已读未读的原理

hechengjin

1. 
   
2. 已读：
   
3. //////////////界面点选中邮件，自动标志为已读的流程///////////////
   
4. 
   
5. messenger.xul
   
6. onselect="ThreadPaneSelectionChanged();"
   
7. function ThreadPaneSelectionChanged()
   
8. {
   
9.   GetThreadTree().view.selectionChanged();
   
10. }
    
11. 
    
12. .\mailnews\base\src\nsMsgDBView.cpp
    
13. NS_IMETHODIMP nsMsgDBView::SelectionChanged()
    
14. {
    
15. ????
    
16. }
    
17. 
    
18. nsImapMailFolder::MarkMessagesRead(nsIArray *messages, bool markRead)
    
19. {
    
20.         StoreImapFlags(kImapMsgSeenFlag, markRead, keysToMarkRead.Elements(), keysToMarkRead.Length(), nullptr);
    
21. }
    
22. nsImapMailFolder::StoreImapFlags(int32_t flags, bool addFlags,
    
23. {
    
24. imapService->AddMessageFlags(this, aUrlListener ? aUrlListener : this,
    
25.                                    nullptr, msgIds, flags, true);
    
26. }
    
27. nsImapService::AddMessageFlags(nsIMsgFolder *aImapMailFolder,
    
28. {
    
29.          return DiddleFlags(aImapMailFolder, aUrlListener, aURL, messageIdentifierList,
    
30.                      "addmsgflags", flags, messageIdsAreUID);
    
31. }
    
32. 
    
33. nsImapService::DiddleFlags(nsIMsgFolder *aImapMailFolder,
    
34. {
    
35.         nsresult rv = CreateStartOfImapUrl(EmptyCString(), getter_AddRefs(imapUrl),
    
36.         rv = uri->SetSpec(urlSpec);
    
37. }
    
38. nsImapUrl::SetSpec(const nsACString &aSpec)
    
39. {
    
40.         rv = ParseUrl();
    
41. }
    
42. nsresult nsImapUrl::ParseUrl()
    
43. {
    
44.         ParseImapPart(unescapedImapPartOfUrl.BeginWriting()+1);
    
45. }
    
46. 
    
47. ??????????
    
48. 
    
49. 
    
50. 
    
51. 
    
52. nsImapProtocol::Run()
    
53. nsImapProtocol::ImapThreadMainLoop()
    
54. nsImapProtocol::ProcessCurrentURL()
    
55. nsImapProtocol::ProcessSelectedStateURL()
    
56. nsImapProtocol::ProcessStoreFlags(...)
    
57. {
    
58.         if (flags & kImapMsgSeenFlag && kImapMsgSeenFlag & settableFlags)
    
59.       flagString .Append("\\Seen ");
    
60. }
    
61. nsImapProtocol::Store(const nsCString &messageList, const char * messageData,
    
62. {
    
63.         12 uid store 28 +Flags (\Seen)
    
64. }
    
65. ---------------------------------
    
66. >        xul.dll!nsMsgDBView::OnHdrFlagsChanged(nsIMsgDBHdr * aHdrChanged, unsigned int aOldFlags, unsigned int aNewFlags, nsIDBChangeListener * aInstigator) Line 5950        C++
    
67.          xul.dll!nsMsgGroupView::OnHdrFlagsChanged(nsIMsgDBHdr * aHdrChanged, unsigned int aOldFlags, unsigned int aNewFlags, nsIDBChangeListener * aInstigator) Line 614        C++
    
68.          xul.dll!nsMsgDatabase::NotifyHdrChangeAll(nsIMsgDBHdr * aHdrChanged, unsigned int aOldFlags, unsigned int aNewFlags, nsIDBChangeListener * aInstigator) Line 837        C++
    
69.          xul.dll!nsMsgDatabase::MarkHdrReadInDB(nsIMsgDBHdr * msgHdr, bool bRead, nsIDBChangeListener * instigator) Line 2134        C++
    
70.          xul.dll!nsMsgDatabase::MarkHdrRead(nsIMsgDBHdr * msgHdr, bool bRead, nsIDBChangeListener * instigator) Line 2574        C++
    
71.          xul.dll!nsMsgDatabase::MarkRead(unsigned int key, bool bRead, nsIDBChangeListener * instigator) Line 2148        C++
    
72.          xul.dll!nsMsgHdr::MarkRead(bool bRead) Line 228        C++
    
73.          xul.dll!nsMsgDBFolder::MarkMessagesRead(nsIArray * messages, bool markRead) Line 4685        C++
    
74.          xul.dll!nsImapMailFolder::MarkMessagesRead(nsIArray * messages, bool markRead) Line 1885        C++
    
75. 
    
76. 
    
77. /////////////////////未读/////////////////
    
78. ///web标志为未读后，客户端的更新流程
    
79. 
    
80. nsIDBChangeListener.idl
    
81. nsMsgDBView::OnHdrFlagsChanged(nsIMsgDBHdr *aHdrChanged, uint32_t aOldFlags,  //数据库变化通知界面
    
82. {
    
83. 
    
84. }
    
85. 
    
86. nsImapMailFolder::SyncFlags(nsIImapFlagAndUidState *flagState)  //分析网络返回设置邮件标志
    
87. {
    
88.         flagState->GetNumberOfMessages(&messageIndex); //获取返回的邮件数量
    
89.         for (int32_t flagIndex = 0; flagIndex < messageIndex; flagIndex++) //对每一个邮件分别进行设置
    
90.   {
    
91.                 flagState->GetUidOfMessage(flagIndex, &uidOfMessage); //获取消息的UID
    
92.                 flagState->GetMessageFlags(flagIndex, &flags); //获取此消息的标志
    
93.                
    
94.         }
    
95. }
    
96. 
    
97. nsImapMailFolder::UpdateImapMailboxInfo(nsIImapProtocol* aProtocol, nsIMailboxSpec* aSpec)
    
98. {
    
99.         nsCOMPtr <nsIImapFlagAndUidState> flagState;
    
100.   aSpec->GetFlagState(getter_AddRefs(flagState));
     
101. }
     
102. 
     
103. nsImapProtocol.cpp
     
104. m_parser.SetFlagState(m_flagState);
     
105. 
     
106. nsImapServerResponseParser.cpp
     
107. void nsImapServerResponseParser::SetFlagState(nsIImapFlagAndUidState *state)
     
108. {
     
109.         fFlagState = state;
     
110. }
     
111. 
     
112. 
     
113. /nsImapFlagAndUidState.cpp
     
114. nsImapFlagAndUidState::AddUidFlagPair(uint32_t uid, imapMessageFlagsType flags, uint32_t zeroBasedIndex)
     
115. {
     
116. }
     
117. 
     
118. 
     
119. DONE
     
120. 
     
121. 15 OK IDLE completed
     
122. 
     
123. 16 uid store 30 +Flags (\Seen)
     
124. 
     
125. 16 OK UID STORE completed
     
126. 
     
127. 17 IDLE
     
128. 
     
129. + Waiting for DONE
     
130. 
     
131. DONE
     
132. 
     
133. 17 OK IDLE completed
     
134. 
     
135. 18 noop
     
136. 
     
137. 18 OK NOOP completed
     
138. 
     
139. 19 UID fetch 32:* (FLAGS)
     
140. 
     
141. * 14 FETCH (UID 31 FLAGS (\Seen))
     
142. 
     
143. 19 OK UID FETCH completed
     
144. 
     
145. 20 IDLE
     
146. 
     
147. + Waiting for DONE
     

复制代码

hechengjin

1.   mailnews/imap/src/nsimapProtocol.cpp
   
2. AppendUid(fetchStr, 1);
   
3.   fetchStr.Append(":*");

复制代码

hechengjin

a unique identifier sequence range of 32:* includes the UID of the last message in the mailbox, even if that value is less than 32.
21 UID fetch 32:* (FLAGS)
* 3 FETCH (UID 31 FLAGS (\Seen))
21 OK UID FETCH completed

hechengjin

1. nsImapCore.h
   
2. #define kNoImapMsgFlag                0x0000
   
3. #define kImapMsgSeenFlag              0x0001
   
4. #define kImapMsgAnsweredFlag          0x0002
   
5. #define kImapMsgFlaggedFlag           0x0004
   
6. #define kImapMsgDeletedFlag           0x0008
   
7. #define kImapMsgDraftFlag             0x0010
   
8. #define kImapMsgRecentFlag            0x0020
   
9. #define        kImapMsgForwardedFlag         0x0040                /* Not always supported, check mailbox folder */
   
10. #define kImapMsgMDNSentFlag           0x0080                /* Not always supported. check mailbox folder */
    
11. #define kImapMsgCustomKeywordFlag     0x0100            /* this msg has a custom keyword */
    
12. #define kImapMsgLabelFlags            0x0E00            /* supports 5 labels only supported if the folder supports keywords */
    
13. #define kImapMsgSupportMDNSentFlag    0x2000
    
14. #define kImapMsgSupportForwardedFlag  0x4000

复制代码

hechengjin

两个情况，一个是服务端真的返回状态不正确，另一个是程序没有全量更新到对应的状态
第一种情况:
新收到的邮件的UID:  102846
在客户端设置为已读后，观察web端，也已经转为已读取状态，但发送下列命令却返回的没有已读标志

对应发送的命令：26 UID fetch 102847:* (FLAGS)    ----发送值也不方便简单的进行减1，因为一次新邮件数可能很多
对应返回的内容：* 325 FETCH (UID 102846 FLAGS ())   ---返回的标志中没有已读取标志 正常为 * 325 FETCH (UID 102846 FLAGS (\Seen))   


