libutils/String16.cpp - android_system_core - Gitiles

 /*
  * 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/String16.h>

 #include <utils/Log.h>

 #include <ctype.h>

 #include "SharedBuffer.h"

 namespace android {

 static const StaticString16 emptyString(u"");
 static inline char16_t* getEmptyString() {
     return const_cast<char16_t*>(emptyString.string());
 }

 // ---------------------------------------------------------------------------

 void* String16::alloc(size_t size)
 {
     SharedBuffer* buf = SharedBuffer::alloc(size);
     buf->mClientMetadata = kIsSharedBufferAllocated;
     return buf;
 }

 char16_t* String16::allocFromUTF8(const char* u8str, size_t u8len)
 {
     if (u8len == 0) return getEmptyString();

     const uint8_t* u8cur = (const uint8_t*) u8str;

     const ssize_t u16len = utf8_to_utf16_length(u8cur, u8len);
     if (u16len < 0) {
         return getEmptyString();
     }

     SharedBuffer* buf = static_cast<SharedBuffer*>(alloc(sizeof(char16_t) * (u16len + 1)));
     if (buf) {
         u8cur = (const uint8_t*) u8str;
         char16_t* u16str = (char16_t*)buf->data();

         utf8_to_utf16(u8cur, u8len, u16str, ((size_t) u16len) + 1);

         //printf("Created UTF-16 string from UTF-8 \"%s\":", in);
         //printHexData(1, str, buf->size(), 16, 1);
         //printf("\n");

         return u16str;
     }

     return getEmptyString();
 }

 char16_t* String16::allocFromUTF16(const char16_t* u16str, size_t u16len) {
     if (u16len >= SIZE_MAX / sizeof(char16_t)) {
         android_errorWriteLog(0x534e4554, "73826242");
         abort();
     }

     SharedBuffer* buf = static_cast<SharedBuffer*>(alloc((u16len + 1) * sizeof(char16_t)));
     ALOG_ASSERT(buf, "Unable to allocate shared buffer");
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memcpy(str, u16str, u16len * sizeof(char16_t));
         str[u16len] = 0;
         return str;
     }
     return getEmptyString();
 }

 // ---------------------------------------------------------------------------

 String16::String16()
     : mString(getEmptyString())
 {
 }

 String16::String16(StaticLinkage)
     : mString(nullptr)
 {
     // this constructor is used when we can't rely on the static-initializers
     // having run. In this case we always allocate an empty string. It's less
     // efficient than using getEmptyString(), but we assume it's uncommon.

     SharedBuffer* buf = static_cast<SharedBuffer*>(alloc(sizeof(char16_t)));
     char16_t* data = static_cast<char16_t*>(buf->data());
     data[0] = 0;
     mString = data;
 }

 String16::String16(const String16& o)
     : mString(o.mString)
 {
     acquire();
 }

 String16::String16(const String16& o, size_t len, size_t begin)
     : mString(getEmptyString())
 {
     setTo(o, len, begin);
 }

 String16::String16(const char16_t* o) : mString(allocFromUTF16(o, strlen16(o))) {}

 String16::String16(const char16_t* o, size_t len) : mString(allocFromUTF16(o, len)) {}

 String16::String16(const String8& o)
     : mString(allocFromUTF8(o.string(), o.size()))
 {
 }

 String16::String16(const char* o)
     : mString(allocFromUTF8(o, strlen(o)))
 {
 }

 String16::String16(const char* o, size_t len)
     : mString(allocFromUTF8(o, len))
 {
 }

 String16::~String16()
 {
     release();
 }

 size_t String16::size() const
 {
     if (isStaticString()) {
         return staticStringSize();
     } else {
         return SharedBuffer::sizeFromData(mString) / sizeof(char16_t) - 1;
     }
 }

 void String16::setTo(const String16& other)
 {
     release();
     mString = other.mString;
     acquire();
 }

 status_t String16::setTo(const String16& other, size_t len, size_t begin)
 {
     const size_t N = other.size();
     if (begin >= N) {
         release();
         mString = getEmptyString();
         return OK;
     }
     if ((begin+len) > N) len = N-begin;
     if (begin == 0 && len == N) {
         setTo(other);
         return OK;
     }

     if (&other == this) {
         LOG_ALWAYS_FATAL("Not implemented");
     }

     return setTo(other.string()+begin, len);
 }

 status_t String16::setTo(const char16_t* other)
 {
     return setTo(other, strlen16(other));
 }

 status_t String16::setTo(const char16_t* other, size_t len)
 {
     if (len >= SIZE_MAX / sizeof(char16_t)) {
         android_errorWriteLog(0x534e4554, "73826242");
         abort();
     }

     SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((len + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memmove(str, other, len*sizeof(char16_t));
         str[len] = 0;
         mString = str;
         return OK;
     }
     return NO_MEMORY;
 }

 status_t String16::append(const String16& other)
 {
     const size_t myLen = size();
     const size_t otherLen = other.size();
     if (myLen == 0) {
         setTo(other);
         return OK;
     } else if (otherLen == 0) {
         return OK;
     }

     if (myLen >= SIZE_MAX / sizeof(char16_t) - otherLen) {
         android_errorWriteLog(0x534e4554, "73826242");
         abort();
     }

     SharedBuffer* buf =
             static_cast<SharedBuffer*>(editResize((myLen + otherLen + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memcpy(str+myLen, other, (otherLen+1)*sizeof(char16_t));
         mString = str;
         return OK;
     }
     return NO_MEMORY;
 }

 status_t String16::append(const char16_t* chrs, size_t otherLen)
 {
     const size_t myLen = size();
     if (myLen == 0) {
         setTo(chrs, otherLen);
         return OK;
     } else if (otherLen == 0) {
         return OK;
     }

     if (myLen >= SIZE_MAX / sizeof(char16_t) - otherLen) {
         android_errorWriteLog(0x534e4554, "73826242");
         abort();
     }

     SharedBuffer* buf =
             static_cast<SharedBuffer*>(editResize((myLen + otherLen + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         memcpy(str+myLen, chrs, otherLen*sizeof(char16_t));
         str[myLen+otherLen] = 0;
         mString = str;
         return OK;
     }
     return NO_MEMORY;
 }

 status_t String16::insert(size_t pos, const char16_t* chrs)
 {
     return insert(pos, chrs, strlen16(chrs));
 }

 status_t String16::insert(size_t pos, const char16_t* chrs, size_t len)
 {
     const size_t myLen = size();
     if (myLen == 0) {
         return setTo(chrs, len);
         return OK;
     } else if (len == 0) {
         return OK;
     }

     if (pos > myLen) pos = myLen;

     #if 0
     printf("Insert in to %s: pos=%d, len=%d, myLen=%d, chrs=%s\n",
            String8(*this).string(), pos,
            len, myLen, String8(chrs, len).string());
     #endif

     SharedBuffer* buf =
             static_cast<SharedBuffer*>(editResize((myLen + len + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         if (pos < myLen) {
             memmove(str+pos+len, str+pos, (myLen-pos)*sizeof(char16_t));
         }
         memcpy(str+pos, chrs, len*sizeof(char16_t));
         str[myLen+len] = 0;
         mString = str;
         #if 0
         printf("Result (%d chrs): %s\n", size(), String8(*this).string());
         #endif
         return OK;
     }
     return NO_MEMORY;
 }

 ssize_t String16::findFirst(char16_t c) const
 {
     const char16_t* str = string();
     const char16_t* p = str;
     const char16_t* e = p + size();
     while (p < e) {
         if (*p == c) {
             return p-str;
         }
         p++;
     }
     return -1;
 }

 ssize_t String16::findLast(char16_t c) const
 {
     const char16_t* str = string();
     const char16_t* p = str;
     const char16_t* e = p + size();
     while (p < e) {
         e--;
         if (*e == c) {
             return e-str;
         }
     }
     return -1;
 }

 bool String16::startsWith(const String16& prefix) const
 {
     const size_t ps = prefix.size();
     if (ps > size()) return false;
     return strzcmp16(mString, ps, prefix.string(), ps) == 0;
 }

 bool String16::startsWith(const char16_t* prefix) const
 {
     const size_t ps = strlen16(prefix);
     if (ps > size()) return false;
     return strncmp16(mString, prefix, ps) == 0;
 }

 bool String16::contains(const char16_t* chrs) const
 {
     return strstr16(mString, chrs) != nullptr;
 }

