summaryrefslogtreecommitdiff
path: root/dpm/strdup8to16.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'dpm/strdup8to16.cpp')
-rw-r--r--dpm/strdup8to16.cpp178
1 files changed, 178 insertions, 0 deletions
diff --git a/dpm/strdup8to16.cpp b/dpm/strdup8to16.cpp
new file mode 100644
index 0000000..8a05ba6
--- /dev/null
+++ b/dpm/strdup8to16.cpp
@@ -0,0 +1,178 @@
+/* libs/cutils/strdup8to16.c
+**
+** Copyright 2006, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+** http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#include "jstring.h"
+
+#include <assert.h>
+#include <limits.h>
+#include <stdlib.h>
+
+/* See http://www.unicode.org/reports/tr22/ for discussion
+ * on invalid sequences
+ */
+
+#define UTF16_REPLACEMENT_CHAR 0xfffd
+
+/* Clever trick from Dianne that returns 1-4 depending on leading bit sequence*/
+#define UTF8_SEQ_LENGTH(ch) (((0xe5000000 >> (((ch) >> 3) & 0x1e)) & 3) + 1)
+
+/* note: macro expands to multiple lines */
+#define UTF8_SHIFT_AND_MASK(unicode, byte) \
+ (unicode)<<=6; (unicode) |= (0x3f & (byte));
+
+#define UNICODE_UPPER_LIMIT 0x10fffd
+
+/**
+ * out_len is an out parameter (which may not be null) containing the
+ * length of the UTF-16 string (which may contain embedded \0's)
+ */
+
+extern char16_t * strdup8to16 (const char* s, size_t *out_len)
+{
+ char16_t *ret;
+ size_t len;
+
+ if (s == NULL) return NULL;
+
+ len = strlen8to16(s);
+
+ // fail on overflow
+ if (len && SIZE_MAX/len < sizeof(char16_t))
+ return NULL;
+
+ // no plus-one here. UTF-16 strings are not null terminated
+ ret = (char16_t *) malloc (sizeof(char16_t) * len);
+
+ return strcpy8to16 (ret, s, out_len);
+}
+
+/**
+ * Like "strlen", but for strings encoded with Java's modified UTF-8.
+ *
+ * The value returned is the number of UTF-16 characters required
+ * to represent this string.
+ */
+extern size_t strlen8to16 (const char* utf8Str)
+{
+ size_t len = 0;
+ int ic;
+ int expected = 0;
+
+ while ((ic = *utf8Str++) != '\0') {
+ /* bytes that start 0? or 11 are lead bytes and count as characters.*/
+ /* bytes that start 10 are extention bytes and are not counted */
+
+ if ((ic & 0xc0) == 0x80) {
+ /* count the 0x80 extention bytes. if we have more than
+ * expected, then start counting them because strcpy8to16
+ * will insert UTF16_REPLACEMENT_CHAR's
+ */
+ expected--;
+ if (expected < 0) {
+ len++;
+ }
+ } else {
+ len++;
+ expected = UTF8_SEQ_LENGTH(ic) - 1;
+
+ /* this will result in a surrogate pair */
+ if (expected == 3) {
+ len++;
+ }
+ }
+ }
+
+ return len;
+}
+
+
+
+/*
+ * Retrieve the next UTF-32 character from a UTF-8 string.
+ *
+ * Stops at inner \0's
+ *
+ * Returns UTF16_REPLACEMENT_CHAR if an invalid sequence is encountered
+ *
+ * Advances "*pUtf8Ptr" to the start of the next character.
+ */
+static inline uint32_t getUtf32FromUtf8(const char** pUtf8Ptr)
+{
+ uint32_t ret;
+ int seq_len;
+ int i;
+
+ /* Mask for leader byte for lengths 1, 2, 3, and 4 respectively*/
+ static const unsigned char leaderMask[4] = {0xff, 0x1f, 0x0f, 0x07};
+
+ /* Bytes that start with bits "10" are not leading characters. */
+ if (((**pUtf8Ptr) & 0xc0) == 0x80) {
+ (*pUtf8Ptr)++;
+ return UTF16_REPLACEMENT_CHAR;
+ }
+
+ /* note we tolerate invalid leader 11111xxx here */
+ seq_len = UTF8_SEQ_LENGTH(**pUtf8Ptr);
+
+ ret = (**pUtf8Ptr) & leaderMask [seq_len - 1];
+
+ if (**pUtf8Ptr == '\0') return ret;
+
+ (*pUtf8Ptr)++;
+ for (i = 1; i < seq_len ; i++, (*pUtf8Ptr)++) {
+ if ((**pUtf8Ptr) == '\0') return UTF16_REPLACEMENT_CHAR;
+ if (((**pUtf8Ptr) & 0xc0) != 0x80) return UTF16_REPLACEMENT_CHAR;
+
+ UTF8_SHIFT_AND_MASK(ret, **pUtf8Ptr);
+ }
+
+ return ret;
+}
+
+
+/**
+ * out_len is an out parameter (which may not be null) containing the
+ * length of the UTF-16 string (which may contain embedded \0's)
+ */
+
+extern char16_t * strcpy8to16 (char16_t *utf16Str, const char*utf8Str,
+ size_t *out_len)
+{
+ char16_t *dest = utf16Str;
+
+ while (*utf8Str != '\0') {
+ uint32_t ret;
+
+ ret = getUtf32FromUtf8(&utf8Str);
+
+ if (ret <= 0xffff) {
+ *dest++ = (char16_t) ret;
+ } else if (ret <= UNICODE_UPPER_LIMIT) {
+ /* Create surrogate pairs */
+ /* See http://en.wikipedia.org/wiki/UTF-16/UCS-2#Method_for_code_points_in_Plane_1.2C_Plane_2 */
+
+ *dest++ = 0xd800 | ((ret - 0x10000) >> 10);
+ *dest++ = 0xdc00 | ((ret - 0x10000) & 0x3ff);
+ } else {
+ *dest++ = UTF16_REPLACEMENT_CHAR;
+ }
+ }
+
+ *out_len = dest - utf16Str;
+
+ return utf16Str;
+}