Merge pull request #45 from nisdas/bufioScanner

Change from ioutil to bufio scanner

Former-commit-id: 2a2148a6bee555f6629fd4cf306e208a556e92d9 [formerly ac00ca1d65a3f7eebc8ebbc52a50f208603d34c6]
Former-commit-id: ab36fb37941e0c2df9a1575db7cc71881a22a8d0

sharding/client.go

@@ -3,11 +3,12 @@ package sharding
 //go:generate abigen --sol contracts/validator_manager.sol --pkg contracts --out contracts/validator_manager.go
 
 import (
+	"bufio"
 	"context"
+	"errors"
 	"fmt"
-	"io/ioutil"
 	"math/big"
-	"strings"
+	"os"
 
 	"github.com/ethereum/go-ethereum"
 
@@ -120,12 +121,21 @@ func (c *Client) unlockAccount(account accounts.Account) error {
 	pass := ""
 
 	if c.ctx.GlobalIsSet(utils.PasswordFileFlag.Name) {
-		blob, err := ioutil.ReadFile(c.ctx.GlobalString(utils.PasswordFileFlag.Name))
+		file, err := os.Open(c.ctx.GlobalString(utils.PasswordFileFlag.Name))
 		if err != nil {
-			return fmt.Errorf("unable to read account password contents in file %s. %v", utils.PasswordFileFlag.Value, err)
+			return fmt.Errorf("unable to open file containing account password %s. %v", utils.PasswordFileFlag.Value, err)
 		}
-		// TODO: Use bufio.Scanner or other reader that doesn't include a trailing newline character.
-		pass = strings.Trim(string(blob), "\n") // Some text files end in new line, remove with strings.Trim.
+		scanner := bufio.NewScanner(file)
+		scanner.Split(bufio.ScanWords)
+		if !scanner.Scan() {
+			err = scanner.Err()
+			if err != nil {
+				return fmt.Errorf("unable to read contents of file %v", err)
+			}
+			return errors.New("password not found in file")
+		}
+
+		pass = scanner.Text()
 	}
 
 	return c.keystore.Unlock(account, pass)

sharding/collator.go

@@ -27,7 +27,12 @@ type collatorClient interface {
 func subscribeBlockHeaders(c collatorClient) error {
 	headerChan := make(chan *types.Header, 16)
 
-	_, err := c.ChainReader().SubscribeNewHead(context.Background(), headerChan)
+	account, err := c.Account()
+	if err != nil {
+		return err
+	}
+
+	_, err = c.ChainReader().SubscribeNewHead(context.Background(), headerChan)
 	if err != nil {
 		return fmt.Errorf("unable to subscribe to incoming headers. %v", err)
 	}
@@ -40,8 +45,19 @@ func subscribeBlockHeaders(c collatorClient) error {
 		// Query the current state to see if we are an eligible proposer
 		log.Info(fmt.Sprintf("Received new header: %v", head.Number.String()))
 		// TODO: Only run this code on certain periods?
-		if err := checkShardsForProposal(c, head); err != nil {
-			return fmt.Errorf("unable to watch shards. %v", err)
+
+		// Check if we are in the validator pool before checking if we are an eligible proposer
+		v, err := isAccountInValidatorSet(c)
+		if err != nil {
+			return fmt.Errorf("unable to verify client in validator pool. %v", err)
+		}
+
+		if v {
+			if err := checkShardsForProposal(c, head); err != nil {
+				return fmt.Errorf("unable to watch shards. %v", err)
+			}
+		} else {
+			log.Warn(fmt.Sprintf("Account %s not in validator pool.", account.Address.String()))
 		}
 
 	}
@@ -82,6 +98,25 @@ func checkShardsForProposal(c collatorClient, head *types.Header) error {
 	return nil
 }
 
+// isAccountInValidatorSet checks if the client is in the validator pool because
+// we can't guarantee our tx for deposit will be in the next block header we receive.
+// The function calls IsValidatorDeposited from the VMC and returns true if
+// the client is in the validator pool
+func isAccountInValidatorSet(c collatorClient) (bool, error) {
+	account, err := c.Account()
+	if err != nil {
+		return false, err
+	}
+
+	// Checks if our deposit has gone through according to the VMC
+	b, err := c.VMCCaller().IsValidatorDeposited(&bind.CallOpts{}, account.Address)
+	if err != nil {
+		return false, err
+	}
+
+	return b, nil
+}
+
 // proposeCollation interacts with the VMC directly to add a collation header
 func proposeCollation(shardID int64) error {
 	// TODO: Adds a collation header to the VMC with the following fields: