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| author | George Hazan <george.hazan@gmail.com> | 2012-11-28 18:45:54 +0000 |
|---|---|---|
| committer | George Hazan <george.hazan@gmail.com> | 2012-11-28 18:45:54 +0000 |
| commit | a70382b0e8bed265a1d314d9f6aae8f2dd48d20b (patch) | |
| tree | 9a99a073c0d7b9483dab51a0eebf04a9119f61ed /plugins/YAMN/docs/YAMN-Readme.developers.txt | |
| parent | 68fb5b69ea8403a3f9dcb70b3133eb10e1711000 (diff) | |
ex-protos moved to the Plugins folder
git-svn-id: http://svn.miranda-ng.org/main/trunk@2545 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
Diffstat (limited to 'plugins/YAMN/docs/YAMN-Readme.developers.txt')
| -rw-r--r-- | plugins/YAMN/docs/YAMN-Readme.developers.txt | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/plugins/YAMN/docs/YAMN-Readme.developers.txt b/plugins/YAMN/docs/YAMN-Readme.developers.txt new file mode 100644 index 0000000000..fdb338707c --- /dev/null +++ b/plugins/YAMN/docs/YAMN-Readme.developers.txt @@ -0,0 +1,205 @@ +==================================================================================
+= YAMN plugin for Miranda (short readme for developers) =
+==================================================================================
+Hello developer! :)
+I hope YAMN will give you what you find, but you can also improve YAMN.
+
+This readme gives you some info about YAMN. Please read it first before you are
+going to look at YAMN sources.
+
+YAMN provides two types of plugins now: protocol plugins and filter plugins.
+
+
+1. What do you need to make your protocol plugin cooperating with YAMN
+ -------------------------------------------------------------------
+
+ If you want to cooperate with YAMN, you have to do some things. YAMN offers you some services,
+ so your work is easier, but YAMN needs some things to be done for proper work. These limits go
+ according thread synchronization and memory mutual exclusion.
+
+ YAMN offers you two types of services. Exported functions and Miranda services. Miranda
+ services are described in header files, exported functions are described in cpp files. All
+ exported functions in YAMN have the suffix Fcn, so you can easy get if the function is
+ exported. Using exported functions is more difficult than using miranda services, but after
+ solving some definitions, the work with exported functions is more clear and easier. Miranda
+ services from YAMN are for miscellaneus functions. The fact Miranda service uses only two
+ parameters and therefore is sometimes very unsuitable leads us to make exported functions.
+ Exported functions are divided in several parts: synchronizing functions (used for thread
+ and account synchronization) and MIME functions (used to work with MIME
+ messages).
+
+ Miranda services are used through Miranda CallService function. YAMN exported functions are avialable
+ when registering plugin. Then YAMN gives you its table of exported functions.
+
+ How to write write your protocol plugin for YAMN? The best way for you is to look at
+ internal POP3 protocol, where all info about this is written. At start, you need to register
+ plugin (it is done in two steps- registering and inserting to YAMN), then get pointers to
+ YAMN's exported functions (using Miranda's service MS_YAMN_GETFCN) you will need in your
+ protocol plugin. These are the first steps you should do when implementing some plugin to
+ YAMN. Next, you should know how YAMN is stuctured. Structures of YAMN are described in
+ chapter 2. And, at the end, you should know something about account synchronizing and some
+ limitations you have to achieve, if you want your plugin works well.
+
+
+2. YAMN structures and memory organization
+ ---------------------------------------
+
+ YAMN uses its own structures, that can change in the future. The problem with change is,
+ that there can occur some incomapatibilities between YAMN and plugins written for old YAMN
+ versions. To avoid problems, YAMN defines versions for services or exported/imported
+ functions, where strucutre version information is passed to/from plugins.
