com.orientechnologies.orient.core.sql.parser

Class OStatementCache

java.lang.Object

com.orientechnologies.orient.core.sql.parser.OStatementCache

public class OStatementCache
extends Object

This class is an LRU cache for already parsed SQL statement executors. It stores itself in the storage as a resource. It also acts an an entry point for the SQL parser.

Author:

Luigi Dell'Aquila (l.dellaquila-(at)-orientdb.com)

Constructor Summary

Constructors

Constructor and Description
OStatementCache(int size)

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	contains(String statement)
OStatement	get(String statement)
static OStatement	get(String statement, ODatabaseDocumentInternal db) returns an already parsed SQL executor, taking it from the cache if it exists or creating a new one (parsing and then putting it into the cache) if it doesn't
protected static OStatement	parse(String statement) parses an SQL statement and returns the corresponding executor
protected static void	throwParsingException(ParseException e, String statement)
protected static void	throwParsingException(TokenMgrError e, String statement)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

OStatementCache

public OStatementCache(int size)

Parameters:

size - the size of the cache

Method Detail

contains

public boolean contains(String statement)

Parameters:

statement - an SQL statement

Returns:

true if the corresponding executor is present in the cache

get

public static OStatement get(String statement,
                             ODatabaseDocumentInternal db)

returns an already parsed SQL executor, taking it from the cache if it exists or creating a new one (parsing and then putting it into the cache) if it doesn't

Parameters:

statement - the SQL statement

db - the current DB instance. If null, cache is ignored and a new executor is created through statement parsing

Returns:

a statement executor from the cache

get

public OStatement get(String statement)

Parameters:

statement - an SQL statement

Returns:

the corresponding executor, taking it from the internal cache, if it exists

parse

protected static OStatement parse(String statement)
                           throws OCommandSQLParsingException

parses an SQL statement and returns the corresponding executor

Parameters:

statement - the SQL statement

Returns:

the corresponding executor

Throws:

OCommandSQLParsingException - if the input parameter is not a valid SQL statement

throwParsingException

protected static void throwParsingException(ParseException e,
                                            String statement)

throwParsingException

protected static void throwParsingException(TokenMgrError e,
                                            String statement)

clear

public void clear()