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Diffstat (limited to 'dpm/strdup8to16.cpp')
-rw-r--r-- | dpm/strdup8to16.cpp | 178 |
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; +} |