cmd, console: split off the console into a reusable package

1 files changed, 369 insertions, 0 deletions

diff --git a/console/console.go b/console/console.go
new file mode 100644
index 000000000..37c9f0afa
--- /dev/null
+++ b/console/console.go
@@ -0,0 +1,369 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package console
+
+import (
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/internal/jsre"
+	"github.com/ethereum/go-ethereum/internal/web3ext"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/peterh/liner"
+	"github.com/robertkrimen/otto"
+)
+
+var (
+	passwordRegexp = regexp.MustCompile("personal.[nus]")
+	onlyWhitespace = regexp.MustCompile("^\\s*$")
+	exit           = regexp.MustCompile("^\\s*exit\\s*;*\\s*$")
+)
+
+// HistoryFile is the file within the data directory to store input scrollback.
+const HistoryFile = "history"
+
+// DefaultPrompt is the default prompt line prefix to use for user input querying.
+const DefaultPrompt = "> "
+
+// Config is te collection of configurations to fine tune the behavior of the
+// JavaScript console.
+type Config struct {
+	DataDir  string       // Data directory to store the console history at
+	DocRoot  string       // Filesystem path from where to load JavaScript files from
+	Client   rpc.Client   // RPC client to execute Ethereum requests through
+	Prompt   string       // Input prompt prefix string (defaults to DefaultPrompt)
+	Prompter UserPrompter // Input prompter to allow interactive user feedback (defaults to TerminalPrompter)
+	Printer  io.Writer    // Output writer to serialize any display strings to (defaults to os.Stdout)
+	Preload  []string     // Absolute paths to JavaScript files to preload
+}
+
+// Console is a JavaScript interpreted runtime environment. It is a fully fleged
+// JavaScript console attached to a running node via an external or in-process RPC
+// client.
+type Console struct {
+	client   rpc.Client   // RPC client to execute Ethereum requests through
+	jsre     *jsre.JSRE   // JavaScript runtime environment running the interpreter
+	prompt   string       // Input prompt prefix string
+	prompter UserPrompter // Input prompter to allow interactive user feedback
+	histPath string       // Absolute path to the console scrollback history
+	history  []string     // Scroll history maintained by the console
+	printer  io.Writer    // Output writer to serialize any display strings to
+}
+
+func New(config Config) (*Console, error) {
+	// Handle unset config values gracefully
+	if config.Prompter == nil {
+		config.Prompter = TerminalPrompter
+	}
+	if config.Prompt == "" {
+		config.Prompt = DefaultPrompt
+	}
+	if config.Printer == nil {
+		config.Printer = os.Stdout
+	}
+	// Initialize the console and return
+	console := &Console{
+		client:   config.Client,
+		jsre:     jsre.New(config.DocRoot, config.Printer),
+		prompt:   config.Prompt,
+		prompter: config.Prompter,
+		printer:  config.Printer,
+		histPath: filepath.Join(config.DataDir, HistoryFile),
+	}
+	if err := console.init(config.Preload); err != nil {
+		return nil, err
+	}
+	return console, nil
+}
+
+// init retrieves the available APIs from the remote RPC provider and initializes
+// the console's JavaScript namespaces based on the exposed modules.
+func (c *Console) init(preload []string) error {
+	// Initialize the JavaScript <-> Go RPC bridge
+	bridge := newBridge(c.client, c.prompter, c.printer)
+	c.jsre.Set("jeth", struct{}{})
+
+	jethObj, _ := c.jsre.Get("jeth")
+	jethObj.Object().Set("send", bridge.Send)
+	jethObj.Object().Set("sendAsync", bridge.Send)
+
+	consoleObj, _ := c.jsre.Get("console")
+	consoleObj.Object().Set("log", c.consoleOutput)
+	consoleObj.Object().Set("error", c.consoleOutput)
+
+	// Load all the internal utility JavaScript libraries
+	if err := c.jsre.Compile("bignumber.js", jsre.BigNumber_JS); err != nil {
+		return fmt.Errorf("bignumber.js: %v", err)
+	}
+	if err := c.jsre.Compile("web3.js", jsre.Web3_JS); err != nil {
+		return fmt.Errorf("web3.js: %v", err)
+	}
+	if _, err := c.jsre.Run("var Web3 = require('web3');"); err != nil {
+		return fmt.Errorf("web3 require: %v", err)
+	}
+	if _, err := c.jsre.Run("var web3 = new Web3(jeth);"); err != nil {
+		return fmt.Errorf("web3 provider: %v", err)
+	}
+	// Load the supported APIs into the JavaScript runtime environment
+	apis, err := c.client.SupportedModules()
+	if err != nil {
+		return fmt.Errorf("api modules: %v", err)
+	}
+	flatten := "var eth = web3.eth; var personal = web3.personal; "
+	for api := range apis {
+		if api == "web3" {
+			continue // manually mapped or ignore
+		}
+		if file, ok := web3ext.Modules[api]; ok {
+			if err = c.jsre.Compile(fmt.Sprintf("%s.js", api), file); err != nil {
+				return fmt.Errorf("%s.js: %v", api, err)
+			}
+			flatten += fmt.Sprintf("var %s = web3.%s; ", api, api)
+		}
+	}
+	if _, err = c.jsre.Run(flatten); err != nil {
+		return fmt.Errorf("namespace flattening: %v", err)
+	}
+	// Initialize the global name register (disabled for now)
+	//c.jsre.Run(`var GlobalRegistrar = eth.contract(` + registrar.GlobalRegistrarAbi + `);   registrar = GlobalRegistrar.at("` + registrar.GlobalRegistrarAddr + `");`)
+
+	// If the console is in interactive mode, instrument password related methods to query the user
+	if c.prompter != nil {
+		// Retrieve the account management object to instrument
+		personal, err := c.jsre.Get("personal")
+		if err != nil {
+			return err
+		}
+		// Override the unlockAccount and newAccount methods since these require user interaction.