+
+
+2.1. Structures of protcol plugin queue
+
+ (PYAMN_PROTOPLUGINQUEUE)FirstPlugin---> =(HYAMNPROTOPLUGIN)= ---> =(HYAMNPROTOPLUGIN)= ---> =(HYAMNPROTOPLUGIN)= ---> NULL
+ | | | | | | | | |
+ | . | | | . | | | . | |
+ | . | | | . | | | . | |
+ | . | | | . | | | . | |
+ -------------------- | |------------------| | |------------------| |
+ | Next |--| | Next |--| | Next |--|
+ ==================== ==================== ====================
+
+ This structure is not needed if you only create protocol plugin for YAMN. YAMN plugin does
+ not see and it is not important for it how YAMN works with plugins and how it stores plugins
+ data. For plugin is important only handle for its own plugin, returned from
+ MS_YAMN_REGISTERPLUGIN service.
+
+
+2.2. Structure of accounts
+
+ Every account in YAMN belongs to exact plugin and its members are allocated with
+ MS_YAMN_CREATEPLUGINACCOUNT service. This service cooperates with your function, which is
+ defined in your function import table. In your function (if you have defined it), you should
+ create the whole account. It is because YAMN cannot know which members in structure did you
+ add. So you create the whole derived structure. If your fcn is not implemented (NULL in
+ import table), YAMN creates standard account structure.
+
+ This structure contains information (members) related to YAMN, to plugin and members shared
+ between both (plugin and YAMN). Therefore it is needed to synchronize access to members (see
+ Ch. 3). Standard YAMN account is defined in m_account.h header file. There's also
+ description for every member how it is synchronised. YAMN creates two synchronizing objects
+ (SO) to synchronise access to members. In m_synchro.h file, there are definitions for easy
+ work with these SO.
+
+ Accounts are queued in plugin:
+
+ =(HYAMNPLUGIN)= ---> ===(HACCOUNT)=== ---> ===(HACCOUNT)=== ---> ===(HACCOUNT)=== ---> NULL
+ | | | | | | | | | | | |
+ | | | | | | | | | | | |
+ | . | | | | | | | | | | |
+ | . | | | | | | | | | | |
+ | . | | | | | | | | | | |
+ | | | |--------------| | |--------------| | |--------------| |
+ | (HACCOUNT) | | | Next |--| | Next |--| | Next |--|
+ | FirstAccount|--| ================ ================ ================
+ |-------------|
+ | |
+ ===============
+
+ Every account has its own back pointer to (HYAMNPLUGIN) in Plugin member, so you can easy
+ look at first account, when you have any other account (see m_account.h).
+
+
+2.3. Structure of mails
+
+ Account has a pointer to mails. Account's pointer to mails is pointer to first mail in fact
+ and mails are queued too:
+
+ ==(HACCOUNT)== ---> ==(HYAMNMAIL)== ---> ==(HYAMNMAIL)== ---> ==(HYAMNMAIL)== ---> NULL
+ | | | | | | | | | | | |
+ | . | | | | | | | | | | |
+ | . | | | | | | | | | | |
+ | . | | | | | | | | | | |
+ | | | |-------------| | |-------------| | |-------------| |
+ | (HYAMNMAIL)| | | Next |--| | Next |--| | Next |--|
+ | Mails|--| =============== =============== ===============
+ |------------|
+ | |
+ ==============
+
+ Standard MIME mail is defined in mails/m_mails.h file.
+
+ Plugin can work with accounts in its own way, but note it is needed to synchronize access.
+ For better work, YAMN offers you some services and exports functions. Description of
+ exported functions is in its declartation; for accounts functions see account.cpp, for mails
+ functions see mails/mails.cpp and so on.
+
+
+3. YAMN thread synchronization
+ ---------------------------
+
+ Because YAMN is multithreaded, more than one thread can access to any member of account
+ structure. Therefore access to these members should be synchronised. YAMN offers two types
+ of synchronization objects (SO): SCOUNTER (Synchronized Counter) and SWMRG (Single
+ Writer/Multiple Readers Guard). To use these objects, you can use exported functions:
+
+ SWMRG: WaitToWriteSO, WaitToWriteSOEx, WriteDoneSO, WaitToReadSO, WaitToReadSOEx, ReadDoneSO
+ SCOUNTER: SCGetNumber, SCInc, SCDec
+
+ To see description for these functions, see m_synchro.h header file and synchro.cpp. Note
+ that in HACCOUNT structure, there are 3 synchronizing members, which you have to use if you
+ want to access to any member of account structure. All access techniques (writing to members
+ and read from members) are used in POP3 protocol plugin. Now, it is important what we have
+ to do when we want to make our plugin be synchronized with YAMN (in POP3 protocol it is
+ described too).
