source: xssim/trunk/src/simulator/workload/reader/xmlJob/TarReader.java @ 104

package simulator.workload.reader.xmlJob;


import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;

import simulator.workload.fileFilters.GrmsJobFileNameFilter;

/**
 * 
 * @author Marcin Krystek
 *
 */
public class TarReader implements WLFileAccess{

        protected TarArchiveInputStream tarStream;
        protected TarArchiveEntry entry;
        
        protected TarReader(){
                
        }
        
        public TarReader(String fileName) throws FileNotFoundException{
                FileInputStream fileStream;
                fileStream = new FileInputStream(fileName);
                this.tarStream = new TarArchiveInputStream(fileStream);
        }
        
        public TarReader(File file) throws FileNotFoundException{
                FileInputStream fileStream;
                fileStream = new FileInputStream(file);
                this.tarStream = new TarArchiveInputStream(fileStream);
        }
        
        /**
         * 
         * @return file name which contains content returned by read() method
         */
        public String getFileName(){
                if(entry == null)
                        return null;
                
                return entry.getName();
        }
        
        /**
         * 
         * @return content of the next file located in tar archive
         * @throws IOException 
         * 
         */
        public String read() throws IOException{

                this.entry = getNextEntry();
                
                if(this.entry == null)
                        return null;

                return readEntry(this.entry);
        }
        
        /**
         * 
         */
        public void close(){
                if(this.tarStream != null)
                        try {
                                this.tarStream.close();
                        } catch (IOException e) {
                                e.printStackTrace();
                        }
        }
        
        /**
         * 
         * @return
         * @throws IOException
         */
        protected TarArchiveEntry getNextEntry() throws IOException{
                
                TarArchiveEntry entry = null;
                
                while((entry = this.tarStream.getNextTarEntry()) != null){
                        if(entry.isDirectory())
                                continue;
                        
                        String name = entry.getName();

                        int pos = name.lastIndexOf(File.separatorChar);
                        if(pos > 0)
                                name = name.substring(pos + 1);

                        if(!name.startsWith(GrmsJobFileNameFilter.FILE_NAME_PREFIX))
                                continue;

                        if(!name.endsWith(".xml"))
                                continue;
                        
                        return entry;
                }
                
                return entry;
        }
        
        /**
         * 
         * @param entry
         * @return
         * @throws IOException
         */
        protected String readEntry(TarArchiveEntry entry) throws IOException{
                
                int size = (int) entry.getSize();
                byte buf[] = new byte[size];
                this.tarStream.read(buf, 0, size);

                String value = new String(buf);
                return value;
        }
        
}