Do not recalculate new committee/validators value in the start of every
subsequent epoch. Use values that was calculated in the PostPersist method
of the previously processed block in the end of the previous epoch.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
No funcional changes, just refactoring. It doesn't need the whole cache,
only the set of committee keys with votes.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Recalculate them once per epoch. Consensus is aware of it and must
call CalculateNextValidators exactly when needed.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
We have two similar blockchain APIs: GetNextBlockValidators and GetValidators.
It's hard to distinguish them, thus renaming it to match the meaning, so what
we have now is:
GetNextBlockValidators literally just returns the top of the committee that
was elected in the start of batch of CommitteeSize blocks batch. It doesn't
change its valie every block.
ComputeNextBlockValidators literally computes the list of validators based on
the most fresh committee members information got from the NeoToken's storage
and based on the latest register/unregister/vote events. The list returned by
this method may be updated every block.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Blockchain passes his own pure unwrapped DAO to
(*Blockchain).ComputeNextBlockValidators which means that native
RW NEO cache structure stored inside this DAO can be modified by
anyone who uses exported ComputeNextBlockValidators Blockchain API,
and technically it's valid, and we should allow this, because it's
the only purpose of `validators` caching. However, at the same time
some RPC server is allowed to request a subsequent wrapped DAO for
some test invocation. It means that descendant wrapped DAO
eventually will request RW NEO cache and try to `Copy()`
the underlying's DAO cache which is in direct use of
ComputeNextBlockValidators. Here's the race:
ComputeNextBlockValidators called by Consensus service tries to
update cached `validators` value, and descendant wrapped DAO
created by the RPC server tries to copy DAO's native cache and
read the cached `validators` value.
So the problem is that native cache not designated to handle
concurrent access between parent DAO layer and derived (wrapped)
DAO layer. I've carefully reviewed all the usages of native cache,
and turns out that the described situation is the only place where
parent DAO is used directly to modify its cache concurrently with
some descendant DAO that is trying to access the cache. All other
usages of native cache (not only NEO, but also all other native
contrcts) strictly rely on the hierarchical DAO structure and don't
try to perform these concurrent operations between DAO layers.
There's also persist operation, but it keeps cache RW lock taken,
so it doesn't have this problem as far. Thus, in this commit we rework
NEO's `validators` cache value so that it always contain the relevant
list for upper Blockchain's DAO and is updated every PostPersist (if
needed).
Note: we must be very careful extending our native cache in the
future, every usage of native cache must be checked against the
described problem.
Close#2989.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
To dump the DB, the service must be stopped.
If this is not the case `dump` command just hangs without any output,
which _may_ be unexpected from the ops POV.
Introduce a 1 second timeous, which is more than enough, given
that bbolt retries doing flock() every 50ms.
Signed-off-by: Evgenii Stratonikov <fyfyrchik@runbox.com>
It can be non-zero even if VoteTo is NULL. Fixes state diff with 3.6.0:
block 41660: value mismatch for key +////xTrvgat3qG/w8hQoD/I4MgUz6rygA==: QQQhAS8hA7yiAAAhAA== vs QQQhAS8hA7yiAAAhB+POSWfBCAE=
Related to #2844.
Signed-off-by: Roman Khimov <roman@nspcc.ru>
IterateVerifiedTransactions iterates through verified transactions in
memory pool and invokes function cont. Where cont callback returns
whether we should continue with the traversal process.
Signed-off-by: Tatiana Nesterenko <tatiana@nspcc.io>
Do not retrieve the whole set of storage items when trying to find
the ones from the specified start. Use DAO's Seek interface
implemented over MPT TrieStore to retrieve only the necessary items.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
So that hardfork name was explicitly present in the test name. We'll
have a set of similar tests later.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
No functional changes, just a refactoring.
Change error text to be able to use this error from external packages.
Signed-off-by: Tatiana Nesterenko <tatiana@nspcc.io>
No functional changes, just a refactoring.
Use more specific and meaningful names to be able to use these errors from external packages.
Signed-off-by: Tatiana Nesterenko <tatiana@nspcc.io>
During new transaction verification if there's an on-chain conflicting
transaction, we should check the signers of this conflicting transaction.
