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AngelScript
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AngelScript
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To serialize scripts the application needs to be able to iterate through all variables, and objects that have any relation to the script and store their content in a way that would allow it to be restored at a later time. For simple values this is trivial, but for objects and handles it becomes more complex as it is necessary to keep track of references between objects and internal structure of both classes defined by scripts and application registered types.
Iterating through the variables and members of objects is already described in the article about reflection, so this article will focus on the storing and restoring of values.
Look at the source code for the Serializer add-on for a sample implementation of serialization.
To serialize the script modules you'll need to enumerate all the global variables and serialize each of them.
When deserializing the module, first compile it normally either from source script or by loading a pre-compiled byte code, except you first need to turn off initialization of global variables by turning off the engine property asEP_INIT_GLOBAL_VARS_AFTER_BUILD.
To serialize a global variable you'll need the name and namespace to use as the key for the variable, and then the type id and address of the variable. You get these with the methods asIScriptModule::GetGlobalVar and asIScriptModule::GetAddressOfGlobalVar. If the type id is for a primitive type, then the value can be stored as is. If it is a handle or reference you'll need to serialize the reference itself and the object it refers to. If the type id is an object type then serialize the object and its content.
To deserialize the global variable, you'll use the name and namespace to look it up, and then use GetAddressOfGlobalVar to get the address of the memory that needs to be restored with the serialized content.
To serialize script objects you'll use the asIScriptObject interface to iterate over the members to store the content. Remember that objects can hold references to other objects and even to itself so it is important to keep track of object instances already serialized and just store a reference if the same object comes up again.
When deserializing the script objects you should first allocate the memory using asIScriptEngine::CreateUninitializedScriptObject so that the constructor is not executed, and then iterate over the members to restore their content.
For application registered types you obviously need to provide your own implementation as the script engine doesn't know the full content of the types and thus cannot provide an interface for serialization.
Serialization of a script context involves storing the full call stack with all the function calls, local variables, registers, etc. To do this you'll use the asIScriptContext interface.
To deserialize a context follow these steps:
The following are some limitations with serialization of contexts:
1.9.6