Fix review comments for query buffer space optimization

Author: cjbj

src/dpi/include/dpiConn.h

@@ -63,7 +63,7 @@ class Conn
                                 // properties
   virtual void stmtCacheSize(unsigned int stmtCacheSize) = 0;
   virtual unsigned int stmtCacheSize() const = 0;
-  virtual int getByteExpansionRation () = 0;
+  virtual int getByteExpansionRatio () = 0;
 
   virtual void lobPrefetchSize(unsigned int lobPrefetchSize) = 0;
   virtual unsigned int lobPrefetchSize() const = 0;

src/dpi/src/dpiConnImpl.cpp

@@ -51,8 +51,6 @@
 using namespace std;
 
 
-
-
 /*---------------------------------------------------------------------------
                            PUBLIC METHODS
   ---------------------------------------------------------------------------*/
@@ -246,9 +244,9 @@ void ConnImpl::stmtCacheSize(unsigned int stmtCacheSize)
    RETURNS:
      Byte expansion ratio (int)
  */
-int ConnImpl::getByteExpansionRation ()
+int ConnImpl::getByteExpansionRatio ()
 {
-  return lxgratio_;
+  return csratio_;
 }
 
 /*****************************************************************************/
@@ -502,8 +500,8 @@ void ConnImpl::initConnImpl ( bool pool, bool externalAuth,
                    ub4 nameLen, const string &user, const string &password )
 {
   OCIServer *srvh = NULL;
-  ub4 mode        = 0;
-  ub2 csid_       = 0;
+  ub4 mode        = OCI_DEFAULT;
+  ub2 csid        = 0;
 
   if ( pool )
     mode = externalAuth ? ( OCI_SESSGET_CREDEXT | OCI_SESSGET_SPOOL ) :
@@ -557,13 +555,10 @@ void ConnImpl::initConnImpl ( bool pool, bool externalAuth,
                         ( ub4 ) OCI_ATTR_SERVER, errh_ ), errh_ );
 
   // Get the DBCHARSET from server
-  ociCall ( OCIAttrGet ( srvh, ( ub4 ) OCI_HTYPE_SERVER, ( void * ) &csid_,
+  ociCall ( OCIAttrGet ( srvh, ( ub4 ) OCI_HTYPE_SERVER, ( void * ) &csid,
                          ( ub4 * ) 0, ( ub4 ) OCI_ATTR_CHARSET_ID, errh_ ),
                           errh_ );
-  if ( csid_ == DPI_AL32UTF8 )
-    lxgratio_ = 1;
-  else
-    lxgratio_ = 3;
+    csratio_ = getCsRatio ( csid );
 }
 
 /*****************************************************************************/

src/dpi/src/dpiConnImpl.h

@@ -54,6 +54,15 @@ class PoolImpl;
 
 
 
+/*
+ * The maximum character expansion ratio from any DB character to 
+ * AL32UTF8 is known to be 3-times
+ */
+#define DPI_WORSTCASE_CHAR_CONVERSION_RATIO    3
+
+// No character expansion required if DB has AL32UTF8 charset
+#define DPI_BESTCASE_CHAR_CONVERSION_RATIO     1
+
 /*---------------------------------------------------------------------------
                      PUBLIC TYPES
   ---------------------------------------------------------------------------*/
@@ -89,7 +98,7 @@ class ConnImpl : public Conn
   virtual void module(const string &module);
 
   virtual void action(const string &action);
-  virtual int getByteExpansionRation ();
+  virtual int getByteExpansionRatio ();
 
                               // interface methods
   virtual Stmt* getStmt(const string &sql);
@@ -124,6 +133,12 @@ class ConnImpl : public Conn
   void initConnImpl( bool pool, bool externalAuth, const string& connClass,
                      OraText *poolNmRconnStr, ub4 nameLen,
                      const string &user, const string &password );
+  int getCsRatio ( ub2 csid )
+  {
+    return ( csid == DPI_AL32UTF8 ) ? DPI_BESTCASE_CHAR_CONVERSION_RATIO :
+             DPI_WORSTCASE_CHAR_CONVERSION_RATIO;
+  }
+  
   void cleanup();
 
