replicant-frameworks_native/libs/utils/String8.cpp
Daisuke Miyakawa 9f220247f6 Add useful functions to String8, which enables users to convert between UTF-8 and UTF-32
It will be used in SQL functions in external/sqlite/android.
See https://android-git.corp.google.com/g/Gerrit#change,5511 for example.

Related internal bug id: 1707173
2009-07-09 09:06:13 +09:00

851 lines
20 KiB
C++

/*
* Copyright (C) 2005 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 <utils/String8.h>
#include <utils/Log.h>
#include <utils/String16.h>
#include <utils/TextOutput.h>
#include <utils/threads.h>
#include <private/utils/Static.h>
#include <ctype.h>
/*
* Functions outside android is below the namespace android, since they use
* functions and constants in android namespace.
*/
// ---------------------------------------------------------------------------
namespace android {
static const char32_t kByteMask = 0x000000BF;
static const char32_t kByteMark = 0x00000080;
// Surrogates aren't valid for UTF-32 characters, so define some
// constants that will let us screen them out.
static const char32_t kUnicodeSurrogateHighStart = 0x0000D800;
static const char32_t kUnicodeSurrogateHighEnd = 0x0000DBFF;
static const char32_t kUnicodeSurrogateLowStart = 0x0000DC00;
static const char32_t kUnicodeSurrogateLowEnd = 0x0000DFFF;
static const char32_t kUnicodeSurrogateStart = kUnicodeSurrogateHighStart;
static const char32_t kUnicodeSurrogateEnd = kUnicodeSurrogateLowEnd;
static const char32_t kUnicodeMaxCodepoint = 0x0010FFFF;
// Mask used to set appropriate bits in first byte of UTF-8 sequence,
// indexed by number of bytes in the sequence.
// 0xxxxxxx
// -> (00-7f) 7bit. Bit mask for the first byte is 0x00000000
// 110yyyyx 10xxxxxx
// -> (c0-df)(80-bf) 11bit. Bit mask is 0x000000C0
// 1110yyyy 10yxxxxx 10xxxxxx
// -> (e0-ef)(80-bf)(80-bf) 16bit. Bit mask is 0x000000E0
// 11110yyy 10yyxxxx 10xxxxxx 10xxxxxx
// -> (f0-f7)(80-bf)(80-bf)(80-bf) 21bit. Bit mask is 0x000000F0
static const char32_t kFirstByteMark[] = {
0x00000000, 0x00000000, 0x000000C0, 0x000000E0, 0x000000F0
};
// Separator used by resource paths. This is not platform dependent contrary
// to OS_PATH_SEPARATOR.
#define RES_PATH_SEPARATOR '/'
// Return number of utf8 bytes required for the character.
static size_t utf32_to_utf8_bytes(char32_t srcChar)
{
size_t bytesToWrite;
// Figure out how many bytes the result will require.
if (srcChar < 0x00000080)
{
bytesToWrite = 1;
}
else if (srcChar < 0x00000800)
{
bytesToWrite = 2;
}
else if (srcChar < 0x00010000)
{
if ((srcChar < kUnicodeSurrogateStart)
|| (srcChar > kUnicodeSurrogateEnd))
{
bytesToWrite = 3;
}
else
{
// Surrogates are invalid UTF-32 characters.
return 0;
}
}
// Max code point for Unicode is 0x0010FFFF.
else if (srcChar <= kUnicodeMaxCodepoint)
{
bytesToWrite = 4;
}
else
{
// Invalid UTF-32 character.
return 0;
}
return bytesToWrite;
}
// Write out the source character to <dstP>.
static void utf32_to_utf8(uint8_t* dstP, char32_t srcChar, size_t bytes)
{
dstP += bytes;
switch (bytes)
{ /* note: everything falls through. */
case 4: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
case 3: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
case 2: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
case 1: *--dstP = (uint8_t)(srcChar | kFirstByteMark[bytes]);
}
}
// ---------------------------------------------------------------------------
static SharedBuffer* gEmptyStringBuf = NULL;
static char* gEmptyString = NULL;
extern int gDarwinCantLoadAllObjects;
int gDarwinIsReallyAnnoying;
static inline char* getEmptyString()
{
gEmptyStringBuf->acquire();
return gEmptyString;
}
void initialize_string8()
{
#ifdef LIBUTILS_NATIVE
// Bite me, Darwin!