If the signers intersect with signers of the incoming transaction, then
the conflict is treated as valid and verification for new incoming
transaction should fail. Otherwise, the conflict is treated as the
malicious attack attempt and will not be taken into account;
verification for the new incoming transaction should continue.
This commint implements the scheme described at
https://github.com/neo-project/neo/pull/2818#issuecomment-1632972055,
thanks to @shargon for digging.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Witnesses are not yet created by the moment we return this error,
thus, it was always 0 as an actual number of witnesses in
ErrInvalidWitnessNum.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
`(*Blockchain).HasTransaction` is one of the oldest methods in our
codebase, and currently it's completely unused. I also doubt that
this method works as expected because it returns `true` if transaction
in the mempool.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Ensure that Scopes can be properly parsed not only from the string
representation, but also from a single byte. transaction.Signer
is not affected (checked against the C# implementation), only
RPC-related signer scopes are allowed to be unmarshalled from byte.
Close#3059.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
This check is good and was present here since #1729, but it was
accidently removed from the reference implementation (see the
discussion in https://github.com/neo-project/neo/issues/2848). The
removal of this check from the C# node leaded to the T5 testnet state
diff since 1670095 heigh which causes inability to process new blocks
since 2272533 height (see #3049). This check was added back to the
C# node in https://github.com/neo-project/neo/pull/2849, but it is
planned to be the part of the upcoming 3.6.0 C# node release.
We need to keep our testnet healthy, thus, strict contract script
check will be temporary removed from the node code and is planned
to be added back to be a part of the next 3.6.0-compatible release.
Close#3049.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Our wrapping optimization relied on the caller context having a TRY block,
but each context (including internal calls!) has an exception handling stack
of its own, which means that for an invocation stack of
entry
A.someMethodFromEntry() # this one has a TRY
A.internalMethodViaCALL() # this one doesn't
B.someMethod()
we get `HasTryBlock() == false` for `A.internalMethodViaCALL()` context, which
leads to missing wrapper and missing rollbacks if B is to THROW. What this
patch does instead is it checks for any context within contract boundaries.
Fixes#3045.
Signed-off-by: Roman Khimov <roman@nspcc.ru>
That's the way how C# node handles equality checks for stackitem.Interop types
for these points. Ref. https://github.com/nspcc-dev/neo-go/issues/3002#issuecomment-1591220501.
Along the way, add GT case for CryptoLib's bls12381Equal method. It should be there since #2940.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
If the contract was deployed then cache must be initialized after
in-memory data reset. If the contract isn't active yet, then no
cache will be initialized on deploy (i.e. on call to Initialize()
method by native Management).
Close#2984.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Make the contracts cache initialization unified. The order of cache
iniitialization is not important and Nottary contract is added to the
bc.contracts.Contracts wrt P2PSigExtensions setting, thus no functional
changes, just refactoring for future applications.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Initialize Prometheus metrics on node start where appropriate and review
the usage of the following metrics:
```
anna@kiwi:~/Documents/GitProjects/nspcc-dev/neo-go$ find | grep prometheus.go
./pkg/network/prometheus.go
./pkg/core/stateroot/prometheus.go
./pkg/core/prometheus.go
./pkg/services/rpcsrv/prometheus.go
./pkg/services/metrics/prometheus.go
```
Close#2970.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Move them to the core/network packages, close#2950. The name of
mempool's unsorted transactions metrics has been changed along the
way to match the core's metrics naming convention.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
I've carefully checked the way how new service can be added to the
Blockchain instance or to be removed from it. Current implemention
of SetNotary and SetOracle methods doesn't contain dangerous code,
and native contracts have atomic values everywhere where service
is stored.
Current implementation of Notary, Oracle and StateRoot services'
reload/disabling/enabling on SIGUSR1 is safe and doesn't require
any adjustment.
This commit closes#2944, it's not a bug in the code, it's just
stale documentation.
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
`cache` persisting operation is concurrent with the storage modifications
made by further state reset stages. We can't allow situation when data
from the next stage are leaking into the previous stage. State reset stages
must be atomic in turms of DB persisting, thus, use another `upperCache`
MemCached store to keep them apart.
