Minix1.5/commands/elvis/modify.c
/* modify.c */
/* This file contains the low-level file modification functions:
* delete(frommark, tomark) - removes line or portions of lines
* add(frommark, text) - inserts new text
* change(frommark, tomark, text) - delete, then add
*/
#include "vi.h"
/* delete a range of text from the file */
delete(frommark, tomark)
MARK frommark; /* first char to be deleted */
MARK tomark; /* AFTER last char to be deleted */
{
int i; /* used to move thru logical blocks */
register char *scan; /* used to scan thru text of the blk */
register char *cpy; /* used when copying chars */
BLK *blk; /* a text block */
long l; /* a line number */
MARK m; /* a traveling version of frommark */
/* if not deleting anything, quit now */
if (frommark == tomark)
{
return;
}
/* This is a change */
changes++;
/* if this is a multi-line change, then we'll have to redraw */
if (markline(frommark) != markline(tomark))
{
mustredraw = TRUE;
redrawrange(markline(frommark), markline(tomark), markline(frommark));
}
/* adjust marks 'a through 'z and '' as needed */
l = markline(tomark);
for (i = 0; i < NMARKS; i++)
{
if (mark[i] < frommark)
{
continue;
}
else if (mark[i] < tomark)
{
mark[i] = MARK_UNSET;
}
else if (markline(mark[i]) == l)
{
if (markline(frommark) == l)
{
mark[i] -= markidx(tomark) - markidx(frommark);
}
else
{
mark[i] -= markidx(tomark);
}
}
else
{
mark[i] -= MARK_AT_LINE(l - markline(frommark));
}
}
/* Reporting... */
if (markidx(frommark) == 0 && markidx(tomark) == 0)
{
rptlines = markline(tomark) - markline(frommark);
rptlabel = "deleted";
}
/* find the block containing frommark */
l = markline(frommark);
for (i = 1; lnum[i] < l; i++)
{
}
/* process each affected block... */
for (m = frommark;
m < tomark && lnum[i] < INFINITY;
m = MARK_AT_LINE(lnum[i - 1] + 1))
{
/* fetch the block */
blk = blkget(i);
/* find the mark in the block */
scan = blk->c;
for (l = markline(m) - lnum[i - 1] - 1; l > 0; l--)
{
while (*scan++ != '\n')
{
}
}
scan += markidx(m);
/* figure out where the changes to this block end */
if (markline(tomark) > lnum[i])
{
cpy = blk->c + BLKSIZE;
}
else if (markline(tomark) == markline(m))
{
cpy = scan - markidx(m) + markidx(tomark);
}
else
{
cpy = scan;
for (l = markline(tomark) - markline(m);
l > 0;
l--)
{
while (*cpy++ != '\n')
{
}
}
cpy += markidx(tomark);
}
/* delete the stuff by moving chars within this block */
while (cpy < blk->c + BLKSIZE)
{
*scan++ = *cpy++;
}
while (scan < blk->c + BLKSIZE)
{
*scan++ = '\0';
}
/* adjust tomark to allow for lines deleted from this block */
tomark -= MARK_AT_LINE(lnum[i] + 1 - markline(m));
/* if this block isn't empty now, then advance i */
if (*blk->c)
{
i++;
}
/* the buffer has changed. Update hdr and lnum. */
blkdirty(blk);
}
/* must have at least 1 line */
if (nlines == 0)
{
blk = blkadd(1);
blk->c[0] = '\n';
blkdirty(blk);
cursor = MARK_FIRST;
}
}
/* add some text a a specific place in the file */
add(atmark, newtext)
MARK atmark; /* where to insert the new text */
char *newtext; /* NUL-terminated string to insert */
{
register char *scan; /* used to move through string */
register char *build; /* used while copying chars */
int addlines; /* number of lines we're adding */
int lastpart; /* size of last partial line */
BLK *blk; /* the block to be modified */
int blkno; /* the logical block# of (*blk) */
register char *newptr; /* where new text starts in blk */
BLK buf; /* holds chars from orig blk */
BLK linebuf; /* holds part of line that didn't fit */
BLK *following; /* the BLK following the last BLK */
int i;
long l;
/* if not adding anything, return now */
if (!*newtext)
{
return;
}
/* This is a change */
changes++;
/* count the number of lines in the new text */
for (scan = newtext, lastpart = addlines = 0; *scan; )
{
if (*scan++ == '\n')
{
addlines++;
lastpart = 0;
}
else
{
lastpart++;
}
}
/* Reporting... */
if (lastpart == 0 && markidx(atmark) == 0)
