Optimize some commonly used utf8 functions by:

- using counted loops instead of searching for terminating null. In
  the important cases the caller already knows the length: change
  the API to pass it in. Keep the old API version as well to avoid
  extensive changes to non-critical debug and test code.

- ensure the common cases are at the start of if/then/else chains.
  Usually 99+% of characters are ASCII even in mixed strings.

- for the "convert" functions, when both utf8 and utf16 lengths are
  passed, and are equal, it means the entire string is ASCII, and a
  specialized loop can be used. The compiler might then unroll or
  even vectorize this.

The functions improved are (tested on Nexus 5 with a 44 character
ASCII string):

CountModifiedUtf8Chars    :  20% faster
ConvertUtf16ToModifiedUtf8:  80% faster
ConvertModifiedUtf8ToUtf16: 200% faster

Also for completeness CountUtf8Bytes has been cleaned up a little, but
the speed is unchanged. Unlike CountModifiedUtf8Chars, it was already
passed the length, rather than searching for null.

Change-Id: I1c9b7dea3eda869fc9f5f6b4dd6be8cdd5bc3ac0

6 files changed, 302 insertions, 45 deletions

diff --git a/runtime/jni_internal.cc b/runtime/jni_internal.cc
index 415109fb06..5e3fa199e5 100644
--- a/runtime/jni_internal.cc
+++ b/runtime/jni_internal.cc
@@ -1689,7 +1689,8 @@ class JNI {
     } else {
       CHECK_NON_NULL_MEMCPY_ARGUMENT(length, buf);
       const jchar* chars = s->GetValue();
-      ConvertUtf16ToModifiedUtf8(buf, chars + start, length);
+      size_t bytes = CountUtf8Bytes(chars + start, length);
+      ConvertUtf16ToModifiedUtf8(buf, bytes, chars + start, length);
     }
   }
 
@@ -1772,7 +1773,7 @@ class JNI {
     char* bytes = new char[byte_count + 1];
     CHECK(bytes != nullptr);  // bionic aborts anyway.
     const uint16_t* chars = s->GetValue();
-    ConvertUtf16ToModifiedUtf8(bytes, chars, s->GetLength());
+    ConvertUtf16ToModifiedUtf8(bytes, byte_count, chars, s->GetLength());
     bytes[byte_count] = '\0';
     return bytes;
   }
diff --git a/runtime/mirror/string.cc b/runtime/mirror/string.cc
index be869d4e6a..33aca0304c 100644
--- a/runtime/mirror/string.cc
+++ b/runtime/mirror/string.cc
@@ -109,12 +109,17 @@ String* String::AllocFromUtf16(Thread* self, int32_t utf16_length, const uint16_
 
 String* String::AllocFromModifiedUtf8(Thread* self, const char* utf) {
   DCHECK(utf != nullptr);
-  size_t char_count = CountModifiedUtf8Chars(utf);
-  return AllocFromModifiedUtf8(self, char_count, utf);
+  size_t byte_count = strlen(utf);
+  size_t char_count = CountModifiedUtf8Chars(utf, byte_count);
+  return AllocFromModifiedUtf8(self, char_count, utf, byte_count);
+}
+
+String* String::AllocFromModifiedUtf8(Thread* self, int32_t utf16_length, const char* utf8_data_in) {
+  return AllocFromModifiedUtf8(self, utf16_length, utf8_data_in, strlen(utf8_data_in));
 }
 
 String* String::AllocFromModifiedUtf8(Thread* self, int32_t utf16_length,
-                                      const char* utf8_data_in) {
+                                      const char* utf8_data_in, int32_t utf8_length) {
   gc::AllocatorType allocator_type = Runtime::Current()->GetHeap()->GetCurrentAllocator();
   SetStringCountVisitor visitor(utf16_length);
   String* string = Alloc<true>(self, utf16_length, allocator_type, visitor);
@@ -122,7 +127,7 @@ String* String::AllocFromModifiedUtf8(Thread* self, int32_t utf16_length,
     return nullptr;
   }
   uint16_t* utf16_data_out = string->GetValue();
-  ConvertModifiedUtf8ToUtf16(utf16_data_out, utf8_data_in);
+  ConvertModifiedUtf8ToUtf16(utf16_data_out, utf16_length, utf8_data_in, utf8_length);
   return string;
 }
 
