func TestCalcWork(t *testing.T) {
tests := []struct {
in uint32
out int64
}{
{10000000, 0},
}
for x, test := range tests {
bits := uint32(test.in)
r := btcchain.CalcWork(bits)
if r.Int64() != test.out {
t.Errorf("TestCalcWork test #%d failed: got %v want %d\n",
x, r.Int64(), test.out)
return
}
}
}
// handleGetNetworkHashPS implements the getnetworkhashps command.
func handleGetNetworkHashPS(s *rpcServer, cmd btcjson.Cmd) (interface{}, error) {
c := cmd.(*btcjson.GetNetworkHashPSCmd)
_, newestHeight, err := s.server.db.NewestSha()
if err != nil {
return nil, btcjson.Error{
Code: btcjson.ErrInternal.Code,
Message: err.Error(),
}
}
// When the passed height is too high or zero, just return 0 now
// since we can't reasonably calculate the number of network hashes
// per second from invalid values. When it's negative, use the current
// best block height.
endHeight := int64(c.Height)
if endHeight > newestHeight || endHeight == 0 {
return 0, nil
}
if endHeight < 0 {
endHeight = newestHeight
}
// Calculate the starting block height based on the passed number of
// blocks. When the passed value is negative, use the last block the
// difficulty changed as the starting height. Also make sure the
// starting height is not before the beginning of the chain.
var startHeight int64
if c.Blocks <= 0 {
startHeight = endHeight - ((endHeight % btcchain.BlocksPerRetarget) + 1)
} else {
startHeight = endHeight - int64(c.Blocks)
}
if startHeight < 0 {
startHeight = 0
}
rpcsLog.Debugf("Calculating network hashes per second from %d to %d",
startHeight, endHeight)
// Find the min and max block timestamps as well as calculate the total
// amount of work that happened between the start and end blocks.
var minTimestamp, maxTimestamp time.Time
totalWork := big.NewInt(0)
for curHeight := startHeight; curHeight <= endHeight; curHeight++ {
hash, err := s.server.db.FetchBlockShaByHeight(curHeight)
if err != nil {
return nil, btcjson.Error{
Code: btcjson.ErrInternal.Code,
Message: err.Error(),
}
}
header, err := s.server.db.FetchBlockHeaderBySha(hash)
if err != nil {
return nil, btcjson.Error{
Code: btcjson.ErrInternal.Code,
Message: err.Error(),
}
}
if curHeight == startHeight {
minTimestamp = header.Timestamp
maxTimestamp = minTimestamp
} else {
totalWork.Add(totalWork, btcchain.CalcWork(header.Bits))
if minTimestamp.After(header.Timestamp) {
minTimestamp = header.Timestamp
}
if maxTimestamp.Before(header.Timestamp) {
maxTimestamp = header.Timestamp
}
}
}
// Calculate the difference in seconds between the min and max block
// timestamps and avoid division by zero in the case where there is no
// time difference.
timeDiff := int64(maxTimestamp.Sub(minTimestamp) / time.Second)
if timeDiff == 0 {
return 0, nil
}
hashesPerSec := new(big.Int).Div(totalWork, big.NewInt(timeDiff))
return hashesPerSec.Int64(), nil
}