/* Caching facts about regions of the buffer, for optimization.
-Copyright (C) 1985-1989, 1993, 1995, 2001-2011
- Free Software Foundation, Inc.
+Copyright (C) 1985-1989, 1993, 1995, 2001-2014 Free Software Foundation,
+Inc.
This file is part of GNU Emacs.
#include <config.h>
#include <stdio.h>
-#include <setjmp.h>
#include "lisp.h"
+#include "character.h"
#include "buffer.h"
#include "region-cache.h"
revalidate_region_cache to see how this helps. */
struct boundary {
- EMACS_INT pos;
+ ptrdiff_t pos;
int value;
};
struct boundary *boundaries;
/* boundaries[gap_start ... gap_start + gap_len - 1] is the gap. */
- EMACS_INT gap_start, gap_len;
+ ptrdiff_t gap_start, gap_len;
/* The number of elements allocated to boundaries, not including the
gap. */
- EMACS_INT cache_len;
+ ptrdiff_t cache_len;
/* The areas that haven't changed since the last time we cleaned out
invalid entries from the cache. These overlap when the buffer is
entirely unchanged. */
- EMACS_INT beg_unchanged, end_unchanged;
+ ptrdiff_t beg_unchanged, end_unchanged;
/* The first and last positions in the buffer. Because boundaries
store their positions relative to the start (BEG) and end (Z) of
Yes, buffer_beg is always 1. It's there for symmetry with
buffer_end and the BEG and BUF_BEG macros. */
- EMACS_INT buffer_beg, buffer_end;
+ ptrdiff_t buffer_beg, buffer_end;
};
/* Return the position of boundary i in cache c. */
struct region_cache *
new_region_cache (void)
{
- struct region_cache *c
- = (struct region_cache *) xmalloc (sizeof (struct region_cache));
+ struct region_cache *c = xmalloc (sizeof *c);
c->gap_start = 0;
c->gap_len = NEW_CACHE_GAP;
c->cache_len = 0;
- c->boundaries =
- (struct boundary *) xmalloc ((c->gap_len + c->cache_len)
- * sizeof (*c->boundaries));
+ c->boundaries = xmalloc ((c->gap_len + c->cache_len)
+ * sizeof (*c->boundaries));
c->beg_unchanged = 0;
c->end_unchanged = 0;
This operation should be logarithmic in the number of cache
entries. It would be nice if it took advantage of locality of
reference, too, by searching entries near the last entry found. */
-static EMACS_INT
-find_cache_boundary (struct region_cache *c, EMACS_INT pos)
+static ptrdiff_t
+find_cache_boundary (struct region_cache *c, ptrdiff_t pos)
{
- EMACS_INT low = 0, high = c->cache_len;
+ ptrdiff_t low = 0, high = c->cache_len;
while (low + 1 < high)
{
/* mid is always a valid index, because low < high and ">> 1"
rounds down. */
- EMACS_INT mid = (low + high) >> 1;
- EMACS_INT boundary = BOUNDARY_POS (c, mid);
+ ptrdiff_t mid = (low >> 1) + (high >> 1) + (low & high & 1);
+ ptrdiff_t boundary = BOUNDARY_POS (c, mid);
if (pos < boundary)
high = mid;
}
/* Some testing. */
- if (BOUNDARY_POS (c, low) > pos
- || (low + 1 < c->cache_len
- && BOUNDARY_POS (c, low + 1) <= pos))
- abort ();
+ eassert (!(BOUNDARY_POS (c, low) > pos
+ || (low + 1 < c->cache_len
+ && BOUNDARY_POS (c, low + 1) <= pos)));
return low;
}
/* Move the gap of cache C to index POS, and make sure it has space
for at least MIN_SIZE boundaries. */
static void
-move_cache_gap (struct region_cache *c, EMACS_INT pos, EMACS_INT min_size)
+move_cache_gap (struct region_cache *c, ptrdiff_t pos, ptrdiff_t min_size)
{
/* Copy these out of the cache and into registers. */
- EMACS_INT gap_start = c->gap_start;
- EMACS_INT gap_len = c->gap_len;
- EMACS_INT buffer_beg = c->buffer_beg;
- EMACS_INT buffer_end = c->buffer_end;
-
- if (pos < 0
- || pos > c->cache_len)
- abort ();
+ ptrdiff_t gap_start = c->gap_start;
+ ptrdiff_t gap_len = c->gap_len;
+ ptrdiff_t buffer_beg = c->buffer_beg;
+ ptrdiff_t buffer_end = c->buffer_end;
/* We mustn't ever try to put the gap before the dummy start
boundary. That must always be start-relative. */
- if (pos == 0)
- abort ();
+ eassert (0 < pos && pos <= c->cache_len);
/* Need we move the gap right? */
while (gap_start < pos)
when the portion after the gap is smallest. */
if (gap_len < min_size)