@@ -217,7 +222,7 @@ std::string String::ToModifiedUtf8() {
   const uint16_t* chars = GetValue();
   size_t byte_count = GetUtfLength();
   std::string result(byte_count, static_cast<char>(0));
-  ConvertUtf16ToModifiedUtf8(&result[0], chars, GetLength());
+  ConvertUtf16ToModifiedUtf8(&result[0], byte_count, chars, GetLength());
   return result;
 }
 
diff --git a/runtime/mirror/string.h b/runtime/mirror/string.h
index 80ebd2cf0f..e2cfb8d5ad 100644
--- a/runtime/mirror/string.h
+++ b/runtime/mirror/string.h
@@ -116,6 +116,10 @@ class MANAGED String FINAL : public Object {
   static String* AllocFromModifiedUtf8(Thread* self, const char* utf)
       SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
 
+  static String* AllocFromModifiedUtf8(Thread* self, int32_t utf16_length,
+                                       const char* utf8_data_in, int32_t utf8_length)
+      SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
+
   static String* AllocFromModifiedUtf8(Thread* self, int32_t utf16_length, const char* utf8_data_in)
       SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!Roles::uninterruptible_);
 
diff --git a/runtime/utf.cc b/runtime/utf.cc
index 10600e2153..5a116980c9 100644
--- a/runtime/utf.cc
+++ b/runtime/utf.cc
@@ -23,28 +23,50 @@
 
 namespace art {
 
+// This is used only from debugger and test code.
 size_t CountModifiedUtf8Chars(const char* utf8) {
+  return CountModifiedUtf8Chars(utf8, strlen(utf8));
+}
+
+/*
+ * This does not validate UTF8 rules (nor did older code). But it gets the right answer
+ * for valid UTF-8 and that's fine because it's used only to size a buffer for later
+ * conversion.
+ *
+ * Modified UTF-8 consists of a series of bytes up to 21 bit Unicode code points as follows:
+ * U+0001  - U+007F   0xxxxxxx
+ * U+0080  - U+07FF   110xxxxx 10xxxxxx
+ * U+0800  - U+FFFF   1110xxxx 10xxxxxx 10xxxxxx
+ * U+10000 - U+1FFFFF 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+ *
+ * U+0000 is encoded using the 2nd form to avoid nulls inside strings (this differs from
+ * standard UTF-8).
+ * The four byte encoding converts to two utf16 characters.
+ */
+size_t CountModifiedUtf8Chars(const char* utf8, size_t byte_count) {
+  DCHECK_LE(byte_count, strlen(utf8));
   size_t len = 0;
-  int ic;
-  while ((ic = *utf8++) != '\0') {
+  const char* end = utf8 + byte_count;
+  for (; utf8 < end; ++utf8) {
+    int ic = *utf8;
     len++;
-    if ((ic & 0x80) == 0) {
-      // one-byte encoding
+    if (LIKELY((ic & 0x80) == 0)) {
+      // One-byte encoding.
       continue;
     }
-    // two- or three-byte encoding
+    // Two- or three-byte encoding.
     utf8++;
     if ((ic & 0x20) == 0) {
-      // two-byte encoding
+      // Two-byte encoding.
       continue;
     }
     utf8++;
     if ((ic & 0x10) == 0) {
-      // three-byte encoding
+      // Three-byte encoding.
       continue;
     }
 
-    // four-byte encoding: needs to be converted into a surrogate
+    // Four-byte encoding: needs to be converted into a surrogate
     // pair.
     utf8++;
     len++;
@@ -52,6 +74,7 @@ size_t CountModifiedUtf8Chars(const char* utf8) {
   return len;
 }
 
+// This is used only from debugger and test code.
 void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_data_out, const char* utf8_data_in) {
   while (*utf8_data_in != '\0') {
     const uint32_t ch = GetUtf16FromUtf8(&utf8_data_in);
@@ -65,13 +88,53 @@ void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_data_out, const char* utf8_data_
   }
 }
 
