From a275f65848f2c1fdd4302f56121defc408e7d8b6 Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Sun, 28 Apr 2019 13:26:38 +0000
Subject: lib/msgstore: protect with a mutex

MessageStore has a lot of exported fields that can be read from the outside.
Each read must be protected, because a call from Update could happen at any
time.
---
 lib/msgstore.go | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

(limited to 'lib')

diff --git a/lib/msgstore.go b/lib/msgstore.go
index 9d537fc..b39d0bb 100644
--- a/lib/msgstore.go
+++ b/lib/msgstore.go
@@ -2,6 +2,7 @@ package lib
 
 import (
 	"io"
+	"sync"
 	"time"
 
 	"github.com/emersion/go-imap"
@@ -9,7 +10,10 @@ import (
 	"git.sr.ht/~sircmpwn/aerc2/worker/types"
 )
 
+// Accesses to fields must be guarded by MessageStore.Lock/Unlock
 type MessageStore struct {
+	sync.Mutex
+
 	Deleted  map[uint32]interface{}
 	DirInfo  types.DirectoryInfo
 	Messages map[uint32]*types.MessageInfo
@@ -45,6 +49,9 @@ func NewMessageStore(worker *types.Worker,
 func (store *MessageStore) FetchHeaders(uids []uint32,
 	cb func(*types.MessageInfo)) {
 
+	store.Lock()
+	defer store.Unlock()
+
 	// TODO: this could be optimized by pre-allocating toFetch and trimming it
 	// at the end. In practice we expect to get most messages back in one frame.
 	var toFetch imap.SeqSet
@@ -67,6 +74,9 @@ func (store *MessageStore) FetchHeaders(uids []uint32,
 }
 
 func (store *MessageStore) FetchFull(uids []uint32, cb func(io.Reader)) {
+	store.Lock()
+	defer store.Unlock()
+
 	// TODO: this could be optimized by pre-allocating toFetch and trimming it
 	// at the end. In practice we expect to get most messages back in one frame.
 	var toFetch imap.SeqSet
@@ -103,8 +113,7 @@ func (store *MessageStore) FetchBodyPart(
 	})
 }
 
-func (store *MessageStore) merge(
-	to *types.MessageInfo, from *types.MessageInfo) {
+func merge(to *types.MessageInfo, from *types.MessageInfo) {
 
 	if from.BodyStructure != nil {
 		to.BodyStructure = from.BodyStructure
@@ -125,6 +134,8 @@ func (store *MessageStore) merge(
 }
 
 func (store *MessageStore) Update(msg types.WorkerMessage) {
+	store.Lock()
+
 	update := false
 	switch msg := msg.(type) {
 	case *types.DirectoryInfo:
@@ -144,7 +155,7 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		update = true
 	case *types.MessageInfo:
 		if existing, ok := store.Messages[msg.Uid]; ok && existing != nil {
-			store.merge(existing, msg)
+			merge(existing, msg)
 		} else {
 			store.Messages[msg.Uid] = msg
 		}
@@ -186,6 +197,9 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		store.Uids = uids
 		update = true
 	}
+
+	store.Unlock()
+
 	if update {
 		store.update()
 	}
@@ -202,11 +216,16 @@ func (store *MessageStore) update() {
 }
 
 func (store *MessageStore) Delete(uids []uint32) {
+	store.Lock()
+
 	var set imap.SeqSet
 	for _, uid := range uids {
 		set.AddNum(uid)
 		store.Deleted[uid] = nil
 	}
+
+	store.Unlock()
+
 	store.worker.PostAction(&types.DeleteMessages{Uids: set}, nil)
 	store.update()
 }
-- 
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