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line.c
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C/C++ Source or Header
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1989-05-30
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17KB
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466 lines
/* line.c */
/*
* The functions in this file are a general set of line management utilities.
* They are the only routines that touch the text. They also touch the buffer
* and window structures, to make sure that the necessary updating gets done.
* There are routines in this file that handle the kill buffer too. It isn't
* here for any good reason.
*
* Note that this code only updates the dot and mark values in the window list.
* Since all the code acts on the current window, the buffer that we are
* editing must be being displayed, which means that "b_nwnd" is non zero,
* which means that the dot and mark values in the buffer headers are nonsense.
*/
#include <stdio.h>
#include "ed.h"
#define NBLOCK 16 /* Line block chunk size */
#define KBLOCK 256 /* Kill buffer block size */
char *kbufp = NULL; /* Kill buffer data */
int kused = 0; /* # of bytes used in KB */
int ksize = 0; /* # of bytes allocated in KB */
/*
* This routine allocates a block of memory large enough to hold a LINE
* containing "used" characters. The block is always rounded up a bit. Return
* a pointer to the new block, or NULL if there isn't any memory left. Print a
* message in the message line if no space.
*/
LINE *
lalloc(used)
register int used;
{
register LINE *lp;
register int size;
size = (used+NBLOCK-1) & ~(NBLOCK-1);
if (size == 0) /* Assume that an empty */
size = NBLOCK; /* line is for type-in. */
if ((lp = (LINE *) malloc(sizeof(LINE)+size)) == NULL) {
mlwrite("Cannot allocate %d bytes", size);
return (NULL);
}
lp->l_size = size;
lp->l_used = used;
return (lp);
}
/*
* Delete line "lp". Fix all of the links that might point at it (they are
* moved to offset 0 of the next line. Unlink the line from whatever buffer it
* might be in. Release the memory. The buffers are updated too; the magic
* conditions described in the above comments don't hold here.
*/
lfree(lp)
register LINE *lp;
{
register BUFFER *bp;
register WINDOW *wp;
wp = wheadp;
while (wp != NULL) {
if (wp->w_linep == lp)
wp->w_linep = lp->l_fp;
if (wp->w_dotp == lp) {
wp->w_dotp = lp->l_fp;
wp->w_doto = 0;
}
if (wp->w_markp == lp) {
wp->w_markp = lp->l_fp;
wp->w_marko = 0;
}
wp = wp->w_wndp;
}
bp = bheadp;
while (bp != NULL) {
if (bp->b_nwnd == 0) {
if (bp->b_dotp == lp) {
bp->b_dotp = lp->l_fp;
bp->b_doto = 0;
}
if (bp->b_markp == lp) {
bp->b_markp = lp->l_fp;
bp->b_marko = 0;
}
}
bp = bp->b_bufp;
}
lp->l_bp->l_fp = lp->l_fp;
lp->l_fp->l_bp = lp->l_bp;
free((char *) lp);
}
/*
* This routine gets called when a character is changed in place in the current
* buffer. It updates all of the required flags in the buffer and window
* system. The flag used is passed as an argument; if the buffer is being
* displayed in more than 1 window we change EDIT t HARD. Set MODE if the
* mode line needs to be updated (the "*" has to be set).
*/
lchange(flag)
register int flag;
{
register WINDOW *wp;
if (curbp->b_nwnd != 1) /* Ensure hard. */
flag = WFHARD;
if ((curbp->b_flag&BFCHG) == 0) { /* First change, so */
flag |= WFMODE; /* update mode lines. */
curbp->b_flag |= BFCHG;
}
wp = wheadp;
while (wp != NULL) {
if (wp->w_bufp == curbp)
wp->w_flag |= flag;
wp = wp->w_wndp;
}
}
/*
* Insert "n" copies of the character "c" at the current location of dot. In
* the easy case all that happens is the text is stored in the line. In the
* hard case, the line has to be reallocated. When the window list is updated,
* take special care; I screwed it up once. You always update dot in the
* current window. You update mark, and a dot in another window, if it is
* greater than the place where you did the insert. Return TRUE if all is
* well, and FALSE on errors.
