Improve db_fetch_array performance

Improve db_fetch_array performance by caching the result from: - db_is_pgsql() - db_is_oracle() Based on profiling, the repeated calls were using up to 20% of total time for the db_fetch_array execution. Fixes #21871, PR #1105
mantisbt · May 15, 2017 · 06e7677 · 06e7677
2 parents b0b56c8 + db1996c
commit 06e7677
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Showing 2 changed files with 91 additions and 75 deletions.
diff --git a/core/constant_inc.php b/core/constant_inc.php
@@ -693,3 +693,10 @@
 define( 'MANAGE_CONFIG_ACTION_CREATE', 'create' );
 define( 'MANAGE_CONFIG_ACTION_CLONE', 'clone' );
 define( 'MANAGE_CONFIG_ACTION_EDIT', 'edit' );
+
+# Databse functional type identifiers.
+define( 'DB_TYPE_UNDEFINED', 0 );
+define( 'DB_TYPE_MYSQL', 1 );
+define( 'DB_TYPE_PGSQL', 2 );
+define( 'DB_TYPE_MSSQL', 3 );
+define( 'DB_TYPE_ORACLE', 4 );
diff --git a/core/database_api.php b/core/database_api.php
@@ -59,6 +59,9 @@
 $ADODB_FETCH_MODE = ADODB_FETCH_ASSOC;
 define( 'ADODB_ASSOC_CASE', ADODB_ASSOC_CASE_LOWER );
 
+# Stores the functional database type based on db driver
+$g_db_functional_type = db_get_type( config_get_global( 'db_type' ) );
+
 /**
  * Mantis Database Parameters Count class
  * Stores the current parameter count, provides method to generate parameters
@@ -126,8 +129,9 @@ public function pop() {
  * @return boolean indicating if the connection was successful
  */
 function db_connect( $p_dsn, $p_hostname = null, $p_username = null, $p_password = null, $p_database_name = null, $p_pconnect = false ) {
-	global $g_db_connected, $g_db;
+	global $g_db_connected, $g_db, $g_db_functional_type;
 	$t_db_type = config_get_global( 'db_type' );
+	$g_db_functional_type = db_get_type( $t_db_type );
 
 	if( !db_check_database_support( $t_db_type ) ) {
 		error_parameters( 0, 'PHP Support for database is not enabled' );
@@ -211,63 +215,64 @@ function db_check_database_support( $p_db_type ) {
 }
 
 /**
- * Checks if the database driver is MySQL
- * @return boolean true if mysql
+ * Maps a db driver type to the functional databse type
+ * @param string	$p_driver_type Database driver name
+ * @return int		Database type
  */
-function db_is_mysql() {
-	$t_db_type = config_get_global( 'db_type' );
-
-	switch( $t_db_type ) {
+function db_get_type( $p_driver_type ) {
+	switch( $p_driver_type ) {
 		case 'mysql':
 		case 'mysqli':
-			return true;
+			return DB_TYPE_MYSQL;
+		case 'postgres':
+		case 'postgres7':
+		case 'pgsql':
+			return DB_TYPE_PGSQL;
+		case 'mssql':
+		case 'mssqlnative':
+		case 'odbc_mssql':
+			return DB_TYPE_MSSQL;
+		case 'oci8':
+			return DB_TYPE_ORACLE;
+		default:
+			return DB_TYPE_UNDEFINED;
 	}
+}
 
-	return false;
+/**
+ * Checks if the database driver is MySQL
+ * @return boolean true if mysql
+ */
+function db_is_mysql() {
+	global $g_db_functional_type;
+	return( DB_TYPE_MYSQL == $g_db_functional_type );
 }
 
 /**
  * Checks if the database driver is PostgreSQL
  * @return boolean true if postgres
  */
 function db_is_pgsql() {
-	$t_db_type = config_get_global( 'db_type' );
-
-	switch( $t_db_type ) {
-		case 'postgres':
-		case 'postgres7':
-		case 'pgsql':
-			return true;
-	}
-
-	return false;
+	global $g_db_functional_type;
+	return( DB_TYPE_PGSQL == $g_db_functional_type );
 }
 
 /**
  * Checks if the database driver is MS SQL
  * @return boolean true if mssql
  */
 function db_is_mssql() {
-	$t_db_type = config_get_global( 'db_type' );
-
-	switch( $t_db_type ) {
-		case 'mssql':
-		case 'mssqlnative':
-		case 'odbc_mssql':
-			return true;
-	}
-
-	return false;
+	global $g_db_functional_type;
+	return( DB_TYPE_MSSQL == $g_db_functional_type );
 }
 