+		// Assign the jeth.unlockAccount and jeth.newAccount in the Console the original web3 callbacks.
+		// These will be called by the jeth.* methods after they got the password from the user and send
+		// the original web3 request to the backend.
+		if obj := personal.Object(); obj != nil { // make sure the personal api is enabled over the interface
+			if _, err = c.jsre.Run(`jeth.unlockAccount = personal.unlockAccount;`); err != nil {
+				return fmt.Errorf("personal.unlockAccount: %v", err)
+			}
+			if _, err = c.jsre.Run(`jeth.newAccount = personal.newAccount;`); err != nil {
+				return fmt.Errorf("personal.newAccount: %v", err)
+			}
+			obj.Set("unlockAccount", bridge.UnlockAccount)
+			obj.Set("newAccount", bridge.NewAccount)
+		}
+	}
+	// The admin.sleep and admin.sleepBlocks are offered by the console and not by the RPC layer.
+	admin, err := c.jsre.Get("admin")
+	if err != nil {
+		return err
+	}
+	if obj := admin.Object(); obj != nil { // make sure the admin api is enabled over the interface
+		obj.Set("sleepBlocks", bridge.SleepBlocks)
+		obj.Set("sleep", bridge.Sleep)
+	}
+	// Preload any JavaScript files before starting the console
+	for _, path := range preload {
+		if err := c.jsre.Exec(path); err != nil {
+			return fmt.Errorf("%s: %v", path, jsErrorString(err))
+		}
+	}
+	// Configure the console's input prompter for scrollback and tab completion
+	if c.prompter != nil {
+		if content, err := ioutil.ReadFile(c.histPath); err != nil {
+			c.prompter.SetScrollHistory(nil)
+		} else {
+			c.prompter.SetScrollHistory(strings.Split(string(content), "\n"))
+		}
+		c.prompter.SetWordCompleter(c.AutoCompleteInput)
+	}
+	return nil
+}
+
+// consoleOutput is an override for the console.log and console.error methods to
+// stream the output into the configured output stream instead of stdout.
+func (c *Console) consoleOutput(call otto.FunctionCall) otto.Value {
+	output := []string{}
+	for _, argument := range call.ArgumentList {
+		output = append(output, fmt.Sprintf("%v", argument))
+	}
+	fmt.Fprintln(c.printer, strings.Join(output, " "))
+	return otto.Value{}
+}
+
+// AutoCompleteInput is a pre-assembled word completer to be used by the user
+// input prompter to provide hints to the user about the methods available.
+func (c *Console) AutoCompleteInput(line string, pos int) (string, []string, string) {
+	// No completions can be provided for empty inputs
+	if len(line) == 0 || pos == 0 {
+		return "", nil, ""
+	}
+	// Chunck data to relevant part for autocompletion
+	// E.g. in case of nested lines eth.getBalance(eth.coinb<tab><tab>
+	start := 0
+	for start = pos - 1; start > 0; start-- {
+		// Skip all methods and namespaces (i.e. including te dot)
+		if line[start] == '.' || (line[start] >= 'a' && line[start] <= 'z') || (line[start] >= 'A' && line[start] <= 'Z') {
+			continue
+		}
+		// Handle web3 in a special way (i.e. other numbers aren't auto completed)
+		if start >= 3 && line[start-3:start] == "web3" {
+			start -= 3
+			continue
+		}
+		// We've hit an unexpected character, autocomplete form here
+		start++
+		break
+	}
+	return line[:start], c.jsre.CompleteKeywords(line[start:pos]), line[pos:]
+}
+
+// Welcome show summary of current Geth instance and some metadata about the
+// console's available modules.
