Initial revision
diff --git a/src/cmd/sam/rasp.c b/src/cmd/sam/rasp.c
new file mode 100644
index 0000000..45ac820
--- /dev/null
+++ b/src/cmd/sam/rasp.c
@@ -0,0 +1,325 @@
+#include "sam.h"
+/*
+ * GROWDATASIZE must be big enough that all errors go out as Hgrowdata's,
+ * so they will be scrolled into visibility in the ~~sam~~ window (yuck!).
+ */
+#define GROWDATASIZE 50 /* if size is > this, send data with grow */
+
+void rcut(List*, Posn, Posn);
+int rterm(List*, Posn);
+void rgrow(List*, Posn, Posn);
+
+static Posn growpos;
+static Posn grown;
+static Posn shrinkpos;
+static Posn shrunk;
+
+/*
+ * rasp routines inform the terminal of changes to the file.
+ *
+ * a rasp is a list of spans within the file, and an indication
+ * of whether the terminal knows about the span.
+ *
+ * optimize by coalescing multiple updates to the same span
+ * if it is not known by the terminal.
+ *
+ * other possible optimizations: flush terminal's rasp by cut everything,
+ * insert everything if rasp gets too large.
+ */
+
+/*
+ * only called for initial load of file
+ */
+void
+raspload(File *f)
+{
+ if(f->rasp == nil)
+ return;
+ grown = f->_.nc;
+ growpos = 0;
+ if(f->_.nc)
+ rgrow(f->rasp, 0, f->_.nc);
+ raspdone(f, 1);
+}
+
+void
+raspstart(File *f)
+{
+ if(f->rasp == nil)
+ return;
+ grown = 0;
+ shrunk = 0;
+ noflush = 1;
+}
+
+void
+raspdone(File *f, int toterm)
+{
+ if(f->dot.r.p1 > f->_.nc)
+ f->dot.r.p1 = f->_.nc;
+ if(f->dot.r.p2 > f->_.nc)
+ f->dot.r.p2 = f->_.nc;
+ if(f->mark.p1 > f->_.nc)
+ f->mark.p1 = f->_.nc;
+ if(f->mark.p2 > f->_.nc)
+ f->mark.p2 = f->_.nc;
+ if(f->rasp == nil)
+ return;
+ if(grown)
+ outTsll(Hgrow, f->tag, growpos, grown);
+ else if(shrunk)
+ outTsll(Hcut, f->tag, shrinkpos, shrunk);
+ if(toterm)
+ outTs(Hcheck0, f->tag);
+ outflush();
+ noflush = 0;
+ if(f == cmd){
+ cmdpt += cmdptadv;
+ cmdptadv = 0;
+ }
+}
+
+void
+raspdelete(File *f, uint p1, uint p2, int toterm)
+{
+ long n;
+
+ n = p2 - p1;
+ if(n == 0)
+ return;
+
+ if(p2 <= f->dot.r.p1){
+ f->dot.r.p1 -= n;
+ f->dot.r.p2 -= n;
+ }
+ if(p2 <= f->mark.p1){
+ f->mark.p1 -= n;
+ f->mark.p2 -= n;
+ }
+
+ if(f->rasp == nil)
+ return;
+
+ if(f==cmd && p1<cmdpt){
+ if(p2 <= cmdpt)
+ cmdpt -= n;
+ else
+ cmdpt = p1;
+ }
+ if(toterm){
+ if(grown){
+ outTsll(Hgrow, f->tag, growpos, grown);
+ grown = 0;
+ }else if(shrunk && shrinkpos!=p1 && shrinkpos!=p2){
+ outTsll(Hcut, f->tag, shrinkpos, shrunk);
+ shrunk = 0;
+ }
+ if(!shrunk || shrinkpos==p2)
+ shrinkpos = p1;
+ shrunk += n;
+ }
+ rcut(f->rasp, p1, p2);
+}
+
+void
+raspinsert(File *f, uint p1, Rune *buf, uint n, int toterm)
+{
+ Range r;
+
+ if(n == 0)
+ return;
+
+ if(p1 < f->dot.r.p1){
+ f->dot.r.p1 += n;
+ f->dot.r.p2 += n;
+ }
+ if(p1 < f->mark.p1){
+ f->mark.p1 += n;
+ f->mark.p2 += n;
+ }
+
+
+ if(f->rasp == nil)
+ return;
+ if(f==cmd && p1<cmdpt)
+ cmdpt += n;
+ if(toterm){
+ if(shrunk){
+ outTsll(Hcut, f->tag, shrinkpos, shrunk);
+ shrunk = 0;
+ }
+ if(n>GROWDATASIZE || !rterm(f->rasp, p1)){
