This commit adds a test for checking known good block scripts in a block
are valid. As a part of this, it adds the infastructure needed to load a
saved transaction store from a file which contains all of the input
transactions needed.
It also contains some changes from running goimports as well as some other
cleanup.
This commit provides a new interface, MedianTimeSource, along with a
concrete implementation which allows improved accuracy of time by making
use of the median network time as calculated from multiple time samples.
The time samples are to be provided by callers and are intended to come
from remote clients.
The calculations performed in this implementation exactly mirror those in
Bitcoin Core because time calculations are part of the consensus rules and
hence need to match exactly.
This commit creates and exports a new constant, MaxTimeOffsetSeconds,
which is the maximum number of seconds a block timestamp is allowed to be
ahead of the current time.
Previously this value was hard coded into the consensus rule path, however
it is useful better to have it defined as a constant and exported so other
callers can access it.
No consensus rules have been changed with this commit.
This commit adds a new behavior flag, BFDryRun which allows the caller
to indicate all checks should be performed against the block as normal
except it will not modify any state. This is useful to test that a block
is valid without actually modifying the current chain or memory state.
This commit also adds a few additional checks which were elided before
since they are implicitly handled by btcwire. However, with the ability
to propose blocks which didn't necessarily come through the btcwire path,
these checks need to be enforced in the chain code as well.
As a part of adding the checks, three new error codes named
ErrBlockTooBig, ErrTooManyTransactions, and ErrTxTooBig have been
introduced.
Closes#5.
This commit adds a new behavior flag, BFNoPoWCheck which allows the caller
to indicate the check which ensures a block hashes to a value less than
required target should not be performed.
This commit changes the RuleError type to a struct which consists of an
error code and human-readable description.
From a usage perspective, existing code should not break since type
asserting an error to a RuleError still works in the same manner. The
difference is the caller can now take that type asserted RuleError and
access the .ErrorCode field on it to programmatically identify the
specific rule that was violated.
ok @jrick
This commit refactors the code to make use of the btcnet package for
network-specific parameters instead of switching on the specific network.
For example, the percentage of the network that needs to run version 2
blocks is different between testnet and mainnet. Previously the code was
using a switch to choose these values. With this refactor, those
parameters are part of the network parameters provided when creating a new
chain instance.
Another example is checkpoints, which have been moved to btcnet so they
can be specified by the caller instead of hard coded into this package.
As a result, the checkpoints for the standard networks are now specified
in the btcnet package.
This makes it easier to add new networks such as a testnet4 should it
become needed. It also allows callers to define their own custom network
parameters without having to modify the code of the package to add new
switch cases for the custom network.
This commit corrects the debug log print to use the hash of referenced
coinbase transaction instead of the hash of the current transation when a
coinbase maturity is not met.
Rather than using the deprecated TxShas function on a btcutil.Block,
convert the checkBIP0030 to use the newer preferred method of ranging over
the Transactions to obtain the cached hash of each transaction.
This is also a little more efficient since it can avoid creating and
caching an extra slice to keep the hashes in addition to having the hash
cached with each transaction.
This commit makes a slight variant of the existing checkConnectBlock
function available to external callers. The new exported version checks
if the passed block will connect to the end of the current main chain.
In order to support this, a few other small modifications have been made
to the initial index generation and the existing checkConnectBlock since
it previously made some assumptions about the state of genesis block which
can no longer be assumed due accepting blocks from callers directly.
Also, add a quick test to ensure the new function fails when checking if
the genesis block will connect again when it's already inserted.
This commit modifies the BuildMerkleTreeStore function to accept a slice
of btcutil.Tx transactions as opposed to a full block. This allows more
flexibility when calculating merkle roots since a full block may not be
created yet (particularly when generating blocks that need to be solved in
mining).
Previously, the BuildMerkleTreeStore function accepted a btcutil.Block
because originally the block itself cached the transaction hashes and it
was necessary to have access to the block to make use of the cached
transactions. However, the code has since been improved such that it
caches transaction hashes directly in each btcutil.Tx. This means the
code can remain as efficient as before while allowing the individual
transacitons to be passed.
This commit adds an additional sanity check to ensure the block that is
being processed does not contain a timestamp with a precision higher than
one second. This is necessary because the consensus rules only deal with
whole seconds in the time comparisons whereas the internal data structures
make use of Go time.Time values which support up to nanosecond precision.
Also, add a test to ensure the new functionality works as expected.
ok @owainga
This commit moves the subsidy halving interval to the chain params so it
can be configured per network. With that change it sets the regression
test halving interval to 150 to match the regression test params of the
reference implementation.
This was pointed out by @flammit.
This commit modifies local variables that are used for more convenient
access to a block's header to use pointers. This avoids copying the
header multiple times.
Rather than defining CheckBlockSanity as a member of a BlockChain
instance, define it at the root level so it is truly context free as
intended. In order to make it context free, the proof of work limit is
now a required parameter.
Profiling showed the duplicate transaction input check was taking around
6% of the total CheckTransactionSanity processing time. This was largely
due to using fmt.Sprintf to generate the map key.
This commit modifies the check instead to use the actual output as a map
key.
The following benchmark results show the difference:
Before: BenchmarkOldDuplicatInputCheck 100000 21787 ns/op
After: BenchmarkNewDuplicatInputCheck 2000000 937 ns/op
Closes#2
This commit modifies the errors that result from missing expected input
transactions to a RuleError. This allows the caller to detect a block was
rejected due to a rule violation as opposed to an unexpected error.
This commit modifies the transaction lookup code to use a set instead of a
slice (list). This allows the lookup to automatically prevent duplicate
requests to the database.
Previously, the code simply added every referenced transaction to a list
without checking for duplicates, which led to multiple requests against
the database for the same transaction. It also meant the request list
could grow quite large with all of the duplicates using far more memory
than required.
While the end result was accurate, operating that way is not as efficient
as only requesting unique transactions.
This commit corrects the reading of the serialized height in coinbase
transactions for block height of version 2 or greater. On mainnet, the
serialized height is always 3 bytes and will continue to be so for
something like another ~159 years, so there was no issue with mainnet.
However on testnet, there are some version 2 blocks which are low enough
in the chain to only take 2 bytes to serialize.
In addition, this commit adds a full tests for the relavant function
including negative tests and variable length serialized lengths for block
heights.
Closes#1.
This commit modifies CheckInputTransactions to ensure that not only must a
transaction exist in the transaction store, it must also not have any
errors associated with it or be nil.
Several of the functions require a map of contextual transaction data to
use as a source for referenced transactions. This commit exports the
underlying TxData type and creates a new type TxStore, which is a map of
points to the under TxData. In addition, this commit exposes a new
function, FetchTransactionStore, which returns a transaction store
(TxStore) containing all of the transactions referenced by the passed
transaction, as well as the existing transaction if it already exists.
This paves the way for subsequent commits which will expose some of the
functions which depend on this transaction store.
