// Base64Order.java
// -----------------------
// part of The Kelondro Database
// (C) by Michael Peter Christen; mc@yacy.net
// first published on http://www.anomic.de
// Frankfurt, Germany, 2005
// created 03.01.2006
//
// $LastChangedDate: 2011-06-19 15:34:55 +0200 (So, 19. Jun 2011) $
// $LastChangedRevision: 7786 $
// $LastChangedBy: orbiter $
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
package net.yacy.kelondro.order;
import java.util.Comparator;
import net.yacy.cora.document.UTF8;
import net.yacy.kelondro.index.HandleSet;
import net.yacy.kelondro.index.RowSpaceExceededException;
public class Base64Order extends AbstractOrder<byte[]> implements ByteOrder, Comparator<byte[]>, Cloneable {
protected static final byte[] alpha_standard = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".getBytes();
protected static final byte[] alpha_enhanced = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_".getBytes();
protected static final byte[] ahpla_standard = new byte[128];
protected static final byte[] ahpla_enhanced = new byte[128];
static {
for (int i = 0; i < 128; i++) {
ahpla_standard[i] = -1;
ahpla_enhanced[i] = -1;
}
for (int i = 0; i < alpha_standard.length; i++) {
ahpla_standard[alpha_standard[i]] = (byte) i;
ahpla_enhanced[alpha_enhanced[i]] = (byte) i;
}
}
public static final Base64Order standardCoder = new Base64Order(true, true);
public static final Base64Order enhancedCoder = new Base64Order(true, false);
private final boolean rfc1113compliant;
private final byte[] alpha;
private final byte[] ahpla;
private final byte[] ab; // decision table for comparisments
public Base64Order(final boolean up, final boolean rfc1113compliant) {
// if we choose not to be rfc1113compliant,
// then we get shorter base64 results which are also filename-compatible
this.rfc1113compliant = rfc1113compliant;
this.asc = up;
this.alpha = (rfc1113compliant) ? alpha_standard : alpha_enhanced;
this.ahpla = (rfc1113compliant) ? ahpla_standard : ahpla_enhanced;
this.ab = new byte[1 << 14];
byte acc, bcc;
byte c;
// pre-compute comparisment results: this omits one single ahpla lookup during comparisment
for (final byte ac: this.alpha) {
for (final byte bc: this.alpha) {
acc = this.ahpla[ac];
bcc = this.ahpla[bc];
c = 0;
if (acc > bcc) c = 1;
if (acc < bcc) c = -1;
this.ab[(ac << 7) | bc] = c;
}
}
}
public HandleSet getHandleSet(final int keylength, final int space) throws RowSpaceExceededException {
return new HandleSet(keylength, this, space);
}
public static byte[] zero(int length) {
final byte[] z = new byte[length];
while (length > 0) {
length--; z[length] = alpha_standard[0];
}
return z;
}
public Order<byte[]> clone() {
final Base64Order o = new Base64Order(this.asc, this.rfc1113compliant);
o.rotate(this.zero);
return o;
}
public final boolean wellformed(final byte[] a) {
return wellformed(a, 0, a.length);
}
public final boolean wellformed(final byte[] a, final int astart, final int alength) {
assert (astart + alength <= a.length) : "astart = " + astart + ", alength = " + alength + ", a.length = " + a.length;
int b;
for (int i = astart + alength - 1; i >= astart; i--) {
b = a[i];
if ((b < 0) || (b >= 128) || (this.ahpla[b] == -1)) return false;
}
return true;
}
public final static ByteOrder bySignature(final String signature) {
if ("Bd".equals(signature)) return new Base64Order(false, false);
if ("bd".equals(signature)) return new Base64Order(false, true);
if ("Bu".equals(signature)) return new Base64Order(true, false);