 /**
  * Checks if the database driver is Oracle (oci8)
  * @return boolean true if oracle
  */
 function db_is_oracle() {
-	$t_db_type = config_get_global( 'db_type' );
-
-	return ( $t_db_type == 'oci8' );
+	global $g_db_functional_type;
+	return( DB_TYPE_ORACLE == $g_db_functional_type );
 }
 
 /**
@@ -460,7 +465,7 @@ function db_affected_rows() {
  * @return array Database result
  */
 function db_fetch_array( IteratorAggregate &$p_result ) {
-	global $g_db, $g_db_type;
+	global $g_db_functional_type;
 
 	if( $p_result->EOF ) {
 		return false;
@@ -470,66 +475,70 @@ function db_fetch_array( IteratorAggregate &$p_result ) {
 	$t_row = $p_result->fields;
 
 	# Additional handling for specific RDBMS
-	if( db_is_pgsql() ) {
-		# pgsql's boolean fields are stored as 't' or 'f' and must be converted
-		static $s_current_result = null, $s_convert_needed;
-
-		if( $s_current_result != $p_result ) {
-			# Processing a new query
-			$s_current_result = $p_result;
-			$s_convert_needed = false;
-		} elseif( !$s_convert_needed ) {
-			# No conversion needed, return the row as-is
-			$p_result->MoveNext();
-			return $t_row;
-		}
+	switch( $g_db_functional_type ) {
+
+		case DB_TYPE_PGSQL:
+			# pgsql's boolean fields are stored as 't' or 'f' and must be converted
+			static $s_current_result = null, $s_convert_needed;
+
+			if( $s_current_result != $p_result ) {
+				# Processing a new query
+				$s_current_result = $p_result;
+				$s_convert_needed = false;
+			} elseif( !$s_convert_needed ) {
+				# No conversion needed, return the row as-is
+				$p_result->MoveNext();
+				return $t_row;
+			}
 
-		foreach( $p_result->FieldTypesArray() as $t_field ) {
-			switch( $t_field->type ) {
-				case 'bool':
-					switch( $t_row[$t_field->name] ) {
-						case 'f':
-							$t_row[$t_field->name] = false;
-							break;
-						case 't':
-							$t_row[$t_field->name] = true;
-							break;
-					}
-					$s_convert_needed = true;
-					break;
+			foreach( $p_result->FieldTypesArray() as $t_field ) {
+				switch( $t_field->type ) {
+					case 'bool':
+						switch( $t_row[$t_field->name] ) {
+							case 'f':
+								$t_row[$t_field->name] = false;
+								break;
+							case 't':
+								$t_row[$t_field->name] = true;
+								break;
+						}
+						$s_convert_needed = true;
+						break;
+				}
 			}
-		}
+			break;
 
-	} elseif( db_is_oracle() ) {
-		# oci8 returns null values for empty strings, convert them back
-		foreach( $t_row as &$t_value ) {
-			if( !isset( $t_value ) ) {
-				$t_value = '';
+		case DB_TYPE_ORACLE:
+			# oci8 returns null values for empty strings, convert them back
+			foreach( $t_row as &$t_value ) {
+				if( !isset( $t_value ) ) {
+					$t_value = '';
+				}
 			}
-		}
+			break;
 	}
 
 	$p_result->MoveNext();
 	return $t_row;
 }
 
 /**
- * Retrieve a result returned from a specific database query
- * @param boolean|IteratorAggregate $p_result Database Query Record Set to retrieve next result for.
- * @param integer                   $p_index1 Row to retrieve (optional).
- * @param integer                   $p_index2 Column to retrieve (optional).
+ * Retrieve a specific field from a database query result
+ * @param boolean|IteratorAggregate $p_result		Database Query Record Set to retrieve the field from.
+ * @param integer                   $p_row_index	Row to retrieve, zero-based (optional).
+ * @param integer                   $p_col_index	Column to retrieve, zero-based (optional).
  * @return mixed Database result
  */
-function db_result( $p_result, $p_index1 = 0, $p_index2 = 0 ) {
+function db_result( $p_result, $p_row_index = 0, $p_col_index = 0 ) {
 	if( $p_result && ( db_num_rows( $p_result ) > 0 ) ) {
-		$p_result->Move( $p_index1 );
-		$t_result = $p_result->GetArray();
+		$p_result->Move( $p_row_index );
+		$t_row = db_fetch_array( $p_result );
 
 		# Make the array numerically indexed. This is required to retrieve the
 		# column ($p_index2), since we use ADODB_FETCH_ASSOC fetch mode.
-		$t_result = array_values( $t_result[0] );
+		$t_result = array_values( $t_row );
 
-		return $t_result[$p_index2];
+		return $t_result[$p_col_index];
 	}
 
 	return false;