/*
* Copyright (c) 2009 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup edit
* @{
*/
/**
* @file
* @brief Prototype implementation of Sheet data structure.
*
* The sheet is an abstract data structure representing a piece of text.
* On top of this data structure we can implement a text editor. It is
* possible to implement the sheet such that the editor can make small
* changes to large files or files containing long lines efficiently.
*
* The sheet structure allows basic operations of text insertion, deletion,
* retrieval and mapping of coordinates to position in the file and vice
* versa. The text that is inserted or deleted can contain tabs and newlines
* which are interpreted and properly acted upon.
*
* This is a trivial implementation with poor efficiency with O(N+n)
* insertion and deletion and O(N) mapping (in both directions), where
* N is the size of the file and n is the size of the inserted/deleted text.
*/
#include <stdlib.h>
#include <str.h>
#include <errno.h>
#include <adt/list.h>
#include <align.h>
#include <macros.h>
#include "sheet.h"
#include "sheet_impl.h"
enum {
TAB_WIDTH = 8,
/** Initial of dat buffer in bytes */
INITIAL_SIZE = 32
};
/** Initialize an empty sheet. */
errno_t sheet_create(sheet_t **rsh)
{
sheet_t *sh;
sh = calloc(1, sizeof(sheet_t));
if (sh == NULL)
return ENOMEM;
sh->dbuf_size = INITIAL_SIZE;
sh->text_size = 0;
sh->data = malloc(sh->dbuf_size);
if (sh->data == NULL)
return ENOMEM;
list_initialize(&sh->tags);
*rsh = sh;
return EOK;
}
/** Insert text into sheet.
*
* @param sh Sheet to insert to.
* @param pos Point where to insert.
* @param dir Whether to insert before or after the point (affects tags).
* @param str The text to insert (printable characters, tabs, newlines).
*
* @return EOK on success or an error code.
*
* @note @a dir affects which way tags that were placed on @a pos will
* move. If @a dir is @c dir_before, the tags will move forward
* and vice versa.
*/
errno_t sheet_insert(sheet_t *sh, spt_t *pos, enum dir_spec dir, char *str)
{
char *ipp;
size_t sz;
char *newp;
sz = str_size(str);
if (sh->text_size + sz > sh->dbuf_size) {
/* Enlarge data buffer. */
newp = realloc(sh->data, sh->dbuf_size * 2);
if (newp == NULL)
return ELIMIT;
sh->data = newp;
sh->dbuf_size = sh->dbuf_size * 2;
}
ipp = sh->data + pos->b_off;
/* Copy data. */
memmove(ipp + sz, ipp, sh->text_size - pos->b_off);
memcpy(ipp, str, sz);
sh->text_size += sz;
/* Adjust tags. */
list_foreach(sh->tags, link, tag_t, tag) {
if (tag->b_off > pos->b_off)
tag->b_off += sz;
else if (tag->b_off == pos->b_off && dir == dir_before)
tag->b_off += sz;
}
return EOK;
}
/** Delete text from sheet.
*
* Deletes the range of text between two points from the sheet.
*
* @param sh Sheet to delete from.
* @param spos Starting point.
* @param epos Ending point.
*
* @return EOK on success or an error code.