if ("bu".equals(signature)) return new Base64Order(true, true);
return null;
}
public final String signature() {
if ((!this.asc) && (!this.rfc1113compliant)) return "Bd";
if ((!this.asc) && ( this.rfc1113compliant)) return "bd";
if (( this.asc) && (!this.rfc1113compliant)) return "Bu";
if (( this.asc) && ( this.rfc1113compliant)) return "bu";
return null;
}
public final char encodeByte(final byte b) {
return (char) this.alpha[b];
}
public final byte decodeByte(final byte b) {
return this.ahpla[b];
}
public final byte decodeByte(final char b) {
return this.ahpla[b];
}
public final StringBuilder encodeLongSB(long c, int length) {
final StringBuilder s = new StringBuilder(length);
s.setLength(length);
while (length > 0) {
s.setCharAt(--length, (char) this.alpha[(byte) (c & 0x3F)]);
c >>= 6;
}
return s;
}
public final byte[] encodeLongBA(long c, int length) {
final byte[] s = new byte[length];
while (length > 0) {
s[--length] = this.alpha[(byte) (c & 0x3F)];
c >>= 6;
}
return s;
}
public final byte[] encodeLongSubstr(long c, int length) {
final byte[] s = new byte[length];
while (length > 0) {
s[--length] = this.alpha[(byte) (c & 0x3F)];
c >>= 6;
}
return s;
}
public final void encodeLong(long c, final byte[] b, final int offset, int length) {
assert offset + length <= b.length;
while (length > 0) {
b[--length + offset] = this.alpha[(byte) (c & 0x3F)];
c >>= 6;
}
}
public final long decodeLong(String s) {
while (s.endsWith("=")) s = s.substring(0, s.length() - 1);
long c = 0;
for (int i = 0; i < s.length(); i++) c = (c << 6) | this.ahpla[s.charAt(i)];
return c;
}
public final long decodeLong(final byte[] s, final int offset, int length) {
while ((length > 0) && (s[offset + length - 1] == '=')) length--;
long c = 0;
for (int i = 0; i < length; i++) c = (c << 6) | this.ahpla[s[offset + i]];
return c;
}
public static long max(final int len) {
// computes the maximum number that can be coded with a base64-encoded
// String of base len
long c = 0;
for (int i = 0; i < len; i++) c = (c << 6) | 63;
return c;
}
public final String encodeString(final String in) {
return encode(UTF8.getBytes(in));
}
// we will use this encoding to encode strings with 2^8 values to
// b64-Strings
// we will do that by grouping each three input bytes to four output bytes.
public final String encode(final byte[] in) {
if (in == null || in.length == 0) return "";
final int lene = in.length / 3 * 4 + 3;
StringBuilder out = new StringBuilder(lene);
int pos = 0;
long l;
while (in.length - pos >= 3) {
l = ((((0XffL & in[pos]) << 8) + (0XffL & in[pos + 1])) << 8) + (0XffL & in[pos + 2]);
pos += 3;
out = out.append(encodeLongSB(l, 4));
}
// now there may be remaining bytes
if (in.length % 3 != 0) out = out.append((in.length % 3 == 2) ? encodeLongSB((((0XffL & in[pos]) << 8) + (0XffL & in[pos + 1])) << 8, 4).substring(0, 3) : encodeLongSB((((0XffL & in[pos])) << 8) << 8, 4).substring(0, 2));
if (this.rfc1113compliant) while (out.length() % 4 > 0) out.append("=");
// return result
//assert lene == out.length() : "lene = " + lene + ", out.len = " + out.length();
return out.toString();
}
public final byte[] encodeSubstring(final byte[] in, final int sublen) {
if (in.length == 0) return null;
final byte[] out = new byte[sublen];
int writepos = 0;
int pos = 0;
long l;
while (in.length - pos >= 3 && writepos < sublen) {
l = ((((0XffL & in[pos]) << 8) + (0XffL & in[pos + 1])) << 8) + (0XffL & in[pos + 2]);
pos += 3;
System.arraycopy(encodeLongSubstr(l, 4), 0, out, writepos, 4);