+ rgrow(f->rasp, p1, n);
+ if(grown && growpos+grown!=p1 && growpos!=p1){
+ outTsll(Hgrow, f->tag, growpos, grown);
+ grown = 0;
+ }
+ if(!grown)
+ growpos = p1;
+ grown += n;
+ }else{
+ if(grown){
+ outTsll(Hgrow, f->tag, growpos, grown);
+ grown = 0;
+ }
+ rgrow(f->rasp, p1, n);
+ r = rdata(f->rasp, p1, n);
+ if(r.p1!=p1 || r.p2!=p1+n)
+ panic("rdata in toterminal");
+ outTsllS(Hgrowdata, f->tag, p1, n, tmprstr(buf, n));
+ }
+ }else{
+ rgrow(f->rasp, p1, n);
+ r = rdata(f->rasp, p1, n);
+ if(r.p1!=p1 || r.p2!=p1+n)
+ panic("rdata in toterminal");
+ }
+}
+
+#define M 0x80000000L
+#define P(i) r->longptr[i]
+#define T(i) (P(i)&M) /* in terminal */
+#define L(i) (P(i)&~M) /* length of this piece */
+
+void
+rcut(List *r, Posn p1, Posn p2)
+{
+ Posn p, x;
+ int i;
+
+ if(p1 == p2)
+ panic("rcut 0");
+ for(p=0,i=0; i<r->nused && p+L(i)<=p1; p+=L(i++))
+ ;
+ if(i == r->nused)
+ panic("rcut 1");
+ if(p < p1){ /* chop this piece */
+ if(p+L(i) < p2){
+ x = p1-p;
+ p += L(i);
+ }else{
+ x = L(i)-(p2-p1);
+ p = p2;
+ }
+ if(T(i))
+ P(i) = x|M;
+ else
+ P(i) = x;
+ i++;
+ }
+ while(i<r->nused && p+L(i)<=p2){
+ p += L(i);
+ dellist(r, i);
+ }
+ if(p < p2){
+ if(i == r->nused)
+ panic("rcut 2");
+ x = L(i)-(p2-p);
+ if(T(i))
+ P(i) = x|M;
+ else
+ P(i) = x;
+ }
+ /* can we merge i and i-1 ? */
+ if(i>0 && i<r->nused && T(i-1)==T(i)){
+ x = L(i-1)+L(i);
+ dellist(r, i--);
+ if(T(i))
+ P(i)=x|M;
+ else
+ P(i)=x;
+ }
+}
+
+void
+rgrow(List *r, Posn p1, Posn n)
+{
+ Posn p;
+ int i;
+
+ if(n == 0)
+ panic("rgrow 0");
+ for(p=0,i=0; i<r->nused && p+L(i)<=p1; p+=L(i++))
+ ;
+ if(i == r->nused){ /* stick on end of file */
+ if(p!=p1)
+ panic("rgrow 1");
+ if(i>0 && !T(i-1))
+ P(i-1)+=n;
+ else
+ inslist(r, i, n);
+ }else if(!T(i)) /* goes in this empty piece */
+ P(i)+=n;
+ else if(p==p1 && i>0 && !T(i-1)) /* special case; simplifies life */
+ P(i-1)+=n;
+ else if(p==p1)
+ inslist(r, i, n);
+ else{ /* must break piece in terminal */
+ inslist(r, i+1, (L(i)-(p1-p))|M);
+ inslist(r, i+1, n);
+ P(i) = (p1-p)|M;
+ }
+}
+
+int
+rterm(List *r, Posn p1)
+{
+ Posn p;
+ int i;
+
+ for(p = 0,i = 0; i<r->nused && p+L(i)<=p1; p+=L(i++))
+ ;
+ if(i==r->nused && (i==0 || !T(i-1)))
+ return 0;
+ return T(i);
+}
+
+Range
+rdata(List *r, Posn p1, Posn n)
+{
+ Posn p;
+ int i;
+ Range rg;
+
+ if(n==0)
+ panic("rdata 0");
+ for(p = 0,i = 0; i<r->nused && p+L(i)<=p1; p+=L(i++))
+ ;
+ if(i==r->nused)
+ panic("rdata 1");
+ if(T(i)){
+ n-=L(i)-(p1-p);
+ if(n<=0){
+ rg.p1 = rg.p2 = p1;
+ return rg;
+ }
+ p+=L(i++);
+ p1 = p;
+ }
+ if(T(i) || i==r->nused)
+ panic("rdata 2");
+ if(p+L(i)<p1+n)
+ n = L(i)-(p1-p);
+ rg.p1 = p1;
+ rg.p2 = p1+n;
+ if(p!=p1){
+ inslist(r, i+1, L(i)-(p1-p));
+ P(i)=p1-p;
+ i++;
+ }
+ if(L(i)!=n){
+ inslist(r, i+1, L(i)-n);
+ P(i)=n;
+ }
+ P(i)|=M;
+ /* now i is set; can we merge? */
+ if(i<r->nused-1 && T(i+1)){
+ P(i)=(n+=L(i+1))|M;
+ dellist(r, i+1);
+ }
+ if(i>0 && T(i-1)){
+ P(i)=(n+L(i-1))|M;
+ dellist(r, i-1);
+ }
+ return rg;
+}
