On 16.08.2012 18:22, Corinna Vinschen wrote:
On Aug 16 09:24, Eric Blake wrote:
On 08/16/2012 08:20 AM, Thomas Wolff wrote:
MB_CUR_MAX does not work because its value is 1 at this point
So what about MB_LEN_MAX then? There's no problem using a multiplier,
but a symbolic constant is always better than a numerical constant.
I've now used _MB_LEN_MAX from newlib.h, rather than MB_LEN_MAX from
limits.h (note the "_" distinction :) ),
because the latter, by its preceding comment, reserves the option to be
changed into a dynamic function in the future, which could then possibly
have the same problems as MB_CUR_MAX.
POSIX requires MB_LEN_MAX to be a constant, only MB_CUR_MAX can be
dynamic. We cannot change MB_LEN_MAX to be dynamic in the future.
...also, Cygwin's include/limits.h doesn't mention to convert to
a function.
Not sure how to interpret exactly what it mentions. Anyway, my updated
patch (using MB_LEN_MAX) proposes a change here as well.
------
Thomas
diff -rup sav/fhandler_clipboard.cc ./fhandler_clipboard.cc
--- sav/fhandler_clipboard.cc 2012-07-08 02:36:47.000000000 +0200
+++ ./fhandler_clipboard.cc 2012-08-17 10:34:41.968750000 +0200
@@ -222,6 +222,7 @@ fhandler_dev_clipboard::read (void *ptr,
UINT formatlist[2];
int format;
LPVOID cb_data;
+ int rach;
if (!OpenClipboard (NULL))
{
@@ -243,12 +244,24 @@ fhandler_dev_clipboard::read (void *ptr,
cygcb_t *clipbuf = (cygcb_t *) cb_data;
if (pos < clipbuf->len)
- {
+ {
ret = ((len > (clipbuf->len - pos)) ? (clipbuf->len - pos) : len);
memcpy (ptr, clipbuf->data + pos , ret);
pos += ret;
}
}
+ else if ((rach = get_readahead ()) >= 0)
+ {
+ /* Deliver from read-ahead buffer. */
+ char * out_ptr = (char *) ptr;
+ * out_ptr++ = rach;
+ ret = 1;
+ while (ret < len && (rach = get_readahead ()) >= 0)
+ {
+ * out_ptr++ = rach;
+ ret++;
+ }
+ }
else
{
wchar_t *buf = (wchar_t *) cb_data;
@@ -256,25 +269,54 @@ fhandler_dev_clipboard::read (void *ptr,
size_t glen = GlobalSize (hglb) / sizeof (WCHAR) - 1;
if (pos < glen)
{
+ /* If caller's buffer is too small to hold at least one
+ max-size character, redirect algorithm to local
+ read-ahead buffer, finally fill class read-ahead buffer
+ with result and feed caller from there. */
+ char * conv_ptr = (char *) ptr;
+ size_t conv_len = len;
+#define cprabuf_len MB_LEN_MAX /* max MB_CUR_MAX of all encodings */
+ char cprabuf [cprabuf_len];
+ if (len < cprabuf_len)
+ {
+ conv_ptr = cprabuf;
+ conv_len = cprabuf_len;
+ }
+
/* Comparing apples and oranges here, but the below loop could become
extremly slow otherwise. We rather return a few bytes less than
possible instead of being even more slow than usual... */
- if (glen > pos + len)
- glen = pos + len;
+ if (glen > pos + conv_len)
+ glen = pos + conv_len;
/* This loop is necessary because the number of bytes returned by
sys_wcstombs does not indicate the number of wide chars used for
it, so we could potentially drop wide chars. */
while ((ret = sys_wcstombs (NULL, 0, buf + pos, glen - pos))
!= (size_t) -1
- && ret > len)
+ && (ret > conv_len
+ /* Skip separated high surrogate: */
+ || ((buf [pos + glen - 1] & 0xFC00) == 0xD800 && glen -
pos > 1)))
--glen;
if (ret == (size_t) -1)
ret = 0;
else
{
- ret = sys_wcstombs ((char *) ptr, (size_t) -1,
+ ret = sys_wcstombs ((char *) conv_ptr, (size_t) -1,
buf + pos, glen - pos);
pos = glen;
+ /* If using read-ahead buffer, copy to class read-ahead buffer
+ and deliver first byte. */
+ if (conv_ptr == cprabuf)
+ {
+ puts_readahead (cprabuf, ret);
+ char * out_ptr = (char *) ptr;
+ ret = 0;
+ while (ret < len && (rach = get_readahead ()) >= 0)
+ {
+ * out_ptr++ = rach;
+ ret++;
+ }
+ }
}
}
}
diff -rup sav/include/limits.h ./include/limits.h
--- sav/include/limits.h 2011-07-21 22:21:49.000000000 +0200
+++ ./include/limits.h 2012-08-16 17:48:34.847141100 +0200
@@ -36,8 +36,7 @@ details. */
/* Maximum length of a multibyte character. */
#ifndef MB_LEN_MAX
-/* TODO: This is newlib's max value. We should probably rather define our
- own _mbtowc_r and _wctomb_r functions which are only codepage dependent. */
+/* Use value from newlib although 4 is sufficient */
#define MB_LEN_MAX 8
#endif
