teichmann@5831: package org.dive4elements.river.artifacts.datacage.templating;
sascha@998: 
sascha@998: import java.util.regex.Pattern;
sascha@998: import java.util.regex.Matcher;
sascha@998: 
sascha@998: import java.util.List;
sascha@998: import java.util.Map;
sascha@998: import java.util.TreeMap;
sascha@998: import java.util.ArrayList;
sascha@998: 
sascha@998: import java.sql.PreparedStatement;
sascha@998: import java.sql.SQLException;
sascha@998: import java.sql.Connection;
sascha@998: import java.sql.ResultSet;
sascha@998: 
sascha@998: import net.sf.ehcache.Cache;
sascha@998: import net.sf.ehcache.Element;
sascha@998: 
teichmann@5831: import org.dive4elements.river.artifacts.cache.CacheFactory;
sascha@998: 
sascha@1023: import org.apache.log4j.Logger;
sascha@1023: 
felix@4615: /** SQL Statement, create PreparedStatement. */
sascha@998: public class CompiledStatement
sascha@998: {
sascha@1023:     private static Logger log = Logger.getLogger(CompiledStatement.class);
sascha@1023: 
sascha@998:     public static final String DATACAGE_DB_CACHE =
sascha@998:         "datacage.db";
sascha@998: 
sascha@998:     public static final Pattern VAR =
sascha@998:         Pattern.compile("\\$\\{([a-zA-Z0-9_-]+)\\}");
sascha@998: 
sascha@998:     protected String original;
sascha@998:     protected String statement;
sascha@998: 
sascha@998:     protected Map<String, List<Integer>> positions;
sascha@998: 
sascha@998:     protected int numVars;
sascha@998: 
sascha@998:     public class Instance {
sascha@998: 
sascha@998:         protected PreparedStatement preparedStatement;
sascha@998: 
sascha@998:         public Instance() {
sascha@998:         }
sascha@998: 
felix@4898:         /** Executes a Statement. */
sascha@998:         protected ResultData executeCached(
sascha@998:             Cache       cache,
sascha@998:             Connection  connection,
sascha@998:             StackFrames frames
sascha@998:         )
sascha@998:         throws SQLException
sascha@998:         {
sascha@1023:             log.debug("executeCached");
sascha@998:             Object [] values = new Object[numVars];
sascha@998: 
sascha@998:             StringBuilder sb = new StringBuilder(original);
sascha@998: 
sascha@998:             for (Map.Entry<String, List<Integer>> entry: positions.entrySet()) {
sascha@998:                 String key   = entry.getKey();
sascha@998:                 Object value = frames.get(key);
sascha@998:                 sb.append(';').append(key).append(':').append(value);
sascha@998:                 for (Integer index: entry.getValue()) {
sascha@998:                     values[index] = value;
sascha@998:                 }
sascha@998:             }
sascha@998: 
sascha@998:             // XXX: Maybe too many collisions?
sascha@998:             // String key = original + Arrays.hashCode(values);
sascha@998:             String key = sb.toString();
sascha@998: 
sascha@998:             Element element = cache.get(key);
sascha@998: 
sascha@998:             if (element != null) {
sascha@998:                 return (ResultData)element.getValue();
sascha@998:             }
sascha@998: 
sascha@998:             if (preparedStatement == null) {
sascha@998:                 preparedStatement = connection.prepareStatement(statement);
sascha@998:             }
sascha@998: 
sascha@998:             for (int i = 0; i < values.length; ++i) {
sascha@998:                 preparedStatement.setObject(i+1, values[i]);
sascha@998:             }
sascha@998: 
sascha@998:             ResultData data;
sascha@998: 
sascha@1097:             if (log.isDebugEnabled()) {
sascha@1097:                 log.debug("executing: " + statement);
sascha@1097:             }
sascha@1097: 
sascha@998:             ResultSet result = preparedStatement.executeQuery();
sascha@998:             try {
sascha@998:                 data = new ResultData(preparedStatement.getMetaData())
sascha@998:                     .addAll(result);
sascha@998:             }
sascha@998:             finally {
sascha@998:                 result.close();
sascha@998:             }
sascha@998: 
sascha@998:             element = new Element(key, data);
sascha@998:             cache.put(element);
sascha@998: 
sascha@998:             return data;
sascha@998:         }
sascha@998: 
sascha@998:         protected ResultData executeUncached(
