments[i] := Attachments[i];
281	end;
282	FTPB := TPB;
283	Start(DefaultCompletion);
284	end;
285
286	constructor TFBTransaction.Create(api: TFBClientAPI; Attachment: IAttachment;
287	Params: array of byte; DefaultCompletion: TTransactionAction; aName: AnsiString);
288	begin
289	Create(api,Attachment,GenerateTPB(Params),DefaultCompletion,aName);
290	end;
291
292	constructor TFBTransaction.Create(api: TFBClientAPI; Attachment: IAttachment; TPB: ITPB;
293	DefaultCompletion: TTransactionAction; aName: AnsiString);
294	begin
295	inherited Create(nil);
296	SetInterface(api);
297	AddMonitor(GetActivityIntf(Attachment));
298	SetLength(FAttachments,1);
299	FAttachments[0] := Attachment;
300	FTPB := TPB;
301	FTransactionName := aName;
302	Start(DefaultCompletion);
303	end;
304
305	destructor TFBTransaction.Destroy;
306	begin
307	DoDefaultTransactionEnd(false);
308	inherited Destroy;
309	end;
310
311	procedure TFBTransaction.DoDefaultTransactionEnd(Force: boolean);
312	var i: integer;
313	intf: IUnknown;
314	user: ITransactionUser;
315	begin
316	if InTransaction then
317	begin
318	for i := 0 to InterfaceCount - 1 do
319	begin
320	intf := GetInterface(i);
321	if (intf <> nil) and (intf.QueryInterface(ITransactionUser,user) = S_OK) then
322	user.TransactionEnding(self,Force);
323	end;
324	case FDefaultCompletion of
325	taRollback:
326	Rollback(Force);
327	taCommit:
328	Commit(Force);
329	end;
330	end;
331	end;
332
333	function TFBTransaction.getTPB: ITPB;
334	begin
335	Result := FTPB;
336	end;
337
338	procedure TFBTransaction.Commit(Force: boolean);
339	var i: integer;
340	TransactionID: integer;
341	TransactionEndNeeded: array of boolean;
342	begin
343	if not GetInTransaction then Exit;
344
345	SetLength(TransactionEndNeeded,Length(FAttachments));
346	TransactionID := GetTransactionID;
347	for i := 0 to Length(FAttachments) - 1 do
348	if (FAttachments[i] <> nil) then
349	TransactionEndNeeded[i] := GetJournalingActive(FAttachments[i])
350	else
351	TransactionEndNeeded[i] := false;
352	InternalCommit(Force);
353	for i := 0 to Length(FAttachments) - 1 do
354	if TransactionEndNeeded[i] then
355	GetJournalIntf(FAttachments[i]).TransactionEnd(TransactionID, TACommit);
356	end;
357
358	procedure TFBTransaction.CommitRetaining;
359	var i: integer;
360	TransactionID: integer;
361	begin
362	if not GetInTransaction then Exit;
363
364	TransactionID := GetTransactionID;
365	InternalCommitRetaining;
366	for i := 0 to Length(FAttachments) - 1 do
367	if (FAttachments[i] <> nil) and GetJournalingActive(FAttachments[i]) then
368	GetJournalIntf(FAttachments[i]).TransactionRetained(self,TransactionID, TACommitRetaining);
369	end;
370
371	function TFBTransaction.GetIsReadOnly: boolean;
372	var Info: ITrInformation;
373	begin
374	Info := GetTrInformation(isc_info_tra_access);
375	if (Info.Count > 0) and (Info[0].getItemType = isc_info_tra_access) then
376	Result := Info[0].getAsInteger = isc_info_tra_readonly
377	else
378	Result := false;
379	end;
380
381	function TFBTransaction.GetTransactionID: integer;
382	var Info: ITrInformation;
383	begin
384	Result := -1;
385	Info := GetTrInformation(isc_info_tra_id);
386	if (Info.Count > 0) and (Info[0].getItemType = isc_info_tra_id) then
387	Result := Info[0].getAsInteger;
388	end;
389
390	function TFBTransaction.GetAttachmentCount: integer;
391	begin
392	Result := Length(FAttachments);
393	end;
394
395	function TFBTransaction.GetAttachment(index: integer): IAttachment;
396	begin
397	if (index >= 0) and (index < Length(FAttachments)) then