Here are the results of mainnet's BoltDB reset from 1.1M to 6K:
This patch:
```
anna@kiwi:~/Documents/GitProjects/nspcc-dev/neo-go$ ./bin/neo-go db reset -m --debug --height 600000
2023-04-11T16:15:25.783+0300 INFO MaxBlockSize is not set or wrong, setting default value {"MaxBlockSize": 262144}
2023-04-11T16:15:25.783+0300 INFO MaxBlockSystemFee is not set or wrong, setting default value {"MaxBlockSystemFee": 900000000000}
2023-04-11T16:15:25.783+0300 INFO MaxTransactionsPerBlock is not set or wrong, using default value {"MaxTransactionsPerBlock": 512}
2023-04-11T16:15:25.783+0300 INFO MaxValidUntilBlockIncrement is not set or wrong, using default value {"MaxValidUntilBlockIncrement": 5760}
2023-04-11T16:15:25.787+0300 INFO restoring blockchain {"version": "0.2.8"}
2023-04-11T16:15:25.906+0300 INFO initializing state reset {"target height": 600000}
2023-04-11T16:15:25.906+0300 DEBUG trying to reset blocks, transactions and AERs
2023-04-11T16:15:57.031+0300 INFO intermediate batch of removed blocks, transactions and AERs is collected {"batch": 1, "took": "31.125057214s"}
2023-04-11T16:16:12.644+0300 DEBUG intermediate batch of removed blocks, transactions and AERs is persisted {"batch": 1, "took": "15.613156971s", "keys": 321895}
2023-04-11T16:16:13.895+0300 INFO intermediate batch of removed blocks, transactions and AERs is collected {"batch": 2, "took": "16.663444208s"}
2023-04-11T16:16:19.784+0300 INFO last batch of removed blocks, transactions and AERs is collected {"batch": 3, "took": "5.760308543s"}
2023-04-11T16:16:19.784+0300 INFO blocks, transactions ans AERs are reset {"took": "53.878632911s"}
2023-04-11T16:16:22.870+0300 DEBUG intermediate batch of removed blocks, transactions and AERs is persisted {"batch": 2, "took": "8.974838893s", "keys": 334823}
2023-04-11T16:16:22.870+0300 DEBUG trying to reset contract storage items
2023-04-11T16:16:27.272+0300 DEBUG last batch of removed blocks, transactions and AERs is persisted {"batch": 3, "took": "7.487357441s", "keys": 208913}
2023-04-11T16:17:23.678+0300 INFO intermediate batch of contract storage items and IDs is collected {"batch": 1, "took": "1m0.80711106s"}
2023-04-11T16:18:00.769+0300 INFO intermediate batch of contract storage items and IDs is collected {"batch": 2, "took": "36.967660061s"}
2023-04-11T16:18:20.478+0300 DEBUG intermediate batch of contract storage items is persisted {"batch": 1, "took": "56.796257788s", "keys": 200000}
2023-04-11T16:18:54.115+0300 INFO intermediate batch of contract storage items and IDs is collected {"batch": 3, "took": "33.637412437s"}
2023-04-11T16:19:18.844+0300 DEBUG intermediate batch of contract storage items is persisted {"batch": 2, "took": "1m18.0737668s", "keys": 200000}
2023-04-11T16:19:27.650+0300 INFO last batch of contract storage items is collected {"batch": 4, "took": "8.806264019s"}
2023-04-11T16:19:27.650+0300 INFO contract storage items are reset {"took": "3m4.780232077s", "keys": 656944}
2023-04-11T16:20:15.660+0300 DEBUG intermediate batch of contract storage items is persisted {"batch": 3, "took": "1m21.544386403s", "keys": 200000}
2023-04-11T16:20:15.660+0300 DEBUG trying to reset headers information
2023-04-11T16:20:16.385+0300 INFO headers information is reset {"took": "725.174932ms"}
2023-04-11T16:20:19.586+0300 DEBUG last batch of contract storage items and IDs is persisted {"batch": 4, "took": "51.936278608s", "keys": 56945}
2023-04-11T16:20:19.587+0300 DEBUG trying to reset state root information and NEP transfers
2023-04-11T16:20:35.845+0300 INFO state root information and NEP transfers are reset {"took": "16.25852114s"}
2023-04-11T16:21:10.000+0300 DEBUG headers information is persisted {"took": "53.613638429s", "keys": 528438}
2023-04-11T16:21:10.003+0300 DEBUG trying to remove stale storage items
