static {
try {
emptyVersion = UUID.nameUUIDFromBytes(MessageDigest.getInstance("MD5").digest());
} catch (NoSuchAlgorithmException e) {
throw new AssertionError();
}
}
/**
* Read schema from system table and calculate MD5 digest of every row, resulting digest will be
* converted into UUID which would act as content-based version of the schema.
*/
public void updateVersion() {
try {
MessageDigest versionDigest = MessageDigest.getInstance("MD5");
for (Row row : SystemTable.serializedSchema()) {
if (invalidSchemaRow(row) || ignoredSchemaRow(row)) continue;
row.cf.updateDigest(versionDigest);
}
version = UUID.nameUUIDFromBytes(versionDigest.digest());
SystemTable.updateSchemaVersion(version);
} catch (Exception e) {
throw new RuntimeException(e);
}
}