mirror of
https://github.com/golang/go
synced 2024-09-25 13:20:13 -06:00
internal/lazytemplate: add a lazy template wrapper
Similar to internal/lazyregexp, this will allow removing unnecessary work from init functions with trivial refactors, thanks to sync.Once. Copy the structure. The only major difference is that a template also carries a name. For #29382. Change-Id: I65d096dc2e2072b310bf59a814cd62669856b5b5 Reviewed-on: https://go-review.googlesource.com/c/164337 Run-TryBot: Daniel Martí <mvdan@mvdan.cc> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This commit is contained in:
parent
8e8abf368d
commit
bd23e84b73
@ -194,11 +194,12 @@ var pkgDeps = map[string][]string{
|
||||
"runtime/trace": {"L0", "context", "fmt"},
|
||||
"text/tabwriter": {"L2"},
|
||||
|
||||
"testing": {"L2", "flag", "fmt", "internal/race", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
|
||||
"testing/iotest": {"L2", "log"},
|
||||
"testing/quick": {"L2", "flag", "fmt", "reflect", "time"},
|
||||
"internal/testenv": {"L2", "OS", "flag", "testing", "syscall"},
|
||||
"internal/lazyregexp": {"L2", "OS", "regexp"},
|
||||
"testing": {"L2", "flag", "fmt", "internal/race", "os", "runtime/debug", "runtime/pprof", "runtime/trace", "time"},
|
||||
"testing/iotest": {"L2", "log"},
|
||||
"testing/quick": {"L2", "flag", "fmt", "reflect", "time"},
|
||||
"internal/testenv": {"L2", "OS", "flag", "testing", "syscall"},
|
||||
"internal/lazyregexp": {"L2", "OS", "regexp"},
|
||||
"internal/lazytemplate": {"L2", "OS", "text/template"},
|
||||
|
||||
// L4 is defined as L3+fmt+log+time, because in general once
|
||||
// you're using L3 packages, use of fmt, log, or time is not a big deal.
|
||||
|
@ -2,6 +2,8 @@
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// Package lazyregexp is a thin wrapper over regexp, allowing the use of global
|
||||
// regexp variables without forcing them to be compiled at init.
|
||||
package lazyregexp
|
||||
|
||||
import (
|
||||
@ -11,6 +13,8 @@ import (
|
||||
"sync"
|
||||
)
|
||||
|
||||
// Regexp is a wrapper around regexp.Regexp, where the underlying regexp will be
|
||||
// compiled the first time it is needed.
|
||||
type Regexp struct {
|
||||
str string
|
||||
once sync.Once
|
||||
@ -61,6 +65,9 @@ func (r *Regexp) SubexpNames() []string {
|
||||
|
||||
var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test")
|
||||
|
||||
// New creates a new lazy regexp, delaying the compiling work until it is first
|
||||
// needed. If the code is being run as part of tests, the regexp compiling will
|
||||
// happen immediately.
|
||||
func New(str string) *Regexp {
|
||||
lr := &Regexp{str: str}
|
||||
if inTest {
|
||||
|
52
src/internal/lazytemplate/lazytemplate.go
Normal file
52
src/internal/lazytemplate/lazytemplate.go
Normal file
@ -0,0 +1,52 @@
|
||||
// Copyright 2019 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// Package lazytemplate is a thin wrapper over text/template, allowing the use
|
||||
// of global template variables without forcing them to be parsed at init.
|
||||
package lazytemplate
|
||||
|
||||
import (
|
||||
"io"
|
||||
"os"
|
||||
"strings"
|
||||
"sync"
|
||||
"text/template"
|
||||
)
|
||||
|
||||
// Template is a wrapper around text/template.Template, where the underlying
|
||||
// template will be parsed the first time it is needed.
|
||||
type Template struct {
|
||||
name, text string
|
||||
|
||||
once sync.Once
|
||||
tmpl *template.Template
|
||||
}
|
||||
|
||||
func (r *Template) tp() *template.Template {
|
||||
r.once.Do(r.build)
|
||||
return r.tmpl
|
||||
}
|
||||
|
||||
func (r *Template) build() {
|
||||
r.tmpl = template.Must(template.New(r.name).Parse(r.text))
|
||||
r.name, r.text = "", ""
|
||||
}
|
||||
|
||||
func (r *Template) Execute(w io.Writer, data interface{}) error {
|
||||
return r.tp().Execute(w, data)
|
||||
}
|
||||
|
||||
var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test")
|
||||
|
||||
// New creates a new lazy template, delaying the parsing work until it is first
|
||||
// needed. If the code is being run as part of tests, the template parsing will
|
||||
// happen immediately.
|
||||
func New(name, text string) *Template {
|
||||
lt := &Template{name: name, text: text}
|
||||
if inTest {
|
||||
// In tests, always parse the templates early.
|
||||
lt.tp()
|
||||
}
|
||||
return lt
|
||||
}
|
Loading…
Reference in New Issue
Block a user