commit 82dc8e6b9664608d6ee1151f9d8e983ebcebd048
parent 649348cbe04526502ce4fa572702d38146ea5d31
Author: Jochen Sprickerhof <git@jochen.sprickerhof.de>
Date: Thu, 11 Apr 2024 10:45:50 +0200
[st][patch][scrollback] update ring buffer to 0.9.2
Diffstat:
2 files changed, 731 insertions(+), 0 deletions(-)
diff --git a/st.suckless.org/patches/scrollback/index.md b/st.suckless.org/patches/scrollback/index.md
@@ -15,6 +15,7 @@ Download
Alternative implementation that uses a ring buffer for more
efficient scrolling:
+* [st-scrollback-ringbuffer-0.9.2.diff](st-scrollback-ringbuffer-0.9.2.diff)
* [st-scrollback-ringbuffer-0.8.5.diff](st-scrollback-ringbuffer-0.8.5.diff)
Apply the following patch on top of the previous to allow column and row reflow.
diff --git a/st.suckless.org/patches/scrollback/st-scrollback-ringbuffer-0.9.2.diff b/st.suckless.org/patches/scrollback/st-scrollback-ringbuffer-0.9.2.diff
@@ -0,0 +1,730 @@
+commit 0663bdf11a409961da5b1120741a69814da8ce65
+Author: Timo Röhling <timo@gaussglocke.de>
+Date: Tue Nov 23 19:45:33 2021 +0100
+
+ Terminal scrollback with ring buffer
+
+ This patch adds a ring buffer for scrollback to the terminal. The
+ advantage of using a ring buffer is that the common case, scrolling with
+ no static screen content, can be achieved very efficiently by
+ incrementing and decrementing the starting line (modulo buffer size).
+
+ The scrollback buffer is limited to HISTSIZE lines in order to bound
+ memory usage. As the lines are allocated on demand, it is possible to
+ implement unlimited scrollback with few changes. If the terminal is
+ reset, the scroll back buffer is reset, too.
+
+diff --git a/config.def.h b/config.def.h
+index 2cd740a..8b25d40 100644
+--- a/config.def.h
++++ b/config.def.h
+@@ -201,6 +201,8 @@ static Shortcut shortcuts[] = {
+ { TERMMOD, XK_Y, selpaste, {.i = 0} },
+ { ShiftMask, XK_Insert, selpaste, {.i = 0} },
+ { TERMMOD, XK_Num_Lock, numlock, {.i = 0} },
++ { ShiftMask, XK_Page_Up, kscrollup, {.i = -1} },
++ { ShiftMask, XK_Page_Down, kscrolldown, {.i = -1} },
+ };
+
+ /*
+diff --git a/st.c b/st.c
+index b9f66e7..d9b163e 100644
+--- a/st.c
++++ b/st.c
+@@ -43,6 +43,10 @@
+ #define ISCONTROL(c) (ISCONTROLC0(c) || ISCONTROLC1(c))
+ #define ISDELIM(u) (u && wcschr(worddelimiters, u))
+
++#define TSCREEN term.screen[IS_SET(MODE_ALTSCREEN)]
++#define TLINEOFFSET(y) (((y) + TSCREEN.cur - TSCREEN.off + TSCREEN.size) % TSCREEN.size)
++#define TLINE(y) (TSCREEN.buffer[TLINEOFFSET(y)])
++
+ enum term_mode {
+ MODE_WRAP = 1 << 0,
+ MODE_INSERT = 1 << 1,
+@@ -109,12 +113,21 @@ typedef struct {
+ int alt;
+ } Selection;
+
++/* Screen lines */
++typedef struct {
++ Line* buffer; /* ring buffer */
++ int size; /* size of buffer */
++ int cur; /* start of active screen */
++ int off; /* scrollback line offset */
++ TCursor sc; /* saved cursor */
++} LineBuffer;
++
+ /* Internal representation of the screen */
+ typedef struct {
+ int row; /* nb row */
+ int col; /* nb col */
+- Line *line; /* screen */
+- Line *alt; /* alternate screen */
++ LineBuffer screen[2]; /* screen and alternate screen */
++ int linelen; /* allocated line length */
+ int *dirty; /* dirtyness of lines */
+ TCursor c; /* cursor */
+ int ocx; /* old cursor col */
+@@ -203,6 +216,8 @@ static void tdeftran(char);
+ static void tstrsequence(uchar);
+
+ static void drawregion(int, int, int, int);
++static void clearline(Line, Glyph, int, int);
++static Line ensureline(Line);
+
+ static void selnormalize(void);
+ static void selscroll(int, int);
+@@ -408,11 +423,12 @@ int
+ tlinelen(int y)
+ {
+ int i = term.col;
++ Line line = TLINE(y);
+
+- if (term.line[y][i - 1].mode & ATTR_WRAP)
++ if (line[i - 1].mode & ATTR_WRAP)
+ return i;
+
+- while (i > 0 && term.line[y][i - 1].u == ' ')
++ while (i > 0 && line[i - 1].u == ' ')
+ --i;
+
+ return i;
+@@ -521,7 +537,7 @@ selsnap(int *x, int *y, int direction)
+ * Snap around if the word wraps around at the end or
+ * beginning of a line.
