0ae8f18dfe build: add -Wgnu to compile flags (fanquake)
3a0fd7726b Remove use of non-standard zero variadic macros (Ben Woosley)
49f6178c3e Drop unused LOG_TIME_MICROS helper (Ben Woosley)
5d4999951e prevector: Avoid unnamed struct, which is a GNU extension (DesWurstes)
Pull request description:
Since we [started using](https://github.com/bitcoin/bitcoin/pull/7165) the `ax_cxx_compile_stdcxx.m4` macro we've been passing `[noext]` to indicate that we don't want to use an extended mode, i.e GNU extensions. Speaking to Cory he clarified that the intention was to "require only vanilla c++11 and turn _off_ extension support so they would fail to compile".
However in the codebase we are currently making use of some GNU extensions. We should either remove there usage, or at least amend our CXX compiler checks. I'd prefer the former.
#### anonymous structs
```bash
./prevector.h:153:9: warning: anonymous structs are a GNU extension [-Wgnu-anonymous-struct]
struct {
```
This is fixed in b849212c1e.
#### variadic macros
```bash
./undo.h:57:50: warning: must specify at least one argument for '...' parameter of variadic macro [-Wgnu-zero-variadic-macro-arguments]
::Unserialize(s, VARINT(nVersionDummy));
```
This is taken care of in #18087.
The `LOG_TIME_*` macros introduced in #16805 make use of a [GNU extension](https://gcc.gnu.org/onlinedocs/cpp/Variadic-Macros.html).
```bash
In file included from validation.cpp:22:
./logging/timer.h:99:99: warning: token pasting of ',' and __VA_ARGS__ is a GNU extension [-Wgnu-zero-variadic-macro-arguments]
BCLog::Timer<std::chrono::milliseconds> PASTE2(logging_timer, __COUNTER__)(__func__, end_msg, ## __VA_ARGS__)
^
./logging/timer.h:99:99: warning: token pasting of ',' and __VA_ARGS__ is a GNU extension [-Wgnu-zero-variadic-macro-arguments]
./logging/timer.h:99:99: warning: token pasting of ',' and __VA_ARGS__ is a GNU extension [-Wgnu-zero-variadic-macro-arguments]
./logging/timer.h:99:99: warning: token pasting of ',' and __VA_ARGS__ is a GNU extension [-Wgnu-zero-variadic-macro-arguments]
./logging/timer.h:99:99: warning: token pasting of ',' and __VA_ARGS__ is a GNU extension [-Wgnu-zero-variadic-macro-arguments]
./logging/timer.h:101:92: warning: token pasting of ',' and __VA_ARGS__ is a GNU extension [-Wgnu-zero-variadic-macro-arguments]
BCLog::Timer<std::chrono::seconds> PASTE2(logging_timer, __COUNTER__)(__func__, end_msg, ## __VA_ARGS__)
^
6 warnings generated.
```
This is fixed in 081a0ab64eb442bc85c4d4a4d3bc2c8e97ac2a6d and 612e8e138b97fc5ad2f38847300132a8fc423c3f.
#### prevention
To ensure that usage doesn't creep back in we can add [`-Wgnu`](https://clang.llvm.org/docs/DiagnosticsReference.html#wgnu) to our compile time flags, which will make Clang warn whenever it encounters GNU extensions.
This would close#14130.
Also related to #17230, where it's suggested we use a GNU extension, the `gnu::pure` attribute.
ACKs for top commit:
practicalswift:
ACK 0ae8f18dfe -- diff looks correct
MarcoFalke:
ACK 0ae8f18dfe
vasild:
utACK 0ae8f18df
dongcarl:
ACK 0ae8f18dfe
Tree-SHA512: c517404681ef8edf04c785731d26105bac9f3c9c958605aa24cbe399c649e7c5ee0c4aa8e714fd2b2d335e2fbea4d571e09b0dec36678ef871f0a6683ba6bb7f
faec3dc2ad init: Remove boost from ThreadImport (MarcoFalke)
Pull request description:
Can be tested by calling `-reindex` or `-loadblock` and then pressing `CTRL`+`C`.
Should print something like:
```
...
2020-04-27T19:34:31Z [loadblk] Reindexing block file blk00005.dat...
^C2020-04-27T19:34:32Z [loadblk] Shutdown requested. Exit ThreadImport
2020-04-27T19:34:32Z [qt-init] Interrupting HTTP server
...
```
ACKs for top commit:
laanwj:
Code review ACK faec3dc2ad
hebasto:
ACK faec3dc2ad, tested on Linux Mint 19.3 (x86_64) both `bitcoind` and `bitcoin-qt` binaries.
Tree-SHA512: e105af18d98296d82ec99f48e478cf44577e3c32f7e4b47617a7bc7cbf71d6becb92722f229a1be38d58ad29712704509ad9740d8ab8cd3104cf90057664b437
692f8307fc test: add test for witness commitment index (fanquake)
06442549f8 validation: Add minimum witness commitment size constant (fanquake)
Pull request description:
16101de5f3: Per [BIP 141](https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#Commitment_structure), the witness commitment structure is at least 38 bytes,
OP_RETURN (0x6a) + 36 (0x24) + 4 byte header (0xaa21a9ed) + 32 byte
SHA256 hash. It can be longer, however any additional data has no
consensus meaning.
54f8c48d6a: As per BIP 141, if there is more than 1 pubkey that matches the witness
commitment structure, the one with the highest output index should be
chosen. This adds a sanity check that we are doing that, which will fail
if anyone tries to "optimize" GetWitnessCommitmentIndex() by returning
early.