 
@@ -136,7 +151,7 @@ class ConnImpl : public Conn
   OCISvcCtx   *svch_;           // OCI service handle
   OCISession  *sessh_;          // OCI Session handle. Do not free this.
   boolean     hasTxn_;          // set if transaction is in progress
-  int         lxgratio_;        // Caches DBCharset ID
+  int         csratio_;         // character expansion ratio
 };
 
 

src/njs/src/njsConnection.cpp

@@ -1376,7 +1376,7 @@ void Connection::DoDefines ( eBaton* executeBaton, const dpi::MetaData* meta,
                              unsigned int numCols )
 {
   Define *defines = executeBaton->defines = new Define[numCols];
-  int lxgratio = executeBaton->dpiconn->getByteExpansionRation ();
+  int csratio = executeBaton->dpiconn->getByteExpansionRatio ();
 
   for (unsigned int col = 0; col < numCols; col++)
   {
@@ -1418,13 +1418,12 @@ void Connection::DoDefines ( eBaton* executeBaton, const dpi::MetaData* meta,
                                              executeBaton->columnNames[col],
                                              meta[col].dbType );
         /*
-         * While fetching non-ascii characters, each byte on the server
-         * can take upto maximum of 3 bytes when it converted to AL32UTF8
-         * because the client character set is always set to AL32UTF8
-         * in node-oracledb. If server has AL32UTF8 then ratio is 1.
+         * the buffer size is increased to account for possible character
+         * size expansion when data is converted from the DB character set
+         * to AL32UTF8
          */
 
-		defines[col].maxSize   = (meta[col].dbSize) * lxgratio;
+		defines[col].maxSize   = (meta[col].dbSize) * csratio;
 
 
         if ( NJS_SIZE_T_OVERFLOW ( defines[col].maxSize,
@@ -2814,7 +2813,7 @@ void Connection::cbDynBufferAllocate ( void *ctx, bool dmlReturning,
   eBaton *executeBaton = (eBaton *)ctx;
   Bind *bind = (Bind *)executeBaton->binds[bndpos];
 
-  if ( NJS_SIZE_T_OVERFLOW ( nRows, sizeof ( short )))
+  if ( NJS_SIZE_T_OVERFLOW ( sizeof ( short ), nRows ) )
   {
     executeBaton->error = NJSMessages::getErrorMsg( errResultsTooLarge );
     return;
@@ -2830,7 +2829,7 @@ void Connection::cbDynBufferAllocate ( void *ctx, bool dmlReturning,
   }
   if ( dmlReturning )
   {
-    if ( NJS_SIZE_T_OVERFLOW ( nRows, sizeof ( unsigned int )))
+    if ( NJS_SIZE_T_OVERFLOW ( sizeof ( unsigned int ), nRows ) )
     {
       executeBaton->error = NJSMessages::getErrorMsg( errResultsTooLarge );
       return;
@@ -2943,10 +2942,6 @@ void Connection::cbDynBufferAllocate ( void *ctx, bool dmlReturning,
       }
     }
     if ( !dmlReturning )
-    {
-      *(bind->len) = sizeof ( unsigned int ) ;
-    }
-    if ( !dmlReturning )
     {
       *(bind->len) = sizeof ( double ) ;
     }
@@ -2968,7 +2963,7 @@ void Connection::cbDynBufferAllocate ( void *ctx, bool dmlReturning,
     }
     else
     {
-      bind->value = (void *)malloc(sizeof(Descriptor *) * bind->rowsReturned);
+      bind->value = (void *)malloc(sizeof(Descriptor *) * nRows);
       if( !bind->value )
       {
         executeBaton->error = NJSMessages::getErrorMsg(

src/njs/src/njsMessages.cpp

@@ -59,7 +59,7 @@ static const char *errMsg[] =
   "NJS-022: invalid LOB",
   "NJS-023: concurrent operations on LOB are not allowed",
   "NJS-024: memory allocation failed",
-  "NJS-025: overflow when calculating results area size"
+  "NJS-025: overflow when calculating results area size",
 };
 
 string NJSMessages::getErrorMsg ( NJSErrorType err, ... )