-void ConvertUtf16ToModifiedUtf8(char* utf8_out, const uint16_t* utf16_in, size_t char_count) {
+void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_data_out, size_t out_chars,
+                                const char* utf8_data_in, size_t in_bytes) {
+  const char *in_start = utf8_data_in;
+  const char *in_end = utf8_data_in + in_bytes;
+  uint16_t *out_p = utf16_data_out;
+
+  if (LIKELY(out_chars == in_bytes)) {
+    // Common case where all characters are ASCII.
+    for (const char *p = in_start; p < in_end;) {
+      // Safe even if char is signed because ASCII characters always have
+      // the high bit cleared.
+      *out_p++ = dchecked_integral_cast<uint16_t>(*p++);
+    }
+    return;
+  }
+
+  // String contains non-ASCII characters.
+  for (const char *p = in_start; p < in_end;) {
+    const uint32_t ch = GetUtf16FromUtf8(&p);
+    const uint16_t leading = GetLeadingUtf16Char(ch);
+    const uint16_t trailing = GetTrailingUtf16Char(ch);
+
+    *out_p++ = leading;
+    if (trailing != 0) {
+      *out_p++ = trailing;
+    }
+  }
+}
+
+void ConvertUtf16ToModifiedUtf8(char* utf8_out, size_t byte_count,
+                                const uint16_t* utf16_in, size_t char_count) {
+  if (LIKELY(byte_count == char_count)) {
+    // Common case where all characters are ASCII.
+    const uint16_t *utf16_end = utf16_in + char_count;
+    for (const uint16_t *p = utf16_in; p < utf16_end;) {
+      *utf8_out++ = dchecked_integral_cast<char>(*p++);
+    }
+    return;
+  }
+
+  // String contains non-ASCII characters.
   while (char_count--) {
     const uint16_t ch = *utf16_in++;
     if (ch > 0 && ch <= 0x7f) {
       *utf8_out++ = ch;
     } else {
-      // char_count == 0 here implies we've encountered an unpaired
+      // Char_count == 0 here implies we've encountered an unpaired
       // surrogate and we have no choice but to encode it as 3-byte UTF
       // sequence. Note that unpaired surrogates can occur as a part of
       // "normal" operation.
@@ -161,34 +224,31 @@ int CompareModifiedUtf8ToUtf16AsCodePointValues(const char* utf8, const uint16_t
 
 size_t CountUtf8Bytes(const uint16_t* chars, size_t char_count) {
   size_t result = 0;
-  while (char_count--) {
+  const uint16_t *end = chars + char_count;
+  while (chars < end) {
     const uint16_t ch = *chars++;
-    if (ch > 0 && ch <= 0x7f) {
-      ++result;
-    } else if (ch >= 0xd800 && ch <= 0xdbff) {
-      if (char_count > 0) {
+    if (LIKELY(ch != 0 && ch < 0x80)) {
+      result++;
+      continue;
+    }
+    if (ch < 0x800) {
+      result += 2;
+      continue;
+    }
+    if (ch >= 0xd800 && ch < 0xdc00) {
+      if (chars < end) {
         const uint16_t ch2 = *chars;
         // If we find a properly paired surrogate, we emit it as a 4 byte
         // UTF sequence. If we find an unpaired leading or trailing surrogate,
         // we emit it as a 3 byte sequence like would have done earlier.
-        if (ch2 >= 0xdc00 && ch2 <= 0xdfff) {
+        if (ch2 >= 0xdc00 && ch2 < 0xe000) {
           chars++;
-          char_count--;
-
           result += 4;
-        } else {
-          result += 3;
+          continue;
         }
-      } else {
-        // This implies we found an unpaired trailing surrogate at the end
-        // of a string.
-        result += 3;
       }
-    } else if (ch > 0x7ff) {
-      result += 3;
-    } else {
-      result += 2;
     }
+    result += 3;
   }
   return result;
 }
diff --git a/runtime/utf.h b/runtime/utf.h
index 1193d29c7d..03158c492d 100644
--- a/runtime/utf.h
+++ b/runtime/utf.h
@@ -40,6 +40,7 @@ namespace mirror {
  * Returns the number of UTF-16 characters in the given modified UTF-8 string.
  */
 size_t CountModifiedUtf8Chars(const char* utf8);
+size_t CountModifiedUtf8Chars(const char* utf8, size_t byte_count);
 