+ */
+- prevgp = &term.line[*y][*x];
++ prevgp = &TLINE(*y)[*x];
+ prevdelim = ISDELIM(prevgp->u);
+ for (;;) {
+ newx = *x + direction;
+@@ -536,14 +552,14 @@ selsnap(int *x, int *y, int direction)
+ yt = *y, xt = *x;
+ else
+ yt = newy, xt = newx;
+- if (!(term.line[yt][xt].mode & ATTR_WRAP))
++ if (!(TLINE(yt)[xt].mode & ATTR_WRAP))
+ break;
+ }
+
+ if (newx >= tlinelen(newy))
+ break;
+
+- gp = &term.line[newy][newx];
++ gp = &TLINE(newy)[newx];
+ delim = ISDELIM(gp->u);
+ if (!(gp->mode & ATTR_WDUMMY) && (delim != prevdelim
+ || (delim && gp->u != prevgp->u)))
+@@ -564,14 +580,14 @@ selsnap(int *x, int *y, int direction)
+ *x = (direction < 0) ? 0 : term.col - 1;
+ if (direction < 0) {
+ for (; *y > 0; *y += direction) {
+- if (!(term.line[*y-1][term.col-1].mode
++ if (!(TLINE(*y-1)[term.col-1].mode
+ & ATTR_WRAP)) {
+ break;
+ }
+ }
+ } else if (direction > 0) {
+ for (; *y < term.row-1; *y += direction) {
+- if (!(term.line[*y][term.col-1].mode
++ if (!(TLINE(*y)[term.col-1].mode
+ & ATTR_WRAP)) {
+ break;
+ }
+@@ -602,13 +618,13 @@ getsel(void)
+ }
+
+ if (sel.type == SEL_RECTANGULAR) {
+- gp = &term.line[y][sel.nb.x];
++ gp = &TLINE(y)[sel.nb.x];
+ lastx = sel.ne.x;
+ } else {
+- gp = &term.line[y][sel.nb.y == y ? sel.nb.x : 0];
++ gp = &TLINE(y)[sel.nb.y == y ? sel.nb.x : 0];
+ lastx = (sel.ne.y == y) ? sel.ne.x : term.col-1;
+ }
+- last = &term.line[y][MIN(lastx, linelen-1)];
++ last = &TLINE(y)[MIN(lastx, linelen-1)];
+ while (last >= gp && last->u == ' ')
+ --last;
+
+@@ -949,12 +965,15 @@ int
+ tattrset(int attr)
+ {
+ int i, j;
++ int y = TLINEOFFSET(0);
+
+ for (i = 0; i < term.row-1; i++) {
++ Line line = TSCREEN.buffer[y];
+ for (j = 0; j < term.col-1; j++) {
+- if (term.line[i][j].mode & attr)
++ if (line[j].mode & attr)
+ return 1;
+ }
++ y = (y+1) % TSCREEN.size;
+ }
+
+ return 0;
+@@ -976,14 +995,17 @@ void
+ tsetdirtattr(int attr)
+ {
+ int i, j;
++ int y = TLINEOFFSET(0);
+
+ for (i = 0; i < term.row-1; i++) {
++ Line line = TSCREEN.buffer[y];
+ for (j = 0; j < term.col-1; j++) {
+- if (term.line[i][j].mode & attr) {
++ if (line[j].mode & attr) {
+ tsetdirt(i, i);
+ break;
+ }
+ }
++ y = (y+1) % TSCREEN.size;
+ }
+ }
+
+@@ -996,27 +1018,19 @@ tfulldirt(void)
+ void
+ tcursor(int mode)
+ {
+- static TCursor c[2];
+- int alt = IS_SET(MODE_ALTSCREEN);
+-
+ if (mode == CURSOR_SAVE) {
+- c[alt] = term.c;