ACKs for top commit:
MarcoFalke:
ACK 692f8307fc🌵
jonatack:
Code review ACK 692f830
ajtowns:
ACK 692f8307fc
jnewbery:
utACK 692f8307fc
laanwj:
ACK 692f8307fc
Tree-SHA512: 7af3fe4b8a52fea2cdd0aec95f7bb935351a77b73d934bc88d6625a3503311b2a062cba5190b2228f97caa76840db3889032d910fc8e318ca8e7810a8afbafa0
Use salted hasher instead of nonce in Script Execution Cache
Don't read more than 32 bytes from GetRand
Apply g_* naming convention to scriptExecutionCache in validation.cpp
Fully apply g_* naming convention to scriptCacheHasher
Write same uint256 nonce twice for cache hash rather than calling getrand twice
Use salted hasher instead of nonce in sigcache
Use salted hasher instead of nonce in Script Execution Cache
Don't read more than 32 bytes from GetRand
Apply g_* naming convention to scriptExecutionCache in validation.cpp
Fully apply g_* naming convention to scriptCacheHasher
Write same uint256 nonce twice for cache hash rather than calling getrand twice
50fc4df6c4 [mempool] Persist unbroadcast set to mempool.dat (Amiti Uttarwar)
297a178536 [test] Integration tests for unbroadcast functionality (Amiti Uttarwar)
6851502472 [refactor/test] Extract P2PTxInvStore into test framework (Amiti Uttarwar)
dc1da48dc5 [wallet] Update the rebroadcast frequency to be ~1/day. (Amiti Uttarwar)
e25e42f20a [p2p] Reattempt initial send of unbroadcast transactions (Amiti Uttarwar)
7e93eecce3 [util] Add method that returns random time in milliseconds (Amiti Uttarwar)
89eeb4a333 [mempool] Track "unbroadcast" transactions (Amiti Uttarwar)
Pull request description:
This PR introduces mempool tracking of unbroadcast transactions and periodic reattempts at initial broadcast. This is a part of the rebroadcast project, and a standalone privacy win.
The current rebroadcast logic is terrible for privacy because 1. only the source wallet rebroadcasts transactions and 2. it does so quite frequently. In the current system, if a user submits a transaction that does not immediately get broadcast to the network (eg. they are offline), this "rebroadcast" behavior is the safety net that can actually serve as the initial broadcast. So, keeping the attempts frequent is important for initial delivery within a reasonable timespan.
This PR aims to improve # 2 by reducing the wallet rebroadcast frequency to ~1/day from ~1/15 min. It achieves this by separating the notion of initial broadcast from rebroadcasts. With these changes, the mempool tracks locally submitted transactions & periodically reattempts initial broadcast. Transactions submitted via the wallet or RPC are added to an "unbroadcast" set & are removed when a peer sends a `getdata` request, or the transaction is removed from the mempool. Every 10-15 minutes, the node reattempts an initial broadcast. This enables reducing the wallet rebroadcast frequency while ensuring the transactions will be propagated to the network.
For privacy improvements around # 1, please see #16698.
Thank you to gmaxwell for the idea of how to break out this subset of functionality (https://github.com/bitcoin/bitcoin/pull/16698#issuecomment-571399346)
ACKs for top commit:
fjahr:
Code review ACK 50fc4df6c4
MarcoFalke:
ACK 50fc4df6c4, I think this is ready for merge now 👻
amitiuttarwar:
The current tip `50fc4df` currently has 6 ACKs on it, so I've opened #18807 to address the last bits.
jnewbery:
utACK 50fc4df6c4.
ariard:
Code Review ACK 50fc4df (minor points no need to invalid other ACKs)
robot-visions:
ACK 50fc4df6c4
sipa:
utACK 50fc4df6c4
naumenkogs:
utACK 50fc4df
Tree-SHA512: 2dd935d645d5e209f8abf87bfaa3ef0e4492705ce7e89ea64279cb27ffd37f4727fa94ad62d41be331177332f8edbebf3c7f4972f8cda10dd951b80a28ab3c0f
Per BIP 141, the witness commitment structure is atleast 38 bytes,
OP_RETURN (0x6a) + 36 (0x24) + 4 byte header (0xaa21a9ed) + 32 byte
SHA256 hash. It can be longer, however any additional data has no
consensus meaning.
21fa0a44ab [docs] use consistent naming for possible_overwrite (John Newbery)
2685c214cc [tests] small whitespace fixup (John Newbery)
e9936966c0 scripted-diff: Rename PRUNED to SPENT in coins tests (John Newbery)
c205979031 [docs] Improve commenting in coins.cpp|h (John Newbery)
Pull request description:
- Add full commenting for spentness / DIRTYness / FRESHness and which combinations are valid
- Remove the 'pruned' terminology, which doesn't make sense since per-txout chainstate db was merged (#10195).
- Rename `potential_overwrite` to `possible_overwrite` to standardize terminology (there were previously examples of both, which made searching the codebase difficult).
- Make other minor improvements to the comments
ACKs for top commit:
jonatack:
Re-ACK 21fa0a4 per `git diff 98bee55 21fa0a4` the only change since my previous review is the following code commenting diff in `src/coins.cpp::L177-179`; rebuilt/ran unit tests anyway as a sanity check on the unit test changes.
Tree-SHA512: 391e01588ef5edb417250080cec17361f982c4454bc5f8c6d78bbd528c68a2bb94373297760691295c24660ce1022ad3ef7599762f736c8eed772ce096d38c3d
f63dec189c [REFACTOR] Initialize PrecomputedTransactionData in CheckInputScripts (Pieter Wuille)
Pull request description:
This is a single commit taken from the Schnorr/Taproot PR #17977.
Add a default constructor to `PrecomputedTransactionData`, which doesn't initialize the struct's members. Instead they're initialized inside the `CheckInputScripts()` function. This allows a later commit to add the spent UTXOs to that structure. The spent UTXOs are required for the schnorr signature hash, since it commits to the scriptPubKeys. See https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki#common-signature-message for details.
By itself, this isn't really an improvement to the code, but I think it makes sense to separate out the refactor/moveonly commits from PR #17977 so that PR is only the logical changes needed for Schnorr/Taproot.
ACKs for top commit:
jonatack:
Re-ACK f63dec1 `git diff 851908d f63dec1` shows no change since last ACK.
sipa:
utACK f63dec189c
theStack:
re-ACK f63dec189c
fjahr:
Re-ACK f63dec189c
ariard:
Code Review ACK f63dec1
Tree-SHA512: ecf9154077824ae4c274b4341e985797f3648c0cb0c31cb25ce382163b923a3acbc7048683720be4ae3663501801129cd0f48c441a36f049cc304ebe9f30994e
Add a default constructor to `PrecomputedTransactionData`, which doesn't
initialize the struct's members. Instead they're initialized inside the
`CheckInputScripts()` function. This allows a later commit to add the
spent UTXOs to that structure.
c9017ce3bc protect g_chainman with cs_main (James O'Beirne)
2b081c4568 test: add basic tests for ChainstateManager (James O'Beirne)
4ae29f5f0c use ChainstateManager to initialize chainstate (James O'Beirne)
5b690f0aae refactor: move RewindBlockIndex to CChainState (James O'Beirne)
89cdf4d569 validation: introduce unused ChainstateManager (James O'Beirne)
8e2ecfe249 validation: add CChainState.m_from_snapshot_blockhash (James O'Beirne)
Pull request description:
This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/master/proposal
---
This changeset introduces `ChainstateManager`, which is responsible for creating and managing access to multiple chainstates. Until we allow chainstate creation from UTXO snapshots (next assumeutxo PR?) it's basically unnecessary, but it is a prerequisite for background IBD support.