*/
linsert(n, c)
{
register char *cp1;
register char *cp2;
register LINE *lp1;
register LINE *lp2;
register LINE *lp3;
register int doto;
register int i;
register WINDOW *wp;
lchange(WFEDIT);
lp1 = curwp->w_dotp; /* Current line */
if (lp1 == curbp->b_linep) { /* At the end: special */
if (curwp->w_doto != 0) {
mlwrite("bug: linsert");
return (FALSE);
}
if ((lp2=lalloc(n)) == NULL) /* Allocate new line */
return (FALSE);
lp3 = lp1->l_bp; /* Previous line */
lp3->l_fp = lp2; /* Link in */
lp2->l_fp = lp1;
lp1->l_bp = lp2;
lp2->l_bp = lp3;
for (i=0; i<n; ++i)
lp2->l_text[i] = c;
curwp->w_dotp = lp2;
curwp->w_doto = n;
return (TRUE);
}
doto = curwp->w_doto; /* Save for later. */
if (lp1->l_used+n > lp1->l_size) { /* Hard: reallocate */
if ((lp2=lalloc(lp1->l_used+n)) == NULL)
return (FALSE);
cp1 = &lp1->l_text[0];
cp2 = &lp2->l_text[0];
while (cp1 != &lp1->l_text[doto])
*cp2++ = *cp1++;
cp2 += n;
while (cp1 != &lp1->l_text[lp1->l_used])
*cp2++ = *cp1++;
lp1->l_bp->l_fp = lp2;
lp2->l_fp = lp1->l_fp;
lp1->l_fp->l_bp = lp2;
lp2->l_bp = lp1->l_bp;
free((char *) lp1);
} else { /* Easy: in place */
lp2 = lp1; /* Pretend new line */
lp2->l_used += n;
cp2 = &lp1->l_text[lp1->l_used];
cp1 = cp2-n;
while (cp1 != &lp1->l_text[doto])
*--cp2 = *--cp1;
}
for (i=0; i<n; ++i) /* Add the characters */
lp2->l_text[doto+i] = c;
wp = wheadp; /* Update windows */
while (wp != NULL) {
if (wp->w_linep == lp1)
wp->w_linep = lp2;
if (wp->w_dotp == lp1) {
wp->w_dotp = lp2;
if (wp==curwp || wp->w_doto>doto)
wp->w_doto += n;
}
if (wp->w_markp == lp1) {
wp->w_markp = lp2;
if (wp->w_marko > doto)
wp->w_marko += n;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* Insert a newline into the buffer at the current location of dot in the
* current window. The funny ass-backwards way it does things is not a botch;
* it just makes the last line in the file not a special case. Return TRUE if
* everything works out and FALSE on error (memory allocation failure). The
* update of dot and mark is a bit easier then in the above case, because the
* split forces more updating.
*/
lnewline()
{
register char *cp1;
register char *cp2;
register LINE *lp1;
register LINE *lp2;
register int doto;
register WINDOW *wp;
lchange(WFHARD);
lp1 = curwp->w_dotp; /* Get the address and */
doto = curwp->w_doto; /* offset of "." */
if ((lp2=lalloc(doto)) == NULL) /* New first half line */
return (FALSE);
cp1 = &lp1->l_text[0]; /* Shuffle text around */
cp2 = &lp2->l_text[0];
while (cp1 != &lp1->l_text[doto])
*cp2++ = *cp1++;
cp2 = &lp1->l_text[0];
while (cp1 != &lp1->l_text[lp1->l_used])
*cp2++ = *cp1++;
lp1->l_used -= doto;
lp2->l_bp = lp1->l_bp;
lp1->l_bp = lp2;
lp2->l_bp->l_fp = lp2;
lp2->l_fp = lp1;
wp = wheadp; /* Windows */
while (wp != NULL) {
if (wp->w_linep == lp1)
wp->w_linep = lp2;
if (wp->w_dotp == lp1) {
if (wp->w_doto < doto)
wp->w_dotp = lp2;
else
wp->w_doto -= doto;
}
if (wp->w_markp == lp1) {
if (wp->w_marko < doto)
wp->w_markp = lp2;
else
wp->w_marko -= doto;
}
wp = wp->w_wndp;
}
return (TRUE);
}
/*
* This function deletes "n" bytes, starting at dot. It understands how do deal
* with end of lines, etc. It returns TRUE if all of the characters were
* deleted, and FALSE if they were not (because dot ran into the end of the
* buffer. The "kflag" is TRUE if the text should be put in the kill buffer.
*/
ldelete(n, kflag)
{
register char *cp1;
register char *cp2;
register LINE *dotp;
register int doto;
register int chunk;
register WINDOW *wp;
while (n != 0) {
dotp = curwp->w_dotp;
doto = curwp->w_doto;
if (dotp == curbp->b_linep) /* Hit end of buffer. */
return (FALSE);
chunk = dotp->l_used-doto; /* Size of chunk. */
if (chunk > n)
chunk = n;
if (chunk == 0) { /* End of line, merge. */
lchange(WFHARD);
if (ldelnewline() == FALSE
|| (kflag!=FALSE && kinsert('\n')==FALSE))
return (FALSE);
--n;
continue;
}
lchange(WFEDIT);
cp1 = &dotp->l_text[doto]; /* Scrunch text. */
cp2 = cp1 + chunk;
if (kflag != FALSE) { /* Kill? */
while (cp1 != cp2) {
if (kinsert(*cp1) == FALSE)
return (FALSE);
++cp1;
}
cp1 = &dotp->l_text[doto];
}
while (cp2 != &dotp->l_text[dotp->l_used])
*cp1++ = *cp2++;
dotp->l_used -= chunk;
wp = wheadp; /* Fix windows */
while (wp != NULL) {
if (wp->w_dotp==dotp && wp->w_doto>=doto) {
wp->w_doto -= chunk;
if (wp->w_doto < doto)
wp->w_doto = doto;
}
if (wp->w_markp==dotp && wp->w_marko>=doto) {
wp->w_marko -= chunk;
if (wp->w_marko < doto)
wp->w_marko = doto;
}
wp = wp->w_wndp;
}
n -= chunk;
}
return (TRUE);
}
/*
* Delete a newline. Join the current line with the next line. If the next line
* is the magic header line always return TRUE; merging the last line with the
* header line can be thought of as always being a successful operation, even
* if nothing is done, and this makes the kill buffer work "right". Easy cases
* can be done by shuffling data around. Hard cases require that lines be moved
* about in memory. Return FALSE on error and TRUE if all looks ok. Called by
* "ldelete" only.