2023-04-11T16:21:18.108+0300 INFO stale storage items are reset {"took": "8.105140658s", "keys": 1350176}
2023-04-11T16:21:18.108+0300 DEBUG trying to remove state reset point
2023-04-11T16:21:18.108+0300 INFO state reset point is removed {"took": "8.554µs"}
2023-04-11T16:21:20.151+0300 DEBUG state root information and NEP transfers are persisted {"took": "44.305707049s", "keys": 602578}
2023-04-11T16:21:20.212+0300 INFO state reset point information is persisted {"took": "2.103764633s", "keys": 2}
2023-04-11T16:21:20.213+0300 INFO reset finished successfully {"took": "5m54.306861367s"}
```
The previous commit:
```
anna@kiwi:~/Documents/GitProjects/nspcc-dev/neo-go$ ./bin/neo-go db reset -m --debug --height 600000
2023-04-11T16:24:04.256+0300 INFO MaxBlockSize is not set or wrong, setting default value {"MaxBlockSize": 262144}
2023-04-11T16:24:04.256+0300 INFO MaxBlockSystemFee is not set or wrong, setting default value {"MaxBlockSystemFee": 900000000000}
2023-04-11T16:24:04.256+0300 INFO MaxTransactionsPerBlock is not set or wrong, using default value {"MaxTransactionsPerBlock": 512}
2023-04-11T16:24:04.256+0300 INFO MaxValidUntilBlockIncrement is not set or wrong, using default value {"MaxValidUntilBlockIncrement": 5760}
2023-04-11T16:24:04.261+0300 INFO restoring blockchain {"version": "0.2.8"}
2023-04-11T16:24:04.368+0300 INFO initializing state reset {"target height": 600000}
2023-04-11T16:24:04.368+0300 DEBUG trying to reset blocks, transactions and AERs
2023-04-11T16:24:30.363+0300 INFO intermediate batch of removed blocks, transactions and AERs is collected {"batch": 1, "took": "25.995261037s"}
2023-04-11T16:24:44.947+0300 DEBUG intermediate batch of removed blocks, transactions and AERs is persisted {"batch": 1, "took": "14.584447338s", "keys": 321897}
2023-04-11T16:24:45.791+0300 INFO intermediate batch of removed blocks, transactions and AERs is collected {"batch": 2, "took": "15.428492824s"}
2023-04-11T16:24:51.252+0300 INFO last batch of removed blocks, transactions and AERs is collected {"batch": 3, "took": "5.460662766s"}
2023-04-11T16:24:51.252+0300 INFO blocks, transactions ans AERs are reset {"took": "46.884558096s"}
2023-04-11T16:24:55.399+0300 DEBUG intermediate batch of removed blocks, transactions and AERs is persisted {"batch": 2, "took": "9.607820004s", "keys": 334821}
2023-04-11T16:24:55.399+0300 DEBUG trying to reset contract storage items
2023-04-11T16:24:59.981+0300 DEBUG last batch of removed blocks, transactions and AERs is persisted {"batch": 3, "took": "8.728713255s", "keys": 208913}
2023-04-11T16:25:50.827+0300 INFO intermediate batch of contract storage items and IDs is collected {"batch": 1, "took": "55.426411416s"}
2023-04-11T16:26:28.734+0300 INFO intermediate batch of contract storage items and IDs is collected {"batch": 2, "took": "37.902647706s"}
2023-04-11T16:26:53.960+0300 DEBUG intermediate batch of contract storage items is persisted {"batch": 1, "took": "1m3.129453265s", "keys": 200001}
2023-04-11T16:27:27.645+0300 INFO intermediate batch of contract storage items and IDs is collected {"batch": 3, "took": "33.685283662s"}
2023-04-11T16:27:52.173+0300 DEBUG intermediate batch of contract storage items is persisted {"batch": 2, "took": "1m23.438465575s", "keys": 199999}
2023-04-11T16:28:00.995+0300 INFO last batch of contract storage items is collected {"batch": 4, "took": "8.821990443s"}
2023-04-11T16:28:00.995+0300 INFO contract storage items are reset {"took": "3m5.595950958s", "keys": 656944}
2023-04-11T16:28:49.164+0300 DEBUG intermediate batch of contract storage items is persisted {"batch": 3, "took": "1m21.518344712s", "keys": 200000}
2023-04-11T16:28:49.164+0300 DEBUG trying to reset headers information
2023-04-11T16:28:49.936+0300 INFO headers information is reset {"took": "772.36435ms"}