gDarwinIsReallyAnnoying = gDarwinCantLoadAllObjects;
#endif
SharedBuffer* buf = SharedBuffer::alloc(1);
char* str = (char*)buf->data();
*str = 0;
gEmptyStringBuf = buf;
gEmptyString = str;
}
void terminate_string8()
{
SharedBuffer::bufferFromData(gEmptyString)->release();
gEmptyStringBuf = NULL;
gEmptyString = NULL;
}
// ---------------------------------------------------------------------------
static char* allocFromUTF8(const char* in, size_t len)
{
if (len > 0) {
SharedBuffer* buf = SharedBuffer::alloc(len+1);
LOG_ASSERT(buf, "Unable to allocate shared buffer");
if (buf) {
char* str = (char*)buf->data();
memcpy(str, in, len);
str[len] = 0;
return str;
}
return NULL;
}
return getEmptyString();
}
template<typename T, typename L>
static char* allocFromUTF16OrUTF32(const T* in, L len)
{
if (len == 0) return getEmptyString();
size_t bytes = 0;
const T* end = in+len;
const T* p = in;
while (p < end) {
bytes += utf32_to_utf8_bytes(*p);
p++;
}
SharedBuffer* buf = SharedBuffer::alloc(bytes+1);
LOG_ASSERT(buf, "Unable to allocate shared buffer");
if (buf) {
p = in;
char* str = (char*)buf->data();
char* d = str;
while (p < end) {
const T c = *p++;
size_t len = utf32_to_utf8_bytes(c);
utf32_to_utf8((uint8_t*)d, c, len);
d += len;
}
*d = 0;
return str;
}
return getEmptyString();
}
// Note: not dealing with expanding surrogate pairs.
static char* allocFromUTF16(const char16_t* in, size_t len)
{
return allocFromUTF16OrUTF32<char16_t, size_t>(in, len);
}
static char* allocFromUTF32(const char32_t* in, size_t len)
{
return allocFromUTF16OrUTF32<char32_t, size_t>(in, len);
}
// ---------------------------------------------------------------------------
String8::String8()
: mString(getEmptyString())
{
}
String8::String8(const String8& o)
: mString(o.mString)
{
SharedBuffer::bufferFromData(mString)->acquire();
}
String8::String8(const char* o)
: mString(allocFromUTF8(o, strlen(o)))
{
if (mString == NULL) {
mString = getEmptyString();
}
}
String8::String8(const char* o, size_t len)
: mString(allocFromUTF8(o, len))
{
if (mString == NULL) {
mString = getEmptyString();
}
}
String8::String8(const String16& o)
: mString(allocFromUTF16(o.string(), o.size()))
{
}
String8::String8(const char16_t* o)
: mString(allocFromUTF16(o, strlen16(o)))
{
}
String8::String8(const char16_t* o, size_t len)
: mString(allocFromUTF16(o, len))
{
}
String8::String8(const char32_t* o)
: mString(allocFromUTF32(o, strlen32(o)))
{
}
String8::String8(const char32_t* o, size_t len)
: mString(allocFromUTF32(o, len))
{
}
String8::~String8()
{
SharedBuffer::bufferFromData(mString)->release();
}
void String8::setTo(const String8& other)
{
SharedBuffer::bufferFromData(other.mString)->acquire();
SharedBuffer::bufferFromData(mString)->release();
mString = other.mString;
}
status_t String8::setTo(const char* other)
{
SharedBuffer::bufferFromData(mString)->release();
mString = allocFromUTF8(other, strlen(other));
if (mString) return NO_ERROR;
mString = getEmptyString();
return NO_MEMORY;
}
status_t String8::setTo(const char* other, size_t len)
{
SharedBuffer::bufferFromData(mString)->release();
mString = allocFromUTF8(other, len);
if (mString) return NO_ERROR;
mString = getEmptyString();
return NO_MEMORY;
}
status_t String8::setTo(const char16_t* other, size_t len)
{
SharedBuffer::bufferFromData(mString)->release();
mString = allocFromUTF16(other, len);
if (mString) return NO_ERROR;
mString = getEmptyString();
return NO_MEMORY;
}
status_t String8::setTo(const char32_t* other, size_t len)
{
SharedBuffer::bufferFromData(mString)->release();
mString = allocFromUTF32(other, len);
if (mString) return NO_ERROR;
mString = getEmptyString();
return NO_MEMORY;
}
status_t String8::append(const String8& other)
