From 17e59ccc22016239a8f6f8eb8f4e02583ee613e0 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 7 Nov 2016 16:15:46 +0530
Subject: [PATCH] LineBuf.insert_lines

---
 kitty/data-types.h       |  2 +-
 kitty/line-buf.c         | 47 +++++++++++++++++++++++++++++++++++-----
 kitty/screen.py          |  7 +-----
 kitty_tests/datatypes.py | 26 ++++++++++++++++++++++
 4 files changed, 69 insertions(+), 13 deletions(-)

diff --git a/kitty/data-types.h b/kitty/data-types.h
index 16f4ad59d..c939236ec 100644
--- a/kitty/data-types.h
+++ b/kitty/data-types.h
@@ -108,7 +108,7 @@ typedef struct {
     PyObject_HEAD
 
     uint8_t *buf;
-    index_type xnum, ynum, *line_map;
+    index_type xnum, ynum, *line_map, *scratch;
     index_type block_size;
     uint8_t *continued_map;
     Line *line;
diff --git a/kitty/line-buf.c b/kitty/line-buf.c
index 36b43f372..44e7c57ce 100644
--- a/kitty/line-buf.c
+++ b/kitty/line-buf.c
@@ -51,9 +51,10 @@ new(PyTypeObject *type, PyObject *args, PyObject UNUSED *kwds) {
         self->block_size = xnum * ynum;
         self->buf = PyMem_Calloc(xnum * ynum, CELL_SIZE);
         self->line_map = PyMem_Calloc(ynum, sizeof(index_type));
+        self->scratch = PyMem_Calloc(ynum, sizeof(index_type));
         self->continued_map = PyMem_Calloc(ynum, sizeof(uint8_t));
         self->line = alloc_line();
-        if (self->buf == NULL || self->line_map == NULL || self->continued_map == NULL || self->line == NULL) {
+        if (self->buf == NULL || self->line_map == NULL || self->scratch == NULL || self->continued_map == NULL || self->line == NULL) {
             PyErr_NoMemory();
             PyMem_Free(self->buf); PyMem_Free(self->line_map); PyMem_Free(self->continued_map); Py_CLEAR(self->line);
             Py_CLEAR(self);
@@ -75,7 +76,7 @@ new(PyTypeObject *type, PyObject *args, PyObject UNUSED *kwds) {
 
 static void
 dealloc(LineBuf* self) {
-    PyMem_Free(self->buf); PyMem_Free(self->line_map); PyMem_Free(self->continued_map);
+    PyMem_Free(self->buf); PyMem_Free(self->line_map); PyMem_Free(self->continued_map); PyMem_Free(self->scratch);
     Py_CLEAR(self->line);
     Py_TYPE(self)->tp_free((PyObject*)self);
 }
@@ -182,6 +183,12 @@ copy_line_to(LineBuf *self, PyObject *args) {
     Py_RETURN_NONE;
 }
 
+#define CLEAR_LINE(l) \
+    for (index_type i = 0; i < self->xnum; i++) l.chars[i] = (1 << ATTRS_SHIFT) | 32; \
+    memset(l.colors, 0, self->xnum * sizeof(color_type)); \
+    memset(l.decoration_fg, 0, self->xnum * sizeof(decoration_type)); \
+    memset(l.combining_chars, 0, self->xnum * sizeof(combining_type));
+
 static PyObject*
 clear_line(LineBuf *self, PyObject *val) {
 #define clear_line_doc "clear_line(y) -> Clear the specified line"
@@ -189,10 +196,7 @@ clear_line(LineBuf *self, PyObject *val) {
     Line l;
     if (y >= self->ynum) { PyErr_SetString(PyExc_ValueError, "Out of bounds"); return NULL; }
     INIT_LINE(self, &l, self->line_map[y]);
-    for (index_type i = 0; i < self->xnum; i++) l.chars[i] = (1 << ATTRS_SHIFT) | 32;
-    memset(l.colors, 0, self->xnum * sizeof(color_type));
-    memset(l.decoration_fg, 0, self->xnum * sizeof(decoration_type));
-    memset(l.combining_chars, 0, self->xnum * sizeof(combining_type));
+    CLEAR_LINE(l);
     self->continued_map[y] = 0;
     Py_RETURN_NONE;
 }
@@ -241,6 +245,36 @@ is_continued(LineBuf *self, PyObject *val) {
     Py_RETURN_FALSE;
 }
 
