public static int calculateNumberOfBlocksUsed(long firstBlock) {
Bits bits = Bits.bitsFromLongs(new long[] {firstBlock});
// bbbb][bbll,llll][yyyy,tttt][kkkk,kkkk][kkkk,kkkk][kkkk,kkkk]
bits.getInt(24); // Get rid of key
bits.getByte(4); // Get rid of short array type
bits.getByte(4); // Get rid of the type
int arrayLength = bits.getByte(6);
int requiredBits = bits.getByte(6);
if (requiredBits == 0) {
requiredBits = 64;
}
return calculateNumberOfBlocksUsed(arrayLength, requiredBits);
}
public static String versionLongToString(long storeVersion) {
if (storeVersion == -1) {
return CommonAbstractStore.UNKNOWN_VERSION;
}
Bits bits = Bits.bitsFromLongs(new long[] {storeVersion});
int length = bits.getShort(8);
if (length == 0 || length > 7) {
throw new IllegalArgumentException(
String.format("The read in version string length %d is not proper.", length));
}
char[] result = new char[length];
for (int i = 0; i < length; i++) {
result[i] = (char) bits.getShort(8);
}
return new String(result);
}
public static Object decode(PropertyBlock block) {
Bits bits =
Bits.bitsFromLongs(Arrays.copyOf(block.getValueBlocks(), block.getValueBlocks().length));
// [][][ ,bbbb][bbll,llll][yyyy,tttt][kkkk,kkkk][kkkk,kkkk][kkkk,kkkk]
bits.getInt(24); // Get rid of key
bits.getByte(4); // Get rid of short array type
int typeId = bits.getByte(4);
int arrayLength = bits.getByte(6);
int requiredBits = bits.getByte(6);
/*
* So, it can be the case that values require 64 bits to store. However, you cannot encode this
* value with 6 bits. calculateRequiredBitsForArray never returns 0, because even for an array of
* all 0s one bit is required for every value. So when writing, we let it overflow and write out
* 0. When we are reading back, we just have to make sure that reading in 0 means 64.
*/
if (requiredBits == 0) {
requiredBits = 64;
}
ShortArray type = typeOf((byte) typeId);
return type.createArray(arrayLength, bits, requiredBits);
}
