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- /*
- * This file is part of the UCB release of Plan 9. It is subject to the license
- * terms in the LICENSE file found in the top-level directory of this
- * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
- * part of the UCB release of Plan 9, including this file, may be copied,
- * modified, propagated, or distributed except according to the terms contained
- * in the LICENSE file.
- */
- #include <u.h>
- #include <libc.h>
- #include <draw.h>
- #include <thread.h>
- #include <cursor.h>
- #include <mouse.h>
- #include <keyboard.h>
- #include <frame.h>
- #include <fcall.h>
- #include <plumb.h>
- #include "dat.h"
- #include "fns.h"
- enum
- {
- Slop = 100, /* room to grow with reallocation */
- };
- static
- void
- sizecache(Buffer *b, uint n)
- {
- if(n <= b->cmax)
- return;
- b->cmax = n+Slop;
- b->c = runerealloc(b->c, b->cmax);
- }
- static
- void
- addblock(Buffer *b, uint i, uint n)
- {
- if(i > b->nbl)
- error("internal error: addblock");
- b->bl = realloc(b->bl, (b->nbl+1)*sizeof b->bl[0]);
- if(i < b->nbl)
- memmove(b->bl+i+1, b->bl+i, (b->nbl-i)*sizeof(Block*));
- b->bl[i] = disknewblock(disk, n);
- b->nbl++;
- }
- static
- void
- delblock(Buffer *b, uint i)
- {
- if(i >= b->nbl)
- error("internal error: delblock");
- diskrelease(disk, b->bl[i]);
- b->nbl--;
- if(i < b->nbl)
- memmove(b->bl+i, b->bl+i+1, (b->nbl-i)*sizeof(Block*));
- b->bl = realloc(b->bl, b->nbl*sizeof b->bl[0]);
- }
- /*
- * Move cache so b->cq <= q0 < b->cq+b->cnc.
- * If at very end, q0 will fall on end of cache block.
- */
- static
- void
- flush(Buffer *b)
- {
- if(b->cdirty || b->cnc==0){
- if(b->cnc == 0)
- delblock(b, b->cbi);
- else
- diskwrite(disk, &b->bl[b->cbi], b->c, b->cnc);
- b->cdirty = FALSE;
- }
- }
- static
- void
- setcache(Buffer *b, uint q0)
- {
- Block **blp, *bl;
- uint i, q;
- if(q0 > b->nc)
- error("internal error: setcache");
- /*
- * flush and reload if q0 is not in cache.
- */
- if(b->nc == 0 || (b->cq<=q0 && q0<b->cq+b->cnc))
- return;
- /*
- * if q0 is at end of file and end of cache, continue to grow this block
- */
- if(q0==b->nc && q0==b->cq+b->cnc && b->cnc<Maxblock)
- return;
- flush(b);
- /* find block */
- if(q0 < b->cq){
- q = 0;
- i = 0;
- }else{
- q = b->cq;
- i = b->cbi;
- }
- blp = &b->bl[i];
- while(q+(*blp)->n <= q0 && q+(*blp)->n < b->nc){
- q += (*blp)->n;
- i++;
- blp++;
- if(i >= b->nbl)
- error("block not found");
- }
- bl = *blp;
- /* remember position */
- b->cbi = i;
- b->cq = q;
- sizecache(b, bl->n);
- b->cnc = bl->n;
- /*read block*/
- diskread(disk, bl, b->c, b->cnc);
- }
- void
- bufinsert(Buffer *b, uint q0, Rune *s, uint n)
- {
- uint i, m, t, off;
- if(q0 > b->nc)
- error("internal error: bufinsert");
- while(n > 0){
- setcache(b, q0);
- off = q0-b->cq;
- if(b->cnc+n <= Maxblock){
- /* Everything fits in one block. */
- t = b->cnc+n;
- m = n;
- if(b->bl == nil){ /* allocate */
- if(b->cnc != 0)
- error("internal error: bufinsert1 cnc!=0");
- addblock(b, 0, t);
- b->cbi = 0;
- }
- sizecache(b, t);
- runemove(b->c+off+m, b->c+off, b->cnc-off);
- runemove(b->c+off, s, m);
- b->cnc = t;
- goto Tail;
- }
- /*
- * We must make a new block. If q0 is at
- * the very beginning or end of this block,
- * just make a new block and fill it.