{
const size_t otherLen = other.bytes();
if (bytes() == 0) {
setTo(other);
return NO_ERROR;
} else if (otherLen == 0) {
return NO_ERROR;
}
return real_append(other.string(), otherLen);
}
status_t String8::append(const char* other)
{
return append(other, strlen(other));
}
status_t String8::append(const char* other, size_t otherLen)
{
if (bytes() == 0) {
return setTo(other, otherLen);
} else if (otherLen == 0) {
return NO_ERROR;
}
return real_append(other, otherLen);
}
status_t String8::real_append(const char* other, size_t otherLen)
{
const size_t myLen = bytes();
SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
->editResize(myLen+otherLen+1);
if (buf) {
char* str = (char*)buf->data();
mString = str;
str += myLen;
memcpy(str, other, otherLen);
str[otherLen] = '\0';
return NO_ERROR;
}
return NO_MEMORY;
}
char* String8::lockBuffer(size_t size)
{
SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
->editResize(size+1);
if (buf) {
char* str = (char*)buf->data();
mString = str;
return str;
}
return NULL;
}
void String8::unlockBuffer()
{
unlockBuffer(strlen(mString));
}
status_t String8::unlockBuffer(size_t size)
{
if (size != this->size()) {
SharedBuffer* buf = SharedBuffer::bufferFromData(mString)
->editResize(size+1);
if (buf) {
char* str = (char*)buf->data();
str[size] = 0;
mString = str;
return NO_ERROR;
}
}
return NO_MEMORY;
}
ssize_t String8::find(const char* other, size_t start) const
{
size_t len = size();
if (start >= len) {
return -1;
}
const char* s = mString+start;
const char* p = strstr(s, other);
return p ? p-mString : -1;
}
void String8::toLower()
{
toLower(0, size());
}
void String8::toLower(size_t start, size_t length)
{
const size_t len = size();
if (start >= len) {
return;
}
if (start+length > len) {
length = len-start;
}
char* buf = lockBuffer(len);
buf += start;
while (length > 0) {
*buf = tolower(*buf);
buf++;
length--;
}
unlockBuffer(len);
}
void String8::toUpper()
{
toUpper(0, size());
}
void String8::toUpper(size_t start, size_t length)
{
const size_t len = size();
if (start >= len) {
return;
}
if (start+length > len) {
length = len-start;
}
char* buf = lockBuffer(len);
buf += start;
while (length > 0) {
*buf = toupper(*buf);
buf++;
length--;
}
unlockBuffer(len);
}
size_t String8::getUtf32Length() const
{
return utf32_length(mString, length());
}
int32_t String8::getUtf32At(size_t index, size_t *next_index) const
{
return utf32_at(mString, length(), index, next_index);
}
size_t String8::getUtf32(char32_t* dst, size_t dst_len) const
{
return utf8_to_utf32(mString, length(), dst, dst_len);
}
TextOutput& operator<<(TextOutput& to, const String8& val)
{
to << val.string();
return to;
}
// ---------------------------------------------------------------------------
// Path functions
void String8::setPathName(const char* name)
{
setPathName(name, strlen(name));
}
void String8::setPathName(const char* name, size_t len)
{
char* buf = lockBuffer(len);
memcpy(buf, name, len);
// remove trailing path separator, if present
if (len > 0 && buf[len-1] == OS_PATH_SEPARATOR)
len--;
buf[len] = '\0';
unlockBuffer(len);
}
String8 String8::getPathLeaf(void) const
{
const char* cp;
const char*const buf = mString;
cp = strrchr(buf, OS_PATH_SEPARATOR);
if (cp == NULL)
return String8(*this);
else
return String8(cp+1);
}
String8 String8::getPathDir(void) const
{
const char* cp;
const char*const str = mString;
cp = strrchr(str, OS_PATH_SEPARATOR);
if (cp == NULL)
return String8("");
else
return String8(str, cp - str);
}
String8 String8::walkPath(String8* outRemains) const
{
const char* cp;
const char*const str = mString;
const char* buf = str;
cp = strchr(buf, OS_PATH_SEPARATOR);
if (cp == buf) {
// don't include a leading '/'.