2023-04-11T16:28:53.122+0300 DEBUG last batch of contract storage items and IDs is persisted {"batch": 4, "took": "52.126928092s", "keys": 56945}
2023-04-11T16:28:53.122+0300 DEBUG trying to reset state root information and NEP transfers
2023-04-11T16:29:09.332+0300 INFO state root information and NEP transfers are reset {"took": "16.20921699s"}
2023-04-11T16:29:46.264+0300 DEBUG headers information is persisted {"took": "56.326715249s", "keys": 528438}
2023-04-11T16:29:46.267+0300 DEBUG trying to remove stale storage items
2023-04-11T16:29:53.986+0300 INFO stale storage items are reset {"took": "7.718950145s", "keys": 1350176}
2023-04-11T16:29:53.986+0300 DEBUG trying to remove state reset point
2023-04-11T16:29:53.986+0300 INFO state reset point is removed {"took": "6.013µs"}
2023-04-11T16:29:55.899+0300 DEBUG state root information and NEP transfers are persisted {"took": "46.567302762s", "keys": 602578}
2023-04-11T16:29:55.929+0300 INFO state reset point information is persisted {"took": "1.942392208s", "keys": 2}
2023-04-11T16:29:55.929+0300 INFO reset finished successfully {"took": "5m51.561573137s"}
```
Master:
```
anna@kiwi:~/Documents/GitProjects/nspcc-dev/neo-go$ ./bin/neo-go db reset -m --debug --height 600000
2023-04-11T16:34:12.410+0300 INFO MaxBlockSize is not set or wrong, setting default value {"MaxBlockSize": 262144}
2023-04-11T16:34:12.410+0300 INFO MaxBlockSystemFee is not set or wrong, setting default value {"MaxBlockSystemFee": 900000000000}
2023-04-11T16:34:12.410+0300 INFO MaxTransactionsPerBlock is not set or wrong, using default value {"MaxTransactionsPerBlock": 512}
2023-04-11T16:34:12.410+0300 INFO MaxValidUntilBlockIncrement is not set or wrong, using default value {"MaxValidUntilBlockIncrement": 5760}
2023-04-11T16:34:12.413+0300 INFO restoring blockchain {"version": "0.2.8"}
2023-04-11T16:34:12.495+0300 INFO initialize state reset {"target height": 600000}
2023-04-11T16:34:12.513+0300 INFO trying to reset blocks, transactions and AERs
2023-04-11T16:35:03.582+0300 INFO intermediate batch of removed blocks, transactions and AERs is persisted {"batches persisted": 1, "took": "51.087226195s", "keys": 321895}
2023-04-11T16:35:31.302+0300 INFO intermediate batch of removed blocks, transactions and AERs is persisted {"batches persisted": 2, "took": "27.719871393s", "keys": 334823}
2023-04-11T16:35:41.309+0300 INFO last batch of removed blocks, transactions and AERs is persisted {"batches persisted": 3, "took": "10.007017388s", "keys": 208913}
2023-04-11T16:35:41.309+0300 INFO blocks, transactions ans AERs are reset {"took": "1m28.814245057s", "overall persisted keys": 865631}
2023-04-11T16:35:41.309+0300 INFO trying to reset contract storage items
2023-04-11T16:37:38.315+0300 INFO intermediate batch of contract storage items and IDs is persisted {"batch": 1, "took": "1m57.00650253s", "keys": 200000}
2023-04-11T16:39:29.704+0300 INFO intermediate batch of contract storage items and IDs is persisted {"batch": 2, "took": "1m51.385224725s", "keys": 200000}
2023-04-11T16:41:14.991+0300 INFO intermediate batch of contract storage items and IDs is persisted {"batch": 3, "took": "1m45.287483794s", "keys": 200000}
2023-04-11T16:41:31.667+0300 INFO last batch of contract storage items and IDs is persisted {"batch": 4, "took": "16.675347478s", "keys": 56945}
2023-04-11T16:41:31.667+0300 INFO contract storage items and IDs are reset {"took": "5m50.357775401s", "keys": 656944}
2023-04-11T16:41:31.667+0300 INFO trying to reset headers information
2023-04-11T16:42:16.779+0300 INFO headers information is reset {"took": "45.111354262s", "keys": 528438}
2023-04-11T16:42:16.784+0300 INFO trying to reset state root information and NEP transfers
2023-04-11T16:42:35.778+0300 INFO state root information and NEP transfers are reset {"took": "18.99373117s", "keys": 602578}
2023-04-11T16:42:35.781+0300 INFO trying to remove stale storage items