 /*
  * Returns the number of modified UTF-8 bytes needed to represent the given
@@ -51,6 +52,8 @@ size_t CountUtf8Bytes(const uint16_t* chars, size_t char_count);
  * Convert from Modified UTF-8 to UTF-16.
  */
 void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_out, const char* utf8_in);
+void ConvertModifiedUtf8ToUtf16(uint16_t* utf16_out, size_t out_chars,
+                                const char* utf8_in, size_t in_bytes);
 
 /*
  * Compare two modified UTF-8 strings as UTF-16 code point values in a non-locale sensitive manner
@@ -71,7 +74,8 @@ int CompareModifiedUtf8ToUtf16AsCodePointValues(const char* utf8, const uint16_t
  * this anyway, so if you want a NUL-terminated string, you know where to
  * put the NUL byte.
  */
-void ConvertUtf16ToModifiedUtf8(char* utf8_out, const uint16_t* utf16_in, size_t char_count);
+void ConvertUtf16ToModifiedUtf8(char* utf8_out, size_t byte_count,
+                                const uint16_t* utf16_in, size_t char_count);
 
 /*
  * The java.lang.String hashCode() algorithm.
diff --git a/runtime/utf_test.cc b/runtime/utf_test.cc
index 94a6ea57e2..64e4eb798b 100644
--- a/runtime/utf_test.cc
+++ b/runtime/utf_test.cc
@@ -48,7 +48,7 @@ static const uint8_t kAllSequences[] = {
 };
 
 // A test string that contains a UTF-8 encoding of a surrogate pair
-// (code point = U+10400)
+// (code point = U+10400).
 static const uint8_t kSurrogateEncoding[] = {
     0xed, 0xa0, 0x81,
     0xed, 0xb0, 0x80,
@@ -66,13 +66,13 @@ TEST_F(UtfTest, GetUtf16FromUtf8) {
   EXPECT_EQ(0, GetTrailingUtf16Char(pair));
   EXPECT_ARRAY_POSITION(1, ptr, start);
 
-  // Two byte sequence
+  // Two byte sequence.
   pair = GetUtf16FromUtf8(&ptr);
   EXPECT_EQ(0xa2, GetLeadingUtf16Char(pair));
   EXPECT_EQ(0, GetTrailingUtf16Char(pair));
   EXPECT_ARRAY_POSITION(3, ptr, start);
 
-  // Three byte sequence
+  // Three byte sequence.
   pair = GetUtf16FromUtf8(&ptr);
   EXPECT_EQ(0x20ac, GetLeadingUtf16Char(pair));
   EXPECT_EQ(0, GetTrailingUtf16Char(pair));
@@ -84,7 +84,7 @@ TEST_F(UtfTest, GetUtf16FromUtf8) {
   EXPECT_EQ(0xdfe0, GetTrailingUtf16Char(pair));
   EXPECT_ARRAY_POSITION(10, ptr, start);
 
-  // Null terminator
+  // Null terminator.
   pair = GetUtf16FromUtf8(&ptr);
   EXPECT_EQ(0, GetLeadingUtf16Char(pair));
   EXPECT_EQ(0, GetTrailingUtf16Char(pair));
@@ -117,7 +117,8 @@ static void AssertConversion(const std::vector<uint16_t> input,
   ASSERT_EQ(expected.size(), CountUtf8Bytes(&input[0], input.size()));
 
   std::vector<uint8_t> output(expected.size());
-  ConvertUtf16ToModifiedUtf8(reinterpret_cast<char*>(&output[0]), &input[0], input.size());
+  ConvertUtf16ToModifiedUtf8(reinterpret_cast<char*>(&output[0]), expected.size(),
+                             &input[0], input.size());
   EXPECT_EQ(expected, output);
 }
 
@@ -139,10 +140,10 @@ TEST_F(UtfTest, CountAndConvertUtf8Bytes) {
   AssertConversion({ 'h', 'e', 'l', 'l', 'o' }, { 0x68, 0x65, 0x6c, 0x6c, 0x6f });
 