398	Result := FAttachments[index]
399	else
400	IBError(ibxeAttachmentListIndexError,[index]);
401	end;
402
403	function TFBTransaction.GetJournalingActive(attachment: IAttachment): boolean;
404	begin
405	Result := false;
406	if (attachment = nil) and (length(FAttachments) > 0) then
407	attachment := FAttachments[0];
408	if attachment <> nil then
409	with attachment do
410	Result := self.GetInTransaction and JournalingActive and
411	((((joReadOnlyTransactions in GetJournalOptions) and self.GetIsReadOnly)) or
412	((joReadWriteTransactions in GetJournalOptions) and not self.GetIsReadOnly));
413	end;
414
415	function TFBTransaction.GetDefaultCompletion: TTransactionCompletion;
416	begin
417	Result := FDefaultCompletion;
418	end;
419
420	procedure TFBTransaction.Rollback(Force: boolean);
421	var i: integer;
422	TransactionID: integer;
423	TransactionEndNeeded: array of boolean;
424	begin
425	if not GetInTransaction then Exit;
426
427	SetLength(TransactionEndNeeded,Length(FAttachments));
428	TransactionID := GetTransactionID;
429	for i := 0 to Length(FAttachments) - 1 do
430	if (FAttachments[i] <> nil) then
431	TransactionEndNeeded[i] := GetJournalingActive(FAttachments[i])
432	else
433	TransactionEndNeeded[i] := false;
434	InternalRollback(Force);
435	for i := 0 to Length(FAttachments) - 1 do
436	if TransactionEndNeeded[i] then
437	GetJournalIntf(FAttachments[i]).TransactionEnd(TransactionID, TARollback);
438	end;
439
440	procedure TFBTransaction.RollbackRetaining;
441	var i: integer;
442	TransactionID: integer;
443	begin
444	if not GetInTransaction then Exit;
445
446	TransactionID := GetTransactionID;
447	InternalRollbackRetaining;
448	for i := 0 to Length(FAttachments) - 1 do
449	if (FAttachments[i] <> nil) and GetJournalingActive(FAttachments[i]) then
450	GetJournalIntf(FAttachments[i]).TransactionRetained(self,TransactionID,TARollbackRetaining);
451	end;
452
453	procedure TFBTransaction.Start(DefaultCompletion: TTransactionCompletion);
454	var i: integer;
455	begin
456	if GetInTransaction then
457	Exit;
458
459	FDefaultCompletion := DefaultCompletion;
460
461	if Length(FAttachments) = 1 then
462	InternalStartSingle(FAttachments[0])
463	else
464	InternalStartMultiple;
465	for i := 0 to Length(FAttachments) - 1 do
466	if (FAttachments[i] <> nil) and GetJournalingActive(FAttachments[i]) then
467	GetJournalIntf(FAttachments[i]).TransactionStart(self);
468	Inc(FSeqNo);
469	end;
470
471	procedure TFBTransaction.Start(TPB: ITPB; DefaultCompletion: TTransactionCompletion
472	);
473	begin
474	FTPB := TPB;
475	Start(DefaultCompletion);
476	end;
477
478	function TFBTransaction.GetTrInformation(Requests: array of byte
479	): ITrInformation;
480	var ReqBuffer: PByte;
481	i: integer;
482	begin
483	CheckHandle;
484	if Length(Requests) = 1 then
485	Result := GetTrInformation(Requests[0])
486	else
487	begin
488	GetMem(ReqBuffer,Length(Requests));
489	try
490	for i := 0 to Length(Requests) - 1 do
491	ReqBuffer[i] := Requests[i];
492
493	Result := GetTrInfo(ReqBuffer,Length(Requests));
494
495	finally
496	FreeMem(ReqBuffer);
497	end;
498	end;
499	end;
500
501	function TFBTransaction.GetTrInformation(Request: byte): ITrInformation;
502	begin
503	CheckHandle;
504	Result := GetTrInfo(@Request,1);
505	end;
506
507	function TFBTransaction.GetTransactionName: AnsiString;
508	begin
509	Result := FTransactionName;
510	end;
511
512	procedure TFBTransaction.SetTransactionName(aValue: AnsiString);
513	begin
514	FTransactionName := aValue;
515	end;
516
517	{ TTPBItem }
518