- */
- if(q0==b->cq || q0==b->cq+b->cnc){
- if(b->cdirty)
- flush(b);
- m = min(n, Maxblock);
- if(b->bl == nil){ /* allocate */
- if(b->cnc != 0)
- error("internal error: bufinsert2 cnc!=0");
- i = 0;
- }else{
- i = b->cbi;
- if(q0 > b->cq)
- i++;
- }
- addblock(b, i, m);
- sizecache(b, m);
- runemove(b->c, s, m);
- b->cq = q0;
- b->cbi = i;
- b->cnc = m;
- goto Tail;
- }
- /*
- * Split the block; cut off the right side and
- * let go of it.
- */
- m = b->cnc-off;
- if(m > 0){
- i = b->cbi+1;
- addblock(b, i, m);
- diskwrite(disk, &b->bl[i], b->c+off, m);
- b->cnc -= m;
- }
- /*
- * Now at end of block. Take as much input
- * as possible and tack it on end of block.
- */
- m = min(n, Maxblock-b->cnc);
- sizecache(b, b->cnc+m);
- runemove(b->c+b->cnc, s, m);
- b->cnc += m;
- Tail:
- b->nc += m;
- q0 += m;
- s += m;
- n -= m;
- b->cdirty = TRUE;
- }
- }
- void
- bufdelete(Buffer *b, uint q0, uint q1)
- {
- uint m, n, off;
- if(!(q0<=q1 && q0<=b->nc && q1<=b->nc))
- error("internal error: bufdelete");
- while(q1 > q0){
- setcache(b, q0);
- off = q0-b->cq;
- if(q1 > b->cq+b->cnc)
- n = b->cnc - off;
- else
- n = q1-q0;
- m = b->cnc - (off+n);
- if(m > 0)
- runemove(b->c+off, b->c+off+n, m);
- b->cnc -= n;
- b->cdirty = TRUE;
- q1 -= n;
- b->nc -= n;
- }
- }
- static int
- bufloader(void *v, uint q0, Rune *r, int nr)
- {
- bufinsert(v, q0, r, nr);
- return nr;
- }
- uint
- loadfile(int fd, uint q0, int *nulls, int(*f)(void*, uint, Rune*, int), void *arg)
- {
- char *p;
- Rune *r;
- int l, m, n, nb, nr;
- uint q1;
- p = emalloc((Maxblock+UTFmax+1)*sizeof p[0]);
- r = runemalloc(Maxblock);
- m = 0;
- n = 1;
- q1 = q0;
- /*
- * At top of loop, may have m bytes left over from
- * last pass, possibly representing a partial rune.
- */
- while(n > 0){
- n = read(fd, p+m, Maxblock);
- if(n < 0){
- warning(nil, "read error in Buffer.load");
- break;
- }
- m += n;
- p[m] = 0;
- l = m;
- if(n > 0)
- l -= UTFmax;
- cvttorunes(p, l, r, &nb, &nr, nulls);
- memmove(p, p+nb, m-nb);
- m -= nb;
- q1 += (*f)(arg, q1, r, nr);
- }
- free(p);
- free(r);
- return q1-q0;
- }
- uint
- bufload(Buffer *b, uint q0, int fd, int *nulls)
- {
- if(q0 > b->nc)
- error("internal error: bufload");
- return loadfile(fd, q0, nulls, bufloader, b);
- }
- void
- bufread(Buffer *b, uint q0, Rune *s, uint n)
- {
- uint m;
- if(!(q0<=b->nc && q0+n<=b->nc))
- error("bufread: internal error");
- while(n > 0){
- setcache(b, q0);
- m = min(n, b->cnc-(q0-b->cq));
- runemove(s, b->c+(q0-b->cq), m);
- q0 += m;
- s += m;
- n -= m;
- }
- }
- void
- bufreset(Buffer *b)
- {
- int i;
- b->nc = 0;
- b->cnc = 0;
- b->cq = 0;
- b->cdirty = 0;
- b->cbi = 0;
- /* delete backwards to avoid n² behavior */
- for(i=b->nbl-1; --i>=0; )
- delblock(b, i);
- }
- void
- bufclose(Buffer *b)
- {
- bufreset(b);
- free(b->c);
- b->c = nil;
- b->cnc = 0;
- free(b->bl);
- b->bl = nil;
- b->nbl = 0;
- }
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