{
rptlines = addlines;
rptlabel = "added";
}
/* extract the line# from atmark */
l = markline(atmark);
/* if more than 0 lines, then we'll have to redraw the screen */
if (addlines > 0)
{
mustredraw = TRUE;
if (markidx(atmark) == 0)
{
redrawrange(l, l, l + addlines);
}
else
{
/* make sure the last line gets redrawn -- it was
* split, so its appearance has changed
*/
redrawrange(l, l + 1L, l + addlines + 1L);
}
}
/* adjust marks 'a through 'z and '' as needed */
for (i = 0; i < NMARKS; i++)
{
if (mark[i] < atmark)
{
continue;
}
else if (markline(mark[i]) > l)
{
mark[i] += MARK_AT_LINE(addlines);
}
else
{
mark[i] += MARK_AT_LINE(addlines) + lastpart;
}
}
/* get the block to be modified */
for (blkno = 1; lnum[blkno] < l && lnum[blkno + 1] < INFINITY; blkno++)
{
}
blk = blkget(blkno);
buf = *blk;
/* figure out where the new text starts */
for (newptr = buf.c, l = markline(atmark) - lnum[blkno - 1] - 1;
l > 0;
l--)
{
while (*newptr++ != '\n')
{
}
}
newptr += markidx(atmark);
/* keep start of old block */
build = blk->c + (newptr - buf.c);
/* fill this block (or blocks) from the newtext string */
while (*newtext)
{
while (*newtext && build < blk->c + BLKSIZE - 1)
{
*build++ = *newtext++;
}
if (*newtext)
{
/* save the excess */
for (scan = linebuf.c + BLKSIZE;
build > blk->c && build[-1] != '\n';
)
{
*--scan = *--build;
}
/* write the block */
while (build < blk->c + BLKSIZE)
{
*build++ = '\0';
}
blkdirty(blk);
/* add another block */
blkno++;
blk = blkadd(blkno);
/* copy in the excess from last time */
for (build = blk->c; scan < linebuf.c + BLKSIZE; )
{
*build++ = *scan++;
}
}
}
/* fill this block(s) from remainder of orig block */
while (newptr < buf.c + BLKSIZE && *newptr)
{
while (newptr < buf.c + BLKSIZE
&& *newptr
&& build < blk->c + BLKSIZE - 1)
{
*build++ = *newptr++;
}
if (newptr < buf.c + BLKSIZE && *newptr)
{
/* save the excess */
for (scan = linebuf.c + BLKSIZE;
build > blk->c && build[-1] != '\n';
)
{
*--scan = *--build;
}
/* write the block */
while (build < blk->c + BLKSIZE)
{
*build++ = '\0';
}
blkdirty(blk);
/* add another block */
blkno++;
blk = blkadd(blkno);
/* copy in the excess from last time */
for (build = blk->c; scan < linebuf.c + BLKSIZE; )
{
*build++ = *scan++;
}
}
}
/* see if we can combine our last block with the following block */
if (lnum[blkno] < nlines && lnum[blkno + 1] - lnum[blkno] < (BLKSIZE >> 6))
{
/* hey, we probably can! Get the following block & see... */
following = blkget(blkno + 1);
if (strlen(following->c) + (build - blk->c) < BLKSIZE - 1)
{
/* we can! Copy text from following to blk */
for (scan = following->c; *scan; )
{
*build++ = *scan++;
}
while (build < blk->c + BLKSIZE)
{
*build++ = '\0';
}
blkdirty(blk);
/* pretend the following was the last blk */
blk = following;
build = blk->c;
}
}
/* that last block is dirty by now */
while (build < blk->c + BLKSIZE)
{
*build++ = '\0';
}
blkdirty(blk);
}
/* change the text of a file */
change(frommark, tomark, newtext)
MARK frommark, tomark;
char *newtext;
{
int i;
long l;
char *text;
BLK *blk;
/* optimize for single-character replacement */
if (frommark + 1 == tomark && newtext[0] && !newtext[1] && newtext[0] != '\n')
{
/* find the block containing frommark */
l = markline(frommark);
for (i = 1; lnum[i] < l; i++)
{
}
/* get the block */
blk = blkget(i);
/* find the line within the block */
for (text = blk->c, i = l - lnum[i - 1] - 1; i > 0; text++)
{
if (*text == '\n')
{
i--;
}
}
/* replace the char */
text += markidx(frommark);
if (*text == newtext[0])
{
/* no change was needed - same char */
return;
}
else if (*text != '\n')
{
/* This is a change */
changes++;
ChangeText
{
*text = newtext[0];
blkdirty(blk);
}
return;
}
/* else it is a complex change involving newline... */
}
/* couldn't optimize, so do delete & add */
ChangeText
{
delete(frommark, tomark);
add(frommark, newtext);
rptlabel = "changed";
}
}