There are quite a few variables in the code that are no longer
(or perhaps never were) in use. These were discovered by enabling
compiler warnings for unused variables and cleaning them up.
In most cases where the unused variables were the result
of a function call the call was left but the variable
assignment removed, unless it was obvious that it was
a simple getter with no side effects.
This reduces the attack surface for data that can come from
malicious sources (exported output and key images, multisig
transactions...) since the monero serialization is already
exposed to the outside, and the boost lib we were using had
a few known crashers.
For interoperability, a new load-deprecated-formats wallet
setting is added (off by default). This allows loading boost
format data if there is no alternative. It will likely go
at some point, along with the ability to load those.
Notably, the peer lists file still uses the boost serialization
code, as the data it stores is define in epee, while the new
serialization code is in monero, and migrating it was fairly
hairy. Since this file is local and not obtained from anyone
else, the marginal risk is minimal, but it could be migrated
later if needed.
Some tests and tools also do, this will stay as is for now.
If the peer (whether pruned or not itself) supports sending pruned blocks
to syncing nodes, the pruned version will be sent along with the hash
of the pruned data and the block weight. The original tx hashes can be
reconstructed from the pruned txes and theur prunable data hash. Those
hashes and the block weights are hashes and checked against the set of
precompiled hashes, ensuring the data we received is the original data.
It is currently not possible to use this system when not using the set
of precompiled hashes, since block weights can not otherwise be checked
for validity.
This is off by default for now, and is enabled by --sync-pruned-blocks
2cd4fd8 Changed the use of boost:value_initialized for C++ list initializer (JesusRami)
4ad191f Removed unused boost/value_init header (whyamiroot)
928f4be Make null hash constants constexpr (whyamiroot)
113e4877 blockchain_stats: fix sign in formatting function (moneromooo-monero)
adaea3ea various: remove unused variables (moneromooo-monero)
631ef00e blockchain: some debug info when adding txes-from-block fails (moneromooo-monero)
This curbs runaway growth while still allowing substantial
spikes in block weight
Original specification from ArticMine:
here is the scaling proposal
Define: LongTermBlockWeight
Before fork:
LongTermBlockWeight = BlockWeight
At or after fork:
LongTermBlockWeight = min(BlockWeight, 1.4*LongTermEffectiveMedianBlockWeight)
Note: To avoid possible consensus issues over rounding the LongTermBlockWeight for a given block should be calculated to the nearest byte, and stored as a integer in the block itself. The stored LongTermBlockWeight is then used for future calculations of the LongTermEffectiveMedianBlockWeight and not recalculated each time.
Define: LongTermEffectiveMedianBlockWeight
LongTermEffectiveMedianBlockWeight = max(300000, MedianOverPrevious100000Blocks(LongTermBlockWeight))
Change Definition of EffectiveMedianBlockWeight
From (current definition)
EffectiveMedianBlockWeight = max(300000, MedianOverPrevious100Blocks(BlockWeight))
To (proposed definition)
EffectiveMedianBlockWeight = min(max(300000, MedianOverPrevious100Blocks(BlockWeight)), 50*LongTermEffectiveMedianBlockWeight)
Notes:
1) There are no other changes to the existing penalty formula, median calculation, fees etc.
2) There is the requirement to store the LongTermBlockWeight of a block unencrypted in the block itself. This is to avoid possible consensus issues over rounding and also to prevent the calculations from becoming unwieldy as we move away from the fork.
3) When the EffectiveMedianBlockWeight cap is reached it is still possible to mine blocks up to 2x the EffectiveMedianBlockWeight by paying the corresponding penalty.
Note: the long term block weight is stored in the database, but not in the actual block itself,
since it requires recalculating anyway for verification.