519	function TTPBItem.getParamTypeName: AnsiString;
520	begin
521	Result := TPBPrefix + TPBConstantNames[getParamType];
522	end;
523
524
525	{TTPB}
526
527	constructor TTPB.Create(api: TFBClientAPI);
528	begin
529	inherited Create(api);
530	FDataLength := 1;
531	FBuffer^ := isc_tpb_version3;
532	end;
533
534	function TTPB.GetParamTypeName(ParamType: byte): Ansistring;
535	begin
536	if ParamType <= isc_tpb_last_tpb_constant then
537	Result := TPBPrefix + TPBConstantNames[ParamType]
538	else
539	Result := '';
540	end;
541
542	function TTPB.AsText: AnsiString;
543	var i: integer;
544	begin
545	Result := '[';
546	for i := 0 to getCount - 1 do
547	begin
548	Result := Result + GetParamTypeName(getItems(i).getParamType);
549	if i < getCount - 1 then
550	Result := Result + ',';
551	end;
552	Result := Result + ']';
553	end;
554
555	{$IFNDEF FPC}
556	function TTPB.GetDPBParamTypeName(ParamType: byte): Ansistring;
557	begin
558	Result := GetParamTypeName(ParamType);
559	end;
560	{$ENDIF}
561
562
563	function TTPB.LookupItemType(ParamTypeName: AnsiString): byte;
564	var i: byte;
565	begin
566	Result := 0;
567	ParamTypeName := LowerCase(ParamTypeName);
568	if (Pos(TPBPrefix, ParamTypeName) = 1) then
569	Delete(ParamTypeName, 1, Length(TPBPrefix));
570
571	for i := 1 to isc_tpb_last_tpb_constant do
572	if (ParamTypeName = TPBConstantNames[i]) then
573	begin
574	Result := i;
575	break;
576	end;
577	end;
578
579	{ TTrInfoItem }
580
581	procedure TTrInfoItem.DecodeTraIsolation(var IsolationType, RecVersion: byte);
582	begin
583	with FFirebirdClientAPI, ItemData^ do
584	if getItemType = isc_info_tra_isolation then
585	begin
586	if FDataLength = 1 then
587	begin
588	IsolationType := getAsInteger;
589	RecVersion := 0;
590	end
591	else
592	begin
593	IsolationType := (FBufPtr + 3)^;
594	RecVersion := (FBufPtr + 4)^;
595	end
596	end
597	else
598	IBError(ibxeInfoBufferTypeError,[integer(FBufPtr^)]);
599	end;
600
601	{ TTrInformation }
602
603	procedure TTrInformation.DoParseBuffer;
604	var P: PByte;
605	index: integer;
606	begin
607	P := Buffer;
608	index := 0;
609	SetLength(FItems,0);
610	while (P^ <> isc_info_end) and (P < Buffer + getBufSize) do
611	begin
612	SetLength(FItems,index+1);
613	case byte(P^) of
614	isc_info_tra_id,
615	isc_info_tra_oldest_interesting,
616	isc_info_tra_oldest_active,
617	isc_info_tra_oldest_snapshot,
618	fb_info_tra_snapshot_number,
619	isc_info_tra_lock_timeout:
620	FItems[index] := AddIntegerItem(P);
621
622	isc_info_tra_isolation,
623	{return transaction isolation mode of current transaction.
624	format of returned clumplets is following:
625
626	isc_info_tra_isolation,
627	1, isc_info_tra_consistency \| isc_info_tra_concurrency
628	\|
629	2, isc_info_tra_read_committed,
630	isc_info_tra_no_rec_version \| isc_info_tra_rec_version
631
632	i.e. for read committed transactions returned 2 items while for
633	other transactions returned 1 item}
634
635	isc_info_tra_access:
636	FItems[index] := AddIntegerItem(P);
637	fb_info_tra_dbpath:
638	FItems[index] := AddStringItem(P);
639	else
640	FItems[index] := AddItem(P);
641	end;
642	P := P + FItems[index]^.FSize;
643	Inc(index);
644	end;
645	end;
646
647	constructor TTrInformation.Create(api: TFBClientAPI; aSize: integer);
648	begin
649	inherited Create(api,aSize);
650	FIntegerType := dtInteger;
651	end;
652
653	{$IFNDEF FPC}
654	function TTrInformation.Find(ItemType: byte): ITrInfoItem;
655	begin
656	Result := inherited Find(ItemType);
657	if Result.GetSize = 0 then
658	Result := nil;
659	end;
660	{$ENDIF}
661
662	end.
663