Refactoring the command line main to allow driver additions.

This change contains a refactor of the main to only leave code for driver
registration. It also enables the use of flags and removes temporary
code used for flag managment.

tools/vcli/bw/assert/assert.go

@@ -27,41 +27,32 @@ import (
 	"github.com/google/badwolf/storage"
 	"github.com/google/badwolf/tools/compliance"
 	"github.com/google/badwolf/tools/vcli/bw/command"
-	"github.com/google/badwolf/tools/vcli/bw/common"
+	"github.com/google/badwolf/tools/vcli/bw/io"
 	"github.com/google/badwolf/triple/literal"
 )
 
 // New creates the help command.
-func New(store storage.Store, builder literal.Builder) *command.Command {
+func New(store storage.Store, builder literal.Builder, chanSize int) *command.Command {
 	cmd := &command.Command{
-		UsageLine: "assert [--channel_size=123] folder_path",
+		UsageLine: "assert folder_path",
 		Short:     "asserts all the stories in the indicated folder.",
 		Long: `Asserts all the stories in the folder. Each story is stored in a JSON
 file containing all the sources and all the assertions to run.
 `,
 	}
 	cmd.Run = func(ctx context.Context, args []string) int {
-		return assertCommand(ctx, cmd, args, store, builder)
+		return assertCommand(ctx, cmd, args, store, builder, chanSize)
 	}
 	return cmd
 }
 
 // assertCommand runs all the BQL statements available in the file.
-func assertCommand(ctx context.Context, cmd *command.Command, args []string, store storage.Store, builder literal.Builder) int {
+func assertCommand(ctx context.Context, cmd *command.Command, args []string, store storage.Store, builder literal.Builder, chanSize int) int {
 	if len(args) < 3 {
 		fmt.Fprintf(os.Stderr, "Missing required folder path. ")
 		cmd.Usage()
 		return 2
 	}
-	chanSize := 0
-	if len(args) >= 4 {
-		c, err := common.ParseChannelSizeFlag(args[2])
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "Fail to parse flag %s with error %v\n", args[2], err)
-			return 2
-		}
-		chanSize = c
-	}
 	// Open the folder.
 	folder := strings.TrimSpace(args[len(args)-1])
 	f, err := os.Open(folder)
@@ -83,7 +74,7 @@ func assertCommand(ctx context.Context, cmd *command.Command, args []string, sto
 			continue
 		}
 		fmt.Printf("\tProcessing file %q... ", fi.Name())
-		lns, err := common.ReadLines(path.Join(folder, fi.Name()))
+		lns, err := io.ReadLines(path.Join(folder, fi.Name()))
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "\n\n\tFailed to read file content with error %v\n\n", err)
 			return 2

tools/vcli/bw/common/common.go

@@ -17,7 +17,6 @@
 package common
 
 import (
-	"bufio"
 	"fmt"
 	"os"
 	"sort"
@@ -26,37 +25,14 @@ import (
 
 	"golang.org/x/net/context"
 
+	"github.com/google/badwolf/storage"
+	"github.com/google/badwolf/tools/vcli/bw/assert"
 	"github.com/google/badwolf/tools/vcli/bw/command"
+	"github.com/google/badwolf/tools/vcli/bw/run"
+	"github.com/google/badwolf/tools/vcli/bw/version"
+	"github.com/google/badwolf/triple/literal"
 )
 
-// ReadLines from a file into a string array.
-func ReadLines(path string) ([]string, error) {
-	f, err := os.Open(path)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-
-	var lines []string
-	scanner := bufio.NewScanner(f)
-	line := ""
-	for scanner.Scan() {
-		l := strings.TrimSpace(scanner.Text())
-		if len(l) == 0 || strings.Index(l, "#") == 0 {
-			continue
-		}
-		line += " " + l
-		if l[len(l)-1:] == ";" {
-			lines = append(lines, strings.TrimSpace(line))
-			line = ""
-		}
-	}
-	if line != "" {
-		lines = append(lines, strings.TrimSpace(line))
-	}
-	return lines, scanner.Err()
-}
-
 // ParseChannelSizeFlag attempts to parse the "channel_size" flag.
 func ParseChannelSizeFlag(flag string) (int, error) {
 	ss := strings.Split(flag, "=")
@@ -100,6 +76,32 @@ func Help(args []string, cmds []*command.Command) int {
 	return 2
 }
 
