Move StringPool to libandroidfw

Test: verified affected tests pass
Bug: 232940948
Change-Id: I22089893d7e5013f759c39ce190bec07fa6435db
diff --git a/tools/aapt2/util/Util.cpp b/tools/aapt2/util/Util.cpp
index efbbf8e..9b7ebdd 100644
--- a/tools/aapt2/util/Util.cpp
+++ b/tools/aapt2/util/Util.cpp
@@ -23,11 +23,12 @@
 
 #include "android-base/stringprintf.h"
 #include "android-base/strings.h"
+#include "androidfw/BigBuffer.h"
 #include "androidfw/StringPiece.h"
+#include "androidfw/Util.h"
 #include "build/version.h"
 #include "text/Unicode.h"
 #include "text/Utf8Iterator.h"
-#include "util/BigBuffer.h"
 #include "utils/Unicode.h"
 
 using ::aapt::text::Utf8Iterator;
@@ -340,107 +341,6 @@
   return true;
 }
 
-std::string Utf8ToModifiedUtf8(const std::string& utf8) {
-  // Java uses Modified UTF-8 which only supports the 1, 2, and 3 byte formats of UTF-8. To encode
-  // 4 byte UTF-8 codepoints, Modified UTF-8 allows the use of surrogate pairs in the same format
-  // of CESU-8 surrogate pairs. Calculate the size of the utf8 string with all 4 byte UTF-8
-  // codepoints replaced with 2 3 byte surrogate pairs
-  size_t modified_size = 0;
-  const size_t size = utf8.size();
-  for (size_t i = 0; i < size; i++) {
-    if (((uint8_t) utf8[i] >> 4) == 0xF) {
-      modified_size += 6;
-      i += 3;
-    } else {
-      modified_size++;
-    }
-  }
-
-  // Early out if no 4 byte codepoints are found
-  if (size == modified_size) {
-    return utf8;
-  }
-
-  std::string output;
-  output.reserve(modified_size);
-  for (size_t i = 0; i < size; i++) {
-    if (((uint8_t) utf8[i] >> 4) == 0xF) {
-      int32_t codepoint = utf32_from_utf8_at(utf8.data(), size, i, nullptr);
-
-      // Calculate the high and low surrogates as UTF-16 would
-      int32_t high = ((codepoint - 0x10000) / 0x400) + 0xD800;
-      int32_t low = ((codepoint - 0x10000) % 0x400) + 0xDC00;
-
-      // Encode each surrogate in UTF-8
-      output.push_back((char) (0xE4 | ((high >> 12) & 0xF)));
-      output.push_back((char) (0x80 | ((high >> 6) & 0x3F)));
-      output.push_back((char) (0x80 | (high & 0x3F)));
-      output.push_back((char) (0xE4 | ((low >> 12) & 0xF)));
-      output.push_back((char) (0x80 | ((low >> 6) & 0x3F)));
-      output.push_back((char) (0x80 | (low & 0x3F)));
-      i += 3;
-    } else {
-      output.push_back(utf8[i]);
-    }
-  }
-
-  return output;
-}
-
-std::string ModifiedUtf8ToUtf8(const std::string& modified_utf8) {
-  // The UTF-8 representation will have a byte length less than or equal to the Modified UTF-8
-  // representation.
-  std::string output;
-  output.reserve(modified_utf8.size());
-
-  size_t index = 0;
-  const size_t modified_size = modified_utf8.size();
-  while (index < modified_size) {
-    size_t next_index;
-    int32_t high_surrogate = utf32_from_utf8_at(modified_utf8.data(), modified_size, index,
-                                                &next_index);
-    if (high_surrogate < 0) {
-      return {};
-    }
-
-    // Check that the first codepoint is within the high surrogate range
-    if (high_surrogate >= 0xD800 && high_surrogate <= 0xDB7F) {
-      int32_t low_surrogate = utf32_from_utf8_at(modified_utf8.data(), modified_size, next_index,
-                                                 &next_index);
-      if (low_surrogate < 0) {
-        return {};
-      }
-
-      // Check that the second codepoint is within the low surrogate range
-      if (low_surrogate >= 0xDC00 && low_surrogate <= 0xDFFF) {
-        const char32_t codepoint = (char32_t) (((high_surrogate - 0xD800) * 0x400)
-            + (low_surrogate - 0xDC00) + 0x10000);
-
-        // The decoded codepoint should represent a 4 byte, UTF-8 character
-        const size_t utf8_length = (size_t) utf32_to_utf8_length(&codepoint, 1);
-        if (utf8_length != 4) {
-          return {};
-        }
-
-        // Encode the UTF-8 representation of the codepoint into the string
-        char* start = &output[output.size()];
-        output.resize(output.size() + utf8_length);
-        utf32_to_utf8((char32_t*) &codepoint, 1, start, utf8_length + 1);
-
-        index = next_index;
-        continue;
-      }
-    }
-
-    // Append non-surrogate pairs to the output string
-    for (size_t i = index; i < next_index; i++) {
-      output.push_back(modified_utf8[i]);
-    }
-    index = next_index;
-  }
-  return output;
-}
-
 std::u16string Utf8ToUtf16(const StringPiece& utf8) {
   ssize_t utf16_length = utf8_to_utf16_length(
       reinterpret_cast<const uint8_t*>(utf8.data()), utf8.length());
@@ -467,7 +367,7 @@
   return utf8;
 }
 
-bool WriteAll(std::ostream& out, const BigBuffer& buffer) {
+bool WriteAll(std::ostream& out, const android::BigBuffer& buffer) {
   for (const auto& b : buffer) {
     if (!out.write(reinterpret_cast<const char*>(b.buffer.get()), b.size)) {
       return false;
@@ -476,17 +376,6 @@
   return true;
 }
 
-std::unique_ptr<uint8_t[]> Copy(const BigBuffer& buffer) {
-  std::unique_ptr<uint8_t[]> data =
-      std::unique_ptr<uint8_t[]>(new uint8_t[buffer.size()]);
-  uint8_t* p = data.get();
-  for (const auto& block : buffer) {
-    memcpy(p, block.buffer.get(), block.size);
-    p += block.size;
-  }
-  return data;
-}
-
 typename Tokenizer::iterator& Tokenizer::iterator::operator++() {
   const char* start = token_.end();
   const char* end = str_.end();
@@ -553,19 +442,5 @@
   return true;
 }
 
-StringPiece16 GetString16(const android::ResStringPool& pool, size_t idx) {
-  if (auto str = pool.stringAt(idx); str.ok()) {
-    return *str;
-  }
-  return StringPiece16();
-}
-
-std::string GetString(const android::ResStringPool& pool, size_t idx) {
-  if (auto str = pool.string8At(idx); str.ok()) {
-    return ModifiedUtf8ToUtf8(str->to_string());
-  }
-  return Utf16ToUtf8(GetString16(pool, idx));
-}
-
 }  // namespace util
 }  // namespace aapt