diff --git a/libs/utils/String8.cpp b/libs/utils/String8.cpp
new file mode 100644
index 0000000..ab843f6
--- /dev/null
+++ b/libs/utils/String8.cpp
@@ -0,0 +1,602 @@
+/*
+ * 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>
+
+namespace android {
+
+// ---------------------------------------------------------------------------
+
+static const uint32_t kByteMask = 0x000000BF;
+static const uint32_t kByteMark = 0x00000080;
+
+// Surrogates aren't valid for UTF-32 characters, so define some
+// constants that will let us screen them out.
+static const uint32_t kUnicodeSurrogateHighStart  = 0x0000D800;
+static const uint32_t kUnicodeSurrogateHighEnd    = 0x0000DBFF;
+static const uint32_t kUnicodeSurrogateLowStart   = 0x0000DC00;
+static const uint32_t kUnicodeSurrogateLowEnd     = 0x0000DFFF;
+static const uint32_t kUnicodeSurrogateStart      = kUnicodeSurrogateHighStart;
+static const uint32_t kUnicodeSurrogateEnd        = kUnicodeSurrogateLowEnd;
+
+// Mask used to set appropriate bits in first byte of UTF-8 sequence,
+// indexed by number of bytes in the sequence.
+static const uint32_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(uint32_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 < 0x00110000)
+    {
+        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, uint32_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();
+}
+
+// Note: not dealing with expanding surrogate pairs.
+static char* allocFromUTF16(const char16_t* in, size_t len)
+{
+    if (len == 0) return getEmptyString();
+    
+    size_t bytes = 0;
+    const char16_t* end = in+len;
+    const char16_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) {
+            uint32_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();
+}
+
+// ---------------------------------------------------------------------------
+
+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()
+{
+    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::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();
+        memcpy(str+myLen, other, otherLen+1);
+        mString = str;
+        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);
+}
+
+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