{
- EMACS_INT i;
-
- /* Always make at least NEW_CACHE_GAP elements, as long as we're
- expanding anyway. */
- if (min_size < NEW_CACHE_GAP)
- min_size = NEW_CACHE_GAP;
+ ptrdiff_t i, nboundaries = c->cache_len;
c->boundaries =
- (struct boundary *) xrealloc (c->boundaries,
- ((min_size + c->cache_len)
- * sizeof (*c->boundaries)));
+ xpalloc (c->boundaries, &nboundaries, min_size - gap_len, -1,
+ sizeof *c->boundaries);
/* Some systems don't provide a version of the copy routine that
can be trusted to shift memory upward into an overlapping
region. memmove isn't widely available. */
- min_size -= gap_len;
+ min_size = nboundaries - c->cache_len - gap_len;
for (i = c->cache_len - 1; i >= gap_start; i--)
{
c->boundaries[i + min_size].pos = c->boundaries[i + gap_len].pos;
/* Insert a new boundary in cache C; it will have cache index I,
and have the specified POS and VALUE. */
static void
-insert_cache_boundary (struct region_cache *c, EMACS_INT i, EMACS_INT pos,
+insert_cache_boundary (struct region_cache *c, ptrdiff_t i, ptrdiff_t pos,
int value)
{
- /* i must be a valid cache index. */
- if (i < 0 || i > c->cache_len)
- abort ();
-
- /* We must never want to insert something before the dummy first
- boundary. */
- if (i == 0)
- abort ();
+ /* I must be a valid cache index, and we must never want
+ to insert something before the dummy first boundary. */
+ eassert (0 < i && i <= c->cache_len);
/* We must only be inserting things in order. */
- if (! (BOUNDARY_POS (c, i - 1) < pos
- && (i == c->cache_len
- || pos < BOUNDARY_POS (c, i))))
- abort ();
+ eassert ((BOUNDARY_POS (c, i - 1) < pos
+ && (i == c->cache_len
+ || pos < BOUNDARY_POS (c, i))));
/* The value must be different from the ones around it. However, we
temporarily create boundaries that establish the same value as
the subsequent boundary, so we're not going to flag that case. */
- if (BOUNDARY_VALUE (c, i - 1) == value)
- abort ();
+ eassert (BOUNDARY_VALUE (c, i - 1) != value);
move_cache_gap (c, i, 1);
static void
delete_cache_boundaries (struct region_cache *c,
- EMACS_INT start, EMACS_INT end)
+ ptrdiff_t start, ptrdiff_t end)
{
- EMACS_INT len = end - start;
+ ptrdiff_t len = end - start;
/* Gotta be in range. */
- if (start < 0
- || end > c->cache_len)
- abort ();
+ eassert (0 <= start && end <= c->cache_len);
/* Gotta be in order. */
- if (start > end)
- abort ();
+ eassert (start <= end);
/* Can't delete the dummy entry. */
- if (start == 0
- && end >= 1)
- abort ();
+ eassert (!(start == 0 && end >= 1));
/* Minimize gap motion. If we're deleting nothing, do nothing. */
if (len == 0)
/* Set the value in cache C for the region START..END to VALUE. */
static void
set_cache_region (struct region_cache *c,
- EMACS_INT start, EMACS_INT end, int value)
+ ptrdiff_t start, ptrdiff_t end, int value)
{
- if (start > end)
- abort ();
- if (start < c->buffer_beg
- || end > c->buffer_end)
- abort ();
+ eassert (start <= end);
+ eassert (c->buffer_beg <= start && end <= c->buffer_end);
/* Eliminate this case; then we can assume that start and end-1 are
both the locations of real characters in the buffer. */
index of the earliest boundary after the last character in
start..end. (This tortured terminology is intended to answer
all the "< or <=?" sort of questions.) */
- EMACS_INT start_ix = find_cache_boundary (c, start);
- EMACS_INT end_ix = find_cache_boundary (c, end - 1) + 1;
+ ptrdiff_t start_ix = find_cache_boundary (c, start);
+ ptrdiff_t end_ix = find_cache_boundary (c, end - 1) + 1;
/* We must remember the value established by the last boundary
before end; if that boundary's domain stretches beyond end,
args to pass are the same before and after such an operation.) */
void
invalidate_region_cache (struct buffer *buf, struct region_cache *c,
- EMACS_INT head, EMACS_INT tail)
+ ptrdiff_t head, ptrdiff_t tail)
{
/* Let chead = c->beg_unchanged, and
ctail = c->end_unchanged.