++ TSCREEN.sc = term.c;
+ } else if (mode == CURSOR_LOAD) {
+- term.c = c[alt];
+- tmoveto(c[alt].x, c[alt].y);
++ term.c = TSCREEN.sc;
++ tmoveto(term.c.x, term.c.y);
+ }
+ }
+
+ void
+ treset(void)
+ {
+- uint i;
+-
+- term.c = (TCursor){{
+- .mode = ATTR_NULL,
+- .fg = defaultfg,
+- .bg = defaultbg
+- }, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
++ int i, j;
++ Glyph g = (Glyph){ .fg = defaultfg, .bg = defaultbg};
+
+ memset(term.tabs, 0, term.col * sizeof(*term.tabs));
+ for (i = tabspaces; i < term.col; i += tabspaces)
+@@ -1028,17 +1042,37 @@ treset(void)
+ term.charset = 0;
+
+ for (i = 0; i < 2; i++) {
+- tmoveto(0, 0);
+- tcursor(CURSOR_SAVE);
+- tclearregion(0, 0, term.col-1, term.row-1);
+- tswapscreen();
++ term.screen[i].sc = (TCursor){{
++ .fg = defaultfg,
++ .bg = defaultbg
++ }};
++ term.screen[i].cur = 0;
++ term.screen[i].off = 0;
++ for (j = 0; j < term.row; ++j) {
++ if (term.col != term.linelen)
++ term.screen[i].buffer[j] = xrealloc(term.screen[i].buffer[j], term.col * sizeof(Glyph));
++ clearline(term.screen[i].buffer[j], g, 0, term.col);
++ }
++ for (j = term.row; j < term.screen[i].size; ++j) {
++ free(term.screen[i].buffer[j]);
++ term.screen[i].buffer[j] = NULL;
++ }
+ }
++ tcursor(CURSOR_LOAD);
++ term.linelen = term.col;
++ tfulldirt();
+ }
+
+ void
+ tnew(int col, int row)
+ {
+- term = (Term){ .c = { .attr = { .fg = defaultfg, .bg = defaultbg } } };
++ int i;
++ term = (Term){};
++ term.screen[0].buffer = xmalloc(HISTSIZE * sizeof(Line));
++ term.screen[0].size = HISTSIZE;
++ term.screen[1].buffer = NULL;
++ for (i = 0; i < HISTSIZE; ++i) term.screen[0].buffer[i] = NULL;
++
+ tresize(col, row);
+ treset();
+ }
+@@ -1046,14 +1080,42 @@ tnew(int col, int row)
+ void
+ tswapscreen(void)
+ {
+- Line *tmp = term.line;
+-
+- term.line = term.alt;
+- term.alt = tmp;
+ term.mode ^= MODE_ALTSCREEN;
+ tfulldirt();
+ }
+
++void
++kscrollup(const Arg *a)
++{
++ int n = a->i;
++
++ if (IS_SET(MODE_ALTSCREEN))
++ return;
++
++ if (n < 0) n = (-n) * term.row;
++ if (n > TSCREEN.size - term.row - TSCREEN.off) n = TSCREEN.size - term.row - TSCREEN.off;
++ while (!TLINE(-n)) --n;
++ TSCREEN.off += n;
++ selscroll(0, n);
++ tfulldirt();
++}
++
++void
++kscrolldown(const Arg *a)
++{
++
++ int n = a->i;
++
++ if (IS_SET(MODE_ALTSCREEN))
++ return;
++
++ if (n < 0) n = (-n) * term.row;
++ if (n > TSCREEN.off) n = TSCREEN.off;
