public boolean initializeUpgrade() throws IOException {
currentUpgrades = getDistributedUpgrades();
if (currentUpgrades == null) {
// set new upgrade state
setUpgradeState(false, FSConstants.LAYOUT_VERSION);
return false;
}
Upgradeable curUO = currentUpgrades.first();
// set and write new upgrade state into disk
setUpgradeState(true, curUO.getVersion());
return true;
}
UOSignature(Upgradeable uo) {
this.version = uo.getVersion();
this.type = uo.getType();
this.className = uo.getClass().getCanonicalName();
}