+static PyObject*
+insert_lines(LineBuf *self, PyObject *args) {
+#define insert_lines_doc "insert_lines(num, y, bottom) -> Insert num blank lines at y, only changing lines in the range [y, bottom]."
+    unsigned int y, num, bottom;
+    if (!PyArg_ParseTuple(args, "III", &num, &y, &bottom)) return NULL;
+    if (y >= self->ynum || y > bottom || bottom >= self->ynum) { PyErr_SetString(PyExc_ValueError, "Out of bounds"); return NULL; }
+    index_type ylimit = bottom + 1;
+    num = MIN(ylimit - y, num);
+    if (num > 0) {
+        for (index_type i = ylimit - num; i < ylimit; i++) {
+            self->scratch[i] = self->line_map[i];
+        }
+        for (index_type i = ylimit - 1; i >= y + num; i--) {
+            self->line_map[i] = self->line_map[i - num];
+            self->continued_map[i] = self->continued_map[i - num];
+        }
+        if (y + num < self->ynum) self->continued_map[y + num] = 0;
+        for (index_type i = 0; i < num; i++) {
+            self->line_map[y + i] = self->scratch[ylimit - num + i];
+        }
+        Line l;
+        for (index_type i = y; i < y + num; i++) {
+            INIT_LINE(self, &l, self->line_map[i]);
+            CLEAR_LINE(l);
+            self->continued_map[i] = 0;
+        }
+    }
+    Py_RETURN_NONE;
+}
+ 
 
 // Boilerplate {{{
 static PyObject*
@@ -258,6 +292,7 @@ static PyMethodDef methods[] = {
     METHOD(set_continued, METH_VARARGS)
     METHOD(index, METH_VARARGS)
     METHOD(reverse_index, METH_VARARGS)
+    METHOD(insert_lines, METH_VARARGS)
     METHOD(is_continued, METH_O)
     {NULL, NULL, 0, NULL}  /* Sentinel */
 };
diff --git a/kitty/screen.py b/kitty/screen.py
index 6a01f20c8..679a9cce7 100644
--- a/kitty/screen.py
+++ b/kitty/screen.py
@@ -570,13 +570,8 @@ class Screen:
 
         # If cursor is outside scrolling margins -- do nothin'.
         if top <= self.cursor.y <= bottom:
-            #                           v +1, because range() is exclusive.
-            for line in range(self.cursor.y,
-                              min(bottom + 1, self.cursor.y + count)):
-                self.linebuf.pop(bottom)
-                self.linebuf.insert(line, Line(self.columns))
+            self.linebuf.insert_lines(count, self.cursor.y, bottom)
             self.update_line_range(self.cursor.y, bottom)
-
             self.carriage_return()
 
     def delete_lines(self, count=1):
diff --git a/kitty_tests/datatypes.py b/kitty_tests/datatypes.py
index db20b9960..4b6a9aa66 100644
--- a/kitty_tests/datatypes.py
+++ b/kitty_tests/datatypes.py
@@ -57,6 +57,32 @@ class TestDataTypes(BaseTest):
         for i in range(1, 5):
             self.ae(lb.line(i), lb2.line(i-1))
 
+        lb = filled_line_buf(5, 5, filled_cursor())
+        clb = filled_line_buf(5, 5, filled_cursor())
+        lb2 = LineBuf(1, 5)
+        lb.insert_lines(2, 1, lb.ynum - 1)
+        self.ae(lb.line(0), clb.line(0))
+        self.ae(lb.line(3), clb.line(1))
+        self.ae(lb.line(4), clb.line(2))
+        self.ae(lb.line(1), lb2.line(0))
+        self.ae(lb.line(2), lb2.line(0))
+        lb = filled_line_buf(5, 5, filled_cursor())
+        lb.insert_lines(10, 0, lb.ynum - 1)
+        for i in range(lb.ynum):
+            self.ae(lb.line(i), lb2.line(0))
+        lb = filled_line_buf(5, 5, filled_cursor())
+        lb.insert_lines(10, 1, lb.ynum - 1)
+        self.ae(lb.line(0), clb.line(0))
+        for i in range(1, lb.ynum):
+            self.ae(lb.line(i), lb2.line(0))
+        lb = filled_line_buf(5, 5, filled_cursor())
+        lb.insert_lines(1, 1, 3)
+        self.ae(lb.line(0), clb.line(0))
+        self.ae(lb.line(1), lb2.line(0))
+        self.ae(lb.line(2), clb.line(1))
+        self.ae(lb.line(3), clb.line(2))
+        self.ae(lb.line(4), clb.line(4))
+
     def test_line(self):
         lb = LineBuf(2, 3)
         for y in range(lb.ynum):