Changes are also made to the initialization process to make use of `g_chainman` and thus clear the way for multiple chainstates being loaded on startup.
One immediate benefit of this change is that we no longer have the `g_blockman` global, but instead have the ChainstateManager inject a reference of its shared BlockManager into any chainstate it creates.
Another immediate benefit is that uses of `ChainActive()` and `ChainstateActive()` are now covered by lock annotations. Because use of `g_chainman` is annotated to require cs_main, these two functions subsequently follow.
Because of whitespace changes, this diff looks bigger than it is. E.g., 4813167d98 is most easily reviewed with
```sh
git show --color-moved=dimmed_zebra -w 4813167d98
```
ACKs for top commit:
MarcoFalke:
re-ACK c9017ce3bc📙
fjahr:
Code Review Re-ACK c9017ce3bc
ariard:
Code Review ACK c9017ce
ryanofsky:
Code review ACK c9017ce3bc. No changes since last review other than a straight rebase
Tree-SHA512: 3f250d0dc95d4bfd70852ef1e39e081a4a9b71a4453f276e6d474c2ae06ad6ae6a32b4173084fe499e1e9af72dd9007f4a8a375c63ce9ac472ffeaada41ab508
Data files are pre-allocated, and upon flush/finalization, they are trimmed down to their resulting size.
Block (blk) files are written to disk as blocks come in, which is often out of order, whereas undo (rev) files are written sequentially, as each block is added to the top of the chain.
When a block file hits the size limit, the system flushes and trims the file down to its final size, and moves on to the next block file.
Case 1: blocks are added to the chain as they come in (synced up node case) -- in this case, we will flush and finalize the undo file together with the block file.
Case 2: blocks are added to the chain after they have been downloaded (syncing node case) -- in this case, we postpone finalizing the undo file until we know the undo data for the last block in the file has been written to disk.
e57980b473 [mempool] Remove NotifyEntryAdded and NotifyEntryRemoved callbacks (John Newbery)
2dd561f361 [validation] Remove pool member from ConnectTrace (John Newbery)
969b65f3f5 [validation] Remove NotifyEntryRemoved callback from ConnectTrace (John Newbery)
5613f9842b [validation] Remove conflictedTxs from PerBlockConnectTrace (John Newbery)
cdb893443c [validation interface] Remove vtxConflicted from BlockConnected (John Newbery)
1168394d75 [wallet] Notify conflicted transactions in TransactionRemovedFromMempool (John Newbery)
Pull request description:
These boost signals were added in #9371, before we had a `TransactionRemovedFromMempool` method in the validation interface. The `NotifyEntryAdded` callback was used by validation to build a vector of conflicted transactions when connecting a block, which the wallet was notified of in the `BlockConnected` CValidationInterface callback.
Now that we have a `TransactionRemovedFromMempool` callback, we can fire that signal directly from the mempool for conflicted transactions.
Note that #9371 was implemented to ensure `-walletnotify` events were fired for these conflicted transaction. We inadvertently stopped sending these notifications in #16624 (Sep 2019 commit 7e89994). We should probably fix that, but in a different PR.
ACKs for top commit:
jonatack:
Re-ACK e57980b
ryanofsky:
Code review ACK e57980b473, no code changes since previous review, but helpful new code comments have been added and the PR description is now more clear about where the old code came from
Tree-SHA512: 3bdbaf1ef2731e788462d4756e69c42a1efdcf168691ce1bbfdaa4b7b55ac3c5b1fd4ab7b90bcdec653703600501b4224d252cfc086aef28f9ce0da3b0563a69
ec30a79f1c Fix UB with bench on genesis block (Gregory Sanders)
Pull request description:
During the loading of the genesis block, the bench print lines in ConnectTip divide by zero due to early return in ConnectBlock.
ACKs for top commit:
practicalswift:
ACK ec30a79f1c
sipa:
utACK ec30a79f1c
promag:
ACK ec30a79, `nBlocksTotal` is only used in logging.
Tree-SHA512: b3bdbb58d10d002a2293d7f99196b227ed9f4ca8c6cd08981e95cc964be47efed98b91fad276ee6da5cf7e6684610998ace7ce9bace172dd6c51c386d985b83c
I'd previously attempted to create a specialized lock for ChainstateManager,
but it turns out that because that lock would be required for functions like
ChainActive() and ChainstateActive(), it created irreconcilable lock inversions
since those functions are used so broadly throughout the codebase.
Instead, I'm just using cs_main to protect the contents of g_chainman.
Co-authored-by: Russell Yanofsky <russ@yanofsky.org>
ChainstateManager is responsible for creating and managing multiple
chainstates, and will provide a high-level interface for accessing the
appropriate chainstate based upon a certain use.
Incorporates feedback from Marco Falke. Additional documentation written
by Russ Yanofsky.
Co-authored-by: Russell Yanofsky <russ@yanofsky.org>
This parameter is unused, but in future commits will allow ChainstateManager to
differentiate between chainstates created from a UTXO snapshot from those that
weren't.
This replaces one remaining instance of the literal "BTC" string with
the CURRENCY_UNIT constant, as is done in most of the codebase already.
The other remaining instance (which is just part of a log message and thus
not really user-visible) is just removed.
After this change, no instance of literal "BTC" remains anywhere in the
non-Qt and non-test codebase.
ConnectTrace used to subscribe to the mempool's NotifyEntryRemoved
callback to be notified of transactions removed for conflict. Since
PerBlockConnectTrace no longer tracks conflicted transactions,
ConnectTrace no longer requires these notifications.
0a50019fde Walk pindexBestHeader back to ChainActive().Tip() if it is invalid (Matt Corallo)
Pull request description:
Instead of keeping pindexBestHeader set to the best header we've
ever seen, reset it back to our validated tip if we find an ancestor
of it turns out to be invalid. While the name is now a bit confusing,
this matches much better with how it is used in practice, see below.