++ TSCREEN.off -= n;
++ selscroll(0, -n);
++ tfulldirt();
++}
++
+ void
+ tscrolldown(int orig, int n)
+ {
+@@ -1062,15 +1124,29 @@ tscrolldown(int orig, int n)
+
+ LIMIT(n, 0, term.bot-orig+1);
+
+- tsetdirt(orig, term.bot-n);
+- tclearregion(0, term.bot-n+1, term.col-1, term.bot);
++ /* Ensure that lines are allocated */
++ for (i = -n; i < 0; i++) {
++ TLINE(i) = ensureline(TLINE(i));
++ }
+
+- for (i = term.bot; i >= orig+n; i--) {
+- temp = term.line[i];
+- term.line[i] = term.line[i-n];
+- term.line[i-n] = temp;
++ /* Shift non-scrolling areas in ring buffer */
++ for (i = term.bot+1; i < term.row; i++) {
++ temp = TLINE(i);
++ TLINE(i) = TLINE(i-n);
++ TLINE(i-n) = temp;
++ }
++ for (i = 0; i < orig; i++) {
++ temp = TLINE(i);
++ TLINE(i) = TLINE(i-n);
++ TLINE(i-n) = temp;
+ }
+
++ /* Scroll buffer */
++ TSCREEN.cur = (TSCREEN.cur + TSCREEN.size - n) % TSCREEN.size;
++ /* Clear lines that have entered the view */
++ tclearregion(0, orig, term.linelen-1, orig+n-1);
++ /* Redraw portion of the screen that has scrolled */
++ tsetdirt(orig+n-1, term.bot);
+ selscroll(orig, n);
+ }
+
+@@ -1082,15 +1158,29 @@ tscrollup(int orig, int n)
+
+ LIMIT(n, 0, term.bot-orig+1);
+
+- tclearregion(0, orig, term.col-1, orig+n-1);
+- tsetdirt(orig+n, term.bot);
++ /* Ensure that lines are allocated */
++ for (i = term.row; i < term.row + n; i++) {
++ TLINE(i) = ensureline(TLINE(i));
++ }
+
+- for (i = orig; i <= term.bot-n; i++) {
+- temp = term.line[i];
+- term.line[i] = term.line[i+n];
+- term.line[i+n] = temp;
++ /* Shift non-scrolling areas in ring buffer */
++ for (i = orig-1; i >= 0; i--) {
++ temp = TLINE(i);
++ TLINE(i) = TLINE(i+n);
++ TLINE(i+n) = temp;
++ }
++ for (i = term.row-1; i >term.bot; i--) {
++ temp = TLINE(i);
++ TLINE(i) = TLINE(i+n);
++ TLINE(i+n) = temp;
+ }
+
++ /* Scroll buffer */
++ TSCREEN.cur = (TSCREEN.cur + n) % TSCREEN.size;
++ /* Clear lines that have entered the view */
++ tclearregion(0, term.bot-n+1, term.linelen-1, term.bot);
++ /* Redraw portion of the screen that has scrolled */
++ tsetdirt(orig, term.bot-n+1);
+ selscroll(orig, -n);
+ }
+
+@@ -1194,6 +1284,7 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ "⎻", "─", "⎼", "⎽", "├", "┤", "┴", "┬", /* p - w */
+ "│", "≤", "≥", "π", "≠", "£", "·", /* x - ~ */
+ };
++ Line line = TLINE(y);
+
+ /*
+ * The table is proudly stolen from rxvt.
