jpayne@68: package server;
jpayne@68: 
jpayne@68: import java.util.BitSet;
jpayne@68: import java.util.HashMap;
jpayne@68: 
jpayne@68: import structures.ByteBuilder;
jpayne@68: 
jpayne@68: public class PercentEncoding {
jpayne@68: 	
jpayne@68: 	public static boolean containsSpecialSymbol(String s){
jpayne@68: 		if(s==null){return false;}
jpayne@68: 		for(int i=0, max=s.length(); i<max; i++){
jpayne@68: 			char c=s.charAt(i);
jpayne@68: 			if(isSpecial.get(c)){
jpayne@68: //				System.err.print("b");
jpayne@68: 				return true;}
jpayne@68: 		}
jpayne@68: //		System.err.print("c");
jpayne@68: 		return false;
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	public static boolean containsCommonSymbol(String s){
jpayne@68: 		if(s==null){return false;}
jpayne@68: 		for(int i=0, max=s.length(); i<max; i++){
jpayne@68: 			char c=s.charAt(i);
jpayne@68: 			if(isCommon.get(c)){return true;}
jpayne@68: 		}
jpayne@68: 		return false;
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	public static String symbolToCode(String s){
jpayne@68: //		System.err.print("a");
jpayne@68: 		if(!containsSpecialSymbol(s)){return s;}
jpayne@68: //		System.err.print("d");
jpayne@68: 		ByteBuilder bb=new ByteBuilder();
jpayne@68: 		for(int i=0, max=s.length(); i<max; i++){
jpayne@68: 			char c=s.charAt(i);
jpayne@68: 			String code=symbolToCodeArray[c];
jpayne@68: 			if(code!=null){
jpayne@68: //				System.err.print("e("+code+")");
jpayne@68: 				bb.append(code);
jpayne@68: 			}else{
jpayne@68: //				System.err.print("f");
jpayne@68: 				bb.append(c);
jpayne@68: 			}
jpayne@68: 		}
jpayne@68: //		System.err.println("g");
jpayne@68: //		System.err.println(bb);
jpayne@68: 		return bb.toString();
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	public static String commonSymbolToCode(String s){
jpayne@68: 		if(!containsCommonSymbol(s)){return s;}
jpayne@68: 		ByteBuilder bb=new ByteBuilder();
jpayne@68: 		for(int i=0, max=s.length(); i<max; i++){
jpayne@68: 			char c=s.charAt(i);
jpayne@68: 			if(isCommon.get(c)){
jpayne@68: 				String code=symbolToCodeArray[c];
jpayne@68: 				assert(code!=null);
jpayne@68: 				bb.append(code);
jpayne@68: 			}else{
jpayne@68: 				bb.append(c);
jpayne@68: 			}
jpayne@68: 		}
jpayne@68: 		return bb.toString();
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	private static int parseCode(String s, int start){
jpayne@68: 		if(s==null || start+2>=s.length()){return -1;}
jpayne@68: 		assert(s.charAt(start)=='%');
jpayne@68: 		int sum=0;
jpayne@68: 		for(int i=start+1; i<=start+2; i++){
jpayne@68: 			sum=sum<<4;
jpayne@68: 			final char c=s.charAt(i);
jpayne@68: 			if(c>='0' && c<='9'){
jpayne@68: 				sum=sum+(c-'0');
jpayne@68: 			}else if(c>='A' && c<'F'){
jpayne@68: 				sum=sum+(10+c-'A');
jpayne@68: 			}else{
jpayne@68: 				return -1;
jpayne@68: 			}
jpayne@68: 		}
jpayne@68: 		return sum;
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	public static String codeToSymbol(String s){
jpayne@68: 		int idx=s.indexOf('%');
jpayne@68: 		if(idx<0){return s;}
jpayne@68: 		
jpayne@68: 		ByteBuilder bb=new ByteBuilder(s.length());
jpayne@68: 		for(int i=0; i<s.length(); i++){
jpayne@68: 			char c=s.charAt(i);
jpayne@68: 			if(c=='%'){
jpayne@68: 				int sym=parseCode(s, i);
jpayne@68: 				if(sym<0){bb.append(c);}
jpayne@68: 				else{
jpayne@68: 					bb.append((char)sym);
jpayne@68: 					i+=2;//Skip next 2 characters
jpayne@68: 				}
jpayne@68: 			}else{bb.append(c);}
jpayne@68: 		}
jpayne@68: 		return (bb.length()==s.length() ? s : bb.toString());