 void* String16::edit() {
     SharedBuffer* buf;
     if (isStaticString()) {
         buf = static_cast<SharedBuffer*>(alloc((size() + 1) * sizeof(char16_t)));
         if (buf) {
             buf->acquire();
             memcpy(buf->data(), mString, (size() + 1) * sizeof(char16_t));
         }
     } else {
         buf = SharedBuffer::bufferFromData(mString)->edit();
         buf->mClientMetadata = kIsSharedBufferAllocated;
     }
     return buf;
 }

 void* String16::editResize(size_t newSize) {
     SharedBuffer* buf;
     if (isStaticString()) {
         size_t copySize = (size() + 1) * sizeof(char16_t);
         if (newSize < copySize) {
             copySize = newSize;
         }
         buf = static_cast<SharedBuffer*>(alloc(newSize));
         if (buf) {
             buf->acquire();
             memcpy(buf->data(), mString, copySize);
         }
     } else {
         buf = SharedBuffer::bufferFromData(mString)->editResize(newSize);
         buf->mClientMetadata = kIsSharedBufferAllocated;
     }
     return buf;
 }

 void String16::acquire()
 {
     if (!isStaticString()) {
         SharedBuffer::bufferFromData(mString)->acquire();
     }
 }

 void String16::release()
 {
     if (!isStaticString()) {
         SharedBuffer::bufferFromData(mString)->release();
     }
 }

 bool String16::isStaticString() const {
     // See String16.h for notes on the memory layout of String16::StaticData and
     // SharedBuffer.
     static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
     const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
     return (*(p - 1) & kIsSharedBufferAllocated) == 0;
 }

 size_t String16::staticStringSize() const {
     // See String16.h for notes on the memory layout of String16::StaticData and
     // SharedBuffer.
     static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
     const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
     return static_cast<size_t>(*(p - 1));
 }

 status_t String16::makeLower()
 {
     const size_t N = size();
     const char16_t* str = string();
     char16_t* edited = nullptr;
     for (size_t i=0; i<N; i++) {
         const char16_t v = str[i];
         if (v >= 'A' && v <= 'Z') {
             if (!edited) {
                 SharedBuffer* buf = static_cast<SharedBuffer*>(edit());
                 if (!buf) {
                     return NO_MEMORY;
                 }
                 edited = (char16_t*)buf->data();
                 mString = str = edited;
             }
             edited[i] = tolower((char)v);
         }
     }
     return OK;
 }

 status_t String16::replaceAll(char16_t replaceThis, char16_t withThis)
 {
     const size_t N = size();
     const char16_t* str = string();
     char16_t* edited = nullptr;
     for (size_t i=0; i<N; i++) {
         if (str[i] == replaceThis) {
             if (!edited) {
                 SharedBuffer* buf = static_cast<SharedBuffer*>(edit());
                 if (!buf) {
                     return NO_MEMORY;
                 }
                 edited = (char16_t*)buf->data();
                 mString = str = edited;
             }
             edited[i] = withThis;
         }
     }
     return OK;
 }

 status_t String16::remove(size_t len, size_t begin)
 {
     const size_t N = size();
     if (begin >= N) {
         release();
         mString = getEmptyString();
         return OK;
     }
     if ((begin+len) > N) len = N-begin;
     if (begin == 0 && len == N) {
         return OK;
     }

     if (begin > 0) {
         SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((N + 1) * sizeof(char16_t)));
         if (!buf) {
             return NO_MEMORY;
         }
         char16_t* str = (char16_t*)buf->data();
         memmove(str, str+begin, (N-begin+1)*sizeof(char16_t));
         mString = str;
     }
     SharedBuffer* buf = static_cast<SharedBuffer*>(editResize((len + 1) * sizeof(char16_t)));
     if (buf) {
         char16_t* str = (char16_t*)buf->data();
         str[len] = 0;
         mString = str;
         return OK;
     }
     return NO_MEMORY;
 }

 }; // namespace android
	/*
	* 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/String16.h>

	#include <utils/Log.h>

	#include <ctype.h>

	#include "SharedBuffer.h"

	namespace android {

	static const StaticString16 emptyString(u"");
	static inline char16_t* getEmptyString() {
	return const_cast<char16_t*>(emptyString.string());
	}