Further, this opens up more use-cases for it in the future, namely
aggressively searching for new peers in case we have discovered
(possibly via some covert channel) headers which we do not know to be
invalid, but which we cannot find block data for.
Places pindexBestHeader is used:
* Various GUI displays of the best header and getblockchaininfo["headers"],
I don't think changing this is bad, and if anything this is less confusing
in the presence of an invalid block.
* IsCurrentForFeeEstimation(): If anything I think ensuring pindexBestHeader
isn't some crazy invalid chain is better than the alternative, even in the
case where you are rejecting the current chain due to hardware error (since
hopefully in that case you won't get any new blocks anyway).
* ConnectBlock assumevalid checks: We use pindexBestHeader to check that the
block we're connecting leads to something with nMinimumChainWork (preventing
a user-set assumevalid from having bogus work) and that the block we're
connecting leads to pindexBestHeader (I'm not too worried about this one -
it's nice to "disable" assumevalid if we have a long invalid headers chain,
but I don't see it as a critical protection).
* BlockRequestAllowed() uses pindexBestHeader as its target to ensure the
requested block is within a month of the "current chain". I don't think this
is a meaningful difference, if we're rejecting the current tip we're
trivially fingerprintable anyway, and if the chain really does have a bunch
of invalid crap near the tip, using the best not-invalid header is likely a
better criteria.
* ProcessGetBlockData uses pindexBestHeader as the "current chain" definition
of whether a block request is "historical" for the purpose of bandwidth
limiting. Similarly, I don't see why this is a meaningful change.
* We use pindexBestHeader for requesting missing headers on receipt of a
headers/compact block message or block inv as well as for initial getheaders.
I think this is definitely wrong, using the best not-invalid header for such
requests is much better.
* We use pindexBestHeader to define the "current chain" for deciding when
we're close to done with initial headers sync. I don't think this is a
meaningful change.
* We use pindexBestHeader to decide if initial headers sync has timed out. If
we're rejecting the chain due to hardware error this may result in
additional cases where we ban a peer, but this is already true, so I think
its fine.
ACKs for top commit:
fjahr:
ACK 0a50019fde
kallewoof:
ACK 0a50019fde
ariard:
utACK 0a50019
Tree-SHA512: 2ecfa973a9878a00313ae7ede94a9bd7710e0caf55b544b10bbc46dc463a0478cbaf477e6cdd072356d5a0c5fb3848e9339284af785a2995c20bae8bd23f23e5
-BEGIN VERIFY SCRIPT-
# Delete outdated alias for RecursiveMutex
sed -i -e '/CCriticalSection/d' ./src/sync.h
# Replace use of outdated alias with RecursiveMutex
sed -i -e 's/CCriticalSection/RecursiveMutex/g' $(git grep -l CCriticalSection)
-END VERIFY SCRIPT-
02b9511d6b tests: add tests for GetCoinsCacheSizeState (James O'Beirne)
b17e91d842 refactoring: introduce CChainState::GetCoinsCacheSizeState (James O'Beirne)
Pull request description:
This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/master/proposal
---
This pulls out the routine for detection of how full the coins cache is from
FlushStateToDisk. We use this logic independently when deciding when to flush
the coins cache during UTXO snapshot activation ([see here](231fb5f17e (diff-24efdb00bfbe56b140fb006b562cc70bR5275))).
ACKs for top commit:
ariard:
Code review ACK 02b9511.
ryanofsky:
Code review ACK 02b9511d6b. Just rebase, new COIN_SIZE comment, and new test message since last review
Tree-SHA512: 8bdd78bf68a4a5d33a776e73fcc2857f050d6d102caa4997ed19ca25468c1358e6e728199d61b423033c02e6bc8f00a1d9da52cf17a2d37d70860fca9237ea7c
3bd8db80d8 [validation] fix comments in CheckInputScripts() (John Newbery)
6f6465cefc scripted-diff: [validation] Rename CheckInputs to CheckInputScripts (John Newbery)
Pull request description:
CheckInputs() used to check no double spends, scripts & sigs and amounts. Since
832e074, the double spend and amount checks
have been moved to CheckTxInputs(), and CheckInputs() now just validates
input scripts. Rename the function to CheckInputScripts().
Also fix incorrect comments.
ACKs for top commit:
MarcoFalke:
re-ACK 3bd8db80d8, did the rebase myself, checked the scripted diff 👡
promag:
ACK 3bd8db80d8 :trollface:
Tree-SHA512: 7b3f8597d210492798fb784ee8ea47ea6377519111190161c7cc34a967509013f4337304f52e9bedc97b7710de7b0ff8880e08cd7f867754567f82e7b02c794c
This separates out some logic for detecting how full the coins cache is from
FlushStateToDisk. We'll want to reuse this logic when deciding when to flush
the coins cache during UTXO snapshot activation.
Commit d449772cf6 stopped setting
COINBASE_FLAGS, and it looks like it hasn't been used since P2SH.
Update the help string to remove "flags", which is not specified in
BIP 22.
2f5f7d6b13 GuessVerificationProgress: cap the ratio to 1 (darosior)
Pull request description:
Noticed `getblockchaininfo` would return a `verificationprogress` > 1, especially while generating. This caps the verification progress to `1`.
Tried to append a check to functional tests but this would pass even without the patch, so it seems better to not add a superfluous check (but this can easily be reproduced by trying to generate blocks in the background and `watch`ing `getblockchainfo`).
ACKs for top commit:
laanwj:
ACK 2f5f7d6b13
promag:
ACK 2f5f7d6b13.
Tree-SHA512: fa3aca12acab9c14dab3b2cc94351082f548ea6e6c588987cd86e928a00feb023e8112433658a0e85084e294bfd940eaafa33fb46c4add94146a0901bc1c4f80
36b68de5b2 Remove getBlockDepth method from Chain::interface (Antoine Riard)
b66c429c56 Remove locked_chain from GetDepthInMainChain and its callers (Antoine Riard)
0ff03871ad Use CWallet::m_last_block_processed_height in GetDepthInMainChain (Antoine Riard)
f77b1de16f Only return early from BlockUntilSyncedToCurrentChain if current tip is exact match (Antoine Riard)
769ff05e48 Refactor some importprunedfunds checks with guard clause (Antoine Riard)
5971d3848e Add block_height field in struct Confirmation (Antoine Riard)
9700fcb47f Replace CWalletTx::SetConf by Confirmation initialization list (Antoine Riard)
5aacc3eff1 Add m_last_block_processed_height field in CWallet (Antoine Riard)
10b4729e33 Pass block height in Chain::BlockConnected/Chain::BlockDisconnected (Antoine Riard)
Pull request description:
Work starter to remove Chain::Lock interface by adding m_last_block_processed_height in CWallet and m_block_height in CMerkleTx to avoid GetDepthInMainChain having to keep a lock . Once this one done, it should ease work to wipe out more cs_main locks from wallet code.