+// StoreGenerator is a function that generate a new valid storage.Store.
+type StoreGenerator func() (storage.Store, error)
+
+// InitializeDriver attemps to initalize the driver.
+func InitializeDriver(driverName string, drivers map[string]StoreGenerator) (storage.Store, error) {
+	f, ok := drivers[driverName]
+	if !ok {
+		var ds []string
+		for k := range drivers {
+			ds = append(ds, k)
+		}
+		return nil, fmt.Errorf("unkown driver name %q; valid drivers [%q]", driverName, strings.Join(ds, ", "))
+	}
+	return f()
+}
+
+// InitializeCommands intializes the avaialbe commands with the given storage
+// instance.
+func InitializeCommands(driver storage.Store, chanSize int) []*command.Command {
+	return []*command.Command{
+		assert.New(driver, literal.DefaultBuilder(), chanSize),
+		run.New(driver, chanSize),
+		version.New(),
+	}
+}
+
 // Eval of the command line version tool. This allows injecting multiple
 // drivers.
 func Eval(ctx context.Context, args []string, cmds []*command.Command) int {
@@ -126,3 +128,13 @@ func Eval(ctx context.Context, args []string, cmds []*command.Command) int {
 	}
 	return 1
 }
+
+// Run executes the main of the command line tool.
+func Run(driverName string, drivers map[string]StoreGenerator, chanSize int) {
+	driver, err := InitializeDriver(driverName, drivers)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(2)
+	}
+	os.Exit(Eval(context.Background(), os.Args, InitializeCommands(driver, chanSize)))
+}

tools/vcli/bw/io/io.go

@@ -0,0 +1,51 @@
+// Copyright 2015 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package io contains helper functions for io operatoins on the command line
+// bw tool.
+package io
+
+import (
+	"bufio"
+	"os"
+	"strings"
+)
+
+// ReadLines from a file into a string array.
+func ReadLines(path string) ([]string, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	var lines []string
+	scanner := bufio.NewScanner(f)
+	line := ""
+	for scanner.Scan() {
+		l := strings.TrimSpace(scanner.Text())
+		if len(l) == 0 || strings.Index(l, "#") == 0 {
+			continue
+		}
+		line += " " + l
+		if l[len(l)-1:] == ";" {
+			lines = append(lines, strings.TrimSpace(line))
+			line = ""
+		}
+	}
+	if line != "" {
+		lines = append(lines, strings.TrimSpace(line))
+	}
+	return lines, scanner.Err()
+}

tools/vcli/bw/main.go

@@ -13,31 +13,41 @@
 // limitations under the License.
 
 // BadWolf command line tools allows you to interact with graphs via BQL.
-
+// This file is a template for creating your own bw tool with custom backend
+// storage drivers. Just *copy* this file to your project, add the required
+// flags that you need to initialize your driver and register your diver on
+// the registeredDriver map in the registerDrivers function.
 package main
 
 import (
-	"os"
+	"flag"
 
+	"github.com/google/badwolf/storage"
 	"github.com/google/badwolf/storage/memory"
-	"github.com/google/badwolf/tools/vcli/bw/assert"
-	"github.com/google/badwolf/tools/vcli/bw/command"
 	"github.com/google/badwolf/tools/vcli/bw/common"
-	"github.com/google/badwolf/tools/vcli/bw/run"
-	"github.com/google/badwolf/tools/vcli/bw/version"
-	"github.com/google/badwolf/triple/literal"
+)
 