	// ---------------------------------------------------------------------------

	void* String16::alloc(size_t size)
	{
	SharedBuffer* buf = SharedBuffer::alloc(size);
	buf->mClientMetadata = kIsSharedBufferAllocated;
	return buf;
	}

	char16_t* String16::allocFromUTF8(const char* u8str, size_t u8len)
	{
	if (u8len == 0) return getEmptyString();

	const uint8_t* u8cur = (const uint8_t*) u8str;

	const ssize_t u16len = utf8_to_utf16_length(u8cur, u8len);
	if (u16len < 0) {
	return getEmptyString();
	}

	SharedBuffer* buf = static_cast<SharedBuffer>(alloc(sizeof(char16_t) (u16len + 1)));
	if (buf) {
	u8cur = (const uint8_t*) u8str;
	char16_t* u16str = (char16_t*)buf->data();

	utf8_to_utf16(u8cur, u8len, u16str, ((size_t) u16len) + 1);

	//printf("Created UTF-16 string from UTF-8 \"%s\":", in);
	//printHexData(1, str, buf->size(), 16, 1);
	//printf("\n");

	return u16str;
	}

	return getEmptyString();
	}

	char16_t* String16::allocFromUTF16(const char16_t* u16str, size_t u16len) {
	if (u16len >= SIZE_MAX / sizeof(char16_t)) {
	android_errorWriteLog(0x534e4554, "73826242");
	abort();
	}

	SharedBuffer* buf = static_cast<SharedBuffer>(alloc((u16len + 1) sizeof(char16_t)));
	ALOG_ASSERT(buf, "Unable to allocate shared buffer");
	if (buf) {
	char16_t* str = (char16_t*)buf->data();
	memcpy(str, u16str, u16len * sizeof(char16_t));
	str[u16len] = 0;
	return str;
	}
	return getEmptyString();
	}

	// ---------------------------------------------------------------------------

	String16::String16()
	: mString(getEmptyString())
	{
	}

	String16::String16(StaticLinkage)
	: mString(nullptr)
	{
	// this constructor is used when we can't rely on the static-initializers
	// having run. In this case we always allocate an empty string. It's less
	// efficient than using getEmptyString(), but we assume it's uncommon.

	SharedBuffer* buf = static_cast<SharedBuffer*>(alloc(sizeof(char16_t)));
	char16_t* data = static_cast<char16_t*>(buf->data());
	data[0] = 0;
	mString = data;
	}

	String16::String16(const String16& o)
	: mString(o.mString)
	{
	acquire();
	}

	String16::String16(const String16& o, size_t len, size_t begin)
	: mString(getEmptyString())
	{
	setTo(o, len, begin);
	}

	String16::String16(const char16_t* o) : mString(allocFromUTF16(o, strlen16(o))) {}

	String16::String16(const char16_t* o, size_t len) : mString(allocFromUTF16(o, len)) {}

	String16::String16(const String8& o)
	: mString(allocFromUTF8(o.string(), o.size()))
	{
	}

	String16::String16(const char* o)
	: mString(allocFromUTF8(o, strlen(o)))
	{
	}

	String16::String16(const char* o, size_t len)
	: mString(allocFromUTF8(o, len))
	{
	}

	String16::~String16()
	{
	release();
	}

	size_t String16::size() const
	{
	if (isStaticString()) {
	return staticStringSize();
	} else {
	return SharedBuffer::sizeFromData(mString) / sizeof(char16_t) - 1;
	}
	}

	void String16::setTo(const String16& other)
	{
	release();
	mString = other.mString;
	acquire();
	}

	status_t String16::setTo(const String16& other, size_t len, size_t begin)
	{
	const size_t N = other.size();
	if (begin >= N) {
	release();
	mString = getEmptyString();
	return OK;
	}
	if ((begin+len) > N) len = N-begin;
	if (begin == 0 && len == N) {
	setTo(other);
	return OK;
	}

	if (&other == this) {
	LOG_ALWAYS_FATAL("Not implemented");
	}

	return setTo(other.string()+begin, len);
	}

	status_t String16::setTo(const char16_t* other)
	{
	return setTo(other, strlen16(other));
	}

	status_t String16::setTo(const char16_t* other, size_t len)
	{
	if (len >= SIZE_MAX / sizeof(char16_t)) {
	android_errorWriteLog(0x534e4554, "73826242");
	abort();
	}

