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pqconnection.pp: use of connection pool instead of creating a new connection for every new transaction.

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git-svn-id: trunk@23228 -
This commit is contained in:
ludob 2012-12-27 18:09:22 +00:00
parent 764f36a179
commit 7075f7aaa3
1 changed files with 111 additions and 20 deletions
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131
packages/fcl-db/src/sqldb/postgres/pqconnection.pp
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@ -40,10 +40,17 @@ type
STATEMENT_POSITION:string;
end;
TTranConnection= class
protected
FPGConn : PPGConn;
FTranActive : boolean
end;
{ TPQConnection }
TPQConnection = class (TSQLConnection)
private
FConnectionPool : array of TTranConnection;
FCursorCount : word;
FConnectString : string;
FSQLDatabaseHandle : pointer;
@ -213,6 +220,7 @@ function TPQConnection.RollBack(trans : TSQLHandle) : boolean;
var
res : PPGresult;
tr : TPQTrans;
i : Integer;
begin
result := false;
@ -223,7 +231,13 @@ begin
CheckResultError(res,tr.PGConn,SErrRollbackFailed);
PQclear(res);
PQFinish(tr.PGConn);
//make connection available in pool
for i:=0 to length(FConnectionPool)-1 do
if FConnectionPool[i].FPGConn=tr.PGConn then
begin
FConnectionPool[i].FTranActive:=false;
break;
end;
result := true;
end;
@ -231,6 +245,7 @@ function TPQConnection.Commit(trans : TSQLHandle) : boolean;
var
res : PPGresult;
tr : TPQTrans;
i : Integer;
begin
result := false;
@ -240,7 +255,13 @@ begin
CheckResultError(res,tr.PGConn,SErrCommitFailed);
PQclear(res);
PQFinish(tr.PGConn);
//make connection available in pool
for i:=0 to length(FConnectionPool)-1 do
if FConnectionPool[i].FPGConn=tr.PGConn then
begin
FConnectionPool[i].FTranActive:=false;
break;
end;
result := true;
end;
@ -248,28 +269,48 @@ function TPQConnection.StartdbTransaction(trans : TSQLHandle; AParams : string)
var
res : PPGresult;
tr : TPQTrans;
i : Integer;
begin
result:=false;
tr := trans as TPQTrans;
tr.PGConn := PQconnectdb(pchar(FConnectString));
if (PQstatus(tr.PGConn) = CONNECTION_BAD) then
//find an unused connection in the pool
i:=0;
while i<length(FConnectionPool) do
if (FConnectionPool[i].FPGConn=nil) or not FConnectionPool[i].FTranActive then
break
else
i:=i+1;
if i=length(FConnectionPool) then //create a new connection
begin
result := false;
PQFinish(tr.PGConn);
DatabaseError(SErrConnectionFailed + ' (PostgreSQL: ' + PQerrorMessage(tr.PGConn) + ')',self);
tr.PGConn := PQconnectdb(pchar(FConnectString));
if (PQstatus(tr.PGConn) = CONNECTION_BAD) then
begin
result := false;
PQFinish(tr.PGConn);
DatabaseError(SErrConnectionFailed + ' (PostgreSQL: ' + PQerrorMessage(tr.PGConn) + ')',self);
end
else
begin
if CharSet <> '' then
PQsetClientEncoding(tr.PGConn, pchar(CharSet));
//store the new connection
SetLength(FConnectionPool,i+1);
FConnectionPool[i]:=TTranConnection.Create;
FConnectionPool[i].FPGConn:=tr.PGConn;
FConnectionPool[i].FTranActive:=true;
end;
end
else
else //re-use existing connection
begin
if CharSet <> '' then