验证：发送 UID fetch 最大UID+1:* (FLAGS)   ----代表只获取新邮件的状态？   only new messages please



总结：服务端的返回有问题，本来已经标志为已读了，可后来同步后又说没读，造成客户端状态改变。


32 uid store 103097 +Flags (\Seen)

* 341 FETCH (FLAGS (\Seen) UID 103097)


正常未读
15 UID fetch 102888:* (FLAGS)
* 329 FETCH (UID 102923 FLAGS ())   ---------不能简单的根据标志是否有进行判断，这样会一直循环下去。


9 UID fetch 1:* (FLAGS)
* 1 FETCH (UID 100002 FLAGS (\Seen))
...
* 332 FETCH (UID 103024 FLAGS ())

C93 UID FETCH 1445233981 (UID FLAGS)
* 9 FETCH (UID 1445233981 FLAGS ())

针对第2种情况的修改方案：

发送store命令为什么没有更新本地缓存中的已读取标志? 或返回成功状态后，本地状态为什么没有变化？
问题原因：
最初始发送一条指令获取所有邮件状态，1:*，这里有一条未读记录为29，
本地将29标志为已读后 uid store 29 +Flags (\Seen)，本地变成已经读取？？？ ---执行了什么？为什么本地没有更新为已读状态？？
下次再获取邮件状态时，则会从32:*获取，里面返回没有29，29却又变成原来的读取状态

跟踪标志变更过程  uid store 29 +Flags (\Seen)
nsImapProtocol::Store(const nsCString &messageList, const char * messageData,
{
  nsresult rv = SendData(protocolString); //protocolString = "9 uid store 31 +Flags (\\Seen)\r\n"
  m_flagChangeCount++;
  ParseIMAPandCheckForNewMail(protocolString);
  if (GetServerStateParser().LastCommandSuccessful() && CheckNeeded())
    Check();
}


nsTArray<nsMsgKey>      fUids;
nsTArray<imapMessageFlagsType> fFlags;
-------------------
修改方案1：
修改标志为已读的变更时，把本地缓存的邮件也保存为未读
但由于原有流程判断是不是进行全量更新的逻辑影响，即如何web又设置了未读，而客户端却只同步最新的一封的状态，造成其它未读状态无法获取到，
因此状又会和远程不一致。所以采用方案2
修改方案2：
修改是否进行全量同步的逻辑(即是否发命令 1:* ),如果本地做过标注，则进行全量同步。(弊端：点一下邮件都会发送标志为已读取的状态变化)



方案1相关代码
mailnews\imap\src\nsImapFlagAndUidState.cpp

void nsImapFlagAndUidState::UpdateUIDandFlagInfo(uint32_t uid, imapMessageFlagsType Flags)
{
        PR_CEnterMonitor(this);
        int32_t ndx = (int32_t)fUids.IndexOfFirstElementGt(uid) - 1;
        bool foundIt = ndx >= 0 && fUids[ndx] == uid;
        if (foundIt)
        {
                fFlags[ndx] |= Flags;
        }
        else if (ndx < fUids.Length())
        {
                fFlags[ndx] = Flags;
        }
        PR_CExitMonitor(this);
}

mailnews\imap\src\nsImapFlagAndUidState.h

void UpdateUIDandFlagInfo(uint32_t uid, imapMessageFlagsType Flags);

mailnews\imap\src\nsImapProtocol.cpp
nsImapProtocol::Store(const nsCString &messageList, const char * messageData,
nsresult rv = SendData(protocolString);
if (NS_SUCCEEDED(rv))
{
  m_flagChangeCount++;
  ParseIMAPandCheckForNewMail(protocolString);
  int32_t msgCount = msgKeys.Length();
  PR_LOG(IMAP, PR_LOG_DEBUG, ("nsImapProtocol::Store m_flagState->UpdateUIDandFlagInfo msgCount:%d \r\n", msgCount));
  if (PL_strstr(messageData, "Seen") && PL_strstr(messageData, "+Flags"))
  {
          for (int32_t i = 0; i < msgCount; i++)
          {
                  PR_LOG(IMAP, PR_LOG_DEBUG, ("nsImapProtocol::Store m_flagState->UpdateUIDandFlagInfo uid:%d \r\n", msgKeys));
                  m_flagState->UpdateUIDandFlagInfo(msgKeys, kImapMsgSeenFlag);
          }
  }
  if (GetServerStateParser().LastCommandSuccessful() && CheckNeeded())
    Check();       
}

--------------
方案2相关代码
mailnews\imap\src\nsImapProtocol.cpp

void nsImapProtocol:rocessMailboxUpdate(bool handlePossibleUndo)
if (m_flagChangeCount > 0 )
  AppendUid(fetchStr, 1);
else
  AppendUid(fetchStr, highestRecordedUID + 1);