3 files changed, 375 insertions, 0 deletions
diff --git a/libs/androidfw/include/androidfw/StringPiece.h b/libs/androidfw/include/androidfw/StringPiece.h
new file mode 100644
index 000000000000..c9effd1a5112
--- /dev/null
+++ b/libs/androidfw/include/androidfw/StringPiece.h
@@ -0,0 +1,279 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#ifndef ANDROIDFW_STRING_PIECE_H
+#define ANDROIDFW_STRING_PIECE_H
+
+#include <ostream>
+#include <string>
+
+#include "utils/JenkinsHash.h"
+#include "utils/Unicode.h"
+
+namespace android {
+
+// Read only wrapper around basic C strings. Prevents excessive copying.
+// StringPiece does not own the data it is wrapping. The lifetime of the underlying
+// data must outlive this StringPiece.
+//
+// WARNING: When creating from std::basic_string<>, moving the original
+// std::basic_string<> will invalidate the data held in a BasicStringPiece<>.
+// BasicStringPiece<> should only be used transitively.
+template <typename TChar>
+class BasicStringPiece {
+ public:
+  using const_iterator = const TChar*;
+  using difference_type = size_t;
+
+  // End of string marker.
+  constexpr static const size_t npos = static_cast<size_t>(-1);
+
+  BasicStringPiece();
+  BasicStringPiece(const BasicStringPiece<TChar>& str);
+  BasicStringPiece(const std::basic_string<TChar>& str);  // NOLINT(implicit)
+  BasicStringPiece(const TChar* str);                     // NOLINT(implicit)
+  BasicStringPiece(const TChar* str, size_t len);
+
+  BasicStringPiece<TChar>& operator=(const BasicStringPiece<TChar>& rhs);
+  BasicStringPiece<TChar>& assign(const TChar* str, size_t len);
+
+  BasicStringPiece<TChar> substr(size_t start, size_t len = npos) const;
+  BasicStringPiece<TChar> substr(BasicStringPiece<TChar>::const_iterator begin,
+                                 BasicStringPiece<TChar>::const_iterator end) const;
+
+  const TChar* data() const;
+  size_t length() const;
+  size_t size() const;
+  bool empty() const;
+  std::basic_string<TChar> to_string() const;
+
+  bool contains(const BasicStringPiece<TChar>& rhs) const;
+  int compare(const BasicStringPiece<TChar>& rhs) const;
+  bool operator<(const BasicStringPiece<TChar>& rhs) const;
+  bool operator>(const BasicStringPiece<TChar>& rhs) const;
+  bool operator==(const BasicStringPiece<TChar>& rhs) const;
+  bool operator!=(const BasicStringPiece<TChar>& rhs) const;
+
+  const_iterator begin() const;
+  const_iterator end() const;
+
+ private:
+  const TChar* data_;
+  size_t length_;
+};
+
+using StringPiece = BasicStringPiece<char>;
+using StringPiece16 = BasicStringPiece<char16_t>;
+
+//
+// BasicStringPiece implementation.
+//
+
+template <typename TChar>
+constexpr const size_t BasicStringPiece<TChar>::npos;
+
+template <typename TChar>
+inline BasicStringPiece<TChar>::BasicStringPiece() : data_(nullptr), length_(0) {}
+
+template <typename TChar>
+inline BasicStringPiece<TChar>::BasicStringPiece(const BasicStringPiece<TChar>& str)
+    : data_(str.data_), length_(str.length_) {}
+
+template <typename TChar>
+inline BasicStringPiece<TChar>::BasicStringPiece(const std::basic_string<TChar>& str)
+    : data_(str.data()), length_(str.length()) {}
+
+template <>
+inline BasicStringPiece<char>::BasicStringPiece(const char* str)
+    : data_(str), length_(str != nullptr ? strlen(str) : 0) {}
+
+template <>
+inline BasicStringPiece<char16_t>::BasicStringPiece(const char16_t* str)
+    : data_(str), length_(str != nullptr ? strlen16(str) : 0) {}
+
+template <typename TChar>
+inline BasicStringPiece<TChar>::BasicStringPiece(const TChar* str, size_t len)
+    : data_(str), length_(len) {}
+
+template <typename TChar>
+inline BasicStringPiece<TChar>& BasicStringPiece<TChar>::operator=(
+    const BasicStringPiece<TChar>& rhs) {
+  data_ = rhs.data_;
+  length_ = rhs.length_;
+  return *this;
+}
+
+template <typename TChar>
+inline BasicStringPiece<TChar>& BasicStringPiece<TChar>::assign(const TChar* str, size_t len) {