-	"golang.org/x/net/context"
+var (
+	// drivers contains the registed drivers available for this command line tool.
+	registeredDrivers map[string]common.StoreGenerator
+	// Available flags.
+	driver         = flag.String("driver", "VOLATILE", "The storage driver to use {VOLATILE}.")
+	bqlChannelSize = flag.Int("bql_channel_size", 0, "Internal channel size to use on BQL queries.")
+	// Add your driver flags below.
 )
 
-// Registration of the available commands. Please keep sorted.
-var cmds = []*command.Command{
-	assert.New(memory.NewStore(), literal.DefaultBuilder()),
-	run.New(memory.NewStore()),
-	version.New(),
+// Registers the available drivers.
+func registerDrivers() {
+	registeredDrivers = map[string]common.StoreGenerator{
+		// Memory only storage driver.
+		"VOLATILE": func() (storage.Store, error) {
+			return memory.NewStore(), nil
+		},
+	}
 }
 
 func main() {
-	ctx, args := context.Background(), os.Args
-	os.Exit(common.Eval(ctx, args, cmds))
+	flag.Parse()
+	registerDrivers()
+	common.Run(*driver, registeredDrivers, *bqlChannelSize)
 }

tools/vcli/bw/run/run.go

@@ -29,48 +29,39 @@ import (
 	"github.com/google/badwolf/bql/table"
 	"github.com/google/badwolf/storage"
 	"github.com/google/badwolf/tools/vcli/bw/command"
-	"github.com/google/badwolf/tools/vcli/bw/common"
+	"github.com/google/badwolf/tools/vcli/bw/io"
 )
 
 // New creates the help command.
-func New(store storage.Store) *command.Command {
+func New(store storage.Store, chanSize int) *command.Command {
 	cmd := &command.Command{
-		UsageLine: "run [--channel_size=123] file_path",
+		UsageLine: "run file_path",
 		Short:     "runs BQL statements.",
 		Long: `Runs all the commands listed in the provided file. Lines in the
 the file starting with # will be ignored. All statements will be run
 sequentially.
 `,
 	}
 	cmd.Run = func(ctx context.Context, args []string) int {
-		return runCommand(ctx, cmd, args, store)
+		return runCommand(ctx, cmd, args, store, chanSize)
 	}
 	return cmd
 }
 
 // runCommand runs all the BQL statements available in the file.
-func runCommand(ctx context.Context, cmd *command.Command, args []string, store storage.Store) int {
+func runCommand(ctx context.Context, cmd *command.Command, args []string, store storage.Store, chanSize int) int {
 	if len(args) < 3 {
 		fmt.Fprintf(os.Stderr, "Missing required file path. ")
 		cmd.Usage()
 		return 2
 	}
-	chanSize := 0
-	if len(args) >= 4 {
-		c, err := common.ParseChannelSizeFlag(args[2])
-		if err != nil {
-			fmt.Fprintf(os.Stderr, "Fail to parse flag %s with error %v\n", args[2], err)
-			return 2
-		}
-		chanSize = c
-	}
 	file := strings.TrimSpace(args[len(args)-1])
 	lines, err := getStatementsFromFile(file)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Failed to read file %s\n\n\t%v\n\n", file, err)
 		return 2
 	}
-	fmt.Printf("Processing file %s\n\n", args[2])
+	fmt.Printf("Processing file %s\n\n", args[len(args)-1])
 	for idx, stm := range lines {
 		fmt.Printf("Processing statement (%d/%d):\n%s\n\n", idx+1, len(lines), stm)
 		tbl, err := runBQL(ctx, stm, store, chanSize)
@@ -110,7 +101,7 @@ func runBQL(ctx context.Context, bql string, s storage.Store, chanSize int) (*ta
 
 // getStatementsFromFile returns the statements found in the provided file.
 func getStatementsFromFile(path string) ([]string, error) {
-	stms, err := common.ReadLines(path)
+	stms, err := io.ReadLines(path)
 	if err != nil {
 		return nil, err
 	}