+
+ 1. We have to use ThreadRunningEV event when YAMN calls our checking/deleting function. This
+ parameter is to stop YAMN called thread until we do not have copied datas from stack. After
+ that, we SetEvent(ThreadRunningEvent) to unblock YAMN to continue in its work.
+
+ 2. We have to use UsingThreads account's member. This is only for YAMN account deleting
+ prevention. We use this counter to set number of threads using account. If no thread is just
+ using account, account is signaled, that it can be deleted (and is deleted when needed).
+ This leads us to do some things: We use SCInc(UsingThreads) as the first thing we can do. We
+ cannot omit, that called thread finished before we call this function. UsingThreads should
+ have "continuous" value greater than zero when using account. E.g. if YAMN creates thread
+ for plugin that checks account for new mail, YAMN waits until we set ThreadRunningEV (see
+ point 1). After setting this event to signal, that YAMN can continue in its work, we
+ increase SCInc(UsingThreads), so we ensure that another thread uses account before YAMN
+ thread, that uses this account ends. And SCDec(UsingThreads) should be the last thing we do
+ in our thread. If we run another thread in our thread, we should wait until it does not
+ SCInc(UsingThreads) and after that we should continue (just like YAMN creates and calls our
+ thread).
+
+ 3. If we use account's SWMRG (AccountAccessSO, MessagesAccessSO), we should test what our
+ function returned. Use the same methods as POP3 protocol does while testing and accessing
+ critical section. Note that we cannot use WaitToWriteSO(MyAccount->AccountAccessSO), but in
+ easy way we can WaitToWrite(AccountAccess) and for mails
+ WaitToWriteSO(MyAccount->MessagesAccessSO) use MsgsWaitToWrite(AccountAccess) and so on. See
+ export.h file for these definitions.
+
+ 4. Deleting account is quite easy, but in YAMN, it is very problematic operation. If you use
+ MS_YAMN_DELETEACCOUNT service, it is the best way to avoid any problem. These problems raise
+ from the facts desribed in the point 2.
+
+ 5. You should use ctritical sections only for short time not to block other threads. You can
+ imagine that users can't browse through mails, because account is blocked by your thread...
+
+ All needed infos in POP3 internal protocol plugin (see proto/pop3/pop3comm.cpp), are
+ described.
+
+
+4. What do you need to make your filter plugin cooperating with YAMN
+ -----------------------------------------------------------------
+
+ Filter plugins are very easy to write in its own way, it much more easier than protocol
+ plugin. But some things are common: you have to register your plugin and insert to YAMN
+ (these are 2 steps, see sources of some filter plugin), You have to import to YAMN your
+ filter function. Filter function can do anything with mails, but the most important is, that
+ it can set Flags member of mail (see mails/m_mails.h file) to one of YAMN_MSG_SPAMLx.
+ Note Mail is in write-access, so your plugin can do anything with mail and avoid the
+ synchronization problem.
+
+ Now YAMN recognizes 4 spam levels:
+ 1. Notifies about this mail, but shows it in mailbrowser with other color than normally
+ 2. Does not notify about this mail, shows it in mailbrowser with other color than normally
+ 3. Deletes mail from server (depends on protocol), does not notify and shows "this spam was
+ deleted"
+ 4. Deletes mail from server (depends on protocol), does not notify, does not show in
+ mailbrowser
+
+ Your plugin can set data for mail in the TranslatedHeader structure, inserting it to the
+ queue. This information is stored, so it is reloaded after protocol read mails from book
+ file.
|