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 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 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 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
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.
This commit implents a basic infrastructure to be used throughout the
tests for creating a new chain instance that is ready to have tests run
against it. It also returns a teardown function the caller can use to
clean up after it is done testing. This paves the way for adding more
tests.
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 updates the calls into btcutil, btcscript, and btcwire for the
latest API changes which remove the need for the protocol version for
serialization and deserialization of blocks and transactions.
This commit modifies the code to use params based on the active network
which paves the way for supporting the special rules and different genesis
blocks used by the test networks.