+func (c *Console) Welcome() {
+	// Print some generic Geth metadata
+	c.jsre.Run(`
+    (function () {
+			console.log("Welcome to the Geth JavaScript console!\n");
+      console.log("instance: " + web3.version.node);
+      console.log("coinbase: " + eth.coinbase);
+      console.log("at block: " + eth.blockNumber + " (" + new Date(1000 * eth.getBlock(eth.blockNumber).timestamp) + ")");
+      console.log(" datadir: " + admin.datadir);
+    })();
+  `)
+	// List all the supported modules for the user to call
+	if apis, err := c.client.SupportedModules(); err == nil {
+		modules := make([]string, 0, len(apis))
+		for api, version := range apis {
+			modules = append(modules, fmt.Sprintf("%s:%s", api, version))
+		}
+		sort.Strings(modules)
+		c.jsre.Run("(function () { console.log(' modules: " + strings.Join(modules, " ") + "'); })();")
+	}
+	c.jsre.Run("(function () { console.log(); })();")
+}
+
+// Evaluate executes code and pretty prints the result to the specified output
+// stream.
+func (c *Console) Evaluate(statement string) error {
+	defer func() {
+		if r := recover(); r != nil {
+			fmt.Fprintf(c.printer, "[native] error: %v\n", r)
+		}
+	}()
+	if err := c.jsre.Evaluate(statement, c.printer); err != nil {
+		fmt.Fprintf(c.printer, "%v\n", jsErrorString(err))
+		return err
+	}
+	return nil
+}
+
+// Interactive starts an interactive user session, where input is propted from
+// the configured user prompter.
+func (c *Console) Interactive() {
+	var (
+		prompt    = c.prompt          // Current prompt line (used for multi-line inputs)
+		indents   = 0                 // Current number of input indents (used for multi-line inputs)
+		input     = ""                // Current user input
+		scheduler = make(chan string) // Channel to send the next prompt on and receive the input
+	)
+	// Start a goroutine to listen for promt requests and send back inputs
+	go func() {
+		for {
+			// Read the next user input
+			line, err := c.prompter.PromptInput(<-scheduler)
+			if err != nil {
+				// In case of an error, either clear the prompt or fail
+				if err == liner.ErrPromptAborted { // ctrl-C
+					prompt, indents, input = c.prompt, 0, ""
+					scheduler <- ""
+					continue
+				}
+				close(scheduler)
+				return
+			}
+			// User input retrieved, send for interpretation and loop
+			scheduler <- line
+		}
+	}()
+	// Monitor Ctrl-C too in case the input is empty and we need to bail
+	abort := make(chan os.Signal, 1)
+	signal.Notify(abort, os.Interrupt)
+
+	// Start sending prompts to the user and reading back inputs
+	for {
+		// Send the next prompt, triggering an input read and process the result
+		scheduler <- prompt
+		select {
+		case <-abort:
+			// User forcefully quite the console
+			fmt.Fprintln(c.printer, "caught interrupt, exiting")
+			return
+
+		case line, ok := <-scheduler:
+			// User input was returned by the prompter, handle special cases
+			if !ok || (indents <= 0 && exit.MatchString(input)) {
+				return
+			}
+			if onlyWhitespace.MatchString(line) {
+				continue
+			}
+			// Append the line to the input and check for multi-line interpretation
+			input += line + "\n"
+
+			indents = strings.Count(input, "{") + strings.Count(input, "(") - strings.Count(input, "}") - strings.Count(input, ")")
+			if indents <= 0 {
+				prompt = c.prompt
+			} else {
+				prompt = strings.Repeat("..", indents*2) + " "
+			}
+			// If all the needed lines are present, save the command and run
+			if indents <= 0 {
+				if len(input) != 0 && input[0] != ' ' && !passwordRegexp.MatchString(input) {
+					c.history = append(c.history, input[:len(input)-1])
+				}
+				c.Evaluate(input)
+				input = ""
+			}
+		}
+	}
+}
+
+// Execute runs the JavaScript file specified as the argument.
+func (c *Console) Execute(path string) error {
+	return c.jsre.Exec(path)
+}
+
+// Stop cleans up the console and terminates the runtime envorinment.
+func (c *Console) Stop(graceful bool) error {
+	if err := ioutil.WriteFile(c.histPath, []byte(strings.Join(c.history, "\n")), os.ModePerm); err != nil {
+		return err
+	}
+	c.jsre.Stop(graceful)
+	return nil
+}
+
+// jsErrorString adds a backtrace to errors generated by otto.
+func jsErrorString(err error) string {
+	if ottoErr, ok := err.(*otto.Error); ok {
+		return ottoErr.String()
+	}
+	return err.Error()
+}