+  data_ = str;
+  length_ = len;
+  return *this;
+}
+
+template <typename TChar>
+inline BasicStringPiece<TChar> BasicStringPiece<TChar>::substr(size_t start, size_t len) const {
+  if (len == npos) {
+    len = length_ - start;
+  }
+
+  if (start > length_ || start + len > length_) {
+    return BasicStringPiece<TChar>();
+  }
+  return BasicStringPiece<TChar>(data_ + start, len);
+}
+
+template <typename TChar>
+inline BasicStringPiece<TChar> BasicStringPiece<TChar>::substr(
+    BasicStringPiece<TChar>::const_iterator begin,
+    BasicStringPiece<TChar>::const_iterator end) const {
+  return BasicStringPiece<TChar>(begin, end - begin);
+}
+
+template <typename TChar>
+inline const TChar* BasicStringPiece<TChar>::data() const {
+  return data_;
+}
+
+template <typename TChar>
+inline size_t BasicStringPiece<TChar>::length() const {
+  return length_;
+}
+
+template <typename TChar>
+inline size_t BasicStringPiece<TChar>::size() const {
+  return length_;
+}
+
+template <typename TChar>
+inline bool BasicStringPiece<TChar>::empty() const {
+  return length_ == 0;
+}
+
+template <typename TChar>
+inline std::basic_string<TChar> BasicStringPiece<TChar>::to_string() const {
+  return std::basic_string<TChar>(data_, length_);
+}
+
+template <>
+inline bool BasicStringPiece<char>::contains(const BasicStringPiece<char>& rhs) const {
+  if (!data_ || !rhs.data_) {
+    return false;
+  }
+  if (rhs.length_ > length_) {
+    return false;
+  }
+  return strstr(data_, rhs.data_) != nullptr;
+}
+
+template <>
+inline int BasicStringPiece<char>::compare(const BasicStringPiece<char>& rhs) const {
+  const char nullStr = '\0';
+  const char* b1 = data_ != nullptr ? data_ : &nullStr;
+  const char* e1 = b1 + length_;
+  const char* b2 = rhs.data_ != nullptr ? rhs.data_ : &nullStr;
+  const char* e2 = b2 + rhs.length_;
+
+  while (b1 < e1 && b2 < e2) {
+    const int d = static_cast<int>(*b1++) - static_cast<int>(*b2++);
+    if (d) {
+      return d;
+    }
+  }
+  return static_cast<int>(length_ - rhs.length_);
+}
+
+inline ::std::ostream& operator<<(::std::ostream& out, const BasicStringPiece<char16_t>& str) {
+  const ssize_t result_len = utf16_to_utf8_length(str.data(), str.size());
+  if (result_len < 0) {
+    // Empty string.
+    return out;
+  }
+
+  std::string result;
+  result.resize(static_cast<size_t>(result_len));
+  utf16_to_utf8(str.data(), str.length(), &*result.begin(), static_cast<size_t>(result_len) + 1);
+  return out << result;
+}
+
+template <>
+inline bool BasicStringPiece<char16_t>::contains(const BasicStringPiece<char16_t>& rhs) const {
+  if (!data_ || !rhs.data_) {
+    return false;
+  }
+  if (rhs.length_ > length_) {
+    return false;
+  }
+  return strstr16(data_, rhs.data_) != nullptr;
+}
+
+template <>
+inline int BasicStringPiece<char16_t>::compare(const BasicStringPiece<char16_t>& rhs) const {
+  const char16_t nullStr = u'\0';
+  const char16_t* b1 = data_ != nullptr ? data_ : &nullStr;
+  const char16_t* b2 = rhs.data_ != nullptr ? rhs.data_ : &nullStr;
+  return strzcmp16(b1, length_, b2, rhs.length_);
+}
+
+template <typename TChar>
+inline bool BasicStringPiece<TChar>::operator<(const BasicStringPiece<TChar>& rhs) const {
+  return compare(rhs) < 0;
+}
+
+template <typename TChar>
+inline bool BasicStringPiece<TChar>::operator>(const BasicStringPiece<TChar>& rhs) const {
+  return compare(rhs) > 0;
+}
+
+template <typename TChar>
+inline bool BasicStringPiece<TChar>::operator==(const BasicStringPiece<TChar>& rhs) const {
+  return compare(rhs) == 0;
+}
+
+template <typename TChar>
+inline bool BasicStringPiece<TChar>::operator!=(const BasicStringPiece<TChar>& rhs) const {
+  return compare(rhs) != 0;
+}
+
+template <typename TChar>
+inline typename BasicStringPiece<TChar>::const_iterator BasicStringPiece<TChar>::begin() const {
+  return data_;
+}
+
+template <typename TChar>