sascha@998:             Connection  connection,
sascha@998:             StackFrames frames
sascha@3076:         )
sascha@998:         throws SQLException
sascha@998:         {
sascha@1023:             log.debug("executeUncached");
sascha@998:             if (preparedStatement == null) {
sascha@1023:                 if (log.isDebugEnabled()) {
sascha@1023:                     log.debug("preparing statement: " + statement);
sascha@1023:                 }
sascha@998:                 preparedStatement = connection.prepareStatement(statement);
sascha@998:             }
sascha@998: 
sascha@998:             for (Map.Entry<String, List<Integer>> entry: positions.entrySet()) {
sascha@998:                 Object value = frames.get(entry.getKey());
sascha@998:                 for (Integer index: entry.getValue()) {
sascha@998:                     preparedStatement.setObject(index+1, value);
sascha@998:                 }
sascha@998:             }
sascha@998: 
sascha@1097:             if (log.isDebugEnabled()) {
sascha@1097:                 log.debug("executing: " + statement);
sascha@1097:             }
sascha@1097: 
sascha@998:             ResultSet result = preparedStatement.executeQuery();
sascha@998:             try {
sascha@998:                 return new ResultData(preparedStatement.getMetaData())
sascha@998:                     .addAll(result);
sascha@998:             }
sascha@998:             finally {
sascha@998:                 result.close();
sascha@998:             }
sascha@998:         }
sascha@998: 
sascha@1011:         public ResultData execute(
sascha@1011:             Connection  connection,
sascha@1011:             StackFrames frames,
sascha@1011:             boolean     cached
sascha@1011:         )
sascha@998:         throws SQLException
sascha@998:         {
sascha@1011:             if (!cached) {
sascha@1011:                 return executeUncached(connection, frames);
sascha@1011:             }
sascha@1011: 
sascha@998:             Cache cache = CacheFactory.getCache(DATACAGE_DB_CACHE);
sascha@998: 
sascha@998:             return cache != null
sascha@998:                 ? executeCached(cache, connection, frames)
sascha@998:                 : executeUncached(connection, frames);
sascha@998:         }
sascha@998: 
sascha@998:         public void close() {
sascha@998:             if (preparedStatement != null) {
sascha@998:                 try {
sascha@998:                     preparedStatement.close();
sascha@998:                 }
sascha@998:                 catch (SQLException sqle) {
sascha@998:                 }
sascha@998:                 preparedStatement = null;
sascha@998:             }
sascha@998:         }
sascha@998:     } // class Instance
sascha@998: 
sascha@998:     public CompiledStatement() {
sascha@998:     }
sascha@998: 
sascha@998:     public CompiledStatement(String original) {
sascha@998:         this.original = original;
sascha@998:         // TreeMap to ensure order
sascha@998:         positions = new TreeMap<String, List<Integer>>();
sascha@998:         compile();
sascha@998:     }
sascha@998: 
sascha@998:     protected void compile() {
sascha@998: 
sascha@998:         StringBuffer sb = new StringBuffer();
sascha@998: 
sascha@998:         Matcher m = VAR.matcher(original);
sascha@998: 
sascha@998:         int index = 0;
sascha@998: 
felix@4805:         // Find variables like ${varname}.
sascha@998:         while (m.find()) {
sascha@1716:             String key = m.group(1).toUpperCase();
sascha@998:             List<Integer> indices = positions.get(key);
sascha@998:             if (indices == null) {
sascha@998:                 indices = new ArrayList<Integer>();
sascha@998:                 positions.put(key, indices);
sascha@998:             }
sascha@998:             indices.add(index);
sascha@998:             m.appendReplacement(sb, "?");
sascha@998:             ++index;
sascha@998:         }
sascha@998: 
sascha@998:         m.appendTail(sb);
sascha@998: 
sascha@998:         numVars = index;
sascha@998: 
sascha@998:         statement = sb.toString();
sascha@998:     }
sascha@998: 
sascha@998:     public String getStatement() {
sascha@998:         return statement;
sascha@998:     }
sascha@998: }
sascha@998: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :