Implement REPLACE_DEFERRED protocol feature #6997
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… the REPLACE_DEFERRED protocol feature. Updated the deferred_test test contract to make it possible to selectively replace existing deferred transaction, which was needed for the above unit test. Added disable_all_subjective_mitigations configuration option to controller to make it possible to write the above unit test. Finally, enabled the part of api_tests/deferred_transaction_tests that deals with replacing deferred transactions.
… field to protocol_state_object
libraries/chain/controller.cpp
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| template<> | ||
| void controller_impl::on_activation<builtin_protocol_feature_t::replace_deferred>() { | ||
| const auto& indx = db.get_index<account_ram_correction_index, by_id>(); | ||
| auto itr = indx.begin(); |
There was a problem hiding this comment.
Looks like this line auto itr = indx.begin(); is redundant and "itr" will be hided by another "itr" in the for loop.
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Couldn't we make the Also, are all these consensus-breaking changes going to be pooled into one release? In any case, it would be very desirable to have backwards-compatible snapshot files. |
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No backwards-compatible snapshot files for the initial release introducing protocol features because we actually want everyone to replay from genesis (or import a v2 snapshot from someone who has replayed from genesis). This will hopefully not be a normal thing required with the introduction of new protocol features. But this particular one, Many consensus protocol upgrades are going to be pooled into the initial release. Future ones are planned that will not make it into the first release. These will (hopefully) be much easier to deploy assuming they do not require state database data structure changes (and especially if they do not require historical information to implement). |
Change Description
Resolves #6103.
This PR adds support for the
REPLACE_DEFERREDprotocol feature which fixes two issues that occurred under the original protocol rules when replacing a deferred transaction:The activation of this protocol feature will also instantaneously correct the RAM usage of any accounts affected by this bug earlier.
Finally, the subjective mitigation that prevented replacing deferred transactions will automatically be removed after activation of
REPLACE_DEFERRED.This PR introduces a new unit test
protocol_feature_tests/replace_deferred_testto test the behavior of this new protocol feature. Thedeferred_testtest contract was augmented to enable functionality to replace deferred transactions which was needed by the new unit test.The changes in this PR also enable a section of an existing test
api_tests/deferred_transaction_testswhich required the replacing deferred transaction functionality to be available.The implementation for
REPLACE_DEFERREDrequired an addition of an index for the newaccount_ram_correction_objectinto the state database. This meant it had an impact on the chain snapshot version. Other prior changes to the expected data structures in chain snapshots which were merged into theprotocol-feature-foundationsbranch were not accompanied with a bump in the chain snapshot version because of the anticipation that further changes would be required (for example with the changes associated with theREPLACE_DEFERREDprotocol feature).Now this changes the current supported version for chain snapshots to 2 and also increases the minimum supported version to 2, to ensure that the new snapshot version is not compatible with the original one (since replay from genesis is required to support this protocol feature). Also, one small addition is made to the
protocol_state_object(the addition of theuint32_tnum_supported_key_typesfield which is initialized to 2) because it will be useful for a future anticipated protocol feature and I don't want that future protocol feature to force another version bump for chain snapshots.Consensus Changes
Makes the
REPLACE_DEFERREDprotocol feature available. See above description and #6103 for details.API Changes
Documentation Additions