PQsetClientEncoding(tr.PGConn, pchar(CharSet));
res := PQexec(tr.PGConn, 'BEGIN');
CheckResultError(res,tr.PGConn,sErrTransactionFailed);
PQclear(res);
result := true;
tr.PGConn:=FConnectionPool[i].FPGConn;
FConnectionPool[i].FTranActive:=true;
end;
res := PQexec(tr.PGConn, 'BEGIN');
CheckResultError(res,tr.PGConn,sErrTransactionFailed);
PQclear(res);
result := true;
end;
procedure TPQConnection.RollBackRetaining(trans : TSQLHandle);
@ -334,11 +375,22 @@ begin
// This only works for pg>=8.0, so timestamps won't work with earlier versions of pg which are compiled with integer_datetimes on
if PQparameterStatus<>nil then
FIntegerDateTimes := PQparameterStatus(FSQLDatabaseHandle,'integer_datetimes') = 'on';
SetLength(FConnectionPool,1);
FConnectionPool[0]:=TTranConnection.Create;
FConnectionPool[0].FPGConn:=FSQLDatabaseHandle;
FConnectionPool[0].FTranActive:=false;
end;
procedure TPQConnection.DoInternalDisconnect;
var i:integer;
begin
PQfinish(FSQLDatabaseHandle);
for i:=0 to length(FConnectionPool)-1 do
begin
if assigned(FConnectionPool[i].FPGConn) then
PQfinish(FConnectionPool[i].FPGConn);
FConnectionPool[i].Free;
end;
Setlength(FConnectionPool,0);
{$IfDef LinkDynamically}
ReleasePostgres3;
{$EndIf}
@ -356,6 +408,7 @@ var
MESSAGE_DETAIL: string;
MESSAGE_HINT: string;
STATEMENT_POSITION: string;
i:Integer;
begin
if (PQresultStatus(res) <> PGRES_COMMAND_OK) then
begin
@ -384,7 +437,17 @@ begin
PQclear(res);
res:=nil;
if assigned(conn) then
begin
PQFinish(conn);
//make connection available in pool
for i:=0 to length(FConnectionPool)-1 do
if FConnectionPool[i].FPGConn=conn then
begin
FConnectionPool[i].FPGConn:=nil;
FConnectionPool[i].FTranActive:=false;
break;
end;
end;
raise E;
end;
end;
@ -719,8 +782,36 @@ begin
end;
function TPQConnection.GetHandle: pointer;
var
i:integer;
begin
Result := FSQLDatabaseHandle;
result:=nil;
if not Connected then
exit;
//Get any handle that is (still) connected
for i:=0 to length(FConnectionPool)-1 do
if assigned(FConnectionPool[i].FPGConn) and (PQstatus(FConnectionPool[i].FPGConn)<>CONNECTION_BAD) then
begin
Result :=FConnectionPool[i].FPGConn;
exit;
end;
//Nothing connected!! Reconnect
if assigned(FConnectionPool[0].FPGConn) then
PQreset(FConnectionPool[0].FPGConn)
else
FConnectionPool[0].FPGConn := PQconnectdb(pchar(FConnectString));
if (PQstatus(FConnectionPool[0].FPGConn) = CONNECTION_BAD) then
begin
result := nil;
PQFinish(FConnectionPool[0].FPGConn);
FConnectionPool[0].FPGConn:=nil;
FConnectionPool[0].FTranActive:=false;
DatabaseError(SErrConnectionFailed + ' (PostgreSQL: ' + PQerrorMessage(FConnectionPool[0].FPGConn) + ')',self);
end
else
if CharSet <> '' then
PQsetClientEncoding(FConnectionPool[0].FPGConn, pchar(CharSet));
result:=FConnectionPool[0].FPGConn;
end;
function TPQConnection.Fetch(cursor : TSQLCursor) : boolean;
@ -1072,7 +1163,7 @@ begin
citServerVersion,
citServerVersionString:
if Connected then
Result:=format('%6.6d', [PQserverVersion(FSQLDatabaseHandle)]);
Result:=format('%6.6d', [PQserverVersion(GetHandle)]);
citClientName:
Result:=TPQConnectionDef.LoadedLibraryName;
else