*/
errno_t sheet_delete(sheet_t *sh, spt_t *spos, spt_t *epos)
{
char *spp;
size_t sz;
char *newp;
size_t shrink_size;
spp = sh->data + spos->b_off;
sz = epos->b_off - spos->b_off;
memmove(spp, spp + sz, sh->text_size - (spos->b_off + sz));
sh->text_size -= sz;
/* Adjust tags. */
list_foreach(sh->tags, link, tag_t, tag) {
if (tag->b_off >= epos->b_off)
tag->b_off -= sz;
else if (tag->b_off >= spos->b_off)
tag->b_off = spos->b_off;
}
/* See if we should free up some memory. */
shrink_size = max(sh->dbuf_size / 4, INITIAL_SIZE);
if (sh->text_size <= shrink_size && sh->dbuf_size > INITIAL_SIZE) {
/* Shrink data buffer. */
newp = realloc(sh->data, shrink_size);
if (newp == NULL) {
/* Failed to shrink buffer... no matter. */
return EOK;
}
sh->data = newp;
sh->dbuf_size = shrink_size;
}
return EOK;
}
/** Read text from sheet. */
void sheet_copy_out(sheet_t *sh, spt_t const *spos, spt_t const *epos,
char *buf, size_t bufsize, spt_t *fpos)
{
char *spp;
size_t range_sz;
size_t copy_sz;
size_t off, prev;
char32_t c;
spp = sh->data + spos->b_off;
range_sz = epos->b_off - spos->b_off;
copy_sz = (range_sz < bufsize - 1) ? range_sz : bufsize - 1;
prev = off = 0;
do {
prev = off;
c = str_decode(spp, &off, copy_sz);
} while (c != '\0');
/* Crop copy_sz down to the last full character. */
copy_sz = prev;
memcpy(buf, spp, copy_sz);
buf[copy_sz] = '\0';
fpos->b_off = spos->b_off + copy_sz;
fpos->sh = sh;
}
/** Get point preceding or following character cell. */
void sheet_get_cell_pt(sheet_t *sh, coord_t const *coord, enum dir_spec dir,
spt_t *pt)
{
size_t cur_pos, prev_pos;
char32_t c;
coord_t cc;
cc.row = cc.column = 1;
cur_pos = prev_pos = 0;
while (true) {
if (prev_pos >= sh->text_size) {
/* Cannot advance any further. */
break;
}
if ((cc.row >= coord->row && cc.column > coord->column) ||
cc.row > coord->row) {
/* We are past the requested coordinates. */
break;
}
prev_pos = cur_pos;
c = str_decode(sh->data, &cur_pos, sh->text_size);
if (c == '\n') {
++cc.row;
cc.column = 1;
} else if (c == '\t') {
cc.column = 1 + ALIGN_UP(cc.column, TAB_WIDTH);
} else {
++cc.column;
}
}
pt->sh = sh;
pt->b_off = (dir == dir_before) ? prev_pos : cur_pos;
}
/** Get the number of character cells a row occupies. */
void sheet_get_row_width(sheet_t *sh, int row, int *length)
{
coord_t coord;
spt_t pt;
/* Especially nasty hack */
coord.row = row;
coord.column = 65536;
sheet_get_cell_pt(sh, &coord, dir_before, &pt);
spt_get_coord(&pt, &coord);
*length = coord.column;
}
/** Get the number of rows in a sheet. */
void sheet_get_num_rows(sheet_t *sh, int *rows)
{
int cnt;
size_t bo;
cnt = 1;
for (bo = 0; bo < sh->dbuf_size; ++bo) {
if (sh->data[bo] == '\n')
cnt += 1;
}
*rows = cnt;
}
/** Get the coordinates of an s-point. */
void spt_get_coord(spt_t const *pos, coord_t *coord)
{
size_t off;
coord_t cc;
char32_t c;
sheet_t *sh;
sh = pos->sh;
cc.row = cc.column = 1;
off = 0;
while (off < pos->b_off && off < sh->text_size) {
c = str_decode(sh->data, &off, sh->text_size);
if (c == '\n') {
++cc.row;
cc.column = 1;
} else if (c == '\t') {
cc.column = 1 + ALIGN_UP(cc.column, TAB_WIDTH);
} else {
++cc.column;
}
}
*coord = cc;
}
/** Test if two s-points are equal. */
bool spt_equal(spt_t const *a, spt_t const *b)
{
return a->b_off == b->b_off;
}
/** Get a character at spt and return next spt */
char32_t spt_next_char(spt_t spt, spt_t *next)
{
char32_t ch = str_decode(spt.sh->data, &spt.b_off, spt.sh->text_size);
if (next)
*next = spt;
return ch;
}
char32_t spt_prev_char(spt_t spt, spt_t *prev)
{
char32_t ch = str_decode_reverse(spt.sh->data, &spt.b_off, spt.sh->text_size);
if (prev)
*prev = spt;
return ch;
}
/** Place a tag on the specified s-point. */
void sheet_place_tag(sheet_t *sh, spt_t const *pt, tag_t *tag)
{
tag->b_off = pt->b_off;
tag->sh = sh;
list_append(&tag->link, &sh->tags);
}
/** Remove a tag from the sheet. */
void sheet_remove_tag(sheet_t *sh, tag_t *tag)
{
list_remove(&tag->link);
}
/** Get s-point on which the tag is located right now. */
void tag_get_pt(tag_t const *tag, spt_t *pt)
{
pt->b_off = tag->b_off;
pt->sh = tag->sh;
}
/** @}
*/