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	private static HashMap<String, String> makeCodeToSymbolMap() {
jpayne@68: 		HashMap<String, String> map=new HashMap<String, String>(129);
jpayne@68: 		assert(reservedSymbol.length==reservedCode.length);
jpayne@68: 		assert(commonSymbol.length==commonCode.length);
jpayne@68: 		for(int i=0; i<reservedSymbol.length; i++){
jpayne@68: 			map.put(reservedCode[i], reservedSymbol[i]);
jpayne@68: 		}
jpayne@68: 		for(int i=0; i<commonSymbol.length; i++){
jpayne@68: 			map.put(commonCode[i], commonSymbol[i]);
jpayne@68: 		}
jpayne@68: 		return map;
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	private static HashMap<String, String> makeSymbolToCodeMap() {
jpayne@68: 		HashMap<String, String> map=new HashMap<String, String>(257);
jpayne@68: 		assert(reservedSymbol.length==reservedCode.length);
jpayne@68: 		assert(commonSymbol.length==commonCode.length);
jpayne@68: 		for(int i=0; i<reservedSymbol.length; i++){
jpayne@68: 			map.put(reservedSymbol[i], reservedCode[i]);
jpayne@68: 		}
jpayne@68: 		for(int i=0; i<commonSymbol.length; i++){
jpayne@68: 			map.put(commonSymbol[i], commonCode[i]);
jpayne@68: 		}
jpayne@68: 		return map;
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	private static String[] makeSymbolToCodeArray() {
jpayne@68: 		final String[] array=new String[128];
jpayne@68: 		for(int i=0; i<reservedSymbol.length; i++){
jpayne@68: 			String s=reservedSymbol[i];
jpayne@68: 			String c=reservedCode[i];
jpayne@68: 			array[s.charAt(0)]=c;
jpayne@68: 		}
jpayne@68: 		for(int i=0; i<commonSymbol.length; i++){
jpayne@68: 			String s=commonSymbol[i];
jpayne@68: 			String c=commonCode[i];
jpayne@68: 			array[s.charAt(0)]=c;
jpayne@68: 		}
jpayne@68: 		return array;
jpayne@68: 	}
jpayne@68: 	
jpayne@68: 	private static final BitSet makeBitSet(String[]...matrix){
jpayne@68: 		BitSet bs=new BitSet(128);
jpayne@68: 		for(String[] array : matrix){
jpayne@68: 			for(String s : array){
jpayne@68: 				char c=s.charAt(0);
jpayne@68: 				bs.set(c);
jpayne@68: 			}
jpayne@68: 		}
jpayne@68: 		return bs;
jpayne@68: 	}
jpayne@68: 
jpayne@68: 	//See https://en.wikipedia.org/wiki/Percent-encoding
jpayne@68: 	public static final String[] reservedSymbol=new String[] {
jpayne@68: 		"!", "#", "$", "&", "'", "(", ")", "*", "+", ",", "/", ":", ";", "=", "?", "@", "[", "]"
jpayne@68: 	};
jpayne@68: 	
jpayne@68: 	public static final String[] reservedCode=new String[] {
jpayne@68: 		"%21", "%23", "%24", "%26", "%27", "%28", "%29", "%2A", "%2B", "%2C", "%2F", "%3A", "%3B", "%3D", "%3F", "%40", "%5B", "%5D"
jpayne@68: 	};
jpayne@68: 	
jpayne@68: 	public static final String[] commonSymbol=new String[] {
jpayne@68: 		"\n", " ", "\"", "%", "<", ">", "\\", "|",
jpayne@68: 	};
jpayne@68: 	
jpayne@68: 	public static final String[] commonCode=new String[] {
jpayne@68: 		"%0A", "%20", "%22", "%25", "%3C", "%3E", "%5C", "%7C"
jpayne@68: 	};
jpayne@68: 
jpayne@68: 	private static final BitSet isSpecial=makeBitSet(reservedSymbol, commonSymbol);
jpayne@68: 	private static final BitSet isCommon=makeBitSet(commonSymbol);
jpayne@68: 
jpayne@68: //	public static final HashMap<String, String> codeToSymbolMap=makeCodeToSymbolMap();
jpayne@68: //	public static final HashMap<String, String> symbolToCodeMap=makeSymbolToCodeMap();
jpayne@68: 	public static final String[] symbolToCodeArray=makeSymbolToCodeArray();
jpayne@68: 	
jpayne@68: 	/** Don't print caught exceptions */
jpayne@68: 	public static boolean suppressErrors=false;
jpayne@68: 	
jpayne@68: }