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authorAndreas Rottmann <a.rottmann@gmx.at>2009-09-14 12:32:44 +0200
committerAndreas Rottmann <a.rottmann@gmx.at>2009-09-14 12:32:44 +0200
commitfa095a4504cbe668e4244547e2c141597bea4ecf (patch)
tree06135820a286ffec47804e75fbf8a147e92acd2e /lib/unistr/u32-to-u16.c
Imported Upstream version 0.9.1upstream/0.9.1
Diffstat (limited to 'lib/unistr/u32-to-u16.c')
-rw-r--r--lib/unistr/u32-to-u16.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/lib/unistr/u32-to-u16.c b/lib/unistr/u32-to-u16.c
new file mode 100644
index 00000000..3a32162c
--- /dev/null
+++ b/lib/unistr/u32-to-u16.c
@@ -0,0 +1,130 @@
+/* Convert UTF-32 string to UTF-16 string.
+ Copyright (C) 2002, 2006-2007 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2002.
+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "unistr.h"
+
+#define FUNC u32_to_u16
+#define SRC_UNIT uint32_t
+#define DST_UNIT uint16_t
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+DST_UNIT *
+FUNC (const SRC_UNIT *s, size_t n, DST_UNIT *resultbuf, size_t *lengthp)
+{
+ const SRC_UNIT *s_end = s + n;
+ /* Output string accumulator. */
+ DST_UNIT *result;
+ size_t allocated;
+ size_t length;
+
+ if (resultbuf != NULL)
+ {
+ result = resultbuf;
+ allocated = *lengthp;
+ }
+ else
+ {
+ result = NULL;
+ allocated = 0;
+ }
+ length = 0;
+ /* Invariants:
+ result is either == resultbuf or == NULL or malloc-allocated.
+ If length > 0, then result != NULL. */
+
+ while (s < s_end)
+ {
+ ucs4_t uc;
+ int count;
+
+ /* Fetch a Unicode character from the input string. */
+ uc = *s++;
+ /* No need to call the safe variant u32_mbtouc, because
+ u16_uctomb will verify uc anyway. */
+
+ /* Store it in the output string. */
+ count = u16_uctomb (result + length, uc, allocated - length);
+ if (count == -1)
+ {
+ if (!(result == resultbuf || result == NULL))
+ free (result);
+ errno = EILSEQ;
+ return NULL;
+ }
+ if (count == -2)
+ {
+ DST_UNIT *memory;
+
+ allocated = (allocated > 0 ? 2 * allocated : 12);
+ if (length + 2 > allocated)
+ allocated = length + 2;
+ if (result == resultbuf || result == NULL)
+ memory = (DST_UNIT *) malloc (allocated * sizeof (DST_UNIT));
+ else
+ memory =
+ (DST_UNIT *) realloc (result, allocated * sizeof (DST_UNIT));
+
+ if (memory == NULL)
+ {
+ if (!(result == resultbuf || result == NULL))
+ free (result);
+ errno = ENOMEM;
+ return NULL;
+ }
+ if (result == resultbuf && length > 0)
+ memcpy ((char *) memory, (char *) result,
+ length * sizeof (DST_UNIT));
+ result = memory;
+ count = u16_uctomb (result + length, uc, allocated - length);
+ if (count < 0)
+ abort ();
+ }
+ length += count;
+ }
+
+ if (length == 0)
+ {
+ if (result == NULL)
+ {
+ /* Return a non-NULL value. NULL means error. */
+ result = (DST_UNIT *) malloc (1);
+ if (result == NULL)
+ {
+ errno = ENOMEM;
+ return NULL;
+ }
+ }
+ }
+ else if (result != resultbuf && length < allocated)
+ {
+ /* Shrink the allocated memory if possible. */
+ DST_UNIT *memory;
+
+ memory = (DST_UNIT *) realloc (result, length * sizeof (DST_UNIT));
+ if (memory != NULL)
+ result = memory;
+ }
+
+ *lengthp = length;
+ return result;
+}