Snapshot what is displayed.

1 files changed, 37 insertions, 13 deletions

diff --git a/pw.c b/pw.c
index e9026b3..e7669f1 100644
--- a/pw.c
+++ b/pw.c
@@ -26,6 +26,9 @@ typedef struct dstr {
 
 #define dstr_of(str) ((dstr *) ((str) - sizeof (dstr)))
 
+char **snapshot;
+int snaplines;
+
 static void panic(const char *fmt, ...)
 {
   va_list vl;
@@ -189,13 +192,20 @@ static void drawstatus(unsigned stat, char *cmd)
 static void redraw(char **circbuf, int nlines, int hpos,
                    int columns, unsigned stat, char *cmd)
 {
+  if (snapshot) {
+    for (int i = 0; i < snaplines; i++)
+     dsdrop(snapshot[i]);
+  }
+  snaplines = nlines;
   printf("\r\033[%dA\033[J", nlines);
-  for (int i = 0; i < nlines; i++)
+  for (int i = 0; i < nlines; i++) {
     drawline(circbuf[i], hpos, columns);
+    snapshot[i] = dsref(circbuf[i]);
+  }
   drawstatus(stat, cmd);
 }
 
-static void execute(char *cmd, char **circbuf, int nlines)
+static void execute(char *cmd)
 {
   char *arg = cmd + 1 + strspn(cmd + 1, " \t");
 
@@ -212,8 +222,8 @@ static void execute(char *cmd, char **circbuf, int nlines)
         break;
       }
 
-      for (int i = 0; ok && i < nlines; i++)
-        if (fprintf(f, "%s\n", circbuf[i]) < 0) {
+      for (int i = 0; ok && i < snaplines; i++)
+        if (fprintf(f, "%s\n", snapshot[i]) < 0) {
           sprintf(cmd, "write error!");
           ok = 0;
           break;
@@ -235,8 +245,8 @@ static void execute(char *cmd, char **circbuf, int nlines)
         break;
       }
 
-      for (int i = 0; i < nlines && ok; i++)
-        if (fprintf(p, "%s\n", circbuf[i]) < 0) {
+      for (int i = 0; i < snaplines && ok; i++)
+        if (fprintf(p, "%s\n", snapshot[i]) < 0) {
           sprintf(cmd, "write error!");
           ok = 0;
           break;
@@ -307,7 +317,9 @@ int main(int argc, char **argv)
   if (maxlines <= 0 || maxlines > 1000)
     error("%d is an unreasonable number of lines to display", maxlines);
 
-  if ((circbuf = malloc(sizeof *circbuf * maxlines)) == 0)
+  if ((circbuf = calloc(sizeof *circbuf, maxlines)) == 0)
+    panic("out of memory");
+  if ((snapshot = calloc(sizeof *snapshot, maxlines)) == 0)
     panic("out of memory");
 
   if (isatty(fd)) {
@@ -388,10 +400,15 @@ int main(int argc, char **argv)
               stat |= stat_dirty;
             }
           } else {
-            circbuf[nlines++] = line;
-            clear_cur_line();
-            drawline(line, hpos, columns);
-            drawstatus(stat, colcmd);
+            if ((stat & stat_susp)) {
+              dsdrop(line);
+            } else {
+              circbuf[nlines++] = line;
+              snapshot[snaplines++] = dsref(line);
+              clear_cur_line();
+              drawline(line, hpos, columns);
+              drawstatus(stat, colcmd);
+            }
           }
         } else {
           if (auto_quit)
@@ -438,8 +455,15 @@ int main(int argc, char **argv)
             stat |= stat_dirty;
             break;
           case ' ':
-            if ((stat & stat_eof) == 0)
+            if ((stat & stat_eof) == 0) {
               stat |= (stat_dirty | stat_susp);
+              for (int i = 0; i < nlines || i < snaplines; i++) {
+                if (i < nlines)
+                  dsdrop(circbuf[i]);
+                circbuf[i] = (i < snaplines) ? dsref(snapshot[i]) : 0;
+              }
+              nlines = snaplines;
+            }
             break;
           case 13:
             stat &= ~stat_susp;
@@ -480,7 +504,7 @@ int main(int argc, char **argv)
             kbd_state = kbd_cmd;
             stat |= stat_dirty;
             if (ch == 13 && cmdbuf[0]) {
-              execute(cmdbuf, circbuf, nlines);
+              execute(cmdbuf);
               stat &= ~stat_dirty;
               kbd_state = kbd_result;
               break;