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Context Management FunctionsContext initialization functions handle the allocation, initialization, and destruction of ASN.1 context variables (variables of type OOCTXT).
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Defines | |
| #define | ZEROCONTEXT(pctxt) memset(pctxt,0,sizeof(OOCTXT)) |
Functions | |
| EXTERN int | initContextBuffer (OOCTXT *pctxt, const ASN1OCTET *bufaddr, ASN1UINT bufsiz) |
| This function assigns a buffer to a context block. | |
| EXTERN int | initContext (OOCTXT *pctxt) |
| This function initializes a context block. | |
| EXTERN void | freeContext (OOCTXT *pctxt) |
| This function frees all dynamic memory associated with a context. | |
| EXTERN OOCTXT * | newContext (void) |
| This function allocates a new OOCTXT block and initializes it. | |
| EXTERN void | copyContext (OOCTXT *pdest, OOCTXT *psrc) |
| EXTERN int | initSubContext (OOCTXT *pctxt, OOCTXT *psrc) |
| EXTERN void | setCtxtFlag (OOCTXT *pctxt, ASN1USINT mask) |
| EXTERN void | clearCtxtFlag (OOCTXT *pctxt, ASN1USINT mask) |
| EXTERN int | setPERBuffer (OOCTXT *pctxt, ASN1OCTET *bufaddr, ASN1UINT bufsiz, ASN1BOOL aligned) |
| EXTERN int | setPERBufferUsingCtxt (OOCTXT *pTarget, OOCTXT *pSource) |
Detailed Description
Context initialization functions handle the allocation, initialization, and destruction of ASN.1 context variables (variables of type OOCTXT).These variables hold all of the working data used during the process of encoding or decoding a message. The context provides thread safe operation by isolating what would otherwise be global variables within this structure. The context variable is passed from function to function as a message is encoded or decoded and maintains state information on the encoding or decoding process.
Function Documentation
This function assigns a buffer to a context block.
The block should have been previously initialized by initContext.
- Parameters:
-
pctxt The pointer to the context structure variable to be initialized. bufaddr For encoding, the address of a memory buffer to receive and encode a message. For decoding the address of a buffer that contains the message data to be decoded. This address will be stored within the context structure. For encoding it might be zero, the dynamic buffer will be used in this case. bufsiz The size of the memory buffer. For encoding, it might be zero; the dynamic buffer will be used in this case.
- Returns:
- Completion status of operation:
- 0 (ASN_OK) = success,
- negative return value is error.
| EXTERN int initContext | ( | OOCTXT * | pctxt | ) |
This function initializes a context block.
It makes sure that if the block was not previosly initialized, that all key working parameters are set to thier correct initial state values (i.e. declared within a function as a normal working variable), it is required that they invoke this function before using it.
- Parameters:
-
pctxt The pointer to the context structure variable to be initialized.
- Returns:
- Completion status of operation:
- 0 (ASN_OK) = success,
- negative return value is error.
| EXTERN void freeContext | ( | OOCTXT * | pctxt | ) |
This function frees all dynamic memory associated with a context.
This includes all memory inside the block (in particular, the list of memory blocks used by the mem functions).
- Parameters:
-
pctxt A pointer to a context structure.
| EXTERN OOCTXT* newContext | ( | void | ) |
This function allocates a new OOCTXT block and initializes it.
Although the block is allocated from the standard heap, it should not be freed using free. The freeContext function should be used because this frees items allocated within the block before freeing the block itself.
- Returns:
- Pointer to newly created context
Objective Open H.323 Stack, 0.9.1