+@@ -1202,25 +1293,25 @@ tsetchar(Rune u, const Glyph *attr, int x, int y)
+ BETWEEN(u, 0x41, 0x7e) && vt100_0[u - 0x41])
+ utf8decode(vt100_0[u - 0x41], &u, UTF_SIZ);
+
+- if (term.line[y][x].mode & ATTR_WIDE) {
++ if (line[x].mode & ATTR_WIDE) {
+ if (x+1 < term.col) {
+- term.line[y][x+1].u = ' ';
+- term.line[y][x+1].mode &= ~ATTR_WDUMMY;
++ line[x+1].u = ' ';
++ line[x+1].mode &= ~ATTR_WDUMMY;
+ }
+- } else if (term.line[y][x].mode & ATTR_WDUMMY) {
+- term.line[y][x-1].u = ' ';
+- term.line[y][x-1].mode &= ~ATTR_WIDE;
++ } else if (line[x].mode & ATTR_WDUMMY) {
++ line[x-1].u = ' ';
++ line[x-1].mode &= ~ATTR_WIDE;
+ }
+
+ term.dirty[y] = 1;
+- term.line[y][x] = *attr;
+- term.line[y][x].u = u;
++ line[x] = *attr;
++ line[x].u = u;
+ }
+
+ void
+ tclearregion(int x1, int y1, int x2, int y2)
+ {
+- int x, y, temp;
++ int x, y, L, S, temp;
+ Glyph *gp;
+
+ if (x1 > x2)
+@@ -1228,15 +1319,16 @@ tclearregion(int x1, int y1, int x2, int y2)
+ if (y1 > y2)
+ temp = y1, y1 = y2, y2 = temp;
+
+- LIMIT(x1, 0, term.col-1);
+- LIMIT(x2, 0, term.col-1);
++ LIMIT(x1, 0, term.linelen-1);
++ LIMIT(x2, 0, term.linelen-1);
+ LIMIT(y1, 0, term.row-1);
+ LIMIT(y2, 0, term.row-1);
+
++ L = TLINEOFFSET(y1);
+ for (y = y1; y <= y2; y++) {
+ term.dirty[y] = 1;
+ for (x = x1; x <= x2; x++) {
+- gp = &term.line[y][x];
++ gp = &TSCREEN.buffer[L][x];
+ if (selected(x, y))
+ selclear();
+ gp->fg = term.c.attr.fg;
+@@ -1244,6 +1336,7 @@ tclearregion(int x1, int y1, int x2, int y2)
+ gp->mode = 0;
+ gp->u = ' ';
+ }
++ L = (L + 1) % TSCREEN.size;
+ }
+ }
+
+@@ -1258,7 +1351,7 @@ tdeletechar(int n)
+ dst = term.c.x;
+ src = term.c.x + n;
+ size = term.col - src;
+- line = term.line[term.c.y];
++ line = TLINE(term.c.y);
+
+ memmove(&line[dst], &line[src], size * sizeof(Glyph));
+ tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
+@@ -1275,7 +1368,7 @@ tinsertblank(int n)
+ dst = term.c.x + n;
+ src = term.c.x;
+ size = term.col - dst;
+- line = term.line[term.c.y];
++ line = TLINE(term.c.y);
+
+ memmove(&line[dst], &line[src], size * sizeof(Glyph));
+ tclearregion(src, term.c.y, dst - 1, term.c.y);
+@@ -2079,7 +2172,7 @@ tdumpline(int n)
+ char buf[UTF_SIZ];
+ const Glyph *bp, *end;
+
+- bp = &term.line[n][0];
++ bp = &TLINE(n)[0];
+ end = &bp[MIN(tlinelen(n), term.col) - 1];
+ if (bp != end || bp->u != ' ') {
+ for ( ; bp <= end; ++bp)
+@@ -2466,11 +2559,11 @@ check_control_code:
+ if (selected(term.c.x, term.c.y))
+ selclear();
+
+- gp = &term.line[term.c.y][term.c.x];
++ gp = &TLINE(term.c.y)[term.c.x];
+ if (IS_SET(MODE_WRAP) && (term.c.state & CURSOR_WRAPNEXT)) {
+ gp->mode |= ATTR_WRAP;
+ tnewline(1);
+- gp = &term.line[term.c.y][term.c.x];
++ gp = &TLINE(term.c.y)[term.c.x];
+ }
+
+ if (IS_SET(MODE_INSERT) && term.c.x+width < term.col) {
+@@ -2483,7 +2576,7 @@ check_control_code:
+ tnewline(1);
+ else
+ tmoveto(term.col - width, term.c.y);
+- gp = &term.line[term.c.y][term.c.x];
++ gp = &TLINE(term.c.y)[term.c.x];
+ }
+
+ tsetchar(u, &term.c.attr, term.c.x, term.c.y);
+@@ -2514,6 +2607,11 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ Rune u;
+ int n;