writepos += 4;
}
// now there may be remaining bytes
if (in.length % 3 != 0 && writepos < sublen) {
if (in.length % 3 == 2) {
System.arraycopy(encodeLongBA((((0XffL & in[pos]) << 8) + (0XffL & in[pos + 1])) << 8, 4), 0, out, writepos, 3);
writepos += 3;
} else {
System.arraycopy(encodeLongBA((((0XffL & in[pos])) << 8) << 8, 4), 0, out, writepos, 2);
writepos += 2;
}
}
if (this.rfc1113compliant) while (writepos % 4 > 0 && writepos < sublen) out[writepos] = '=';
//assert encode(in).substring(0, sublen).equals(ASCII.String(out));
return out;
}
public final String decodeString(final String in) {
return UTF8.String(decode(in));
}
public final byte[] decode(String in) {
if ((in == null) || (in.length() == 0)) return new byte[0];
try {
int posIn = 0;
int posOut = 0;
if (this.rfc1113compliant) while (in.charAt(in.length() - 1) == '=') in = in.substring(0, in.length() - 1);
final byte[] out = new byte[in.length() / 4 * 3 + (((in.length() % 4) == 0) ? 0 : in.length() % 4 - 1)];
long l;
while (posIn + 3 < in.length()) {
l = decodeLong(in.substring(posIn, posIn + 4));
out[posOut + 2] = (byte) (l % 256);
l = l / 256;
out[posOut + 1] = (byte) (l % 256);
l = l / 256;
out[posOut] = (byte) (l % 256);
l = l / 256;
posIn += 4;
posOut += 3;
}
if (posIn < in.length()) {
if (in.length() - posIn == 3) {
l = decodeLong(in.substring(posIn) + "A");
l = l / 256;
out[posOut + 1] = (byte) (l % 256);
l = l / 256;
out[posOut] = (byte) (l % 256);
l = l / 256;
} else {
l = decodeLong(in.substring(posIn) + "AA");
l = l / 256 / 256;
out[posOut] = (byte) (l % 256);
l = l / 256;
}
}
return out;
} catch (final ArrayIndexOutOfBoundsException e) {
// maybe the input was not base64
// TODO: Throw exception again
// throw new RuntimeException("input probably not base64");
System.err.println("wrong string receive: " + in);
return new byte[0];
}
}
private final long cardinalI(final String key) {
// returns a cardinal number in the range of 0 .. Long.MAX_VALUE
long c = 0;
int p = 0;
byte b;
while ((p < 10) && (p < key.length())) {
b = this.ahpla[key.charAt(p++)];
if (b < 0) return -1;
c = (c << 6) | b;
}
while (p++ < 10) c = (c << 6);
c = (c << 3) | 7;
assert c >= 0;
return c;
}
private final long cardinalI(final byte[] key, int off, final int len) {
// returns a cardinal number in the range of 0 .. Long.MAX_VALUE
long c = 0;
final int lim = off + Math.min(10, len);
final int lim10 = off + 10;
byte b;
while (off < lim) {
b = key[off++];
if (b < 0) return -1;
b = this.ahpla[b];
if (b < 0) return -1;
c = (c << 6) | b;
}
while (off++ < lim10) c = (c << 6);
c = (c << 3) | 7;
assert c >= 0;
return c;
}
public final byte[] uncardinal(long c) {
c = c >> 3;
final byte[] b = new byte[12];
for (int p = 9; p >= 0; p--) {
b[p] = this.alpha[(int) (c & 0x3fL)];
c = c >> 6;
}
b[10] = this.alpha[0x3f];
b[11] = this.alpha[0x3f];
return b;
}
public final long cardinal(final byte[] key) {
if (this.zero == null) return cardinalI(key, 0, key.length);
final long zeroCardinal = cardinalI(this.zero, 0, this.zero.length);
final long keyCardinal = cardinalI(key, 0, key.length);
if (keyCardinal > zeroCardinal) return keyCardinal - zeroCardinal;
return Long.MAX_VALUE - keyCardinal + zeroCardinal;
}
public final long cardinal(final byte[] key, final int off, final int len) {
if (this.zero == null) return cardinalI(key, off, len);
final long zeroCardinal = cardinalI(this.zero, 0, this.zero.length);
final long keyCardinal = cardinalI(key, off, len);
if (keyCardinal > zeroCardinal) return keyCardinal - zeroCardinal;