buf = buf+1;
cp = strchr(buf, OS_PATH_SEPARATOR);
}
if (cp == NULL) {
String8 res = buf != str ? String8(buf) : *this;
if (outRemains) *outRemains = String8("");
return res;
}
String8 res(buf, cp-buf);
if (outRemains) *outRemains = String8(cp+1);
return res;
}
/*
* Helper function for finding the start of an extension in a pathname.
*
* Returns a pointer inside mString, or NULL if no extension was found.
*/
char* String8::find_extension(void) const
{
const char* lastSlash;
const char* lastDot;
int extLen;
const char* const str = mString;
// only look at the filename
lastSlash = strrchr(str, OS_PATH_SEPARATOR);
if (lastSlash == NULL)
lastSlash = str;
else
lastSlash++;
// find the last dot
lastDot = strrchr(lastSlash, '.');
if (lastDot == NULL)
return NULL;
// looks good, ship it
return const_cast<char*>(lastDot);
}
String8 String8::getPathExtension(void) const
{
char* ext;
ext = find_extension();
if (ext != NULL)
return String8(ext);
else
return String8("");
}
String8 String8::getBasePath(void) const
{
char* ext;
const char* const str = mString;
ext = find_extension();
if (ext == NULL)
return String8(*this);
else
return String8(str, ext - str);
}
String8& String8::appendPath(const char* name)
{
// TODO: The test below will fail for Win32 paths. Fix later or ignore.
if (name[0] != OS_PATH_SEPARATOR) {
if (*name == '\0') {
// nothing to do
return *this;
}
size_t len = length();
if (len == 0) {
// no existing filename, just use the new one
setPathName(name);
return *this;
}
// make room for oldPath + '/' + newPath
int newlen = strlen(name);
char* buf = lockBuffer(len+1+newlen);
// insert a '/' if needed
if (buf[len-1] != OS_PATH_SEPARATOR)
buf[len++] = OS_PATH_SEPARATOR;
memcpy(buf+len, name, newlen+1);
len += newlen;
unlockBuffer(len);
return *this;
} else {
setPathName(name);
return *this;
}
}
String8& String8::convertToResPath()
{
#if OS_PATH_SEPARATOR != RES_PATH_SEPARATOR
size_t len = length();
if (len > 0) {
char * buf = lockBuffer(len);
for (char * end = buf + len; buf < end; ++buf) {
if (*buf == OS_PATH_SEPARATOR)
*buf = RES_PATH_SEPARATOR;
}
unlockBuffer(len);
}
#endif
return *this;
}
}; // namespace android
// ---------------------------------------------------------------------------
size_t strlen32(const char32_t *s)
{
const char32_t *ss = s;
while ( *ss )
ss++;
return ss-s;
}
size_t strnlen32(const char32_t *s, size_t maxlen)
{
const char32_t *ss = s;
while ((maxlen > 0) && *ss) {
ss++;
maxlen--;
}
return ss-s;
}
size_t utf8_codepoint_count(const char *src)
{
const char *cur = src;
size_t ret = 0;
while (*cur != '\0') {
const char first_char = *cur++;
if ((first_char & 0x80) == 0) { // ASCII
ret += 1;
continue;
}
// (UTF-8's character must not be like 10xxxxxx,
// but 110xxxxx, 1110xxxx, ... or 1111110x)
if ((first_char & 0x40) == 0) {
return 0;
}
int32_t mask, to_ignore_mask;
size_t num_to_read = 0;
char32_t utf32 = 0;
for (num_to_read = 1, mask = 0x40, to_ignore_mask = 0x80;
num_to_read < 5 && (first_char & mask);
num_to_read++, to_ignore_mask |= mask, mask >>= 1) {
if ((*cur & 0xC0) != 0x80) { // must be 10xxxxxx
