fastdbcli.cs

嵌入式数据库软件 嵌入式数据库软件 嵌入式数据库软件

     * Returns:
     *     >= 0 - number of tables in the database (Metatable is not returned/counted)
     *     < 0  - result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_show_tables(
      int session, 
      //[In, Out] CliTableDescriptor[] tables
      ref IntPtr tables);   // 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
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_create_table(
      int       session, 
      string    tableName, 
      int       nFields, 
      [In, Out] CliFieldDescriptor[] fields);  // cli_field_descriptor* fields

    /*=====================================================================
     * cli_alter_table
     *     Change table format
     * Parameters:
     *     session   - session descriptor as returned by cli_open
     *     tableName - name of existing table
     *     nFields   - number of columns in the table
     *     fields    - array with new table columns descriptors
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_alter_table(
      int    session, 
      string tableName, 
      int    nFields, 
      [MarshalAs(UnmanagedType.LPArray)]
      CliFieldDescriptor[] fields);  // 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
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_drop_table(int session, string 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
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_alter_index(
      int session, string tableName, string fieldName, 
      FieldFlags 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
     */
    public delegate void CliErrorHandler(int error, 
      [MarshalAs(UnmanagedType.LPStr)] string msg, int msgarg, IntPtr context); 
    
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern CliErrorHandler cli_set_error_handler(int session, CliErrorHandler new_handler, IntPtr context);

    /*=====================================================================
     * cli_freeze
     *    Freeze cursor. Make it possible to reused cursor after commit of the current transaction.
     * Parameters:
     *     statement   - statememt descriptor returned by cli_statement
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_freeze(int statement);

    /*=====================================================================
     * cli_unfreeze
     *    Unfreeze cursor. Reuse previously frozen cursor.
     * Parameters:
     *     statement   - statememt descriptor returned by cli_statement
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_unfreeze(int statement);


    /*=====================================================================
     * cli_attach
     *    Attach thread to the database. Each thread except one opened the database should first
     *    attach to the database before any access to the database, and detach after end of the work with database
     * Parameters:
     *     session - session descriptor returned by cli_open
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_attach(int session);

    /*=====================================================================
     * cli_detach
     *    Detach thread from the database. Each thread except one opened the database should perform 
     *    attach to the database before any access to the database, and detach after end of the work with database
     * Parameters:
     *     session - session descriptor returned by cli_open
     *     detach_mode - bit mask representing detach mode
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [Flags]
      public enum CliDetachMode : int {
      cli_commit_on_detach          = 1,
      cli_destroy_context_on_detach = 2
    };

    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_detach(int session, CliDetachMode detach_mode);


    /*=====================================================================
     * cli_free_memory
     *    Free memory allocated by cli_show_tables and cli_describe
     * Parameters:
     *     session - session descriptor returned by cli_open
     *     ptr - pointer to the allocated buffer
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern unsafe void cli_free_memory(int session, void* ptr);

    [ StructLayout( LayoutKind.Sequential, CharSet=CharSet.Ansi )]
      public struct CliDatabaseMonitor {
      public int n_readers;
      public int n_writers;
      public int n_blocked_readers;
      public int n_blocked_writers;
      public int n_users;
    }; 

    /*=====================================================================
     * cli_get_database_state
     *    Obtain information about current state of the database
     * Parameters:
     *     session - session descriptor returned by cli_open
     *     monitor - pointer to the monitor structure. The folloing fields are set:
     *       n_readers: number of granted shared locks
     *       n_writers: number of granted exclusive locks
     *       n_blocked_reader: number of threads which shared lock request was blocked
     *       n_blocked_writers: number of threads which exclusive lock request was blocked
     *       n_users: number of processes openned the database
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_get_database_state(int session, ref CliDatabaseMonitor monitor);

    /*=====================================================================
     * cli_set_trace_function
     *    Set trace function which will be used to output FastDB trace messages
     * Parameters:
     *     func - pointer to trace function which receives trace message terminated with new line character
     */
    public delegate void CliTraceFunction(string msg);

    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern void cli_set_trace_function(CliTraceFunction func);

    /*=====================================================================
     * cli_prepare_query
     *     Prepare SubSQL query statement. 
     * Parameters:
     *     session - session descriptor returned by cli_open
     *     query   - query string with optional parameters. Parameters are specified
     *               as '%T' where T is one or two character code of parameter type using the same notation
     *               as in printf: %d or %i - int, %f - float or double, %ld - int8, %s - string, %p - oid...
     * Returns:
     *     >= 0 - statement descriptor
     *     <  0 - error code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_prepare_query(int session, string query);

    /* 
     * cli_execute_query
     *     Execute query previously prepared by cli_prepare_query
     * Parameters:
     *     statement - statement descriptor returned by cli_prepare_query
     *     for_update - not zero if fetched rows will be updated 
     *     record_struct - structure to receive selected record fields
     *     ...     - varying list of query parameters
     * Returns:
     *     >= 0 - success, for select statements number of fetched rows is returned
     *     <  0 - error code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_execute_query(
      int          statement, 
      QueryType    queryType, 
      IntPtr       record_struct, // void*
      params object[] list);

    /*
     * cli_insert_struct
     *     Insert new record represented as C structure
     * Parameters:
     *     session - session descriptor returned by cli_open
     *     table_name - name of the destination table
     *     record_struct - structure specifying value of record fields
     *     oid - pointer to the location to receive OID of created record (may be NULL)
     * Returns:
     *     result code as described in cli_result_code enum
     */
    [DllImport(libname,
       CharSet           = CharSet.Ansi,  // We want ANSI String
       CallingConvention = CallingConvention.Cdecl)]
    internal static extern int cli_insert_struct(
      int session, 
      string table_name, 
      IntPtr record_struct, // void*
      ref uint oid);
  }
}