hugo/hugolib/pageSort.go
2016-04-22 20:43:18 +02:00

214 lines
5.4 KiB
Go

// Copyright 2015 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 hugolib
import (
"sort"
)
var spc = newPageCache()
/*
* Implementation of a custom sorter for Pages
*/
// A pageSorter implements the sort interface for Pages
type pageSorter struct {
pages Pages
by pageBy
}
// pageBy is a closure used in the Sort.Less method.
type pageBy func(p1, p2 *Page) bool
// Sort stable sorts the pages given the receiver's sort order.
func (by pageBy) Sort(pages Pages) {
ps := &pageSorter{
pages: pages,
by: by, // The Sort method's receiver is the function (closure) that defines the sort order.
}
sort.Stable(ps)
}
// defaultPageSort is the default sort for pages in Hugo:
// Order by Weight, Date, LinkTitle and then full file path.
var defaultPageSort = func(p1, p2 *Page) bool {
if p1.Weight == p2.Weight {
if p1.Date.Unix() == p2.Date.Unix() {
if p1.LinkTitle() == p2.LinkTitle() {
return (p1.FullFilePath() < p2.FullFilePath())
}
return (p1.LinkTitle() < p2.LinkTitle())
}
return p1.Date.Unix() > p2.Date.Unix()
}
return p1.Weight < p2.Weight
}
func (ps *pageSorter) Len() int { return len(ps.pages) }
func (ps *pageSorter) Swap(i, j int) { ps.pages[i], ps.pages[j] = ps.pages[j], ps.pages[i] }
// Less is part of sort.Interface. It is implemented by calling the "by" closure in the sorter.
func (ps *pageSorter) Less(i, j int) bool { return ps.by(ps.pages[i], ps.pages[j]) }
// Sort sorts the pages by the default sort order defined:
// Order by Weight, Date, LinkTitle and then full file path.
func (p Pages) Sort() {
pageBy(defaultPageSort).Sort(p)
}
// Limit limits the number of pages returned to n.
func (p Pages) Limit(n int) Pages {
if len(p) > n {
return p[0:n]
}
return p
}
// ByWeight sorts the Pages by weight and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByWeight() Pages {
key := "pageSort.ByWeight"
pages, _ := spc.get(key, p, pageBy(defaultPageSort).Sort)
return pages
}
// ByTitle sorts the Pages by title and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByTitle() Pages {
key := "pageSort.ByTitle"
title := func(p1, p2 *Page) bool {
return p1.Title < p2.Title
}
pages, _ := spc.get(key, p, pageBy(title).Sort)
return pages
}
// ByLinkTitle sorts the Pages by link title and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByLinkTitle() Pages {
key := "pageSort.ByLinkTitle"
linkTitle := func(p1, p2 *Page) bool {
return p1.linkTitle < p2.linkTitle
}
pages, _ := spc.get(key, p, pageBy(linkTitle).Sort)
return pages
}
// ByDate sorts the Pages by date and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByDate() Pages {
key := "pageSort.ByDate"
date := func(p1, p2 *Page) bool {
return p1.Date.Unix() < p2.Date.Unix()
}
pages, _ := spc.get(key, p, pageBy(date).Sort)
return pages
}
// ByPublishDate sorts the Pages by publish date and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByPublishDate() Pages {
key := "pageSort.ByPublishDate"
pubDate := func(p1, p2 *Page) bool {
return p1.PublishDate.Unix() < p2.PublishDate.Unix()
}
pages, _ := spc.get(key, p, pageBy(pubDate).Sort)
return pages
}
// ByLastmod sorts the Pages by the last modification date and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByLastmod() Pages {
key := "pageSort.ByLastmod"
date := func(p1, p2 *Page) bool {
return p1.Lastmod.Unix() < p2.Lastmod.Unix()
}
pages, _ := spc.get(key, p, pageBy(date).Sort)
return pages
}
// ByLength sorts the Pages by length and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) ByLength() Pages {
key := "pageSort.ByLength"
length := func(p1, p2 *Page) bool {
return len(p1.Content) < len(p2.Content)
}
pages, _ := spc.get(key, p, pageBy(length).Sort)
return pages
}
// Reverse reverses the order in Pages and returns a copy.
//
// Adjacent invocactions on the same receiver will return a cached result.
//
// This may safely be executed in parallel.
func (p Pages) Reverse() Pages {
key := "pageSort.Reverse"
reverseFunc := func(pages Pages) {
for i, j := 0, len(pages)-1; i < j; i, j = i+1, j-1 {
pages[i], pages[j] = pages[j], pages[i]
}
}
pages, _ := spc.get(key, p, reverseFunc)
return pages
}