There are 3 pieces of data that are maintained on disk. The actual block
and undo data, the block index (which can refer to positions on disk),
and the chainstate (which refers to the best block hash).
Earlier, there was no guarantee that blocks were written to disk before
block index entries referring to them were written. This commit introduces
dirty flags for block index data, and delays writing entries until the actual
block data is flushed.
With this stricter ordering in writes, it is now safe to not always flush
after every block, so there is no need for the IsInitialBlockDownload()
check there - instead we just write whenever enough time has passed or
the cache size grows too large. Also updating the wallet's best known block
is delayed until this is done, otherwise the wallet may end up referring to an
unknown block.
In addition, only do a write inside the block processing loop if necessary
(because of cache size exceeded). Otherwise, move the writing to a point
after processing is done, after relaying.
Add a sanity check to prevent cosmic rays from flipping a bit in the
generated public key, or bugs in the elliptic curve code. This is
simply done by signing a (randomized) message, and verifying the
result.
This turns STRICTENC turn into a softforking-safe change (even though it
is not intended as a consensus rule), and as a result guarantee that using
it for mempool validation only results in consensus-valid transactions in
the mempool.
99f41b9 MOVEONLY: core.o -> core/block.o (jtimon)
561e9e9 MOVEONLY: Move script/compressor out of script and put CTxOutCompressor (from core) with it (jtimon)
999a2ab MOVEONLY: separate CTxUndo out of core (jtimon)
4a3587d MOVEONLY: Separate CTransaction and dependencies from core (jtimon)
eda3733 MOVEONLY: Move CFeeRate and Amount constants to amount.o (jtimon)
50f71cd boost: code movement only: split CECKey into separate files (Cory Fields)
bdaec6a boost: remove CPubKey dependency from CECKey. Follow-up of e405aa48 (Cory Fields)
5f4bcf6 boost: drop boost dependency in version.cpp. (Cory Fields)
352058e boost: drop boost dependency in utilstrencodings.cpp (Cory Fields)
e1c9467 boost: drop boost dependency in core.cpp (Cory Fields)
e405aa4 boost: remove CPrivKey dependency from CECKey (Cory Fields)
5295506 boost: drop dependency on tuple in serialization (Cory Fields)
1d9b86d boost: drop dependency on is_fundamental in serialization (Cory Fields)
Previous refactorings broke the ability to rebuild the chainstate by deleting the chainstate
directory, resulting in an incorrect "Incorrect or no genesis block found" error message. Fix
that.
Also, improve the performance of ActivateBestBlockStep by using the skiplist to only discover
a few potential blocks to connect at a time, instead of all blocks forever - as we likely bail
out after connecting a single one anyway.
Instead of skipping to the last reindexed block in each file (which could
jump over processed out-of-order blocks), just skip each already processed
block individually.
Many changes:
* Do not use 'getblocks', but 'getheaders', and use it to build a headers tree.
* Blocks are fetched in parallel from all available outbound peers, using a
limited moving window. When one peer stalls the movement of the window, it is
disconnected.
* No more orphan blocks. At all. We only ever request a block for which we have
verified the headers, and store it to disk immediately. This means that a
disk-fill attack would require PoW.
* Require protocol version 31800 for every peer (released in december 2010).
* No more syncnode (we sync from everyone we can, though limited to 1 during
initial *headers* sync).
* Introduce some extra named constants, comments and asserts.
d0c4197 change exit(1) to an assert in CWallet::EncryptWallet (Philip Kaufmann)
870da77 fix possible memory leaks in CWallet::EncryptWallet (Philip Kaufmann)
f606bb9 fix a possible memory leak in CWalletDB::Recover (Philip Kaufmann)
* Delete canonical_tests.cpp, and move the tests to script_tests.cpp.
* Split off SCRIPT_VERIFY_DERSIG from SCRIPT_VERIFY_STRICTENC (the BIP62 part of it).
* Change signature STRICTENC/DERSIG semantics to fail the script entirely rather than the CHECKSIG result (softfork safety, and BIP62 requirement).
* Add many autogenerated tests for several odd cases.
* Mention specific BIP62 rules in the script verification flags.
7c70438 Get rid of the dummy CCoinsViewCache constructor arg (Pieter Wuille)
ed27e53 Add coins_tests with a large randomized CCoinViewCache test. (Pieter Wuille)
058b08c Do not keep fully spent but unwritten CCoins entries cached. (Pieter Wuille)
c9d1a81 Get rid of CCoinsView's SetCoins and SetBestBlock. (Pieter Wuille)
f28aec0 Use ModifyCoins instead of mutable GetCoins. (Pieter Wuille)
Move the txid duplicates check into BuildMerkleTree, where it can be done
much more efficiently (without needing to build a full txid set to detect
duplicates).
The previous version (using the std::set<uint256> to detect duplicates) was
also slightly too weak. A block mined with actual duplicate transactions
(which is invalid, due to the inputs of the duplicated transactions being
seen as double spends) would trigger the duplicates logic, resulting in the
block not being stored on disk, and rerequested. This change fixes that by
only triggering in the case of duplicated transactions that can actually
result in an identical merkle root.
Instead of storing CCoins entries directly in CCoinsMap, store a CCoinsCacheEntry
which additionally keeps track of whether a particular entry is:
* dirty: potentially different from its parent view.
* fresh: the parent view is known to not have a non-pruned version.
This allows us to skip non-dirty cache entries when pushing batches of changes up,
and to remove CCoins entries about transactions that are fully spent before the
parent cache learns about them.
All direct modifications are now done through ModifyCoins, and BatchWrite is
used for pushing batches of queued modifications up, so we don't need the
low-level SetCoins and SetBestBlock anymore in the top-level CCoinsView class.
Replace the mutable non-copying GetCoins method with a ModifyCoins, which
returns an encapsulated iterator, so we can keep track of concurrent
modifications (as iterators can be invalidated by those) and run cleanup
code after a modification is finished.
This also removes the overloading of the 'GetCoins' name.
Pieter Wuille