return Long.MAX_VALUE - keyCardinal + zeroCardinal;
}
public final long cardinal(final String key) {
if (this.zero == null) return cardinalI(key);
final long zeroCardinal = cardinalI(this.zero, 0, this.zero.length);
final long keyCardinal = cardinalI(key);
if (keyCardinal > zeroCardinal) return keyCardinal - zeroCardinal;
return Long.MAX_VALUE - keyCardinal + zeroCardinal;
}
private static final int sig(final int x) {
return (x > 0) ? 1 : (x < 0) ? -1 : 0;
}
public final boolean equal(final byte[] a, final byte[] b) {
if ((a == null) && (b == null)) return true;
if ((a == null) || (b == null)) return false;
if (a.length != b.length) return false;
int astart = 0;
int bstart = 0;
int length = a.length;
while (length-- != 0) {
if (a[astart++] != b[bstart++]) return false;
}
return true;
}
public final boolean equal(final byte[] a, int astart, final byte[] b, int bstart, int length) {
if ((a == null) && (b == null)) return true;
if ((a == null) || (b == null)) return false;
while (length-- != 0) {
if (a[astart++] != b[bstart++]) return false;
}
return true;
}
public final int compare(final byte[] a, final byte[] b) {
try {
return (this.asc) ?
((this.zero == null) ? compares(a, b) : compare0(a, 0, b, 0, a.length))
:
((this.zero == null) ? compares(b, a) : compare0(b, 0, a, 0, a.length));
} catch (final Exception e) {
// if a or b is not well-formed, an ArrayIndexOutOfBoundsException may occur
// in that case we don't want that the exception makes databse functions
// unusable and effective creates a showstopper. In such cases we apply
// a different order on the objects and treat not well-formed objects
// as bigger as all others. If both object are not well-formed, they are
// compared with the natural order.
final boolean wfa = wellformed(a);
final boolean wfb = wellformed(b);
if (wfa && wfb) {
// uh strange. throw the exception
if (e instanceof ArrayIndexOutOfBoundsException) throw (ArrayIndexOutOfBoundsException) e;
throw new RuntimeException(e.getMessage());
}
if (wfa) return (this.asc) ? -1 : 1;
if (wfb) return (this.asc) ? 1 : -1;
return ((this.asc) ? 1 : -1) * NaturalOrder.naturalOrder.compare(a, b);
}
}
public final int compare(final byte[] a, final int aoffset, final byte[] b, final int boffset, final int length) {
try {
return (this.asc) ?
compare0(a, aoffset, b, boffset, length)
:
compare0(b, boffset, a, aoffset, length);
} catch (final Exception e) {
// same handling as in simple compare method above
final boolean wfa = wellformed(a, aoffset, length);
final boolean wfb = wellformed(b, boffset, length);
if (wfa && wfb) {
// uh strange. throw the exception
if (e instanceof ArrayIndexOutOfBoundsException) throw (ArrayIndexOutOfBoundsException) e;
throw new RuntimeException(e.getMessage());
}
if (wfa) return (this.asc) ? -1 : 1;
if (wfb) return (this.asc) ? 1 : -1;
return ((this.asc) ? 1 : -1) * NaturalOrder.naturalOrder.compare(a, aoffset, b, boffset, length);
}
}
private final int compare0(final byte[] a, final int aoffset, final byte[] b, final int boffset, final int length) {
if (this.zero == null) return compares(a, aoffset, b, boffset, length);
// we have an artificial start point. check all combinations
final int az = compares(a, aoffset, this.zero, 0, Math.min(length, this.zero.length)); // -1 if a < z; 0 if a == z; 1 if a > z
final int bz = compares(b, boffset, this.zero, 0, Math.min(length, this.zero.length)); // -1 if b < z; 0 if b == z; 1 if b > z
if (az == bz) return compares(a, aoffset, b, boffset, length);
