cli.h

一个功能强大的内存数据库源代码,c++编写,有详细的注释

 *     for_update - not zero if fetched rows will be updated 
 * Returns:
 *     >= 0 - success, for select statements number of fetched rows is returned
 *     <  0 - error code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_fetch(int statement, int for_update);

/*********************************************************************
 * cli_insert
 *     Execute insert statement.
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 *     oid        - object identifier of created record. 
 * Returns:
 *     status code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_insert(int statement, cli_oid_t* oid);

/*********************************************************************
 * cli_get_first
 *     Get first row of the selection.
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_get_first(int statement);

/*********************************************************************
 * cli_get_last
 *     Get last row of the selection.
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_get_last(int statement);

/*********************************************************************
 * cli_get_next
 *     Get next row of the selection. If get_next records is called
 *     exactly after cli_fetch function call, is will fetch the first record
 *     in selection.
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_get_next(int statement);

/*********************************************************************
 * cli_get_prev
 *     Get previous row of the selection. If get_next records is called
 *     exactly after cli_fetch function call, is will fetch the last record
 *     in selection.
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_get_prev(int statement);

/*********************************************************************
 * cli_skip
 *     Skip specified number of rows. 
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 *     n          - number of objects to be skipped
 *                - if "n" is positive, then this function has the same effect as
 *                     executing cli_get_next() function "n" times.
 *                - if "n" is negative, then this function has the same effect as
 *                     executing cli_get_prev() function "-n" times.
 *                - if "n"  is zero, this method has no effect
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_skip(int statement, int n);

/*********************************************************************
 * cli_get_oid
 *     Get object identifier of the current record
 * Parameters:
 *     statement  - statememt descriptor returned by cli_statement
 * Returns:
 *     object identifier or 0 if no object is seleected
 */
cli_oid_t FASTDB_DLL_ENTRY cli_get_oid(int statement);

/*********************************************************************
 * cli_update
 *     Update the current row in the selection. You have to set
 *     for_update parameter of cli_fetch to 1 in order to be able 
 *     to perform updates. Updated value of row fields will be taken
 *     from bound column variables. 
 * Parameters:
 *     statement   - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_update(int statement);

/*********************************************************************
 * cli_remove
 *     Remove all selected records. You have to set
 *     for_update parameter of cli_fetch to 1 in order to be able 
 *     to remove records. 
 * Parameters:
 *     statement   - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_remove(int statement);

/*********************************************************************
 * cli_free
 *     Deallocate statement and all associated data
 * Parameters:
 *     statement   - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_free(int statement);

/*********************************************************************
 * cli_commit
 *     Commit current database transaction
 * Parameters:
 *     session - session descriptor as returned by cli_open
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_commit(int session);

/*********************************************************************
 * cli_precommit
 *     Release all locks set by transaction. This methods allows other clients
 *     to proceed, but it doesn't flush transaction to the disk.
 * Parameters:
 *     session - session descriptor as returned by cli_open
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_precommit(int session);

/*********************************************************************
 * cli_abort
 *     Abort current database transaction
 * Parameters:
 *     session - session descriptor as returned by cli_open
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_abort(int session);


enum cli_field_flags { 
    cli_hashed           = 1, /* field should be indexed usnig hash table */
    cli_indexed          = 2  /* field should be indexed using B-Tree */
};

typedef struct cli_field_descriptor { 
    enum cli_var_type type;
    int               flags;
    char const*       name;
    char const*       refTableName;
    char const*       inverseRefFieldName;
} cli_field_descriptor;

/*********************************************************************
 * cli_describe
 *     Describe fileds of specified table
 * Parameters:
 *     session - session descriptor as returned by cli_open
 *     table   - name of the table
 *     fields  - adress of the pointer to the array of fields descriptors, 
 *               this array should be later deallocated by application by free()
 * Returns:
 *     >= 0 - number of fields in the table
 *     < 0  - result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_describe(int session, char const* table, cli_field_descriptor** fields);


typedef struct cli_table_descriptor {
    char const*       name;
} cli_table_descriptor;

/*********************************************************************
 * cli_show_tables
 *     Show all tables of specified database
 * Parameters:
 *     session - session descriptor as returned by cli_open
 *     tables  - address of the pointer to the array of tables descriptors,
 *               this array should be later deallocated by application by free()
 * Returns:
 *     >= 0 - number of tables in the database (Metatable is not returned/counted)
 *     < 0  - result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_show_tables(int session, cli_table_descriptor** tables);


/*********************************************************************
 * cli_create_table
 *     Create new table
 * Parameters:
 *     session   - session descriptor as returned by cli_open
 *     tableName - name of new table
 *     nFields   - number of columns in the table
 *     fields    - array with table columns descriptors
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_create_table(int session, char const* tableName, int nFields, 
					cli_field_descriptor* fields);

/*********************************************************************
 * cli_drop_table
 *     drop the table
 * Parameters:
 *     session   - session descriptor as returned by cli_open
 *     tableName - name of deleted table
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_drop_table(int session, char const* tableName);


/*********************************************************************
 * cli_alter_index
 *     add or remove column index
 * Parameters:
 *     session   - session descriptor as returned by cli_open
 *     tableName - name of the table
 *     fieldName - name of field
 *     newFlags  - new flags of the field, if index exists for this field, but is not specified in 
 *                 <code>newFlags</code> mask, then it will be removed; if index not exists, but is 
 *                 specified in <code>newFlags</code> mask, then it will be created. *                   
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_alter_index(int session, char const* tableName, char const* fieldName, 
                                     int newFlags);


/*********************************************************************
 * cli_set_error_handler
 *     Set FastDB erro handler. Handler should be no-return function which perform stack unwind.
 * Parameters:
 *     session   - session descriptor as returned by cli_open
 *     handler   - error handler
 * Returns:
 *     previous handler
 */
enum cli_error_class { 
    cli_no_error, 
    cli_query_error,
    cli_arithmetic_error,
    cli_index_out_of_range_error,
    cli_database_open_error,
    cli_file_error,
    cli_out_of_memory_error,
    cli_deadlock,
    cli_null_reference_error,
    cli_lock_revoked,
    cli_file_limit_exeeded        
};
typedef void (*cli_error_handler)(int error, char const* msg, int msgarg); 
cli_error_handler FASTDB_DLL_ENTRY cli_set_error_handler(int session, cli_error_handler new_handler);

/*********************************************************************
 * cli_freeze
 *    Freeze cursor
 * Parameters:
 *     statement   - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_freeze(int statement);

/*********************************************************************
 * cli_unfreeze
 *    Unfreeze cursor
 * Parameters:
 *     statement   - statememt descriptor returned by cli_statement
 * Returns:
 *     result code as described in cli_result_code enum
 */
int FASTDB_DLL_ENTRY cli_unfreeze(int statement);



#ifdef __cplusplus
}
#endif

#endif