return 0;
}
// 0x3F == 00111111
utf32 = (utf32 << 6) + (*cur++ & 0x3F);
}
// "first_char" must be (110xxxxx - 11110xxx)
if (num_to_read == 5) {
return 0;
}
to_ignore_mask |= mask;
utf32 |= ((~to_ignore_mask) & first_char) << (6 * (num_to_read - 1));
if (utf32 > android::kUnicodeMaxCodepoint) {
return 0;
}
ret += num_to_read;
}
return ret;
}
size_t utf32_length(const char *src, size_t src_len)
{
if (src == NULL || src_len == 0) {
return 0;
}
size_t ret = 0;
const char* cur;
const char* end;
size_t num_to_skip;
for (cur = src, end = src + src_len, num_to_skip = 1;
cur < end;
cur += num_to_skip, ret++) {
const char first_char = *cur;
num_to_skip = 1;
if ((first_char & 0x80) == 0) { // ASCII
continue;
}
int32_t mask;
for (mask = 0x40; (first_char & mask); num_to_skip++, mask >>= 1) {
}
}
return ret;
}
size_t utf8_length_from_utf32(const char32_t *src, size_t src_len)
{
if (src == NULL || src_len == 0) {
return 0;
}
size_t ret = 0;
const char32_t *end = src + src_len;
while (src < end) {
ret += android::utf32_to_utf8_bytes(*src++);
}
return ret;
}
static int32_t utf32_at_internal(const char* cur, size_t *num_read)
{
const char first_char = *cur;
if ((first_char & 0x80) == 0) { // ASCII
*num_read = 1;
return *cur;
}
cur++;
char32_t mask, to_ignore_mask;
size_t num_to_read = 0;
char32_t utf32 = first_char;
for (num_to_read = 1, mask = 0x40, to_ignore_mask = 0xFFFFFF80;
(first_char & mask);
num_to_read++, to_ignore_mask |= mask, mask >>= 1) {
// 0x3F == 00111111
utf32 = (utf32 << 6) + (*cur++ & 0x3F);
}
to_ignore_mask |= mask;
utf32 &= ~(to_ignore_mask << (6 * (num_to_read - 1)));
*num_read = num_to_read;
return static_cast<int32_t>(utf32);
}
int32_t utf32_at(const char *src, size_t src_len,
size_t index, size_t *next_index)
{
if (index >= src_len) {
return -1;
}
size_t dummy_index;
if (next_index == NULL) {
next_index = &dummy_index;
}
size_t num_read;
int32_t ret = utf32_at_internal(src + index, &num_read);
if (ret >= 0) {
*next_index = index + num_read;
}
return ret;
}
size_t utf8_to_utf32(const char* src, size_t src_len,
char32_t* dst, size_t dst_len)
{
if (src == NULL || src_len == 0 || dst == NULL || dst_len == 0) {
return 0;
}
const char* cur = src;
const char* end = src + src_len;
char32_t* cur_utf32 = dst;
const char32_t* end_utf32 = dst + dst_len;
while (cur_utf32 < end_utf32 && cur < end) {
size_t num_read;
*cur_utf32++ =
static_cast<char32_t>(utf32_at_internal(cur, &num_read));
cur += num_read;
}
if (cur_utf32 < end_utf32) {
*cur_utf32 = 0;
}
return static_cast<size_t>(cur_utf32 - dst);
}
size_t utf32_to_utf8(const char32_t* src, size_t src_len,
char* dst, size_t dst_len)
{
if (src == NULL || src_len == 0 || dst == NULL || dst_len == 0) {
return 0;
}
const char32_t *cur_utf32 = src;
const char32_t *end_utf32 = src + src_len;
char *cur = dst;
const char *end = dst + dst_len;
while (cur_utf32 < end_utf32 && cur < end) {
size_t len = android::utf32_to_utf8_bytes(*cur_utf32);
android::utf32_to_utf8((uint8_t *)cur, *cur_utf32++, len);
cur += len;
}
if (cur < end) {
*cur = '\0';
}
return cur - dst;
}