working on sharding entrypoint

Former-commit-id: 50c0ab4bad92d27bf980e83e64088940544e94c2 [formerly 5dbfb91e925f14a743390f7da6bb2db1a30371db]
Former-commit-id: 66fb852ec273f74baaaf25b5a80987ac284c56ee

cmd/geth/main.go

@@ -164,6 +164,8 @@ func init() {
 		consoleCommand,
 		attachCommand,
 		javascriptCommand,
+		// See shardingcmd.go:
+		shardingClientCommand,
 		// See misccmd.go:
 		makecacheCommand,
 		makedagCommand,

cmd/geth/shardingcmd.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/sharding"
+
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	cli "gopkg.in/urfave/cli.v1"
+)
+
+var (
+	shardingClientCommand = cli.Command{
+		Action:      utils.MigrateFlags(shardingClient),
+		Name:        "shard",
+		Usage:       "Start a sharding client",
+		ArgsUsage:   "[endpoint]",
+		Category:    "SHARDING COMMANDS",
+		Description: "TODO(prestonvanloon)- Add sharding client description",
+	}
+)
+
+func shardingClient(ctx *cli.Context) error {
+	log.Info("hello world!")
+	c := sharding.MakeShardingClient(ctx)
+	if err := c.Start(); err != nil {
+		return err
+	}
+	c.Wait()
+	return nil
+}

sharding/client.go

@@ -0,0 +1,29 @@
+package sharding
+
+import (
+	"github.com/ethereum/go-ethereum/log"
+	cli "gopkg.in/urfave/cli.v1"
+)
+
+type Client struct {
+}
+
+func MakeShardingClient(ctx *cli.Context) *Client {
+	// TODO: Setup client
+	return &Client{}
+}
+
+func (c *Client) Start() error {
+	log.Info("Starting sharding client")
+	// TODO: Dial to RPC
+	// TODO: Verify VMC
+	if err := c.verifyVMC(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c *Client) Wait() {
+	// TODO: Blocking lock
+}

sharding/config.go

@@ -0,0 +1,18 @@
+package sharding
+
+import "math/big"
+
+var (
+	// Number of network shards
+	shardCount = 100
+	// Address of the validator management contract
+	validatorManagerAddress = "" // TODO
+	// Gas limit for verifying signatures
+	sigGasLimit = 40000
+	// Number of blocks in a period
+	periodLength = 5
+	// Number of periods to lookahead for ??? TODO(prestonvanloon) finish this comment.
+	lookaheadPeriods = 4
+	// Required deposit size in wei
+	depositSize = new(big.Int).Exp(big.NewInt(10), big.NewInt(20), nil) // 100 ETH
+)

sharding/config_test.go

@@ -0,0 +1,16 @@
+package sharding
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestDepositSize(t *testing.T) {
+	want, err := new(big.Int).SetString("100000000000000000000", 10) // 100 ETH
+	if !err {
+		t.Fatalf("Failed to setup test")
+	}
+	if depositSize.Cmp(want) != 0 {
+		t.Errorf("depositSize incorrect. Wanted %d, got %d", want, depositSize)
+	}
+}

sharding/vmc.go

@@ -0,0 +1,8 @@
+package sharding
+
+func (c *Client) verifyVMC() error {
+	// TODO: Fetch validator manager contract.
+	// TODO: Assert that the contract contents/ABI are as expected.
+	// TODO: Upload VMC if does not exist.
+	return nil
+}