Previous review

In the last blog post , We introduced the registry initialization operation in the client , Briefly introduces the functions of other functions .
Today we will deeply analyze the implementation process of each function , And describe the process in the form of a simple flow chart .

Function realization

Because the function of each function needs to call the initialization operation , So I won't introduce it anymore , Please refer to the previous blog for the initialization process ： What happened to the client

SAMGR_RegisterServiceApi

The function of this function is to build a remote register service application programming interface , Steps are as follows ：
① Registry initialization （InitializeRegistry）
② Add a router （SAMGR_AddRouter）
③ Return the strategy of the process （SAMGR_ProcPolicy）

SAMGR_AddRouter

Adding a router is also divided into the following steps ：
① Query interface （QueryInterface）
② Lock multiple writes , Press the key to find （VECTOR_FindByKey）
③ Apply for a temporary space （SAMGR_Malloc）
④ Add elements to vectors （VECTOR_Add）
⑤ Release space （SAMGR_Free）

SAMGR_ProcPolicy

The implementation of process strategy is also divided into several steps ：
① First get the registered identity of a user （RegisterIdentity）

• Get the remote policy in the process of obtaining identity （GetRemotePolicy）

② Add the policy of the process to the router （AddPolicyToRouter）

The step flow chart of building the remote register service application programming interface is as follows ：

SAMGR_FindServiceApi

The function of this function is to find the service Api, The realization process of its function is divided into the following steps ：
① Registry initialization （InitializeRegistry）
② Use vector keys to find , Get the element at the specified location （VECTOR_FindByKey、VECTOR_At）
③ Create a proxy server （SAMGR_CreateIProxy）
④ Again, use the vector key to find , Get the element at the specified location （VECTOR_FindByKey、VECTOR_At）
⑤ Add elements to vectors （VECTOR_Add）

SAMGR_CreateIProxy

Creating a proxy server also requires some steps ：
① Query user identity （QueryIdentity）
② Create client （SAMGR_CreateIClient）
③ Apply for a temporary space （SAMGR_Malloc）
④ Register death callback （RegisterDeathCallback）

    entry->iUnknown.Invoke = ProxyInvoke;   // Proxy call 
    entry->iUnknown.AddRef = AddRef;    // Add reference 
    entry->iUnknown.Release = Release;  // Release space 

The implementation flow chart of this function is as follows ：

If the functions of the above two functions are to verify the identity of users , Provide users with a platform for manipulation , Then the next function function is to provide users with the ability to obtain functions

I call these three functions Service functions , Three service functions are provided ：

SAMGR_RegisterSystemCapabilityApi	// Register system capabilities Api
SAMGR_QuerySystemCapabilityApi	// Query system functions Api
SAMGR_GetSystemCapabilitiesApi	// Get system functions Api

For specific functions, you can check the previous code annotation blog ：OpenHarmony Module two samgr_client File header and source file parsing

Next up

In the next issue, we will start to conduct in-depth analysis of the server , Mainly based on module II samgr_server Files are objects , Carefully analyze the construction process of the server and the construction and implementation steps of service functions .

What if you want to know what happened , Let's hear the decomposition next time