+
++ if (TSCREEN.off) {
++ TSCREEN.off = 0;
++ tfulldirt();
++ }
++
+ for (n = 0; n < buflen; n += charsize) {
+ if (IS_SET(MODE_UTF8)) {
+ /* process a complete utf8 char */
+@@ -2540,56 +2638,85 @@ twrite(const char *buf, int buflen, int show_ctrl)
+ }
+
+ void
+-tresize(int col, int row)
++clearline(Line line, Glyph g, int x, int xend)
+ {
+ int i;
++ g.mode = 0;
++ g.u = ' ';
++ for (i = x; i < xend; ++i) {
++ line[i] = g;
++ }
++}
++
++Line
++ensureline(Line line)
++{
++ if (!line) {
++ line = xmalloc(term.linelen * sizeof(Glyph));
++ }
++ return line;
++}
++
++void
++tresize(int col, int row)
++{
++ int i, j;
+ int minrow = MIN(row, term.row);
+ int mincol = MIN(col, term.col);
++ int linelen = MAX(col, term.linelen);
+ int *bp;
+- TCursor c;
+
+- if (col < 1 || row < 1) {
++ if (col < 1 || row < 1 || row > HISTSIZE) {
+ fprintf(stderr,
+ "tresize: error resizing to %dx%d\n", col, row);
+ return;
+ }
+
+- /*
+- * slide screen to keep cursor where we expect it -
+- * tscrollup would work here, but we can optimize to
+- * memmove because we're freeing the earlier lines
+- */
+- for (i = 0; i <= term.c.y - row; i++) {
+- free(term.line[i]);
+- free(term.alt[i]);
++ /* Shift buffer to keep the cursor where we expect it */
++ if (row <= term.c.y) {
++ term.screen[0].cur = (term.screen[0].cur - row + term.c.y + 1) % term.screen[0].size;
++ }
++
++ /* Resize and clear line buffers as needed */
++ if (linelen > term.linelen) {
++ for (i = 0; i < term.screen[0].size; ++i) {
++ if (term.screen[0].buffer[i]) {
++ term.screen[0].buffer[i] = xrealloc(term.screen[0].buffer[i], linelen * sizeof(Glyph));
++ clearline(term.screen[0].buffer[i], term.c.attr, term.linelen, linelen);
++ }
++ }
++ for (i = 0; i < minrow; ++i) {
++ term.screen[1].buffer[i] = xrealloc(term.screen[1].buffer[i], linelen * sizeof(Glyph));
++ clearline(term.screen[1].buffer[i], term.c.attr, term.linelen, linelen);
++ }
+ }
+- /* ensure that both src and dst are not NULL */
+- if (i > 0) {
+- memmove(term.line, term.line + i, row * sizeof(Line));
+- memmove(term.alt, term.alt + i, row * sizeof(Line));
++ /* Allocate all visible lines for regular line buffer */
++ for (j = term.screen[0].cur, i = 0; i < row; ++i, j = (j + 1) % term.screen[0].size)
++ {
++ if (!term.screen[0].buffer[j]) {
++ term.screen[0].buffer[j] = xmalloc(linelen * sizeof(Glyph));
++ }
++ if (i >= term.row) {
++ clearline(term.screen[0].buffer[j], term.c.attr, 0, linelen);
++ }
+ }
+- for (i += row; i < term.row; i++) {
+- free(term.line[i]);
+- free(term.alt[i]);
++ /* Resize alt screen */
++ term.screen[1].cur = 0;
++ term.screen[1].size = row;
++ for (i = row; i < term.row; ++i) {
++ free(term.screen[1].buffer[i]);
++ }
++ term.screen[1].buffer = xrealloc(term.screen[1].buffer, row * sizeof(Line));
++ for (i = term.row; i < row; ++i) {
++ term.screen[1].buffer[i] = xmalloc(linelen * sizeof(Glyph));
++ clearline(term.screen[1].buffer[i], term.c.attr, 0, linelen);
+ }
+
+ /* resize to new height */
+- term.line = xrealloc(term.line, row * sizeof(Line));
+- term.alt = xrealloc(term.alt, row * sizeof(Line));