   AssertConversion({
-      0xd802, 0xdc02,  // Surrogate pair
-      0xdef0, 0xdcff,  // Three byte encodings
-      0x0101, 0x0000,  // Two byte encodings
-      'p'   , 'p'      // One byte encoding
+      0xd802, 0xdc02,  // Surrogate pair.
+      0xdef0, 0xdcff,  // Three byte encodings.
+      0x0101, 0x0000,  // Two byte encodings.
+      'p'   , 'p'      // One byte encoding.
     }, {
       0xf0, 0x90, 0xa0, 0x82,
       0xed, 0xbb, 0xb0, 0xed, 0xb3, 0xbf,
@@ -160,4 +161,186 @@ TEST_F(UtfTest, CountAndConvertUtf8Bytes_UnpairedSurrogate) {
   AssertConversion({ 'h', 0xdc00, 0xdc00, 'e' }, { 'h', 0xed, 0xb0, 0x80, 0xed, 0xb0, 0x80, 'e' });
 }
 
+// Old versions of functions, here to compare answers with optimized versions.
+
+size_t CountModifiedUtf8Chars_reference(const char* utf8) {
+  size_t len = 0;
+  int ic;
+  while ((ic = *utf8++) != '\0') {
+    len++;
+    if ((ic & 0x80) == 0) {
+      // one-byte encoding
+      continue;
+    }
+    // two- or three-byte encoding
+    utf8++;
+    if ((ic & 0x20) == 0) {
+      // two-byte encoding
+      continue;
+    }
+    utf8++;
+    if ((ic & 0x10) == 0) {
+      // three-byte encoding
+      continue;
+    }
+
+    // four-byte encoding: needs to be converted into a surrogate
+    // pair.
+    utf8++;
+    len++;
+  }
+  return len;
+}
+
+static size_t CountUtf8Bytes_reference(const uint16_t* chars, size_t char_count) {
+  size_t result = 0;
+  while (char_count--) {
+    const uint16_t ch = *chars++;
+    if (ch > 0 && ch <= 0x7f) {
+      ++result;
+    } else if (ch >= 0xd800 && ch <= 0xdbff) {
+      if (char_count > 0) {
+        const uint16_t ch2 = *chars;
+        // If we find a properly paired surrogate, we emit it as a 4 byte
+        // UTF sequence. If we find an unpaired leading or trailing surrogate,
+        // we emit it as a 3 byte sequence like would have done earlier.
+        if (ch2 >= 0xdc00 && ch2 <= 0xdfff) {
+          chars++;
+          char_count--;
+
+          result += 4;
+        } else {
+          result += 3;
+        }
+      } else {
+        // This implies we found an unpaired trailing surrogate at the end
+        // of a string.
+        result += 3;
+      }
+    } else if (ch > 0x7ff) {
+      result += 3;
+    } else {
+      result += 2;
+    }
+  }
+  return result;
+}
+
+static void ConvertUtf16ToModifiedUtf8_reference(char* utf8_out, const uint16_t* utf16_in,
+                                                 size_t char_count) {
+  while (char_count--) {
+    const uint16_t ch = *utf16_in++;
+    if (ch > 0 && ch <= 0x7f) {
+      *utf8_out++ = ch;
+    } else {
+      // Char_count == 0 here implies we've encountered an unpaired
+      // surrogate and we have no choice but to encode it as 3-byte UTF
+      // sequence. Note that unpaired surrogates can occur as a part of
+      // "normal" operation.
+      if ((ch >= 0xd800 && ch <= 0xdbff) && (char_count > 0)) {
+        const uint16_t ch2 = *utf16_in;
+
+        // Check if the other half of the pair is within the expected
+        // range. If it isn't, we will have to emit both "halves" as
+        // separate 3 byte sequences.
+        if (ch2 >= 0xdc00 && ch2 <= 0xdfff) {
+          utf16_in++;
+          char_count--;
+          const uint32_t code_point = (ch << 10) + ch2 - 0x035fdc00;
+          *utf8_out++ = (code_point >> 18) | 0xf0;
+          *utf8_out++ = ((code_point >> 12) & 0x3f) | 0x80;
+          *utf8_out++ = ((code_point >> 6) & 0x3f) | 0x80;