I think it's ready for a first round of review before to get further.
- `BlockUntilSyncedToCurrent` : restrain isPotentialTip to isTip because we want to be sure that wallet see BlockDisconnected callbacks if its height differs from the Chain one. It means during a reorg, an RPC could return before the BlockDisconnected callback had been triggered. This could cause a tx that had been included in the disconnected block to be displayed as confirmed, for example.
~~- `AbandonTransaction` : in case of conflicted tx (nIndex = -1), we set its m_block_height to the one of conflicting blocks, but if this height is superior to CWallet::m_last_block_processed_height, that means tx isn't conflicted anymore so we return 0 as tx is again unconfirmed~~ After #16624, we instead rely on Confirmation.
~~- `AddToWalletIfInvolvingMe`: in case of block disconnected, transactions are added to mempool again, so we need to replace old txn in `mapWallet` with a height set to zero so we remove check on block_hash.IsNull~~ Already done in #16624
ACKs for top commit:
jnewbery:
@jkczyz you've ACKed an intermediate commit (github annoyingly orders commits in date order, not commit order). Did you mean to ACK the final commit in this branch (36b68de5b2).
jkczyz:
> @jkczyz you've ACKed an intermediate commit (github annoyingly orders commits in date order, not commit order). Did you mean to ACK the final commit in this branch ([36b68de](36b68de5b2)).
meshcollider:
utACK 36b68de5b2
ryanofsky:
Code review ACK 36b68de5b2. Changes since last review: new jkczyz refactor importprunedfunds commit, changed BlockUntilSyncedToCurrentChainChanges commit title and description, changed Confirmation struct field order and line-wrapped comment
jnewbery:
utACK 36b68de5b2
promag:
Code review ACK 36b68de5b2.
Tree-SHA512: 08b89a0bcc39f67c82a6cb6aee195e6a11697770c788ba737b90986b4893f44e90d1ab9ef87239ea3766508b7e24ea882b7199df41173ab27a3d000328c14644
CheckInputs() used to check no double spends, scripts & sigs and amounts. Since
832e0744cb, the double spend and amount checks
have been moved to CheckTxInputs(), and CheckInputs() now just validates
input scripts. Rename the function to CheckInputScripts().
-BEGIN VERIFY SCRIPT-
sed -i -E -e 's/CheckInputs\b/CheckInputScripts/g' $(git grep -l CheckInputs | grep -v doc/)
-END VERIFY SCRIPT-
5506ecfe7a [refactor] Replace global int nScriptCheckThreads with bool (John Newbery)
d9957623b4 [tests] Don't use TestingSetup in the checkqueue_tests (John Newbery)
Pull request description:
The meaning of this value is confusing. Refactor it and add comments.
ACKs for top commit:
sipa:
ACK 5506ecfe7a
promag:
ACK 5506ecfe7a, only change was addressing my nits.
laanwj:
Code review ACK 5506ecfe7a
MarcoFalke:
ACK 5506ecfe7a🥐
Tree-SHA512: 78536727c98d2c23f3c0f3f169131474fef9a4486ae65029011caf06eab30f6f70ff73a65b2fb04a5d969fc1150858d1c6ea4767f04d48c1eea6b829316d0e63
The global nScriptCheckThreads int is confusing and is only needed for
its int-ness in AppInitMain. Move all `-par` parsing logic there and
replace the int nScriptCheckThreads with a bool
g_parallel_script_checks.
Also tidy up logic and improve comments.
dcef9a2922 logs: add timing information to FlushStateToDisk() (James O'Beirne)
41edaf227a logs: add BCLog::Timer and related macros (James O'Beirne)
Pull request description:
It's currently annoying to detect FlushStateToDisk() calls when benchmarking since they have to be inferred from a drop in coins count from the `UpdateTip: ` log messages. This adds a new logging utility, `BCLog::Timer`, and some related macros that are generally useful for printing timing-related logging messages, and a message that is unconditionally written when the coins cache is flushed to disk.
```
2019-09-04T20:17:51Z FlushStateToDisk: write block and undo data to disk completed (3ms)
2019-09-04T20:17:51Z FlushStateToDisk: write block index to disk completed (370ms)
2019-09-04T20:17:51Z FlushStateToDisk: write coins cache to disk (2068451 coins, 294967kB) completed (21481ms)
```
ACKs for top commit:
laanwj:
Thanks, ACK dcef9a2922
ryanofsky:
Code review ACK dcef9a2922. No changes since last review other than moving code to new timer.h header
Tree-SHA512: 6d61e48a062d3edb48d0e056a6f0b1f8031773cc99289ee4544f8349d24526b88519e1e304009d56e428f1eaf76c857bf8e7e1c0b6873a6f270306accb5edc3d
To do so we update CValidationInterface::BlockDisconnect to take a
CBlockIndex pointing to the block being disconnected.
This new parameter will be use in the following commit to establish
wallet height.
Instead of keeping pindexBestHeader set to the best header we've
ever seen, reset it back to our validated tip if we find an ancestor
of it turns out to be invalid. While the name is now a bit confusing,
this matches much better with how it is used in practice, see below.
Further, this opens up more use-cases for it in the future, namely
aggressively searching for new peers in case we have discovered
(possibly via some covert channel) headers which we do not know to be
invalid, but which we cannot find block data for.
Places pindexBestHeader is used:
* Various GUI displays of the best header and getblockchaininfo["headers"],
I don't think changing this is bad, and if anything this is less confusing
in the presence of an invalid block.
* IsCurrentForFeeEstimation(): If anything I think ensuring pindexBestHeader
isn't some crazy invalid chain is better than the alternative, even in the
case where you are rejecting the current chain due to hardware error (since
hopefully in that case you won't get any new blocks anyway).
