58 lines
1.3 KiB
Go
58 lines
1.3 KiB
Go
|
package timeline
|
||
|
|
|
||
|
|
import (
|
||
|
|
"container/list"
|
||
|
|
"errors"
|
||
|
|
)
|
||
|
|
|
||
|
|
type postIndex struct {
|
||
|
|
data *list.List
|
||
|
|
}
|
||
|
|
|
||
|
|
type postIndexEntry struct {
|
||
|
|
statusID string
|
||
|
|
}
|
||
|
|
|
||
|
|
func (p *postIndex) insertIndexed(i *postIndexEntry) error {
|
||
|
|
if p.data == nil {
|
||
|
|
p.data = &list.List{}
|
||
|
|
}
|
||
|
|
|
||
|
|
// if we have no entries yet, this is both the newest and oldest entry, so just put it in the front
|
||
|
|
if p.data.Len() == 0 {
|
||
|
|
p.data.PushFront(i)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
var insertMark *list.Element
|
||
|
|
// We need to iterate through the index to make sure we put this post in the appropriate place according to when it was created.
|
||
|
|
// We also need to make sure we're not inserting a duplicate post -- this can happen sometimes and it's not nice UX (*shudder*).
|
||
|
|
for e := p.data.Front(); e != nil; e = e.Next() {
|
||
|
|
entry, ok := e.Value.(*postIndexEntry)
|
||
|
|
if !ok {
|
||
|
|
return errors.New("index: could not parse e as a postIndexEntry")
|
||
|
|
}
|
||
|
|
|
||
|
|
// if the post to index is newer than e, insert it before e in the list
|
||
|
|
if insertMark == nil {
|
||
|
|
if i.statusID > entry.statusID {
|
||
|
|
insertMark = e
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// make sure we don't insert a duplicate
|
||
|
|
if entry.statusID == i.statusID {
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if insertMark != nil {
|
||
|
|
p.data.InsertBefore(i, insertMark)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// if we reach this point it's the oldest post we've seen so put it at the back
|
||
|
|
p.data.PushBack(i)
|
||
|
|
return nil
|
||
|
|
}
|