Replace String CharArray with internal uint16_t array.

Summary of high level changes:
  - Adds compiler inliner support to identify string init methods
  - Adds compiler support (quick & optimizing) with new invoke code path
    that calls method off the thread pointer
  - Adds thread entrypoints for all string init methods
  - Adds map to verifier to log when receiver of string init has been
    copied to other registers. used by compiler and interpreter

Change-Id: I797b992a8feb566f9ad73060011ab6f51eb7ce01
diff --git a/runtime/native/libcore_util_CharsetUtils.cc b/runtime/native/libcore_util_CharsetUtils.cc
new file mode 100644
index 0000000..1216824
--- /dev/null
+++ b/runtime/native/libcore_util_CharsetUtils.cc
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2010 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 "jni_internal.h"
+#include "mirror/string.h"
+#include "mirror/string-inl.h"
+#include "native/libcore_util_CharsetUtils.h"
+#include "scoped_fast_native_object_access.h"
+#include "ScopedPrimitiveArray.h"
+#include "unicode/utf16.h"
+
+#include <string.h>
+
+namespace art {
+
+/**
+ * Approximates java.lang.UnsafeByteSequence so we don't have to pay the cost of calling back into
+ * Java when converting a char[] to a UTF-8 byte[]. This lets us have UTF-8 conversions slightly
+ * faster than ICU for large char[]s without paying for the NIO overhead with small char[]s.
+ *
+ * We could avoid this by keeping the UTF-8 bytes on the native heap until we're done and only
+ * creating a byte[] on the Java heap when we know how big it needs to be, but one shouldn't lie
+ * to the garbage collector (nor hide potentially large allocations from it).
+ *
+ * Because a call to append might require an allocation, it might fail. Callers should always
+ * check the return value of append.
+ */
+class NativeUnsafeByteSequence {
+ public:
+  explicit NativeUnsafeByteSequence(JNIEnv* env)
+    : mEnv(env), mJavaArray(nullptr), mRawArray(nullptr), mSize(-1), mOffset(0) {
+  }
+
+  ~NativeUnsafeByteSequence() {
+    // Release our pointer to the raw array, copying changes back to the Java heap.
+    if (mRawArray != nullptr) {
+      mEnv->ReleaseByteArrayElements(mJavaArray, mRawArray, 0);
+    }
+  }
+
+  bool append(jbyte b) {
+    if (mOffset == mSize && !resize(mSize * 2)) {
+      return false;
+    }
+    mRawArray[mOffset++] = b;
+    return true;
+  }
+
+  bool resize(int newSize) {
+    if (newSize == mSize) {
+      return true;
+    }
+
+    // Allocate a new array.
+    jbyteArray newJavaArray = mEnv->NewByteArray(newSize);
+    if (newJavaArray == nullptr) {
+      return false;
+    }
+    jbyte* newRawArray = mEnv->GetByteArrayElements(newJavaArray, nullptr);
+    if (newRawArray == nullptr) {
+      return false;
+    }
+
+    // Copy data out of the old array and then let go of it.
+    // Note that we may be trimming the array.
+    if (mRawArray != nullptr) {
+      memcpy(newRawArray, mRawArray, mOffset);
+      mEnv->ReleaseByteArrayElements(mJavaArray, mRawArray, JNI_ABORT);
+      mEnv->DeleteLocalRef(mJavaArray);
+    }
+
+    // Point ourselves at the new array.
+    mJavaArray = newJavaArray;
+    mRawArray = newRawArray;
+    mSize = newSize;
+    return true;
+  }
+
+  jbyteArray toByteArray() {
+    // Trim any unused space, if necessary.
+    bool okay = resize(mOffset);
+    return okay ? mJavaArray : nullptr;
+  }
+
+ private:
+  JNIEnv* mEnv;
+  jbyteArray mJavaArray;
+  jbyte* mRawArray;
+  jint mSize;
+  jint mOffset;
+
+  // Disallow copy and assignment.
+  NativeUnsafeByteSequence(const NativeUnsafeByteSequence&);
+  void operator=(const NativeUnsafeByteSequence&);
+};
+
+static void CharsetUtils_asciiBytesToChars(JNIEnv* env, jclass, jbyteArray javaBytes, jint offset,
+                                           jint length, jcharArray javaChars) {
+  ScopedByteArrayRO bytes(env, javaBytes);
+  if (bytes.get() == nullptr) {
+    return;
+  }
+  ScopedCharArrayRW chars(env, javaChars);
+  if (chars.get() == nullptr) {
+    return;
+  }
+
+  const jbyte* src = &bytes[offset];
+  jchar* dst = &chars[0];
+  static const jchar REPLACEMENT_CHAR = 0xfffd;
+  for (int i = length - 1; i >= 0; --i) {
+    jchar ch = static_cast<jchar>(*src++ & 0xff);
+    *dst++ = (ch <= 0x7f) ? ch : REPLACEMENT_CHAR;
+  }
+}
+
+static void CharsetUtils_isoLatin1BytesToChars(JNIEnv* env, jclass, jbyteArray javaBytes,
+                                               jint offset, jint length, jcharArray javaChars) {
+  ScopedByteArrayRO bytes(env, javaBytes);
+  if (bytes.get() == nullptr) {
+    return;
+  }
+  ScopedCharArrayRW chars(env, javaChars);
+  if (chars.get() == nullptr) {
+    return;
+  }
+
+  const jbyte* src = &bytes[offset];
+  jchar* dst = &chars[0];
+  for (int i = length - 1; i >= 0; --i) {
+    *dst++ = static_cast<jchar>(*src++ & 0xff);
+  }
+}
+
+/**
+ * Translates the given characters to US-ASCII or ISO-8859-1 bytes, using the fact that
+ * Unicode code points between U+0000 and U+007f inclusive are identical to US-ASCII, while
+ * U+0000 to U+00ff inclusive are identical to ISO-8859-1.