* ConnectBlock assumevalid checks: We use pindexBestHeader to check that the
block we're connecting leads to something with nMinimumChainWork (preventing
a user-set assumevalid from having bogus work) and that the block we're
connecting leads to pindexBestHeader (I'm not too worried about this one -
it's nice to "disable" assumevalid if we have a long invalid headers chain,
but I don't see it as a critical protection).
* BlockRequestAllowed() uses pindexBestHeader as its target to ensure the
requested block is within a month of the "current chain". I don't think this
is a meaningful difference, if we're rejecting the current tip we're
trivially fingerprintable anyway, and if the chain really does have a bunch
of invalid crap near the tip, using the best not-invalid header is likely a
better criteria.
* ProcessGetBlockData uses pindexBestHeader as the "current chain" definition
of whether a block request is "historical" for the purpose of bandwidth
limiting. Similarly, I don't see why this is a meaningful change.
* We use pindexBestHeader for requesting missing headers on receipt of a
headers/compact block message or block inv as well as for initial getheaders.
I think this is definitely wrong, using the best not-invalid header for such
requests is much better.
* We use pindexBestHeader to define the "current chain" for deciding when
we're close to done with initial headers sync. I don't think this is a
meaningful change.
* We use pindexBestHeader to decide if initial headers sync has timed out. If
we're rejecting the chain due to hardware error this may result in
additional cases where we ban a peer, but this is already true, so I think
its fine.
ValidationState::Invalid() takes a parameter `ret` which is returned to
the caller. All call sites set this to false. Remove the `ret` parameter
and just return false always.
This is in preparation for the next commit, which removes the useless
`ret` parameter from ValidationState::Invalid().
error() is simply a convenience wrapper that calls LogPrintf and returns
false. Call LogPrintf explicitly and substitute the error() call for a
false bool literal.
0a433fc876 [validation] Remove unused cacheSigStore from CheckInputsFromMempoolAndCache (John Newbery)
Pull request description:
CheckInputsFromMempoolAndCache() is only called in one place, and
cacheSigStore is set to true in that call site. Remove the argument
entirely.
Also improve commenting.
ACKs for top commit:
MarcoFalke:
unsigned ACK 0a433fc876 Comment looks good
jamesob:
ACK 0a433fc876
laanwj:
ACK 0a433fc876
fanquake:
ACK 0a433fc876. Checked that `CheckInputsFromMempoolAndCache` is only called once, in `MemPoolAccept::ConsensusScriptChecks`, and that `cacheSigStore` is true.
Tree-SHA512: e4b4d2550e35df55c8f8fa4c539174cc2d3728112ddb937cb2ff759d8630a01566b5ec42a70a82e33994e6586f5a457a75a59f64b15d27c65331c723cbb097af
CheckInputsFromMempoolAndCache() is only called in one place, and
cacheSigStore is set to true in that call site. Remove the argument
entirely.
Also improve commenting.
9075d13153 [docs] Add release notes for removal of REJECT reasons (John Newbery)
04a2f326ec [validation] Fix REJECT message comments (John Newbery)
e9d5a59e34 [validation] Remove REJECT code from CValidationState (John Newbery)
0053e16714 [logging] Don't log REJECT code when transaction is rejected (John Newbery)
a1a07cfe99 [validation] Fix peer punishment for bad blocks (John Newbery)
Pull request description:
We no longer send BIP 61 REJECT messages, so there's no need to set
a REJECT code in the CValidationState object.
Note that there is a minor bug fix in p2p behaviour here. Because the
call to `MaybePunishNode()` in `PeerLogicValidation::BlockChecked()` only
previously happened if the REJECT code was > 0 and < `REJECT_INTERNAL`,
then there are cases were `MaybePunishNode()` can get called where it
wasn't previously:
- when `AcceptBlockHeader()` fails with `CACHED_INVALID`.
- when `AcceptBlockHeader()` fails with `BLOCK_MISSING_PREV`.
Note that `BlockChecked()` cannot fail with an 'internal' reject code. The
only internal reject code was `REJECT_HIGHFEE`, which was only set in
ATMP.
This reverts a minor bug introduced in 5d08c9c579.
ACKs for top commit:
ariard:
ACK 9075d13, changes since last reviewed are splitting them in separate commits to ease understanding and fix nits
fjahr:
ACK 9075d13153, confirmed diff to last review was fixing nits in docs/comments.
ryanofsky:
Code review ACK 9075d13153. Only changes since last review are splitting the main commit and updating comments
Tree-SHA512: 58e8a1a4d4e6f156da5d29fb6ad6a62fc9c594bbfc6432b3252e962d0e9e10149bf3035185dc5320c46c09f3e49662bc2973ec759679c0f3412232087cb8a3a7
faec689bed txmempool: Make entry time type-safe (std::chrono) (MarcoFalke)
faaa1f01da util: Add count_seconds time helper (MarcoFalke)
1111170f2f test: mempool entry time is persisted (MarcoFalke)
Pull request description:
This changes the type of the entry time of txs into the mempool from `int64_t` to `std::chrono::seconds`.
The benefits:
* Documents the type for developers
* Type violations result in compile errors
* After compilation, the two are equivalent (at no run time cost)
ACKs for top commit:
ajtowns:
utACK faec689bed
laanwj:
ACK faec689bed
Tree-SHA512: d958e058755d1a1d54cef536a8b30a11cc502b7df0d6ecf84a0ab1d38bc8105a67668a99cd5087a444f6de2421238111c5fca133cdf8e2e2273cb12cb6957845
2a4e60b482 Fix block index inconsistency in InvalidateBlock() (Suhas Daftuar)
Pull request description:
Previously, we could release `cs_main` while leaving the block index in a state
that would fail `CheckBlockIndex()`, because `setBlockIndexCandidates` was not being
fully populated before releasing `cs_main`.
ACKs for top commit:
TheBlueMatt:
utACK 2a4e60b482. I also discovered another issue in InvalidateBlock while reviewing, see #16856.
Sjors:
ACK 2a4e60b. Tested on top of #16899. Also tested `invalidateblock` with `-checkblockindex=1`.
fjahr:
ACK 2a4e60b. Ran tests, reviewed code, inspected behavior while manually testing `invalidateblock`.
