diff options
Diffstat (limited to 'src/indent.c')
| -rw-r--r-- | src/indent.c | 60 |
1 files changed, 53 insertions, 7 deletions
diff --git a/src/indent.c b/src/indent.c index d2dfaee254e..cb368024d97 100644 --- a/src/indent.c +++ b/src/indent.c @@ -306,8 +306,8 @@ and point (e.g., control characters will have a width of 2 or 4, tabs will have a variable width). Ignores finite width of frame, which means that this function may return values greater than (frame-width). -In a buffer with very long lines, the value can be zero, because calculating -the exact number is very expensive. +In a buffer with very long lines, the value will be an approximation, +because calculating the exact number is very expensive. Whether the line is visible (if `selective-display' is t) has no effect; however, ^M is treated as end of line when `selective-display' is t. Text that has an invisible property is considered as having width 0, unless @@ -316,8 +316,6 @@ Text that has an invisible property is considered as having width 0, unless { Lisp_Object temp; - if (current_buffer->long_line_optimizations_p) - return make_fixnum (0); XSETFASTINT (temp, current_column ()); return temp; } @@ -346,6 +344,14 @@ current_column (void) && MODIFF == last_known_column_modified) return last_known_column; + ptrdiff_t line_beg = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, + NULL, NULL, 1); + + /* Avoid becoming abysmally slow for very long lines. */ + if (current_buffer->long_line_optimizations_p + && !NILP (Vlong_line_threshold) + && PT - line_beg > XFIXNUM (Vlong_line_threshold)) + return PT - line_beg; /* this is an approximation! */ /* If the buffer has overlays, text properties, or multibyte characters, use a more general algorithm. */ if (buffer_intervals (current_buffer) @@ -561,13 +567,53 @@ scan_for_column (ptrdiff_t *endpos, EMACS_INT *goalcol, ptrdiff_t scan, scan_byte, next_boundary, prev_pos, prev_bpos; scan = find_newline (PT, PT_BYTE, BEGV, BEGV_BYTE, -1, NULL, &scan_byte, 1); - next_boundary = scan; - prev_pos = scan; - prev_bpos = scan_byte; window = Fget_buffer_window (Fcurrent_buffer (), Qnil); w = ! NILP (window) ? XWINDOW (window) : NULL; + if (current_buffer->long_line_optimizations_p) + { + bool lines_truncated = false; + + if (!NILP (BVAR (current_buffer, truncate_lines))) + lines_truncated = true; + else if (w && FIXNUMP (Vtruncate_partial_width_windows)) + lines_truncated = + w->total_cols < XFIXNAT (Vtruncate_partial_width_windows); + else if (w && !NILP (Vtruncate_partial_width_windows)) + lines_truncated = + w->total_cols < FRAME_COLS (XFRAME (WINDOW_FRAME (w))); + /* Special optimization for buffers with long and truncated + lines: assumes that each character is a single column. */ + if (lines_truncated) + { + ptrdiff_t bolpos = scan; + /* The newline which ends this line or ZV. */ + ptrdiff_t eolpos = + find_newline (PT, PT_BYTE, ZV, ZV_BYTE, 1, NULL, NULL, 1); + + scan = bolpos + goal; + if (scan > end) + scan = end; + if (scan > eolpos) + scan = (eolpos == ZV ? ZV : eolpos - 1); + col = scan - bolpos; + if (col > large_hscroll_threshold) + { + prev_col = col - 1; + prev_pos = scan - 1; + prev_bpos = CHAR_TO_BYTE (scan); + goto endloop; + } + /* Restore the values we've overwritten above. */ + scan = bolpos; + col = 0; + } + } + next_boundary = scan; + prev_pos = scan; + prev_bpos = scan_byte; + memset (&cmp_it, 0, sizeof cmp_it); cmp_it.id = -1; composition_compute_stop_pos (&cmp_it, scan, scan_byte, end, Qnil); |