2023-04-11T16:42:43.884+0300 INFO stale storage items are reset {"took": "8.103929306s", "keys": 1350176}
2023-04-11T16:42:43.885+0300 INFO trying to remove state reset point
2023-04-11T16:42:43.926+0300 INFO stale reset point is removed {"took": "41.858883ms", "keys": 2}
2023-04-11T16:42:43.932+0300 INFO reset finished successfully {"took": "8m31.437493325s"}
```
Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
Everywhere including examples, external interop APIs, bindings generators
code and in other valuable places. A couple of `interface{}` usages are
intentionally left in the CHANGELOG.md, documentation and tests.
We have both from and to here, so technically we can either drop the neg/neg
trick from the processTokenTransfer() or drop one field from the structure
(the other side is a part of the key). Drop the field since this can make the
DB a bit more compact. Change Amount to be a pointer along the way since
that's the "native" thing for big.Int, we've used non-pointer field
specifically to avoid Neg/Neg problems, but it looks like this is not
necessary.
This structure is only used by the RPC server and I doubt anyone uses it via
the *Blockchain.
d5a9af5860 is incompatible with the NeoFS
mainnet sidechain, so we add the old logic to the pre-Aspidochelone
behaviour. Changing flags at newMethodAndPrice() is a bit less convenient
unfortunately because this will affect interop validity checks, so let's have
this kludge here.
It directly affects node security and the default here MUST BE the safe choice
which is to do the verification. Otherwise it's just dangerous, absent any
VerifyBlocks configuration we'll get an insecure node. This option is not
supposed to be frequently used and it doesn't affect the ability to process
blocks, so breaking compatibility (in a safe manner) should be OK here.
And include some node-specific configurations there with backwards
compatibility. Note that in the future we'll remove Ledger's
fields from the ProtocolConfiguration and it'll be possible to access them in
Blockchain directly (not via .Ledger).
The other option tried was using two configuration types separately, but that
incurs more changes to the codebase, single structure that behaves almost like
the old one is better for backwards compatibility.
Fixes#2676.
It doesn't store id->hash mappings for native contracts. We need blockchain's
GetContractScriptHash to serve both anyway, so it was changed a bit. The only
other direct user of native.GetContractScriptHash is the VM CLI, but I doubt
anyone will use it for native contracts (they have ~zero VM code anyway).
It's more generic and convenient than MillisecondsPerBlock. This setting is
made in backwards-compatible fashion, but it'll override SecondsPerBlock if
both are used. Configurations are specifically not changed here, it's
important to check compatibility.
Fixes#2675.
Follow neo-project/neo#2807. Notice that this data is not cached, our previous
implementation wasn't too and it shouldn't be a problem (not on the hot path).
They can stay in the memory pool forever because consensus process will never
accept these transactions (and maybe even block consensus process at all).
We're paging these hashes, so we need a previous full page and a current one
plus some cache for various requests. Storing 1M of hashes is 32M of memory
and it grows quickly. It also seriously affects node startup time, most of
what it's doing is reading these hashes, the longer the chain the more time it
needs to do that.
Notice that this doesn't change the underlying DB scheme in any way.
If we only have genesis block (or <2000 headers) then we might as well use
generic logic below with zero targetHash because genesis block has zero
PrevHash (and its hash will naturally be the last on the chain going
backwards).