From 614d14c999777898a8d560235767eca03faa9424 Mon Sep 17 00:00:00 2001
From: Ali Gholami Rudi <ali@rudi.ir>
Date: Sun, 21 Dec 2014 16:40:06 +0330
Subject: [PATCH] scrsnap: allocate memory for snapshots only when needed

---
 fbpad.c   |   7 +++--
 fbpad.h   |   7 +++--
 scrsnap.c | 104 +++++++++++++++++++++++++++++---------------------------------
 3 files changed, 56 insertions(+), 62 deletions(-)
 rewrite scrsnap.c (81%)

diff --git a/fbpad.c b/fbpad.c
index c5e391f..80225fe 100644
--- a/fbpad.c
+++ b/fbpad.c
@@ -77,12 +77,12 @@ static struct term *mainterm(void)
 static void switchterm(int oidx, int nidx, int show, int save, int load)
 {
 	if (save && TERMOPEN(oidx) && TERMSNAP(oidx))
-		scr_snap(&terms[oidx]);
+		scr_snap(oidx);
 	term_save(&terms[oidx]);
 	term_load(&terms[nidx], show);
 	if (show)
 		term_redraw(load && (!TERMOPEN(nidx) || !TERMSNAP(nidx) ||
-					scr_load(&terms[nidx])));
+					scr_load(nidx)));
 }
 
 static void showterm(int n)
@@ -255,7 +255,7 @@ static int pollterms(void)
 		if (ufds[i].revents & POLLIN) {
 			term_read();
 		} else {
-			scr_free(&terms[term_idx[i]]);
+			scr_free(term_idx[i]);
 			term_end();
 			if (cmdmode)
 				exitit = 1;
@@ -344,6 +344,7 @@ int main(int argc, char **argv)
 		args++;
 	mainloop(args[0] ? args : NULL);
 	pad_free();
+	scr_done();
 failed:
 	write(1, show, strlen(show));
 	return 0;
diff --git a/fbpad.h b/fbpad.h
index 136158e..26c475b 100644
--- a/fbpad.h
+++ b/fbpad.h
@@ -70,6 +70,7 @@ int font_cols(struct font *font);
 int font_bitmap(struct font *font, void *dst, int c);
 
 /* scrsnap.c */
-void scr_snap(void *owner);
-int scr_load(void *owner);
-void scr_free(void *owner);
+void scr_snap(int idx);
+int scr_load(int idx);
+void scr_free(int idx);
+void scr_done(void);
diff --git a/scrsnap.c b/scrsnap.c
dissimilarity index 81%
index b977b84..1f0d93a 100644
--- a/scrsnap.c
+++ b/scrsnap.c
@@ -1,56 +1,48 @@
-#include <stdlib.h>
-#include <string.h>
-#include "config.h"
-#include "draw.h"
-
-#define NSCRS		((sizeof(saved) - 1) * 2)
-#define SNAPSZ		(1 << 23)
-
-static char saved[] = TAGS_SAVED;
-static char scrs[NSCRS][SNAPSZ];
-static void *owners[NSCRS];
-
-static int scr_find(void *owner)
-{
-	int i;
-	for (i = 0; i < NSCRS; i++)
-		if (owners[i] == owner)
-			return i;
-	return -1;
-}
-
-static int scr_slot(void)
-{
-	int index = scr_find(NULL);
-	return index > -1 ? index : 0;
-}
-
-void scr_snap(void *owner)
-{
-	int rowsz = sizeof(fbval_t) * fb_cols();
-	int scr = scr_slot();
-	int i;
-	for (i = 0; i < fb_rows(); i++)
-		memcpy(scrs[scr] + i * rowsz, fb_mem(i), rowsz);
-	owners[scr] = owner;
-}
-
-void scr_free(void *owner)
-{
-	int scr = scr_find(owner);
-	if (scr != -1)
-		owners[scr] = NULL;
-}
-
-int scr_load(void *owner)
-{
-	int rowsz = sizeof(fbval_t) * fb_cols();
-	int scr = scr_find(owner);
-	int i;
-	if (scr == -1)
-		return -1;
-	for (i = 0; i < fb_rows(); i++)
-		memcpy(fb_mem(i), scrs[scr] + i * rowsz, rowsz);
-	owners[scr] = NULL;
-	return 0;
-}
+#include <stdlib.h>
+#include <string.h>
+#include "draw.h"
+#include "fbpad.h"
+
+#define NSCRS		128
+
+static void *scrs[NSCRS];
+
+void scr_snap(int idx)
+{
+	int rowsz = FBM_BPP(fb_mode()) * fb_cols();
+	int i;
+	if (idx >= NSCRS)
+		return;
+	if (!scrs[idx])
+		scrs[idx] = malloc(fb_rows() * rowsz);
+	if (!scrs[idx])
+		return;
+	for (i = 0; i < fb_rows(); i++)
+		memcpy(scrs[idx] + i * rowsz, fb_mem(i), rowsz);
+}
+
+void scr_free(int idx)
+{
+	if (idx < NSCRS) {
+		free(scrs[idx]);
+		scrs[idx] = NULL;
+	}
+}
+
+int scr_load(int idx)
+{
+	int rowsz = FBM_BPP(fb_mode()) * fb_cols();
+	int i;
+	if (idx >= NSCRS || !scrs[idx])
+		return -1;
+	for (i = 0; i < fb_rows(); i++)
+		memcpy(fb_mem(i), scrs[idx] + i * rowsz, rowsz);
+	return 0;
+}
+
+void scr_done(void)
+{
+	int i;
+	for (i = 0; i < LEN(scrs); i++)
+		free(scrs[i]);
+}
-- 
2.11.4.GIT