Tree-SHA512: ced12f9dfff0d413258c709921543fb154789898165590b30d1ee0cdc72863382f189744f7669a7c924d3689a1cc623efdf4e5ae3efc60054572c1e6826de612
fdb3e8f8b2 Ignore old versionbit activations (Anthony Towns)
Pull request description:
PR 16060 removed the CSV and Segwit BIP9 softfork definitions and hard-coded ('buried') the activation heights. The versionbits code will warn users if an undefined softfork has been signalled in block header versions, and removing the CSV/Segwit definitions caused those warnings to be triggered.
Change the BIP 9 warning code to only check for unknown softforks after the segwit activation height.
ACKs for top commit:
MarcoFalke:
ACK fdb3e8f8b2
ajtowns:
ACK fdb3e8f8b2 for what it's worth
achow101:
ACK fdb3e8f8b2
Sjors:
ACK fdb3e8f8b2. It makes the bit 0 warning go away in mainnet and testnet QT when a new block arrives. I think the code is clear enough.
jonatack:
ACK fdb3e8f8b2
Tree-SHA512: e6fd34e8902f8c7affb28e8951803e47d542710d5f1229000746656a37ee59d754439fc33e36b7eef87544262e5aac374645db91b74cb507e73514003ca7a67f
3cf36736e5 refactoring: move ReplayBlocks under CChainState (James O'Beirne)
bcf73d3b84 refactoring: move LoadChainTip to CChainState method (James O'Beirne)
f5809d5b13 doc: fix CChainState::ActivateBestChain doc (James O'Beirne)
Pull request description:
This is part of the [assumeutxo project](https://github.com/bitcoin/bitcoin/projects/11):
Parent PR: #15606
Issue: #15605
Specification: https://github.com/jamesob/assumeutxo-docs/tree/master/proposal
---
Move more chainstate-related functionality to methods on CChainState. Nothing too interesting here, but needed to work with multiple chainstates. And brief to review. :)
Also fixes doc on ActivateBestChain.
ACKs for top commit:
MarcoFalke:
ACK 3cf36736e5
ryanofsky:
Can confirm. utACK 3cf36736e5. Removes wrapper functions and removes more ::ChainActive() and ::ChainstateActive() calls than it adds, so seems good.
Tree-SHA512: 4bf8a1dd454ca9d61c85f6736910fa7354c57acc0002e3a8e5ce494035d8280e4c20e066f03478eeff7d44195e7912c282a486526da9be53854b478b961affaa
c4b0c08f7c Update tx-size-small comment with relevant CVE disclosure (Gregory Sanders)
Pull request description:
Code first introduced under https://github.com/bitcoin/bitcoin/pull/11423 with essentially no description and no discussion.
ACKs for top commit:
MarcoFalke:
ACK c4b0c08f7c
fanquake:
ACK c4b0c08f7c
Tree-SHA512: 95d5c92998b8b1e944c477dbaee265b62612b6e815099ab31d9ff580b4dff777abaf7f326a284644709f918aa1510412d62310689b1250ef6e64de7b19ca9f71
4a87c5cfdf [refactor] Rewrite AcceptToMemoryPoolWorker() using smaller parts (Suhas Daftuar)
Pull request description:
This is in preparation for re-using these validation components for a new version of AcceptToMemoryPool() that can operate on multiple transactions ("package relay").
ACKs for top commit:
MarcoFalke:
re-ACK 4a87c5cfdf (did the rebase myself and arrived at the same result, mod whitespace)
laanwj:
ACK 4a87c5cfdf
Tree-SHA512: b0495c026ffe06146258bace3d5e0c9aaf23fa65f89f258abc4af5980812e68e63a799f1d923e78ac1ee6bcafaf1222b2c2690a527df9b65dff7b48a013f154e
0c62e3aa73 New regression testing for CVE-2018-17144, CVE-2012-2459, and CVE-2010-5137. (lucash-dev)
38bfca6bb2 Added comments referencing multiple CVEs in tests and production code. (lucash-dev)
Pull request description:
This functional test includes two scenarios that test for regressions of vulnerabilities, but they are only briefly described. There are freely available documents explaining in detail the issues, but without explicit mentions, the developer trying to maintain the code needs an additional step of digging in commit history and PR conversations to figure it out.
Added comments to explicitly mention CVE-2018-17144 and CVE-2012-2459, for more complete documentation.
This improves developer experience by making understanding the tests easier.
ACKs for top commit:
laanwj:
ACK 0c62e3aa73, checked the CVE numbers, thanks for adding documentation
Tree-SHA512: 3ee05351745193b8b959e4a25d50f25a693b2d24b0732ed53cf7d5882df40b5dd0f1877bd5c69cffb921d4a7acf9deb3cc1160b96dc730d9b5984151ad06b7c9
This is in preparation for re-using these validation components for a new
version of AcceptToMemoryPool() that can operate on multiple transactions
("package relay").
fa912a8ad5 doc: move-only ActivateBestChain doxygen comment to header (MarcoFalke)
fa99efd054 doc: ActivateBestChainStep return value (MarcoFalke)
Pull request description:
It will always return true, unless a system error such as #15305 occurred
ACKs for top commit:
laanwj:
ACK fa912a8ad5
Tree-SHA512: d439da844a467f9705014b946d7d987fb62cb63fe6a325b2fdbbb73a6578fc0ade3f60892044f02face43948204fc4e3c9fa70d108233d4ca8eef27984059689
Previously, we could release cs_main while leaving the block index in a state
that would fail CheckBlockIndex, because setBlockIndexCandidates was not being
fully populated before releasing cs_main.
5ce822efbe Conservatively accept RBF bumps bumping one tx at the package limits (Matt Corallo)
Pull request description:
Based on #15681, this adds support for some simple cases of RBF inside of large packages. Issue pointed out by sdaftuar in #15681, and this fix (or a broader one) is required ot make #15681 fully useful.
Accept RBF bumps of single transactions (ie which evict exactly one
transaction) even when that transaction is a member of a package
which is currently at the package limit iff the new transaction
does not add any additional mempool dependencies from the original.
This could be made a bit looser in the future and still be safe,
but for now this fixes the case that a transaction which was
accepted by the carve-out rule will not be directly RBF'able
ACKs for top commit:
instagibbs:
re-ACK 5ce822efbe
ajtowns:
ACK 5ce822efbe ; GetSizeWithDescendants is only change and makes sense
sipa:
Code review ACK 5ce822efbe. I haven't thought hard about the effect on potential DoS issues this policy change may have.