	SharedBuffer* buf = static_cast<SharedBuffer>(editResize((len + 1) sizeof(char16_t)));
	if (buf) {
	char16_t* str = (char16_t*)buf->data();
	memmove(str, other, len*sizeof(char16_t));
	str[len] = 0;
	mString = str;
	return OK;
	}
	return NO_MEMORY;
	}

	status_t String16::append(const String16& other)
	{
	const size_t myLen = size();
	const size_t otherLen = other.size();
	if (myLen == 0) {
	setTo(other);
	return OK;
	} else if (otherLen == 0) {
	return OK;
	}

	if (myLen >= SIZE_MAX / sizeof(char16_t) - otherLen) {
	android_errorWriteLog(0x534e4554, "73826242");
	abort();
	}

	SharedBuffer* buf =
	static_cast<SharedBuffer>(editResize((myLen + otherLen + 1) sizeof(char16_t)));
	if (buf) {
	char16_t* str = (char16_t*)buf->data();
	memcpy(str+myLen, other, (otherLen+1)*sizeof(char16_t));
	mString = str;
	return OK;
	}
	return NO_MEMORY;
	}

	status_t String16::append(const char16_t* chrs, size_t otherLen)
	{
	const size_t myLen = size();
	if (myLen == 0) {
	setTo(chrs, otherLen);
	return OK;
	} else if (otherLen == 0) {
	return OK;
	}

	if (myLen >= SIZE_MAX / sizeof(char16_t) - otherLen) {
	android_errorWriteLog(0x534e4554, "73826242");
	abort();
	}

	SharedBuffer* buf =
	static_cast<SharedBuffer>(editResize((myLen + otherLen + 1) sizeof(char16_t)));
	if (buf) {
	char16_t* str = (char16_t*)buf->data();
	memcpy(str+myLen, chrs, otherLen*sizeof(char16_t));
	str[myLen+otherLen] = 0;
	mString = str;
	return OK;
	}
	return NO_MEMORY;
	}

	status_t String16::insert(size_t pos, const char16_t* chrs)
	{
	return insert(pos, chrs, strlen16(chrs));
	}

	status_t String16::insert(size_t pos, const char16_t* chrs, size_t len)
	{
	const size_t myLen = size();
	if (myLen == 0) {
	return setTo(chrs, len);
	return OK;
	} else if (len == 0) {
	return OK;
	}

	if (pos > myLen) pos = myLen;

	#if 0
	printf("Insert in to %s: pos=%d, len=%d, myLen=%d, chrs=%s\n",
	String8(*this).string(), pos,
	len, myLen, String8(chrs, len).string());
	#endif

	SharedBuffer* buf =
	static_cast<SharedBuffer>(editResize((myLen + len + 1) sizeof(char16_t)));
	if (buf) {
	char16_t* str = (char16_t*)buf->data();
	if (pos < myLen) {
	memmove(str+pos+len, str+pos, (myLen-pos)*sizeof(char16_t));
	}
	memcpy(str+pos, chrs, len*sizeof(char16_t));
	str[myLen+len] = 0;
	mString = str;
	#if 0
	printf("Result (%d chrs): %s\n", size(), String8(*this).string());
	#endif
	return OK;
	}
	return NO_MEMORY;
	}

	ssize_t String16::findFirst(char16_t c) const
	{
	const char16_t* str = string();
	const char16_t* p = str;
	const char16_t* e = p + size();
	while (p < e) {
	if (*p == c) {
	return p-str;
	}
	p++;
	}
	return -1;
	}

	ssize_t String16::findLast(char16_t c) const
	{
	const char16_t* str = string();
	const char16_t* p = str;
	const char16_t* e = p + size();
	while (p < e) {
	e--;
	if (*e == c) {
	return e-str;
	}
	}
	return -1;
	}

	bool String16::startsWith(const String16& prefix) const
	{
	const size_t ps = prefix.size();
	if (ps > size()) return false;
	return strzcmp16(mString, ps, prefix.string(), ps) == 0;
	}

	bool String16::startsWith(const char16_t* prefix) const
	{
	const size_t ps = strlen16(prefix);
	if (ps > size()) return false;
	return strncmp16(mString, prefix, ps) == 0;
	}

	bool String16::contains(const char16_t* chrs) const
	{
	return strstr16(mString, chrs) != nullptr;
	}

	void* String16::edit() {
	SharedBuffer* buf;
	if (isStaticString()) {
	buf = static_cast<SharedBuffer>(alloc((size() + 1) sizeof(char16_t)));
	if (buf) {
	buf->acquire();
	memcpy(buf->data(), mString, (size() + 1) * sizeof(char16_t));
	}
	} else {
	buf = SharedBuffer::bufferFromData(mString)->edit();
	buf->mClientMetadata = kIsSharedBufferAllocated;
	}
	return buf;
	}

	void* String16::editResize(size_t newSize) {
	SharedBuffer* buf;
	if (isStaticString()) {
	size_t copySize = (size() + 1) * sizeof(char16_t);
	if (newSize < copySize) {
	copySize = newSize;
	}
	buf = static_cast<SharedBuffer*>(alloc(newSize));
	if (buf) {
	buf->acquire();
	memcpy(buf->data(), mString, copySize);
	}
	} else {
	buf = SharedBuffer::bufferFromData(mString)->editResize(newSize);
	buf->mClientMetadata = kIsSharedBufferAllocated;
	}
	return buf;
	}

	void String16::acquire()
	{
	if (!isStaticString()) {
	SharedBuffer::bufferFromData(mString)->acquire();
	}
	}

	void String16::release()
	{
	if (!isStaticString()) {
	SharedBuffer::bufferFromData(mString)->release();
	}
	}

	bool String16::isStaticString() const {
	// See String16.h for notes on the memory layout of String16::StaticData and
	// SharedBuffer.
	static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
	const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
	return (*(p - 1) & kIsSharedBufferAllocated) == 0;
	}

	size_t String16::staticStringSize() const {
	// See String16.h for notes on the memory layout of String16::StaticData and
	// SharedBuffer.
	static_assert(sizeof(SharedBuffer) - offsetof(SharedBuffer, mClientMetadata) == 4);
	const uint32_t* p = reinterpret_cast<const uint32_t*>(mString);
	return static_cast<size_t>(*(p - 1));
	}

	status_t String16::makeLower()
	{
	const size_t N = size();
	const char16_t* str = string();
	char16_t* edited = nullptr;
	for (size_t i=0; i<N; i++) {
	const char16_t v = str[i];
	if (v >= 'A' && v <= 'Z') {
	if (!edited) {
	SharedBuffer* buf = static_cast<SharedBuffer*>(edit());
	if (!buf) {
	return NO_MEMORY;
	}
	edited = (char16_t*)buf->data();
	mString = str = edited;
	}
	edited[i] = tolower((char)v);
	}
	}
	return OK;
	}

	status_t String16::replaceAll(char16_t replaceThis, char16_t withThis)
	{
	const size_t N = size();
	const char16_t* str = string();
	char16_t* edited = nullptr;
	for (size_t i=0; i<N; i++) {
	if (str[i] == replaceThis) {
	if (!edited) {
	SharedBuffer* buf = static_cast<SharedBuffer*>(edit());
	if (!buf) {
	return NO_MEMORY;
	}
	edited = (char16_t*)buf->data();
	mString = str = edited;
	}
	edited[i] = withThis;
	}
	}
	return OK;
	}

	status_t String16::remove(size_t len, size_t begin)
	{
	const size_t N = size();
	if (begin >= N) {
	release();
	mString = getEmptyString();
	return OK;
	}
	if ((begin+len) > N) len = N-begin;
	if (begin == 0 && len == N) {
	return OK;
	}

	if (begin > 0) {
	SharedBuffer* buf = static_cast<SharedBuffer>(editResize((N + 1) sizeof(char16_t)));
	if (!buf) {
	return NO_MEMORY;
	}
	char16_t* str = (char16_t*)buf->data();
	memmove(str, str+begin, (N-begin+1)*sizeof(char16_t));
	mString = str;
	}
	SharedBuffer* buf = static_cast<SharedBuffer>(editResize((len + 1) sizeof(char16_t)));
	if (buf) {
	char16_t* str = (char16_t*)buf->data();
	str[len] = 0;
	mString = str;
	return OK;
	}
	return NO_MEMORY;
	}

	}; // namespace android