From c5face0b6f922781f1d2ae754c00fdee6c58af20 Mon Sep 17 00:00:00 2001
From: Koni Marti <koni.marti@gmail.com>
Date: Thu, 20 Oct 2022 16:43:41 +0200
Subject: store: reverse message list order with iterators

Reverse the order of the messages in the message list. The complexity of
reversing the order is abstracted away by the iterators. To reverse the
message list, add the following to your aerc.conf:

[ui]
reverse-msglist-order=true

Thanks to |cos| for sharing his initial implementation of reversing the
order in the message list [0].

[0]: https://git.netizen.se/aerc/commit/?h=topic/asc_sort_imap

Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>
---
 lib/threadbuilder.go | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

(limited to 'lib/threadbuilder.go')

diff --git a/lib/threadbuilder.go b/lib/threadbuilder.go
index 6cd98e87..75a80797 100644
--- a/lib/threadbuilder.go
+++ b/lib/threadbuilder.go
@@ -4,6 +4,7 @@ import (
 	"sync"
 	"time"
 
+	"git.sr.ht/~rjarry/aerc/lib/iterator"
 	"git.sr.ht/~rjarry/aerc/logging"
 	"git.sr.ht/~rjarry/aerc/models"
 	"git.sr.ht/~rjarry/aerc/worker/types"
@@ -16,13 +17,15 @@ type ThreadBuilder struct {
 	messageidToUid map[string]uint32
 	seen           map[uint32]bool
 	threadedUids   []uint32
+	iterFactory    iterator.Factory
 }
 
-func NewThreadBuilder() *ThreadBuilder {
+func NewThreadBuilder(i iterator.Factory) *ThreadBuilder {
 	tb := &ThreadBuilder{
 		threadBlocks:   make(map[uint32]jwz.Threadable),
 		messageidToUid: make(map[string]uint32),
 		seen:           make(map[uint32]bool),
+		iterFactory:    i,
 	}
 	return tb
 }
@@ -154,17 +157,20 @@ func (builder *ThreadBuilder) sortThreads(threads []*types.Thread, orderedUids [
 // RebuildUids rebuilds the uids from the given slice of threads
 func (builder *ThreadBuilder) RebuildUids(threads []*types.Thread) {
 	uids := make([]uint32, 0, len(threads))
-	for i := len(threads) - 1; i >= 0; i-- {
-		_ = threads[i].Walk(func(t *types.Thread, level int, currentErr error) error {
-			uids = append(uids, t.Uid)
-			return nil
-		})
+	iterT := builder.iterFactory.NewIterator(threads)
+	for iterT.Next() {
+		_ = iterT.Value().(*types.Thread).Walk(
+			func(t *types.Thread, level int, currentErr error) error {
+				uids = append(uids, t.Uid)
+				return nil
+			})
 	}
-	// copy in reverse as msgList displays backwards
-	for i, j := 0, len(uids)-1; i < j; i, j = i+1, j-1 {
-		uids[i], uids[j] = uids[j], uids[i]
+	result := make([]uint32, 0, len(uids))
+	iterU := builder.iterFactory.NewIterator(uids)
+	for iterU.Next() {
+		result = append(result, iterU.Value().(uint32))
 	}
-	builder.threadedUids = uids
+	builder.threadedUids = result
 }
 
 // threadable implements the jwz.threadable interface which is required for the
-- 
cgit