+ */
+static jbyteArray charsToBytes(JNIEnv* env, jstring java_string, jint offset, jint length,
+                               jchar maxValidChar) {
+  ScopedObjectAccess soa(env);
+  StackHandleScope<1> hs(soa.Self());
+  Handle<mirror::String> string(hs.NewHandle(soa.Decode<mirror::String*>(java_string)));
+  if (string.Get() == nullptr) {
+    return nullptr;
+  }
+
+  jbyteArray javaBytes = env->NewByteArray(length);
+  ScopedByteArrayRW bytes(env, javaBytes);
+  if (bytes.get() == nullptr) {
+    return nullptr;
+  }
+
+  const jchar* src = &(string->GetValue()[offset]);
+  jbyte* dst = &bytes[0];
+  for (int i = length - 1; i >= 0; --i) {
+    jchar ch = *src++;
+    if (ch > maxValidChar) {
+      ch = '?';
+    }
+    *dst++ = static_cast<jbyte>(ch);
+  }
+
+  return javaBytes;
+}
+
+static jbyteArray CharsetUtils_toAsciiBytes(JNIEnv* env, jclass, jstring java_string, jint offset,
+                                            jint length) {
+    return charsToBytes(env, java_string, offset, length, 0x7f);
+}
+
+static jbyteArray CharsetUtils_toIsoLatin1Bytes(JNIEnv* env, jclass, jstring java_string,
+                                                jint offset, jint length) {
+    return charsToBytes(env, java_string, offset, length, 0xff);
+}
+
+static jbyteArray CharsetUtils_toUtf8Bytes(JNIEnv* env, jclass, jstring java_string, jint offset,
+                                           jint length) {
+  ScopedObjectAccess soa(env);
+  StackHandleScope<1> hs(soa.Self());
+  Handle<mirror::String> string(hs.NewHandle(soa.Decode<mirror::String*>(java_string)));
+  if (string.Get() == nullptr) {
+    return nullptr;
+  }
+
+  NativeUnsafeByteSequence out(env);
+  if (!out.resize(length)) {
+    return nullptr;
+  }
+
+  const int end = offset + length;
+  for (int i = offset; i < end; ++i) {
+    jint ch = string->CharAt(i);
+    if (ch < 0x80) {
+      // One byte.
+      if (!out.append(ch)) {
+        return nullptr;
+      }
+    } else if (ch < 0x800) {
+      // Two bytes.
+      if (!out.append((ch >> 6) | 0xc0) || !out.append((ch & 0x3f) | 0x80)) {
+        return nullptr;
+      }
+    } else if (U16_IS_SURROGATE(ch)) {
+      // A supplementary character.
+      jchar high = static_cast<jchar>(ch);
+      jchar low = (i + 1 != end) ? string->CharAt(i + 1) : 0;
+      if (!U16_IS_SURROGATE_LEAD(high) || !U16_IS_SURROGATE_TRAIL(low)) {
+        if (!out.append('?')) {
+          return nullptr;
+        }
+        continue;
+      }
+      // Now we know we have a *valid* surrogate pair, we can consume the low surrogate.
+      ++i;
+      ch = U16_GET_SUPPLEMENTARY(high, low);
+      // Four bytes.
+      jbyte b1 = (ch >> 18) | 0xf0;
+      jbyte b2 = ((ch >> 12) & 0x3f) | 0x80;
+      jbyte b3 = ((ch >> 6) & 0x3f) | 0x80;
+      jbyte b4 = (ch & 0x3f) | 0x80;
+      if (!out.append(b1) || !out.append(b2) || !out.append(b3) || !out.append(b4)) {
+        return nullptr;
+      }
+    } else {
+      // Three bytes.
+      jbyte b1 = (ch >> 12) | 0xe0;
+      jbyte b2 = ((ch >> 6) & 0x3f) | 0x80;
+      jbyte b3 = (ch & 0x3f) | 0x80;
+      if (!out.append(b1) || !out.append(b2) || !out.append(b3)) {
+        return nullptr;
+      }
+    }
+  }
+  return out.toByteArray();
+}
+
+static JNINativeMethod gMethods[] = {
+  NATIVE_METHOD(CharsetUtils, asciiBytesToChars, "!([BII[C)V"),
+  NATIVE_METHOD(CharsetUtils, isoLatin1BytesToChars, "!([BII[C)V"),
+  NATIVE_METHOD(CharsetUtils, toAsciiBytes, "!(Ljava/lang/String;II)[B"),
+  NATIVE_METHOD(CharsetUtils, toIsoLatin1Bytes, "!(Ljava/lang/String;II)[B"),
+  NATIVE_METHOD(CharsetUtils, toUtf8Bytes, "!(Ljava/lang/String;II)[B"),
+};
+
+void register_libcore_util_CharsetUtils(JNIEnv* env) {
+  REGISTER_NATIVE_METHODS("libcore/util/CharsetUtils");
+}
+
+}  // namespace art