From d7f11ecb06688186d4c68b5933fb1437279ce03d Mon Sep 17 00:00:00 2001
From: Luis Fernando Muñoz Mejías <Luis.Fernando.Munoz.Mejias@cern.ch>
Date: Wed, 8 Apr 2009 16:50:57 +0200
Subject: Make it work in batches of statements.

Currently, all statements to be executed are stored on the same
structure. When the batch size is reached, all statements are executed
in a single transaction, and then committed.

There are many corner cases in which an error may happen and the batch
may be left in an inconsistent state, perhaps leaking memory or
crashing. They will be fixed.
---
 plugins/omoracle/omoracle.c | 71 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 60 insertions(+), 11 deletions(-)

diff --git a/plugins/omoracle/omoracle.c b/plugins/omoracle/omoracle.c
index ea910d3a..9b1ec42d 100644
--- a/plugins/omoracle/omoracle.c
+++ b/plugins/omoracle/omoracle.c
@@ -15,7 +15,8 @@
     $OmoracleDBPassword: password to log in on the database.
     $OmoracleDB: connection string (an Oracle easy connect or a db
     name as specified by tnsnames.ora)
-    
+    $OmoracleBatchSize: Number of elements to send to the DB.
+
     All fields are mandatory. The dbstring can be an Oracle easystring
     or a DB name, as present in the tnsnames.ora file.
 
@@ -50,6 +51,18 @@ MODULE_TYPE_OUTPUT
 DEF_OMOD_STATIC_DATA
 DEFobjCurrIf(errmsg)
 
+/**  */
+struct oracle_batch
+{
+	/* Batch size */
+	int size;
+	/* Last element inserted in the buffer. The batch will be
+	 * executed when n == size */
+	int n;
+	/* Statements to run on this transaction */
+	char** statements;
+};
+
 typedef struct _instanceData {
 	/* Environment handler, the base for any OCI work. */
 	OCIEnv* environment;
@@ -67,6 +80,8 @@ typedef struct _instanceData {
 	OCIBind* binding;
 	/* Connection string, kept here for possible retries. */
 	char* connection;
+	/* Batch */
+	struct oracle_batch batch;
 } instanceData;
 
 /** Database name, to be filled by the $OmoracleDB directive */
@@ -76,6 +91,8 @@ static char* db_name;
 static char* db_user;
 /** Database password, to be filled by the $OmoracleDBPassword */
 static char* db_password;
+/** Batch size. */
+static int batch_size;
 
 /** Generic function for handling errors from OCI.
 
@@ -148,6 +165,12 @@ CODESTARTcreateInstance
 		 OCIHandleAlloc(pData->environment, (void*) &(pData->statement),
 				OCI_HTYPE_STMT, 0, NULL));
 
+	pData->batch.n = 0;
+	pData->batch.size = batch_size;
+	pData->batch.statements = calloc(pData->batch.size,
+					 sizeof *pData->batch.statements);
+	CHKmalloc(pData->batch.statements);
+
 finalize_it:
 ENDcreateInstance
 
@@ -163,6 +186,9 @@ CODESTARTfreeInstance
 	OCIHandleFree(pData->authinfo, OCI_HTYPE_AUTHINFO);
 	OCIHandleFree(pData->statement, OCI_HTYPE_STMT);
 	free(pData->connection);
+	while (pData->batch.size--) 
+		free(pData->batch.statements[pData->batch.size]);
+	free(pData->batch.statements);
 	dbgprintf ("omoracle freed all its resources\n");
 	RETiRet;
 
@@ -263,21 +289,41 @@ CODE_STD_FINALIZERparseSelectorAct
 ENDparseSelectorAct
 
 BEGINdoAction
+	int i;
+	int n;
 CODESTARTdoAction
 	dbgprintf("omoracle attempting to execute statement %s\n", *ppString);
-	CHECKERR(pData->error,
-		 OCIStmtPrepare(pData->statement, pData->error, *ppString,
-				strlen(*ppString), OCI_NTV_SYNTAX,
-				OCI_DEFAULT));
-	CHECKERR(pData->error,
-		 OCIStmtExecute(pData->service, pData->statement, pData->error,
-				1, 0, NULL, NULL, OCI_DEFAULT));
-	CHECKERR(pData->error,
-		 OCITransCommit(pData->service, pData->error, 0));
+
+	if (pData->batch.n == pData->batch.size) {
+		dbgprintf("omoracle batch size limit hit, sending into DB\n");
+		for (i = 0; i < pData->batch.n; i++) {
+			if (pData->batch.statements[i] == NULL)
+				continue;
+			n = strlen(pData->batch.statements[i]);
+			CHECKERR(pData->error,
+				 OCIStmtPrepare(pData->statement,
+						pData->error,
+						pData->batch.statements[i], n,
+						OCI_NTV_SYNTAX, OCI_DEFAULT));
+			CHECKERR(pData->error,
+				 OCIStmtExecute(pData->service,
+						pData->statement,
+						pData->error,
+						1, 0, NULL, NULL, OCI_DEFAULT));
+			free(pData->batch.statements[i]);
+			pData->batch.statements[i] = NULL;
+		}
+		CHECKERR(pData->error,
+			 OCITransCommit(pData->service, pData->error, 0));
+		pData->batch.n = 0;
+	}
+	pData->batch.statements[pData->batch.n] = strdup(*ppString);
+	CHKmalloc(pData->batch.statements[pData->batch.n]);
+	pData->batch.n++;
+
 finalize_it:
 	dbgprintf ("omoracle %s at executing statement %s\n",
 		   iRet?"did not succeed":"succeeded", *ppString);
-/* Clean credentials to avoid leakage in case of core dump. */
 ENDdoAction
 
 BEGINmodExit
@@ -331,4 +377,7 @@ CODEmodInit_QueryRegCFSLineHdlr
 	CHKiRet(omsdRegCFSLineHdlr((uchar*) "omoracledb", 0,
 				   eCmdHdlrGetWord, NULL, &db_name,
 				   STD_LOADABLE_MODULE_ID));
+	CHKiRet(omsdRegCFSLineHdlr((uchar*) "omoraclebatchsize", 0,
+				   eCmdHdlrInt, NULL, &batch_size,
+				   STD_LOADABLE_MODULE_ID));
 ENDmodInit
-- 
cgit