hugo/tpl/collections/apply.go

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// Copyright 2017 The Hugo Authors. 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 collections
import (
"errors"
"fmt"
"reflect"
"strings"
"github.com/gohugoio/hugo/tpl"
)
// Apply takes a map, array, or slice and returns a new slice with the function fname applied over it.
func (ns *Namespace) Apply(seq interface{}, fname string, args ...interface{}) (interface{}, error) {
if seq == nil {
return make([]interface{}, 0), nil
}
if fname == "apply" {
return nil, errors.New("can't apply myself (no turtles allowed)")
}
seqv := reflect.ValueOf(seq)
seqv, isNil := indirect(seqv)
if isNil {
return nil, errors.New("can't iterate over a nil value")
}
fnv, found := ns.lookupFunc(fname)
if !found {
return nil, errors.New("can't find function " + fname)
}
// fnv := reflect.ValueOf(fn)
switch seqv.Kind() {
case reflect.Array, reflect.Slice:
r := make([]interface{}, seqv.Len())
for i := 0; i < seqv.Len(); i++ {
vv := seqv.Index(i)
vvv, err := applyFnToThis(fnv, vv, args...)
if err != nil {
return nil, err
}
r[i] = vvv.Interface()
}
return r, nil
default:
return nil, fmt.Errorf("can't apply over %v", seq)
}
}
func applyFnToThis(fn, this reflect.Value, args ...interface{}) (reflect.Value, error) {
n := make([]reflect.Value, len(args))
for i, arg := range args {
if arg == "." {
n[i] = this
} else {
n[i] = reflect.ValueOf(arg)
}
}
num := fn.Type().NumIn()
if fn.Type().IsVariadic() {
num--
}
// TODO(bep) see #1098 - also see template_tests.go
/*if len(args) < num {
return reflect.ValueOf(nil), errors.New("Too few arguments")
} else if len(args) > num {
return reflect.ValueOf(nil), errors.New("Too many arguments")
}*/
for i := 0; i < num; i++ {
// AssignableTo reports whether xt is assignable to type targ.
if xt, targ := n[i].Type(), fn.Type().In(i); !xt.AssignableTo(targ) {
return reflect.ValueOf(nil), errors.New("called apply using " + xt.String() + " as type " + targ.String())
}
}
res := fn.Call(n)
if len(res) == 1 || res[1].IsNil() {
return res[0], nil
}
return reflect.ValueOf(nil), res[1].Interface().(error)
}
func (ns *Namespace) lookupFunc(fname string) (reflect.Value, bool) {
if !strings.ContainsRune(fname, '.') {
tpl/tplimpl: Rework template management to get rid of concurrency issues This more or less completes the simplification of the template handling code in Hugo started in v0.62. The main motivation was to fix a long lasting issue about a crash in HTML content files without front matter. But this commit also comes with a big functional improvement. As we now have moved the base template evaluation to the build stage we now use the same lookup rules for `baseof` as for `list` etc. type of templates. This means that in this simple example you can have a `baseof` template for the `blog` section without having to duplicate the others: ``` layouts ├── _default │   ├── baseof.html │   ├── list.html │   └── single.html └── blog └── baseof.html ``` Also, when simplifying code, you often get rid of some double work, as shown in the "site building" benchmarks below. These benchmarks looks suspiciously good, but I have repeated the below with ca. the same result. Compared to master: ``` name old time/op new time/op delta SiteNew/Bundle_with_image-16 13.1ms ± 1% 10.5ms ± 1% -19.34% (p=0.029 n=4+4) SiteNew/Bundle_with_JSON_file-16 13.0ms ± 0% 10.7ms ± 1% -18.05% (p=0.029 n=4+4) SiteNew/Tags_and_categories-16 46.4ms ± 2% 43.1ms ± 1% -7.15% (p=0.029 n=4+4) SiteNew/Canonify_URLs-16 52.2ms ± 2% 47.8ms ± 1% -8.30% (p=0.029 n=4+4) SiteNew/Deep_content_tree-16 77.9ms ± 1% 70.9ms ± 1% -9.01% (p=0.029 n=4+4) SiteNew/Many_HTML_templates-16 43.0ms ± 0% 37.2ms ± 1% -13.54% (p=0.029 n=4+4) SiteNew/Page_collections-16 58.2ms ± 1% 52.4ms ± 1% -9.95% (p=0.029 n=4+4) name old alloc/op new alloc/op delta SiteNew/Bundle_with_image-16 3.81MB ± 0% 2.22MB ± 0% -41.70% (p=0.029 n=4+4) SiteNew/Bundle_with_JSON_file-16 3.60MB ± 0% 2.01MB ± 0% -44.20% (p=0.029 n=4+4) SiteNew/Tags_and_categories-16 19.3MB ± 1% 14.1MB ± 0% -26.91% (p=0.029 n=4+4) SiteNew/Canonify_URLs-16 70.7MB ± 0% 69.0MB ± 0% -2.40% (p=0.029 n=4+4) SiteNew/Deep_content_tree-16 37.1MB ± 0% 31.2MB ± 0% -15.94% (p=0.029 n=4+4) SiteNew/Many_HTML_templates-16 17.6MB ± 0% 10.6MB ± 0% -39.92% (p=0.029 n=4+4) SiteNew/Page_collections-16 25.9MB ± 0% 21.2MB ± 0% -17.99% (p=0.029 n=4+4) name old allocs/op new allocs/op delta SiteNew/Bundle_with_image-16 52.3k ± 0% 26.1k ± 0% -50.18% (p=0.029 n=4+4) SiteNew/Bundle_with_JSON_file-16 52.3k ± 0% 26.1k ± 0% -50.16% (p=0.029 n=4+4) SiteNew/Tags_and_categories-16 336k ± 1% 269k ± 0% -19.90% (p=0.029 n=4+4) SiteNew/Canonify_URLs-16 422k ± 0% 395k ± 0% -6.43% (p=0.029 n=4+4) SiteNew/Deep_content_tree-16 401k ± 0% 313k ± 0% -21.79% (p=0.029 n=4+4) SiteNew/Many_HTML_templates-16 247k ± 0% 143k ± 0% -42.17% (p=0.029 n=4+4) SiteNew/Page_collections-16 282k ± 0% 207k ± 0% -26.55% (p=0.029 n=4+4) ``` Fixes #6716 Fixes #6760 Fixes #6768 Fixes #6778
2020-01-15 14:59:56 +00:00
templ := ns.deps.Tmpl().(tpl.TemplateFuncGetter)
return templ.GetFunc(fname)
}
ss := strings.SplitN(fname, ".", 2)
// namespace
nv, found := ns.lookupFunc(ss[0])
if !found {
return reflect.Value{}, false
}
// method
m := nv.MethodByName(ss[1])
// if reflect.DeepEqual(m, reflect.Value{}) {
if m.Kind() == reflect.Invalid {
return reflect.Value{}, false
}
return m, true
}
// indirect is borrowed from the Go stdlib: 'text/template/exec.go'
func indirect(v reflect.Value) (rv reflect.Value, isNil bool) {
for ; v.Kind() == reflect.Ptr || v.Kind() == reflect.Interface; v = v.Elem() {
if v.IsNil() {
return v, true
}
if v.Kind() == reflect.Interface && v.NumMethod() > 0 {
break
}
}
return v, false
}
func indirectInterface(v reflect.Value) (rv reflect.Value, isNil bool) {
for ; v.Kind() == reflect.Interface; v = v.Elem() {
if v.IsNil() {
return v, true
}
if v.Kind() == reflect.Interface && v.NumMethod() > 0 {
break
}
}
return v, false
}