-
-
Notifications
You must be signed in to change notification settings - Fork 34
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
9 changed files
with
484 additions
and
2 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
191 changes: 191 additions & 0 deletions
191
centrifuge/src/main/java/io/github/centrifugal/centrifuge/Fossil.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,191 @@ | ||
package io.github.centrifugal.centrifuge; | ||
|
||
import java.io.ByteArrayOutputStream; | ||
|
||
|
||
public class Fossil { | ||
|
||
private static final int[] zValue = new int[] { | ||
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, | ||
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, | ||
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, | ||
8, 9, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, | ||
20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, | ||
-1, 36, -1, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, | ||
51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, -1, -1, -1, 63, -1, | ||
}; | ||
|
||
// Reader class | ||
static class Reader { | ||
private byte[] a; | ||
private int pos; | ||
|
||
public Reader(byte[] array) { | ||
this.a = array; | ||
this.pos = 0; | ||
} | ||
|
||
public boolean haveBytes() { | ||
return this.pos < this.a.length; | ||
} | ||
|
||
public int getByte() { | ||
if (this.pos >= this.a.length) { | ||
throw new IndexOutOfBoundsException("out of bounds"); | ||
} | ||
int b = this.a[this.pos++] & 0xFF; | ||
return b; | ||
} | ||
|
||
public char getChar() { | ||
return (char) getByte(); | ||
} | ||
|
||
public int getInt() { | ||
int v = 0; | ||
int c; | ||
while (haveBytes() && (c = zValue[getByte() & 0x7F]) >= 0) { | ||
v = (v << 6) + c; | ||
} | ||
this.pos--; | ||
return v; | ||
} | ||
} | ||
|
||
// Writer class | ||
static class Writer { | ||
private ByteArrayOutputStream a = new ByteArrayOutputStream(); | ||
|
||
public byte[] toByteArray() { | ||
return a.toByteArray(); | ||
} | ||
|
||
// Copy from array 'arr' from 'start' to 'end' (exclusive) | ||
public void putArray(byte[] arr, int start, int end) { | ||
if (start < 0 || end > arr.length || start > end) { | ||
throw new IndexOutOfBoundsException("Invalid start or end index"); | ||
} | ||
a.write(arr, start, end - start); | ||
} | ||
} | ||
|
||
// Checksum function | ||
public static long checksum(byte[] arr) { | ||
int sum0 = 0, sum1 = 0, sum2 = 0, sum3 = 0; | ||
int z = 0; | ||
int N = arr.length; | ||
while (N >= 16) { | ||
sum0 += (arr[z + 0] & 0xFF); | ||
sum1 += (arr[z + 1] & 0xFF); | ||
sum2 += (arr[z + 2] & 0xFF); | ||
sum3 += (arr[z + 3] & 0xFF); | ||
|
||
sum0 += (arr[z + 4] & 0xFF); | ||
sum1 += (arr[z + 5] & 0xFF); | ||
sum2 += (arr[z + 6] & 0xFF); | ||
sum3 += (arr[z + 7] & 0xFF); | ||
|
||
sum0 += (arr[z + 8] & 0xFF); | ||
sum1 += (arr[z + 9] & 0xFF); | ||
sum2 += (arr[z + 10] & 0xFF); | ||
sum3 += (arr[z + 11] & 0xFF); | ||
|
||
sum0 += (arr[z + 12] & 0xFF); | ||
sum1 += (arr[z + 13] & 0xFF); | ||
sum2 += (arr[z + 14] & 0xFF); | ||
sum3 += (arr[z + 15] & 0xFF); | ||
|
||
z += 16; | ||
N -= 16; | ||
} | ||
while (N >= 4) { | ||
sum0 += (arr[z + 0] & 0xFF); | ||
sum1 += (arr[z + 1] & 0xFF); | ||
sum2 += (arr[z + 2] & 0xFF); | ||
sum3 += (arr[z + 3] & 0xFF); | ||
z += 4; | ||
N -= 4; | ||
} | ||
sum3 += (sum2 << 8) + (sum1 << 16) + (sum0 << 24); | ||
switch (N) { | ||
case 3: | ||
sum3 += (arr[z + 2] & 0xFF) << 8; | ||
case 2: | ||
sum3 += (arr[z + 1] & 0xFF) << 16; | ||
case 1: | ||
sum3 += (arr[z + 0] & 0xFF) << 24; | ||
break; | ||
default: | ||
break; | ||
} | ||
return sum3 & 0xFFFFFFFFL; | ||
} | ||
|
||
/** | ||
* Apply a delta byte array to a source byte array, returning the target byte array. | ||
*/ | ||
public static byte[] applyDelta(byte[] source, byte[] delta) throws Exception { | ||
int total = 0; | ||
Reader zDelta = new Reader(delta); | ||
int lenSrc = source.length; | ||
int lenDelta = delta.length; | ||
|
||
int limit = zDelta.getInt(); | ||
char c = zDelta.getChar(); | ||
if (c != '\n') { | ||
throw new Exception("size integer not terminated by '\\n'"); | ||
} | ||
Writer zOut = new Writer(); | ||
while (zDelta.haveBytes()) { | ||
int cnt = zDelta.getInt(); | ||
int ofst; | ||
|
||
c = zDelta.getChar(); | ||
switch (c) { | ||
case '@': | ||
ofst = zDelta.getInt(); | ||
if (zDelta.haveBytes() && zDelta.getChar() != ',') { | ||
throw new Exception("copy command not terminated by ','"); | ||
} | ||
total += cnt; | ||
if (total > limit) { | ||
throw new Exception("copy exceeds output file size"); | ||
} | ||
if (ofst + cnt > lenSrc) { | ||
throw new Exception("copy extends past end of input"); | ||
} | ||
zOut.putArray(source, ofst, ofst + cnt); | ||
break; | ||
|
||
case ':': | ||
total += cnt; | ||
if (total > limit) { | ||
throw new Exception("insert command gives an output larger than predicted"); | ||
} | ||
if (cnt > lenDelta - zDelta.pos) { | ||
throw new Exception("insert count exceeds size of delta"); | ||
} | ||
zOut.putArray(zDelta.a, zDelta.pos, zDelta.pos + cnt); | ||
zDelta.pos += cnt; | ||
break; | ||
|
||
case ';': | ||
byte[] out = zOut.toByteArray(); | ||
long checksumValue = checksum(out); | ||
if (cnt != (int) checksumValue) { | ||
throw new Exception("bad checksum"); | ||
} | ||
if (total != limit) { | ||
throw new Exception("generated size does not match predicted size"); | ||
} | ||
return out; | ||
|
||
default: | ||
System.out.println(c); | ||
throw new Exception("unknown delta operator"); | ||
} | ||
} | ||
throw new Exception("unterminated delta"); | ||
} | ||
|
||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
|
@@ -23,7 +23,6 @@ void setInfo(ClientInfo info) { | |
|
||
private ClientInfo info; | ||
|
||
|
||
public long getOffset() { | ||
return offset; | ||
} | ||
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.