corresponds to the modified region of the buffer. */
else
{
- EMACS_INT modified_ix;
+ ptrdiff_t modified_ix;
/* These positions are correct, relative to both the cache basis
and the buffer basis. */
no newlines", in the case of the line cache). */
void
know_region_cache (struct buffer *buf, struct region_cache *c,
- EMACS_INT start, EMACS_INT end)
+ ptrdiff_t start, ptrdiff_t end)
{
revalidate_region_cache (buf, c);
\f
/* Interface: using the cache. */
-/* Return true if the text immediately after POS in BUF is known, for
- the purposes of CACHE. If NEXT is non-zero, set *NEXT to the nearest
- position after POS where the knownness changes. */
+/* Return the value for the text immediately after POS in BUF if the value
+ is known, for the purposes of CACHE, and return zero otherwise.
+ If NEXT is non-zero, set *NEXT to the nearest
+ position after POS where the knowledge changes. */
int
region_cache_forward (struct buffer *buf, struct region_cache *c,
- EMACS_INT pos, EMACS_INT *next)
+ ptrdiff_t pos, ptrdiff_t *next)
{
revalidate_region_cache (buf, c);
{
- EMACS_INT i = find_cache_boundary (c, pos);
+ ptrdiff_t i = find_cache_boundary (c, pos);
int i_value = BOUNDARY_VALUE (c, i);
- EMACS_INT j;
+ ptrdiff_t j;
/* Beyond the end of the buffer is unknown, by definition. */
if (pos >= BUF_Z (buf))
}
}
-/* Return true if the text immediately before POS in BUF is known, for
- the purposes of CACHE. If NEXT is non-zero, set *NEXT to the nearest
- position before POS where the knownness changes. */
-int region_cache_backward (struct buffer *buf, struct region_cache *c,
- EMACS_INT pos, EMACS_INT *next)
+/* Return the value for the text immediately before POS in BUF if the
+ value is known, for the purposes of CACHE, and return zero
+ otherwise. If NEXT is non-zero, set *NEXT to the nearest
+ position before POS where the knowledge changes. */
+int
+region_cache_backward (struct buffer *buf, struct region_cache *c,
+ ptrdiff_t pos, ptrdiff_t *next)
{
revalidate_region_cache (buf, c);
}
{
- EMACS_INT i = find_cache_boundary (c, pos - 1);
+ ptrdiff_t i = find_cache_boundary (c, pos - 1);
int i_value = BOUNDARY_VALUE (c, i);
- EMACS_INT j;
+ ptrdiff_t j;
if (next)
{
}
}
-\f
+#ifdef ENABLE_CHECKING
+
/* Debugging: pretty-print a cache to the standard error output. */
void pp_cache (struct region_cache *) EXTERNALLY_VISIBLE;
void
pp_cache (struct region_cache *c)
{
- int i;
- EMACS_INT beg_u = c->buffer_beg + c->beg_unchanged;
- EMACS_INT end_u = c->buffer_end - c->end_unchanged;
+ ptrdiff_t i;
+ ptrdiff_t beg_u = c->buffer_beg + c->beg_unchanged;
+ ptrdiff_t end_u = c->buffer_end - c->end_unchanged;
fprintf (stderr,
- "basis: %"pI"d..%"pI"d modified: %"pI"d..%"pI"d\n",
+ "basis: %"pD"d..%"pD"d modified: %"pD"d..%"pD"d\n",
c->buffer_beg, c->buffer_end,
beg_u, end_u);
for (i = 0; i < c->cache_len; i++)
{
- EMACS_INT pos = BOUNDARY_POS (c, i);
+ ptrdiff_t pos = BOUNDARY_POS (c, i);
putc (((pos < beg_u) ? 'v'
: (pos == beg_u) ? '-'
: (pos == end_u) ? '-'
: ' '),
stderr);
- fprintf (stderr, "%"pI"d : %d\n", pos, BOUNDARY_VALUE (c, i));
+ fprintf (stderr, "%"pD"d : %d\n", pos, BOUNDARY_VALUE (c, i));
}
}
+
+#endif /* ENABLE_CHECKING */
HCoop / bpt / emacs.git / blobdiff