*/
ldelnewline()
{
register char *cp1;
register char *cp2;
register LINE *lp1;
register LINE *lp2;
register LINE *lp3;
register WINDOW *wp;
lp1 = curwp->w_dotp;
lp2 = lp1->l_fp;
if (lp2 == curbp->b_linep) { /* At the buffer end. */
if (lp1->l_used == 0) /* Blank line. */
lfree(lp1);
return (TRUE);
}
if (lp2->l_used <= lp1->l_size-lp1->l_used) {
cp1 = &lp1->l_text[lp1->l_used];
cp2 = &lp2->l_text[0];
while (cp2 != &lp2->l_text[lp2->l_used])
*cp1++ = *cp2++;
wp = wheadp;
while (wp != NULL) {
if (wp->w_linep == lp2)
wp->w_linep = lp1;
if (wp->w_dotp == lp2) {
wp->w_dotp = lp1;
wp->w_doto += lp1->l_used;
}
if (wp->w_markp == lp2) {
wp->w_markp = lp1;
wp->w_marko += lp1->l_used;
}
wp = wp->w_wndp;
}
lp1->l_used += lp2->l_used;
lp1->l_fp = lp2->l_fp;
lp2->l_fp->l_bp = lp1;
free((char *) lp2);
return (TRUE);
}
if ((lp3=lalloc(lp1->l_used+lp2->l_used)) == NULL)
return (FALSE);
cp1 = &lp1->l_text[0];
cp2 = &lp3->l_text[0];
while (cp1 != &lp1->l_text[lp1->l_used])
*cp2++ = *cp1++;
cp1 = &lp2->l_text[0];
while (cp1 != &lp2->l_text[lp2->l_used])
*cp2++ = *cp1++;
lp1->l_bp->l_fp = lp3;
lp3->l_fp = lp2->l_fp;
lp2->l_fp->l_bp = lp3;
lp3->l_bp = lp1->l_bp;
wp = wheadp;
while (wp != NULL) {
if (wp->w_linep==lp1 || wp->w_linep==lp2)
wp->w_linep = lp3;
if (wp->w_dotp == lp1)
wp->w_dotp = lp3;
else if (wp->w_dotp == lp2) {
wp->w_dotp = lp3;
wp->w_doto += lp1->l_used;
}
if (wp->w_markp == lp1)
wp->w_markp = lp3;
else if (wp->w_markp == lp2) {
wp->w_markp = lp3;
wp->w_marko += lp1->l_used;
}
wp = wp->w_wndp;
}
free((char *) lp1);
free((char *) lp2);
return (TRUE);
}
/*
* Delete all of the text saved in the kill buffer. Called by commands when a
* new kill context is being created. The kill buffer array is released, just
* in case the buffer has grown to immense size. No errors.
*/
kdelete()
{
if (kbufp != NULL) {
free((char *) kbufp);
kbufp = NULL;
kused = 0;
ksize = 0;
}
}
/*
* Insert a character to the kill buffer, enlarging the buffer if there isn't
* any room. Always grow the buffer in chunks, on the assumption that if you
* put something in the kill buffer you are going to put more stuff there too
* later. Return TRUE if all is well, and FALSE on errors.
*/
kinsert(c)
{
register char *nbufp;
register int i;
if (kused == ksize) {
if ((nbufp=malloc(ksize+KBLOCK)) == NULL)
return (FALSE);
for (i=0; i<ksize; ++i)
nbufp[i] = kbufp[i];
if (kbufp != NULL)
free((char *) kbufp);
kbufp = nbufp;
ksize += KBLOCK;
}
kbufp[kused++] = c;
return (TRUE);
}
/*
* This function gets characters from the kill buffer. If the character index
* "n" is off the end, it returns "-1". This lets the caller just scan along
* until it gets a "-1" back.
*/
kremove(n)
{
if (n >= kused)
return (-1);
else
return (kbufp[n] & 0xFF);
}