+          *utf8_out++ = (code_point & 0x3f) | 0x80;
+          continue;
+        }
+      }
+
+      if (ch > 0x07ff) {
+        // Three byte encoding.
+        *utf8_out++ = (ch >> 12) | 0xe0;
+        *utf8_out++ = ((ch >> 6) & 0x3f) | 0x80;
+        *utf8_out++ = (ch & 0x3f) | 0x80;
+      } else /*(ch > 0x7f || ch == 0)*/ {
+        // Two byte encoding.
+        *utf8_out++ = (ch >> 6) | 0xc0;
+        *utf8_out++ = (ch & 0x3f) | 0x80;
+      }
+    }
+  }
+}
+
+// Exhaustive test of converting a single code point to UTF-16, then UTF-8, and back again.
+
+static void codePointToSurrogatePair(uint32_t code_point, uint16_t &first, uint16_t &second) {
+  first = (code_point >> 10) + 0xd7c0;
+  second = (code_point & 0x03ff) + 0xdc00;
+}
+
+static void testConversions(uint16_t *buf, int char_count) {
+  char bytes_test[8], bytes_reference[8];
+  uint16_t out_buf_test[4], out_buf_reference[4];
+  int byte_count_test, byte_count_reference;
+  int char_count_test, char_count_reference;
+
+  // Calculate the number of utf-8 bytes for the utf-16 chars.
+  byte_count_reference = CountUtf8Bytes_reference(buf, char_count);
+  byte_count_test = CountUtf8Bytes(buf, char_count);
+  EXPECT_EQ(byte_count_reference, byte_count_test);
+
+  // Convert the utf-16 string to utf-8 bytes.
+  ConvertUtf16ToModifiedUtf8_reference(bytes_reference, buf, char_count);
+  ConvertUtf16ToModifiedUtf8(bytes_test, byte_count_test, buf, char_count);
+  for (int i = 0; i < byte_count_test; ++i) {
+    EXPECT_EQ(bytes_reference[i], bytes_test[i]);
+  }
+
+  // Calculate the number of utf-16 chars from the utf-8 bytes.
+  bytes_reference[byte_count_reference] = 0;  // Reference function needs null termination.
+  char_count_reference = CountModifiedUtf8Chars_reference(bytes_reference);
+  char_count_test = CountModifiedUtf8Chars(bytes_test, byte_count_test);
+  EXPECT_EQ(char_count, char_count_reference);
+  EXPECT_EQ(char_count, char_count_test);
+
+  // Convert the utf-8 bytes back to utf-16 chars.
+  // Does not need copied _reference version of the function because the original
+  // function with the old API is retained for debug/testing code.
+  ConvertModifiedUtf8ToUtf16(out_buf_reference, bytes_reference);
+  ConvertModifiedUtf8ToUtf16(out_buf_test, char_count_test, bytes_test, byte_count_test);
+  for (int i = 0; i < char_count_test; ++i) {
+    EXPECT_EQ(buf[i], out_buf_reference[i]);
+    EXPECT_EQ(buf[i], out_buf_test[i]);
+  }
+}
+
+TEST_F(UtfTest, ExhaustiveBidirectionalCodePointCheck) {
+  for (int codePoint = 0; codePoint <= 0x10ffff; ++codePoint) {
+    uint16_t buf[4];
+    if (codePoint <= 0xffff) {
+      if (codePoint >= 0xd800 && codePoint <= 0xdfff) {
+        // According to the Unicode standard, no character will ever
+        // be assigned to these code points, and they can not be encoded
+        // into either utf-16 or utf-8.
+        continue;
+      }
+      buf[0] = 'h';
+      buf[1] = codePoint;
+      buf[2] = 'e';
+      testConversions(buf, 2);
+      testConversions(buf, 3);
+      testConversions(buf + 1, 1);
+      testConversions(buf + 1, 2);
+    } else {
+      buf[0] = 'h';
+      codePointToSurrogatePair(codePoint, buf[1], buf[2]);
+      buf[3] = 'e';
+      testConversions(buf, 2);
+      testConversions(buf, 3);
+      testConversions(buf, 4);
+      testConversions(buf + 1, 1);
+      testConversions(buf + 1, 2);
+      testConversions(buf + 1, 3);
+    }
+  }
+}
+
 }  // namespace art