+inline typename BasicStringPiece<TChar>::const_iterator BasicStringPiece<TChar>::end() const {
+  return data_ + length_;
+}
+
+inline ::std::ostream& operator<<(::std::ostream& out, const BasicStringPiece<char>& str) {
+  return out.write(str.data(), str.size());
+}
+
+}  // namespace android
+
+namespace std {
+
+template <typename TChar>
+struct hash<android::BasicStringPiece<TChar>> {
+  size_t operator()(const android::BasicStringPiece<TChar>& str) const {
+    uint32_t hashCode = android::JenkinsHashMixBytes(
+        0, reinterpret_cast<const uint8_t*>(str.data()), sizeof(TChar) * str.size());
+    return static_cast<size_t>(hashCode);
+  }
+};
+
+}  // namespace std
+
+#endif  // ANDROIDFW_STRING_PIECE_H
diff --git a/libs/androidfw/tests/Android.mk b/libs/androidfw/tests/Android.mk
index 6754cd89944a..650f8138366b 100644
--- a/libs/androidfw/tests/Android.mk
+++ b/libs/androidfw/tests/Android.mk
@@ -34,6 +34,7 @@ testFiles := \
     LoadedArsc_test.cpp \
     ResTable_test.cpp \
     Split_test.cpp \
+    StringPiece_test.cpp \
     TestHelpers.cpp \
     TestMain.cpp \
     Theme_test.cpp \
diff --git a/libs/androidfw/tests/StringPiece_test.cpp b/libs/androidfw/tests/StringPiece_test.cpp
new file mode 100644
index 000000000000..316a5c1bf40e
--- /dev/null
+++ b/libs/androidfw/tests/StringPiece_test.cpp
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2015 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 "androidfw/StringPiece.h"
+
+#include <algorithm>
+#include <string>
+#include <vector>
+
+#include "TestHelpers.h"
+
+namespace android {
+
+TEST(StringPieceTest, CompareNonNullTerminatedPiece) {
+  StringPiece a("hello world", 5);
+  StringPiece b("hello moon", 5);
+  EXPECT_EQ(a, b);
+
+  StringPiece16 a16(u"hello world", 5);
+  StringPiece16 b16(u"hello moon", 5);
+  EXPECT_EQ(a16, b16);
+}
+
+TEST(StringPieceTest, PiecesHaveCorrectSortOrder) {
+  std::string testing("testing");
+  std::string banana("banana");
+  std::string car("car");
+
+  EXPECT_TRUE(StringPiece(testing) > banana);
+  EXPECT_TRUE(StringPiece(testing) > car);
+  EXPECT_TRUE(StringPiece(banana) < testing);
+  EXPECT_TRUE(StringPiece(banana) < car);
+  EXPECT_TRUE(StringPiece(car) < testing);
+  EXPECT_TRUE(StringPiece(car) > banana);
+}
+
+TEST(StringPieceTest, PiecesHaveCorrectSortOrderUtf8) {
+  std::string testing("testing");
+  std::string banana("banana");
+  std::string car("car");
+
+  EXPECT_TRUE(StringPiece(testing) > banana);
+  EXPECT_TRUE(StringPiece(testing) > car);
+  EXPECT_TRUE(StringPiece(banana) < testing);
+  EXPECT_TRUE(StringPiece(banana) < car);
+  EXPECT_TRUE(StringPiece(car) < testing);
+  EXPECT_TRUE(StringPiece(car) > banana);
+}
+
+TEST(StringPieceTest, ContainsOtherStringPiece) {
+  StringPiece text("I am a leaf on the wind.");
+  StringPiece start_needle("I am");
+  StringPiece end_needle("wind.");
+  StringPiece middle_needle("leaf");
+  StringPiece empty_needle("");
+  StringPiece missing_needle("soar");
+  StringPiece long_needle("This string is longer than the text.");
+
+  EXPECT_TRUE(text.contains(start_needle));
+  EXPECT_TRUE(text.contains(end_needle));
+  EXPECT_TRUE(text.contains(middle_needle));
+  EXPECT_TRUE(text.contains(empty_needle));
+  EXPECT_FALSE(text.contains(missing_needle));
+  EXPECT_FALSE(text.contains(long_needle));
+
+  StringPiece16 text16(u"I am a leaf on the wind.");
+  StringPiece16 start_needle16(u"I am");
+  StringPiece16 end_needle16(u"wind.");
+  StringPiece16 middle_needle16(u"leaf");
+  StringPiece16 empty_needle16(u"");
+  StringPiece16 missing_needle16(u"soar");
+  StringPiece16 long_needle16(u"This string is longer than the text.");
+
+  EXPECT_TRUE(text16.contains(start_needle16));
+  EXPECT_TRUE(text16.contains(end_needle16));
+  EXPECT_TRUE(text16.contains(middle_needle16));
+  EXPECT_TRUE(text16.contains(empty_needle16));
+  EXPECT_FALSE(text16.contains(missing_needle16));
+  EXPECT_FALSE(text16.contains(long_needle16));
+}
+
+}  // namespace android