This clarifies a bit more the ways in which the new script execution
cache could break consensus in the future if additional data from
the CCoins object were to be used as a part of script execution.
After this change, any such consensus breaks should be very visible
to reviewers, hopefully ensuring no such changes can be made.
The new functions are:
* CCoinsViewCache::AddCoin: Add a single COutPoint/Coin pair.
* CCoinsViewCache::SpendCoin: Remove a single COutPoint.
* AddCoins: utility function that invokes CCoinsViewCache::AddCoin for
each output in a CTransaction.
* AccessByTxid: utility function that searches for any output with
a given txid.
* CCoinsViewCache::AccessCoin: retrieve the Coin for a COutPoint.
* CCoinsViewCache::HaveCoins: check whether a non-empty Coin exists
for a given COutPoint.
The AddCoin and SpendCoin methods will eventually replace ModifyCoins
and ModifyNewCoins, AddCoins will replace CCoins::FromTx, and the new
AccessCoins and HaveCoins functions will replace their per-txid
counterparts.
Note that AccessCoin for now returns a copy of the Coin object. In a
later commit it will be change to returning a const reference (which
keeps working in all call sites).
The earlier CTxInUndo class now holds the same information as the Coin
class. Instead of duplicating functionality, replace CTxInUndo with a
serialization adapter for Coin.
6d7104c99 [Qt] make sure transaction table entry gets updated after bump (Jonas Schnelli)
32325a3f5 [Qt] hide bump context menu action if tx already has been bumped (Jonas Schnelli)
Tree-SHA512: d3e5991145879b7f6b212d9d9c6f423609dc8e6fa7f6feb7df931691f1dec2acb6ab162c2fb7e758d3ca3f3fb14363df2f50f0e83e83068da5cc7e6de35e69d2
b6fbfc2 net: only enforce the services required to connect (Cory Fields)
Tree-SHA512: 88943bff63213a734f3c96c45760cadaeb9ba18287c8a20c279851ebaf058a334c969028fb2180f155508e3eea4b838147382e4f2b655e7a9aa098eadc81d53e
ac9cd95 contrib: Update location of seeds.txt (Wladimir J. van der Laan)
Tree-SHA512: c12a75787ba87f03707c21731da083b466762a7e0af9ca501107695ea1074025907cc24805c7c87f4a66daa7f4f13e574da16be1681e61deaf1acbd72176b3ff
cd5622d Make bitcoind invalid argument error message specific (Wladimir J. van der Laan)
Tree-SHA512: 78999b9359685c4090f9a112e1d02bdddac22173f5f04600773b042acb9481ebb54d0f73d9d6d74249f845f497927a58d59de69bf33e3dccf096c3c80c7ebf6b
1983c87 devtools: Retry after signing fails in github-merge (Wladimir J. van der Laan)
Tree-SHA512: f5ef91c93f4e53c9b234e7dc3ac398c6715144021d92c8592174d02c672ae99d27e88faefd52239c2a74c8e49cfd3a979e0229580016ce9a74829bdb0af206ec
This commit marks the start/stop functions in util.py as private module
functions. A future PR will remove these entirely and move the
functionality directly into the BitcoinTestFramework class, but setting them as
private in this PR will prevent anyone from accidentally calling them
before that future PR is merged.
This is a well-intentioned but realistically annoying warning. Unfortunately,
it's too easy for a warning in one header to cause dozens of repeated warnings.
Previously, transaction metadata (height, coinbase or not, and before
the previous commit also nVersion) was only stored for undo records
that correspond to the last output of a transaction being spent.
This only saves 2 bytes per undo record. Change this to storing this
information for every undo record, and stop complaining for having it
in non-last output spends. This means that undo dat written with
this patch won't be readable by older versions anymore.
This makes the following changes:
* In undo data and the chainstate database, the transaction nVersion
field is removed from the data structures, always written as 0, and
ignored when reading.
* The definition of hash_serialized in gettxoutsetinfo is changed to no
longer incude the nVersion field. It is renamed to hash_serialized_2
to avoid confusion. The new definition also includes transaction
height and coinbase information, as this information was missing
before.
This depends on having a CHashVerifier-based undo data checksum
verifier.
Apart from changing the definition of serialized_hash, downgrading
after using this patch is supported, as no release ever used the value
of nVersion field in UTXO entries.
This is necessary later, when we drop the nVersion field from the undo
data. At that point deserializing and reserializing the data won't
roundtrip anymore, and thus that approach can't be used to verify
checksums anymore.
With this CHashVerifier approach, we can deserialize while hashing the
exact serialized form that was used. This is both more efficient and
more correct in that case.
The error() function unconditionally reports an error. It should only
be used for actually exception situations, and not for the type of
inconsistencies that ApplyTxInUndo/DisconnectBlock can graciously deal
with.
This also makes a subtle semantics change: in ApplyTxInUndo, when a
record with metadata is encountered (indicating it is the last spend
from a tx), don't wipe the CCoins record if it wasn't empty at that
point. This makes sure that UTXO operations never affect any other
UTXOs (including those from the same tx).
