package railo.commons.io;
import java.io.IOException;
import java.io.InputStream;
import railo.commons.io.res.Resource;
import railo.commons.lang.StringUtil;
public class FileRotation {
public static void checkFile(Resource res, long maxFileSize, int maxFiles, byte[] header) throws IOException {
boolean writeHeader=false;
// create file
if(!res.exists()) {
res.createFile(true);
writeHeader=true;
}
else if(res.length()==0) {
writeHeader=true;
}
// create new file
else if(res.length()>maxFileSize) {
Resource parent = res.getParentResource();
String name = res.getName();
int lenMaxFileSize=(""+maxFiles).length();
for(int i=maxFiles;i>0;i--) {
Resource to=parent.getRealResource(name+"."+StringUtil.addZeros(i, lenMaxFileSize)+".bak");
Resource from=parent.getRealResource(name+"."+StringUtil.addZeros(i-1,lenMaxFileSize)+".bak");
if(from.exists()) {
if(to.exists())to.delete();
from.renameTo(to);
}
}
res.renameTo(parent.getRealResource(name+"."+StringUtil.addZeros(1,lenMaxFileSize)+".bak"));
res=parent.getRealResource(name);//new File(parent,name);
res.createNewFile();
writeHeader=true;
}
else if(header!=null && header.length>0) {
byte[] buffer = new byte[header.length];
int len;
InputStream in = null;
try{
in = res.getInputStream();
boolean headerOK = true;
len = in.read(buffer);
if(len==header.length){
for(int i=0;i<header.length;i++) {
if(header[i]!=buffer[i]){
headerOK=false;
break;
}
}
}
else headerOK=false;
if(!headerOK)writeHeader=true;
}
finally {
IOUtil.closeEL(in);
}
}
if(writeHeader) {
if(header==null)header=new byte[0];
IOUtil.write(res, header,false);
}
}
}