Tree-SHA512: 1cee3bc57393940a30206679eb60c3ec8cb4f4825d27d40d1f062c86bd22542dd5944fa5567601c74c8d9fd425333ed3e686195170925cfc68777e861844bd55
3109a1f948 refactor: Avoid locking cs_main in ProcessNewBlockHeaders (João Barbosa)
Pull request description:
Builds on #16774, this change avoids locking `cs_main` in `ProcessNewBlockHeaders` when the tip has changed - in this case the removed lock was necessary to just log a message.
Top commit has no ACKs.
Tree-SHA512: 31be6d319fa122804f72fa813cec5ed041dd7e4aef3c1921124a1f03016925c43cd4d9a272d80093e77fa7600e3506ef47b7bb821afcbffe01e6be9bceb6dc00
Accept RBF bumps of single transactions (ie which conflict with one
transaction) even when that transaction is a member of a package
which is currently at the package limit iff the new transaction
does not add any additional mempool dependencies from the original.
This could be made a bit looser in the future and still be safe,
but for now this fixes the case that a transaction which was
accepted by the carve-out rule will not be directly RBF'able.
dcc448e3d2 Avoid unnecessary "Synchronizing blockheaders" log messages (Jonas Schnelli)
Pull request description:
Fixes#16773
I'm not entirely sure why 16773 happend, but probably due to headers fallback in a compact block.
However, this PR should fix it and should have been included in #15615.
ACKs for top commit:
ajtowns:
ACK dcc448e3d2 ; code review only, haven't compiled or tested.
promag:
ACK dcc448e3d2.
TheBlueMatt:
utACK dcc448e3d2. Went and read how pindexBestHeader is handled and this code looks correct (worst case it breaks a LogPrint, so whatever). I also ran into this on #16762.
fanquake:
ACK dcc448e3d2
Tree-SHA512: f8cac3b6eb9d4e8fab53a535b55f9ea9b058e3ab6ade64801ebc56439ede4f54b5fee36d5d2b316966ab987b65b13ab9dc18849f345d08b81ecdf2722a3f5f5a
9b92538ade Remove unused fScriptChecks parameter from CheckInputs (Matt Corallo)
Pull request description:
fScriptChecks = false just short-circuits the entire function, so
passing it in is entirely useless.
This is extracted from #13233 /cc TheBlueMatt.
Recommend reviewing with `git show --ignore-all-space`, i.e.:
https://github.com/bitcoin/bitcoin/pull/13868/files?w=1
ACKs for top commit:
TheBlueMatt:
utACK 9b92538ade. Checked diff had no functional change and new comment copy looks correct.
kallewoof:
ACK 9b92538ade
ajtowns:
ACK 9b92538ade ; code review, checked tests work. Looks right to me, and fanquake's notes make sense. Could change the coinbase early exit to `assert(!tx.IsCoinBase());`.
fanquake:
ACK 9b92538ade - Notes / testing below.
Tree-SHA512: add253a3e8cf4b33eddbc49efcec333c14b5ea61c7d34e43230351d40cff6adc919a75b91c72c4de8647a395284db74a61639f4c67848d4b2fec3a705b557790
d75e704ac0 Add log output during initial header sync (Jonas Schnelli)
Pull request description:
The non debug log output is completely quiet during the header sync. I see two main reasons to add infos about the state of the initial header sync...
* users may think the node did fail to start sync
* it's a little complicate to check if your getting throttled during header sync (repeatedly calling `getchaintips` or similar)
ACKs for top commit:
fanquake:
Concept ACK d75e704ac0
practicalswift:
utACK d75e704ac0
laanwj:
Tested ACK d75e704ac0
Tree-SHA512: 2e738571b703d7251290864603c3a829729645962c2fa3187250bab0585e66a5f01fce892e9b5b98da451fab2b40a2e4784f9b2e5a9cad75ff62c535affe7430
e78aaf41f4 [docs] Add release notes for burying bip 9 soft fork deployments (John Newbery)
8319e738f9 [tests] Add coverage for the content of getblockchaininfo.softforks (James O'Beirne)
0328dcdcfc [Consensus] Bury segwit deployment (John Newbery)
1c93b9b31c [Consensus] Bury CSV deployment height (John Newbery)
3862e473f0 [rpc] Tidy up reporting of buried and ongoing softforks (John Newbery)
Pull request description:
This hardcodes CSV and segwit activation heights, similar to the BIP 90 buried deployments for BIPs 34, 65 and 66.
CSV and segwit have been active for over 18 months. Hardcoding the activation height is a code simplification, makes it easier to understand segwit activation status, and reduces technical debt.
This was originally attempted by jl2012 in #11398 and again by me in #12360.
ACKs for top commit:
ajtowns:
ACK e78aaf41f4 ; checked diff to previous acked commit, checked tests still work
ariard:
ACK e78aaf4, check diff, run the tests again and successfully activated csv/segwit heights on mainnet as expected.
MarcoFalke:
ACK e78aaf41f4 (still didn't check if the mainnet block heights are correct, but the code looks good now)
Tree-SHA512: 7e951829106e21a81725f7d3e236eddbb59349189740907bb47e33f5dbf95c43753ac1231f47ae7bee85c8c81b2146afcdfdc11deb1503947f23093a9c399912
i.e. any CoinsViews members. Adds a lock acquisition to `gettxoutsetinfo` RPC
to comply with added annotations.
Co-authored-by: Russell Yanofsky <russ@yanofsky.org>
This change encapsulates UTXO set data within CChainState instances, removing
global data `pcoinsTip` and `pcoinsviewdb`. This is necessary if we want to
maintain multiple chainstates with their own rendering of the UTXO set.
We introduce a class CoinsViews which consolidates the construction of a
CCoins* hierarchy. Construction of its various pieces (db, coinscatcher,
in-memory cache) is split up so that we avoid flushing bad state to disk if
startup is interrupted.
We also introduce `CChainState::CanFlushToDisk()` which tells us when it is
safe to flush the chainstate based on this partial construction.
This commit could be broken into smaller pieces, but it would require more
ephemeral diffs to, e.g., temporarily change CCoinsViewDB's constructor
invocations.
Other changes:
- A parameter has been added to the CCoinsViewDB constructor that allows the
name of the corresponding leveldb directory to be specified.
Thanks to Russell Yanofsky and Marco Falke for helpful feedback.