+ term.dirty = xrealloc(term.dirty, row * sizeof(*term.dirty));
+ term.tabs = xrealloc(term.tabs, col * sizeof(*term.tabs));
+
+- /* resize each row to new width, zero-pad if needed */
+- for (i = 0; i < minrow; i++) {
+- term.line[i] = xrealloc(term.line[i], col * sizeof(Glyph));
+- term.alt[i] = xrealloc(term.alt[i], col * sizeof(Glyph));
+- }
+-
+- /* allocate any new rows */
+- for (/* i = minrow */; i < row; i++) {
+- term.line[i] = xmalloc(col * sizeof(Glyph));
+- term.alt[i] = xmalloc(col * sizeof(Glyph));
+- }
++ /* fix tabstops */
+ if (col > term.col) {
+ bp = term.tabs + term.col;
+
+@@ -2599,26 +2726,16 @@ tresize(int col, int row)
+ for (bp += tabspaces; bp < term.tabs + col; bp += tabspaces)
+ *bp = 1;
+ }
++
+ /* update terminal size */
+ term.col = col;
+ term.row = row;
++ term.linelen = linelen;
+ /* reset scrolling region */
+ tsetscroll(0, row-1);
+ /* make use of the LIMIT in tmoveto */
+ tmoveto(term.c.x, term.c.y);
+- /* Clearing both screens (it makes dirty all lines) */
+- c = term.c;
+- for (i = 0; i < 2; i++) {
+- if (mincol < col && 0 < minrow) {
+- tclearregion(mincol, 0, col - 1, minrow - 1);
+- }
+- if (0 < col && minrow < row) {
+- tclearregion(0, minrow, col - 1, row - 1);
+- }
+- tswapscreen();
+- tcursor(CURSOR_LOAD);
+- }
+- term.c = c;
++ tfulldirt();
+ }
+
+ void
+@@ -2630,14 +2747,15 @@ resettitle(void)
+ void
+ drawregion(int x1, int y1, int x2, int y2)
+ {
+- int y;
++ int y, L;
+
++ L = TLINEOFFSET(y1);
+ for (y = y1; y < y2; y++) {
+- if (!term.dirty[y])
+- continue;
+-
+- term.dirty[y] = 0;
+- xdrawline(term.line[y], x1, y, x2);
++ if (term.dirty[y]) {
++ term.dirty[y] = 0;
++ xdrawline(TSCREEN.buffer[L], x1, y, x2);
++ }
++ L = (L + 1) % TSCREEN.size;
+ }
+ }
+
+@@ -2652,14 +2770,15 @@ draw(void)
+ /* adjust cursor position */
+ LIMIT(term.ocx, 0, term.col-1);
+ LIMIT(term.ocy, 0, term.row-1);
+- if (term.line[term.ocy][term.ocx].mode & ATTR_WDUMMY)
++ if (TLINE(term.ocy)[term.ocx].mode & ATTR_WDUMMY)
+ term.ocx--;
+- if (term.line[term.c.y][cx].mode & ATTR_WDUMMY)
++ if (TLINE(term.c.y)[cx].mode & ATTR_WDUMMY)
+ cx--;
+
+ drawregion(0, 0, term.col, term.row);
+- xdrawcursor(cx, term.c.y, term.line[term.c.y][cx],
+- term.ocx, term.ocy, term.line[term.ocy][term.ocx]);
++ if (TSCREEN.off == 0)
++ xdrawcursor(cx, term.c.y, TLINE(term.c.y)[cx],
++ term.ocx, term.ocy, TLINE(term.ocy)[term.ocx]);
+ term.ocx = cx;
+ term.ocy = term.c.y;
+ xfinishdraw();
+diff --git a/st.h b/st.h
+index fd3b0d8..3cea73b 100644
+--- a/st.h
++++ b/st.h
+@@ -19,6 +19,7 @@
+
+ #define TRUECOLOR(r,g,b) (1 << 24 | (r) << 16 | (g) << 8 | (b))
+ #define IS_TRUECOL(x) (1 << 24 & (x))
++#define HISTSIZE 2000
+
+ enum glyph_attribute {
+ ATTR_NULL = 0,
+diff --git a/x.c b/x.c
+index bd23686..25785a6 100644
+--- a/x.c
++++ b/x.c
+@@ -59,6 +59,8 @@ static void zoom(const Arg *);
+ static void zoomabs(const Arg *);
+ static void zoomreset(const Arg *);
+ static void ttysend(const Arg *);
++void kscrollup(const Arg *);
++void kscrolldown(const Arg *);
+
+ /* config.h for applying patches and the configuration. */
+ #include "config.h"
