sascha@372: package de.intevation.flys.artifacts.services.meta;
sascha@372: 
sascha@372: import java.util.regex.Pattern;
sascha@372: import java.util.regex.Matcher;
sascha@372: 
sascha@372: import java.util.List;
sascha@372: import java.util.Map;
sascha@972: import java.util.TreeMap;
sascha@372: import java.util.ArrayList;
sascha@372: 
sascha@372: import java.sql.PreparedStatement;
sascha@372: import java.sql.SQLException;
sascha@372: import java.sql.Connection;
sascha@372: import java.sql.ResultSet;
sascha@372: 
sascha@972: import net.sf.ehcache.Cache;
sascha@972: import net.sf.ehcache.Element;
sascha@972: 
sascha@972: import de.intevation.flys.artifacts.cache.CacheFactory;
sascha@972: 
sascha@372: public class CompiledStatement
sascha@372: {
sascha@972:     public static final String DATACAGE_DB_CACHE =
sascha@972:         "datacage.db";
sascha@972: 
sascha@969:     public static final Pattern VAR =
sascha@969:         Pattern.compile("\\$\\{([a-zA-Z0-9_-]+)\\}");
sascha@372: 
sascha@372:     protected String original;
sascha@372:     protected String statement;
sascha@372: 
sascha@372:     protected Map<String, List<Integer>> positions;
sascha@372: 
sascha@973:     protected int numVars;
sascha@372: 
sascha@973:     public class Instance {
sascha@973: 
sascha@973:         protected PreparedStatement preparedStatement;
sascha@973: 
sascha@973:         public Instance() {
sascha@973:         }
sascha@973: 
sascha@973:         protected ResultData executeCached(
sascha@973:             Cache       cache,
sascha@973:             Connection  connection,
sascha@973:             StackFrames frames
sascha@973:         )
sascha@973:         throws SQLException
sascha@973:         {
sascha@973:             Object [] values = new Object[numVars];
sascha@973: 
sascha@973:             StringBuilder sb = new StringBuilder(original);
sascha@973: 
sascha@973:             for (Map.Entry<String, List<Integer>> entry: positions.entrySet()) {
sascha@973:                 String key   = entry.getKey();
sascha@973:                 Object value = frames.get(key);
sascha@973:                 sb.append(';').append(key).append(':').append(value);
sascha@973:                 for (Integer index: entry.getValue()) {
sascha@973:                     values[index] = value;
sascha@973:                 }
sascha@973:             }
sascha@973: 
sascha@973:             // XXX: Maybe too many collisions?
sascha@973:             // String key = original + Arrays.hashCode(values);
sascha@973:             String key = sb.toString();
sascha@973: 
sascha@973:             Element element = cache.get(key);
sascha@973: 
sascha@973:             if (element != null) {
sascha@973:                 return (ResultData)element.getValue();
sascha@973:             }
sascha@973: 
sascha@973:             if (preparedStatement == null) {
sascha@973:                 preparedStatement = connection.prepareStatement(statement);
sascha@973:             }
sascha@973: 
sascha@973:             for (int i = 0; i < values.length; ++i) {
sascha@973:                 preparedStatement.setObject(i+1, values[i]);
sascha@973:             }
sascha@973: 
sascha@973:             ResultData data;
sascha@973: 
sascha@973:             ResultSet result = preparedStatement.executeQuery();
sascha@973:             try {
sascha@973:                 data = new ResultData(preparedStatement.getMetaData())
sascha@973:                     .addAll(result);
sascha@973:             }
sascha@973:             finally {
sascha@973:                 result.close();
sascha@973:             }
sascha@973: 
sascha@973:             element = new Element(key, data);
sascha@973:             cache.put(element);
sascha@973: 
sascha@973:             return data;
sascha@973:         }
sascha@973: 
sascha@973:         protected ResultData executeUncached(
sascha@973:             Connection  connection,
sascha@973:             StackFrames frames
sascha@973:         ) 
sascha@973:         throws SQLException
sascha@973:         {
sascha@973:             if (preparedStatement == null) {
sascha@973:                 preparedStatement = connection.prepareStatement(statement);
sascha@973:             }
sascha@973: 
sascha@973:             for (Map.Entry<String, List<Integer>> entry: positions.entrySet()) {
sascha@973:                 Object value = frames.get(entry.getKey());
sascha@973:                 for (Integer index: entry.getValue()) {
sascha@973:                     preparedStatement.setObject(index+1, value);
sascha@973:                 }
sascha@973:             }
sascha@973: 
sascha@973:             ResultSet result = preparedStatement.executeQuery();
sascha@973:             try {
sascha@973:                 return new ResultData(preparedStatement.getMetaData())
sascha@973:                     .addAll(result);
sascha@973:             }
sascha@973:             finally {
sascha@973:                 result.close();
sascha@973:             }
sascha@973:         }
sascha@973: 
sascha@973:         public ResultData execute(Connection connection, StackFrames frames)
sascha@973:         throws SQLException
sascha@973:         {
sascha@973:             Cache cache = CacheFactory.getCache(DATACAGE_DB_CACHE);
sascha@973: 
sascha@973:             return cache != null
sascha@973:                 ? executeCached(cache, connection, frames)
sascha@973:                 : executeUncached(connection, frames);
sascha@973:         }
sascha@973: 
sascha@973:         public void close() {
sascha@973:             if (preparedStatement != null) {
sascha@973:                 try {
sascha@973:                     preparedStatement.close();
sascha@973:                 }
sascha@973:                 catch (SQLException sqle) {
sascha@973:                 }
sascha@973:                 preparedStatement = null;
sascha@973:             }
sascha@973:         }
sascha@973:     } // class Instance
sascha@972: 
sascha@372:     public CompiledStatement() {
sascha@372:     }
sascha@372: 
sascha@372:     public CompiledStatement(String original) {
sascha@372:         this.original = original;
sascha@972:         // TreeMap to ensure order
sascha@972:         positions = new TreeMap<String, List<Integer>>();
sascha@372:         compile();
sascha@372:     }
sascha@372: 
sascha@372:     protected void compile() {
sascha@372: 
sascha@372:         StringBuffer sb = new StringBuffer();
sascha@372: 
sascha@372:         Matcher m = VAR.matcher(original);
sascha@372: 
sascha@972:         int index = 0;
sascha@372: 
sascha@372:         while (m.find()) {
sascha@372:             String key = m.group(1);
sascha@372:             List<Integer> indices = positions.get(key);
sascha@372:             if (indices == null) {
sascha@372:                 indices = new ArrayList<Integer>();
sascha@372:                 positions.put(key, indices);
sascha@372:             }
sascha@372:             indices.add(index);
sascha@372:             m.appendReplacement(sb, "?");
sascha@372:             ++index;
sascha@372:         }
sascha@372: 
sascha@372:         m.appendTail(sb);
sascha@372: 
sascha@972:         numVars = index;
sascha@972: 
sascha@372:         statement = sb.toString();
sascha@372:     }
sascha@372: 
sascha@372:     public String getStatement() {
sascha@372:         return statement;
sascha@372:     }
sascha@372: }
sascha@372: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :