Remove reflection on CLI init

before:
```
$ time docker --help
real  0m0.177s
user  0m0.000s
sys 0m0.040s
```

after:
```
$ time docker --help
real  0m0.010s
user  0m0.000s
sys 0m0.000s
```

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This commit is contained in:
Brian Goff 2016-04-29 11:16:34 -04:00
parent 0c4f21fee3
commit 89d78abcdc
1 changed files with 14 additions and 15 deletions

29
cli.go
View File

@ -5,7 +5,6 @@ import (
"fmt" "fmt"
"io" "io"
"os" "os"
"reflect"
"strings" "strings"
flag "github.com/docker/docker/pkg/mflag" flag "github.com/docker/docker/pkg/mflag"
@ -21,7 +20,9 @@ type Cli struct {
// Handler holds the different commands Cli will call // Handler holds the different commands Cli will call
// It should have methods with names starting with `Cmd` like: // It should have methods with names starting with `Cmd` like:
// func (h myHandler) CmdFoo(args ...string) error // func (h myHandler) CmdFoo(args ...string) error
type Handler interface{} type Handler interface {
Command(name string) func(...string) error
}
// Initializer can be optionally implemented by a Handler to // Initializer can be optionally implemented by a Handler to
// initialize before each call to one of its commands. // initialize before each call to one of its commands.
@ -50,22 +51,13 @@ func (cli *Cli) command(args ...string) (func(...string) error, error) {
if c == nil { if c == nil {
continue continue
} }
camelArgs := make([]string, len(args)) if cmd := c.Command(strings.Join(args, " ")); cmd != nil {
for i, s := range args { if ci, ok := c.(Initializer); ok {
if len(s) == 0 { if err := ci.Initialize(); err != nil {
return nil, errors.New("empty command")
}
camelArgs[i] = strings.ToUpper(s[:1]) + strings.ToLower(s[1:])
}
methodName := "Cmd" + strings.Join(camelArgs, "")
method := reflect.ValueOf(c).MethodByName(methodName)
if method.IsValid() {
if c, ok := c.(Initializer); ok {
if err := c.Initialize(); err != nil {
return nil, initErr{err} return nil, initErr{err}
} }
} }
return method.Interface().(func(...string) error), nil return cmd, nil
} }
} }
return nil, errors.New("command not found") return nil, errors.New("command not found")
@ -103,6 +95,13 @@ func (cli *Cli) noSuchCommand(command string) {
os.Exit(1) os.Exit(1)
} }
// Command returns a command handler, or nil if the command does not exist
func (cli *Cli) Command(name string) func(...string) error {
return map[string]func(...string) error{
"help": cli.CmdHelp,
}[name]
}
// CmdHelp displays information on a Docker command. // CmdHelp displays information on a Docker command.
// //
// If more than one command is specified, information is only shown for the first command. // If more than one command is specified, information is only shown for the first command.