def backup_from_undo_info(self, claim_id, undo_claim_info):
"""
Undo information holds a claim state **before** a transaction changes it
There are 4 possibilities when processing it, of which only 3 are valid ones:
1. the claim is known and the undo info has info, it was an update
2. the claim is known and the undo info doesn't hold any info, it was claimed
3. the claim in unknown and the undo info has info, it was abandoned
4. the claim is unknown and the undo info does't hold info, error!
"""
undo_claim_info = ClaimInfo(*undo_claim_info) if undo_claim_info else None
current_claim_info = self.db.get_claim_info(claim_id)
if current_claim_info and undo_claim_info:
# update, remove current claim
self.db.remove_claim_id_for_outpoint(current_claim_info.txid, current_claim_info.nout)
if current_claim_info.cert_id:
self.db.remove_claim_from_certificate_claims(current_claim_info.cert_id, claim_id)
elif current_claim_info and not undo_claim_info:
# claim, abandon it
self.db.abandon_spent(current_claim_info.txid, current_claim_info.nout)
elif not current_claim_info and undo_claim_info:
# abandon, reclaim it (happens below)
pass
else:
# should never happen, unless the database got into an inconsistent state
raise Exception("Unexpected situation occurred on backup, this means the database is inconsistent. "
"Please report. Resetting the data folder (reindex) solves it for now.")
if undo_claim_info:
self.db.put_claim_info(claim_id, undo_claim_info)
if undo_claim_info.cert_id:
cert_id = self._checksig(undo_claim_info.name, undo_claim_info.value, undo_claim_info.address)
self.db.put_claim_id_signed_by_cert_id(cert_id, claim_id)
self.db.put_claim_for_name(undo_claim_info.name, claim_id)
self.db.put_claim_id_for_outpoint(undo_claim_info.txid, undo_claim_info.nout, claim_id)
def claim_info_from_output(self, output, txid, nout, height):
amount = output.value
address = self.coin.address_from_script(output.pk_script)
name, value, cert_id = output.claim.name, output.claim.value, None
assert txid and address
cert_id = self._checksig(name, value, address)
return ClaimInfo(name, value, txid, nout, amount, address, height, cert_id)
def get_claim_info(self, claim_id):
serialized = self.claim_cache.get(claim_id) or self.claims_db.get(
claim_id)
return ClaimInfo.from_serialized(serialized) if serialized else None