Esempio n. 1
0
// This example demonstrates how to convert the compact "bits" in a block header
// which represent the target difficulty to a big integer and display it using
// the typical hex notation.
func ExampleCompactToBig() {
	// Convert the bits from block 300000 in the main Decred block chain.
	bits := uint32(419465580)
	targetDifficulty := blockchain.CompactToBig(bits)

	// Display it in hex.
	fmt.Printf("%064x\n", targetDifficulty.Bytes())

	// Output:
	// 0000000000000000896c00000000000000000000000000000000000000000000
}
Esempio n. 2
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func (s *ProxyServer) fetchPendingBlock(data string) (uint64, *big.Int, error) {
	blockNumberStr, err := hex.DecodeString(data[256:264])
	if err != nil {
		log.Println("Can't parse pending block number")
		// TODO: valami alap difficultyt!!
		return 0, nil, err
	}
	blockNumber := binary.LittleEndian.Uint32(blockNumberStr)
	blockDiffStr, err := hex.DecodeString(data[232:240])
	if err != nil {
		log.Println("Can't parse pending block difficulty")
		return 0, nil, err
	}
	blockDiff := binary.LittleEndian.Uint32(blockDiffStr)
	return uint64(blockNumber), blockchain.CompactToBig(blockDiff), nil
}
Esempio n. 3
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// getDifficultyRatio returns the proof-of-work difficulty as a multiple of the
// minimum difficulty using the passed bits field from the header of a block.
func GetDifficultyRatio(bits uint32) float64 {
	// The minimum difficulty is the max possible proof-of-work limit bits
	// converted back to a number.  Note this is not the same as the the
	// proof of work limit directly because the block difficulty is encoded
	// in a block with the compact form which loses precision.
	max := PowLimit // blockchain.CompactToBig(chaincfg.TestNetParams.PowLimitBits)
	target := blockchain.CompactToBig(bits)

	difficulty := new(big.Rat).SetFrac(max, target)
	outString := difficulty.FloatString(8)
	diff, err := strconv.ParseFloat(outString, 64)
	if err != nil {
		//rpcsLog.Errorf("Cannot get difficulty: %v", err)
		return 0
	}
	return diff
}
Esempio n. 4
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func TestCompactToBig(t *testing.T) {
	tests := []struct {
		in  uint32
		out int64
	}{
		{10000000, 0},
	}

	for x, test := range tests {
		n := blockchain.CompactToBig(test.in)
		want := big.NewInt(test.out)
		if n.Cmp(want) != 0 {
			t.Errorf("TestCompactToBig test #%d failed: got %d want %d\n",
				x, n.Int64(), want.Int64())
			return
		}
	}
}
Esempio n. 5
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// solveBlock attempts to find some combination of a nonce, extra nonce, and
// current timestamp which makes the passed block hash to a value less than the
// target difficulty.  The timestamp is updated periodically and the passed
// block is modified with all tweaks during this process.  This means that
// when the function returns true, the block is ready for submission.
//
// This function will return early with false when conditions that trigger a
// stale block such as a new block showing up or periodically when there are
// new transactions and enough time has elapsed without finding a solution.
func (m *CPUMiner) solveBlock(msgBlock *wire.MsgBlock, ticker *time.Ticker,
	quit chan struct{}) bool {

	blockHeight := int64(msgBlock.Header.Height)

	// Choose a random extra nonce offset for this block template and
	// worker.
	enOffset, err := wire.RandomUint64()
	if err != nil {
		minrLog.Errorf("Unexpected error while generating random "+
			"extra nonce offset: %v", err)
		enOffset = 0
	}

	// Create a couple of convenience variables.
	header := &msgBlock.Header
	targetDifficulty := blockchain.CompactToBig(header.Bits)

	// Initial state.
	lastGenerated := time.Now()
	lastTxUpdate := m.server.txMemPool.LastUpdated()
	hashesCompleted := uint64(0)

	// Note that the entire extra nonce range is iterated and the offset is
	// added relying on the fact that overflow will wrap around 0 as
	// provided by the Go spec.
	for extraNonce := uint64(0); extraNonce < maxExtraNonce; extraNonce++ {
		// Get the old nonce values.
		ens := getCoinbaseExtranonces(msgBlock)
		ens[2] = extraNonce + enOffset

		// Update the extra nonce in the block template with the
		// new value by regenerating the coinbase script and
		// setting the merkle root to the new value.  The
		UpdateExtraNonce(msgBlock, blockHeight, ens)

		// Search through the entire nonce range for a solution while
		// periodically checking for early quit and stale block
		// conditions along with updates to the speed monitor.
		for i := uint32(0); i <= maxNonce; i++ {
			select {
			case <-quit:
				return false

			case <-ticker.C:
				m.updateHashes <- hashesCompleted
				hashesCompleted = 0

				// The current block is stale if the memory pool
				// has been updated since the block template was
				// generated and it has been at least 3 seconds,
				// or if it's been one minute.
				if (lastTxUpdate != m.server.txMemPool.LastUpdated() &&
					time.Now().After(lastGenerated.Add(3*time.Second))) ||
					time.Now().After(lastGenerated.Add(60*time.Second)) {
					return false
				}

				UpdateBlockTime(msgBlock, m.server.blockManager)

			default:
				// Non-blocking select to fall through
			}

			// Update the nonce and hash the block header.
			header.Nonce = i
			hash := header.BlockSha()
			hashesCompleted += 1

			// The block is solved when the new block hash is less
			// than the target difficulty.  Yay!
			if blockchain.ShaHashToBig(&hash).Cmp(targetDifficulty) <= 0 {
				m.updateHashes <- hashesCompleted
				return true
			}
		}
	}

	return false
}