a_server_context structure

typedef struct a_server_context {
    void (SQL_CALLBACK *set_error)( a_server_context  *this
                                   , a_sql_uint32     error_code
                                   , const char       *error_string
                                   , short            error_string_length
                                  );
    a_sql_uint32 (SQL_CALLBACK *get_is_cancelled)( a_server_context *this
                                    );
    void (SQL_CALLBACK *log_message)( a_server_context *this
                                    , const char       *message_string
                                    , short            message_string_length
                                    );
    void *_context;
} a_server_context, *p_server_context;

Member name Type Description

set_error

void

This method allows external prefilters and term breakers to set an error in the database server by providing an error code and error string. The database server rolls back the current operation and returns the error code and string to the user in the following form:

"Error from external library: -<error_code>: <error_string>"

error_code must be a positive integer greater than 17000.

error_string must be a null-terminated string.

str_len is the length of error_string, in bytes.

get_is_cancelled

a_sql_uint32

External prefilters and term breakers must periodically call this method to check if the current operation has been interrupted. This method returns 1 if the current operation was interrupted, and 0 if it was not interrupted. In the case of returning 1, the caller should stop further processing and return immediately.

log_message

void

This method allows external prefilters and term breakers to log messages to the database server log.

message must be a null-terminated string.

msg_len is the length of message, in bytes.

_context

void

For internal use. A pointer to the database server context.

The a_server_context structure is defined by a header file named exttxtcmn.h, in the SDK\Include subdirectory of your SQL Anywhere installation directory.

The external library should not be using any operating system synchronization primitives when calling the methods exposed by a_server_context structure.

a_server_context structure

Syntax

Members

Remarks