src/editor/editbuffer.h

   1 /** \file
   2  *  \brief Header: text keep buffer for WEdit
   3  */
   4
   5 #ifndef MC__EDIT_BUFFER_H
   6 #define MC__EDIT_BUFFER_H
   7
   8 /*** typedefs(not structures) and defined constants **********************************************/
   9
  10 /*
  11  * The editor keeps data in two arrays of buffers.
  12  * All buffers have the same size, which must be a power of 2.
  13  */
  14
  15 /* Configurable: log2 of the buffer size in bytes */
  16 #ifndef S_EDIT_BUF_SIZE
  17 #define S_EDIT_BUF_SIZE 16
  18 #endif
  19
  20 /* Size of the buffer */
  21 #define EDIT_BUF_SIZE (((off_t) 1) << S_EDIT_BUF_SIZE)
  22
  23 /* Buffer mask (used to find cursor position relative to the buffer) */
  24 #define M_EDIT_BUF_SIZE (EDIT_BUF_SIZE - 1)
  25
  26 /*
  27  * Configurable: Maximal allowed number of buffers in each buffer array.
  28  * This number can be increased for systems with enough physical memory.
  29  */
  30 #ifndef MAXBUFF
  31 #define MAXBUFF 1024
  32 #endif
  33
  34 /* Maximal length of file that can be opened */
  35 #define SIZE_LIMIT (EDIT_BUF_SIZE * (MAXBUFF - 2))
  36
  37 /*** enums ***************************************************************************************/
  38
  39 /*** structures declarations (and typedefs of structures)*****************************************/
  40
  41 typedef struct edit_buffer_struct {
  42     off_t curs1;                /* position of the cursor from the beginning of the file. */
  43     off_t curs2;                /* position from the end of the file */
  44     GPtrArray *b1;              /* all data up to curs1 */
  45     GPtrArray *b2;              /* all data from end of file down to curs2 */
  46 } edit_buffer_t;
  47
  48 /*** global variables defined in .c file *********************************************************/
  49
  50 /*** declarations of public functions ************************************************************/
  51
  52 void edit_buffer_init (edit_buffer_t * buf);
  53 void edit_buffer_clean (edit_buffer_t * buf);
  54
  55 int edit_buffer_get_byte (const edit_buffer_t * buf, off_t byte_index);
  56 #ifdef HAVE_CHARSET
  57 int edit_buffer_get_utf (const edit_buffer_t * buf, off_t byte_index, int *char_width);
  58 int edit_buffer_get_prev_utf (const edit_buffer_t * buf, off_t byte_index, int *char_width);
  59 #endif
  60
  61 void edit_buffer_insert (edit_buffer_t * buf, int c);
  62 void edit_buffer_insert_ahead (edit_buffer_t * buf, int c);
  63 int edit_buffer_delete (edit_buffer_t * buf);
  64 int edit_buffer_backspace (edit_buffer_t * buf);
  65
  66 off_t edit_buffer_read_file (edit_buffer_t * buf, int fd, off_t size);
  67 off_t edit_buffer_write_file (edit_buffer_t * buf, int fd);
  68
  69 /*** inline functions ****************************************************************************/
  70
  71 static inline int
  72 edit_buffer_get_current_byte (const edit_buffer_t * buf)
  73 {
  74     return edit_buffer_get_byte (buf, buf->curs1);
  75 }
  76
  77 /* --------------------------------------------------------------------------------------------- */
  78
  79 static inline int
  80 edit_buffer_get_previous_byte (const edit_buffer_t * buf)
  81 {
  82     return edit_buffer_get_byte (buf, buf->curs1 - 1);
  83 }
  84
  85 /* --------------------------------------------------------------------------------------------- */
  86
  87 #endif  /* MC__EDIT_BUFFER_H */