return sig(az - bz);
}
private final int compares(final byte[] a, final byte[] b) {
assert (this.ahpla.length == 128);
short i = 0;
final int al = a.length;
final int bl = b.length;
final short ml = (short) Math.min(al, bl);
byte ac, bc;
while (i < ml) { // trace point
assert (i < a.length) : "i = " + i + ", aoffset = " + 0 + ", a.length = " + a.length + ", a = " + NaturalOrder.arrayList(a, 0, al);
assert (i < b.length) : "i = " + i + ", boffset = " + 0 + ", b.length = " + b.length + ", b = " + NaturalOrder.arrayList(b, 0, al);
ac = a[i];
assert (ac >= 0) && (ac < 128) : "ac = " + ac + ", a = " + NaturalOrder.arrayList(a, 0, al);
bc = b[i];
assert (bc >= 0) && (bc < 128) : "bc = " + bc + ", b = " + NaturalOrder.arrayList(b, 0, al);
assert ac != 0;
assert bc != 0;
//if ((ac == 0) && (bc == 0)) return 0; // zero-terminated length
if (ac != bc) return this.ab[(ac << 7) | bc];
i++;
}
// compare length
if (al > bl) return 1;
if (al < bl) return -1;
// they are equal
return 0;
}
private final int compares(final byte[] a, final int aoffset, final byte[] b, final int boffset, final int length) {
assert (aoffset + length <= a.length) : "a.length = " + a.length + ", aoffset = " + aoffset + ", alength = " + length;
assert (boffset + length <= b.length) : "b.length = " + b.length + ", boffset = " + boffset + ", blength = " + length;
assert (this.ahpla.length == 128);
short i = 0;
byte ac, bc;
//byte acc, bcc;
//int c = 0;
while (i < length) {
assert (i + aoffset < a.length) : "i = " + i + ", aoffset = " + aoffset + ", a.length = " + a.length + ", a = " + NaturalOrder.arrayList(a, aoffset, length);
assert (i + boffset < b.length) : "i = " + i + ", boffset = " + boffset + ", b.length = " + b.length + ", b = " + NaturalOrder.arrayList(b, boffset, length);
ac = a[aoffset + i];
assert (ac >= 0) && (ac < 128) : "ac = " + ac + ", a = " + NaturalOrder.arrayList(a, aoffset, length);
bc = b[boffset + i];
assert (bc >= 0) && (bc < 128) : "bc = " + bc + ", b = " + NaturalOrder.arrayList(b, boffset, length);
assert ac != 0;
assert bc != 0;
//if ((ac == 0) && (bc == 0)) return 0; // zero-terminated length
if (ac == bc) {
// shortcut in case of equality: we don't need to lookup the ahpla value
i++;
continue;
}
return this.ab[(ac << 7) | bc];
}
// they are equal
return 0;
}
public static void main(final String[] s) {
// java -classpath classes de.anomic.kelondro.kelondroBase64Order
final Base64Order b64 = new Base64Order(true, true);
if (s.length == 0) {
System.out.println("usage: -[ec|dc|es|ds|clcn] <arg>");
System.exit(0);
}
if ("-ec".equals(s[0])) {
// generate a b64 encoding from a given cardinal
System.out.println(b64.encodeLongSB(Long.parseLong(s[1]), 4));
}
if ("-dc".equals(s[0])) {
// generate a b64 decoding from a given cardinal
System.out.println(b64.decodeLong(s[1]));
}
if ("-es".equals(s[0])) {
// generate a b64 encoding from a given string
System.out.println(b64.encodeString(s[1]));
}
if ("-ds".equals(s[0])) {
// generate a b64 decoding from a given string
System.out.println(b64.decodeString(s[1]));
}
if ("-cl".equals(s[0])) {
// return the cardinal of a given string as long value with the enhanced encoder
System.out.println(Base64Order.enhancedCoder.cardinal(s[1].getBytes()));
}
if ("-cn".equals(s[0])) {
// return the cardinal of a given string as normalized float 0 .. 1 with the enhanced encoder
System.out.println(((double) Base64Order.enhancedCoder.cardinal(s[1].getBytes())) / ((double) Long.MAX_VALUE));
}
}
}