// fil InnBBUtBB.java
import inf101.*;
// BB st?r for 'Bits & Bytes'
/**
* Utvider klassen Inn med metode for ? lese enkeltbit eller
* en kode p? opptil 21000 verdier p? fil i en eller to byter,
* og en metode for ? lese neste ord p? fila.
************************************************************/
class InnBB extends Inn {
private int bitInnVerdi = 0;
private int antBitIgjen = 0;
/** Avoids cotrol characters. : 10, 13, 128-160
* @param i a byte value read from file with inChar()
* @return 'code' as used when calling corresponding utKonv(int code)
*/
int inKonv (int i) {
int ret = i;
if (i >= 10 ) ret -= 4;
if (i >= 128 ) ret -= 32;
return ret;
}
InnBB (String s) { super(s);}
InnBB (){super();}
/**
* Reads next code from file. : lower 100 values (2 digits in code) in byte 1.
* if value of code on file >= 100 then byte 1 > 100 and byte 2 = upper 3 digits (up to 210 values).
* @return max value = 210*100 (can easily be extended to 3,4.. byte encoding)
*************************************************************************/
public int innKode( ) {
int c,k;
c = inKonv((int) inChar());
if (c >= 100) {
k = c - 100;
c = inKonv((int) inChar());
return c*100 +k;
} else {
return c;
}
} // end innKode
/**
* Reads next word from file. Skips whitespace as determined
* by parameter to inString()
*/
public String lesNesteOrd () {
return inString(" "); // Pr?v her andre avgrnsninger i tillegg som :.,\n-
}
/**
* Reads next 13 bit Huffman code from file.
*/
int innBKode() {
// gets 2 byte input from utKode. All leading bits might be '0'
int i = innKode();
if ( i >= 20000 ) bitInnVerdi = i - 20000;
else bitInnVerdi = i;
return bitInnVerdi;
} // end outKode
/**
* Writes bit value in int i' to file: 14 bits in two bytes.
* Remember to call flushBit to get out last bits
*/
public int innBit() {
if (antBitIgjen == 0 ) {
bitInnVerdi = innBKode() << (31-13); // upper bit to read
antBitIgjen = 13;
}
antBitIgjen--;
bitInnVerdi <<= 1;
if ( bitInnVerdi < 0) return 1 ; else return 0;
} // end innBit
} // end class InnB
/**
* Utvider klassen Ut med metode for ? skrive enten bitm?nstre eller
* en kode p? opptil 21000 verdier p? fil i en eller to byter.
* BB = Bit og Byte
************************************************************/
class UtBB extends Ut {
private int bitUtVerdi = 0;
private int antBitSkrevet = 0;
/** Avoids cotrol characters. : 10, 13, 128-160
@return 'code' to be output on file, read by corresponding innKonv(int code) **/
int utKonv(int i) {
int ret = i;
if (i >= 10 ) ret += 4;
if (i >= 124 ) ret += 32;
return ret;
}
UtBB (String s) { super(s);}
UtBB (){super();}
/**
* Writes code 'k' to file: lower 100 values (2 digits in code) in byte 1.
* if value of code >= 100 then byte 1 >=100 and byte 2 = upper 3 digits (up to 210 values).
* Max code value = 210*100 (can easily be extended to 3,4.. byte encoding)
*/
public void utKode(int k) {
int c1,c2;
if (k >= 100) {
c1 = utKonv( (k %100) + 100 );
outChar( (char) c1);
c2 = utKonv(k/100);
outChar( (char) c2 );
} else {
c1 = utKonv(k);
outChar((char)c1);
}
} // end outKode
/**
* Writes code 'k' to file: lower 100 values (2 digits in code) in byte 1.
* if value of code >= 100 then byte 1 >=100 and byte 2 = upper 3 digits (up to 210 values).
* Max code value = 210*100 (can easily be extended to 3,4.. byte encoding)
*/
public void utBKode(int k) {
// assure 2 byte output from utKode. All leading bits might be '0'
if ( k < 100) utKode( k + 20000);
else utKode(k);
} // end outKode
/**
* Writes bit value in int i' to file: 13 bits in two bytes.
* Assumes i == 0 or i == 1.
* Remember to call flushBit to get out last bits
*************************************************************************/
public void utBit(int i) {
antBitSkrevet++;
bitUtVerdi = (bitUtVerdi <<1) | i;
if (antBitSkrevet == 13 ) {
utBKode(bitUtVerdi);
bitUtVerdi = 0;
antBitSkrevet = 0;
}
} // end utBit
/**
* Writes 'len' bitsin int 'i' to file.
* Remember to call flushBit to get out last bits
*************************************************************************/
public void utHuffKode(int i, int len) {
if (13 - antBitSkrevet > len ) {
antBitSkrevet += len;
bitUtVerdi = (bitUtVerdi <<len) + i;
} else if (13 - antBitSkrevet == len) {
utBKode((bitUtVerdi <<len) + i);
antBitSkrevet = 0;
bitUtVerdi = 0;
} else {
// too many bits in i
int len1 = (13 - antBitSkrevet),
len2 = len - len1;
int kode1 = i >>> len2,
kode2 = i - ( kode1 << len2);
utBKode((bitUtVerdi <<len1) + kode1);
bitUtVerdi = 0;
antBitSkrevet = 0;
utHuffKode(kode2,len2); // take any code length
}
} // end utHiffKode
/**
* Flushes bitbuffer used by utBit & utHuffKode
*/
public void flushBit() { if (antBitSkrevet > 0 ) {
utKode(bitUtVerdi<<(13 -antBitSkrevet));
bitUtVerdi = 0;
antBitSkrevet = 0;
}
} // end flushBit
} // end class UtB