1 files changed, 81 insertions, 0 deletions
diff --git a/third_party/image_io/src/base/byte_buffer.cc b/third_party/image_io/src/base/byte_buffer.cc
new file mode 100644
index 0000000..ac4d387
--- /dev/null
+++ b/third_party/image_io/src/base/byte_buffer.cc
@@ -0,0 +1,81 @@
+#include "image_io/base/byte_buffer.h"
+
+#include <cstring>
+#include <utility>
+
+namespace photos_editing_formats {
+namespace image_io {
+
+using std::string;
+using std::unique_ptr;
+
+/// @param byte_data The byte data to write to the buffer at pos.
+/// @param pos The location in a buffer to write the byte data to.
+/// @return The number of bytes written to the buffer at pos.
+static size_t WriteBytes(const ByteData& byte_data, Byte* pos) {
+  size_t byte_count = byte_data.GetByteCount();
+  if (!byte_count) {
+    return 0;
+  }
+  if (byte_data.GetType() == ByteData::kHex) {
+    const string& value = byte_data.GetValue();
+    for (size_t index = 0; index < byte_count; ++index) {
+      if (!ByteData::Hex2Byte(value[2 * index], value[2 * index + 1], pos++)) {
+        return 0;
+      }
+    }
+  } else {
+    std::memcpy(pos, byte_data.GetValue().c_str(), byte_count);
+  }
+  return byte_count;
+}
+
+ByteBuffer::ByteBuffer(size_t size, std::unique_ptr<Byte[]> buffer)
+    : buffer_(std::move(buffer)), size_(size) {
+  if (!buffer_) {
+    size_ = 0;
+  }
+  if (!size_) {
+    buffer_.reset();
+  }
+}
+
+ByteBuffer::ByteBuffer(const std::vector<ByteData>& byte_data_vector) {
+  size_ = 0;
+  for (const auto& byte_data : byte_data_vector) {
+    size_ += byte_data.GetByteCount();
+  }
+  if (!size_) {
+    return;
+  }
+  // Note that within google3, std::make_unique is not available, and clangtidy
+  // says use absl::make_unique. This library attempts to minimize the number of
+  // dependencies on google3, hence the no lint on the next line.
+  buffer_.reset(new Byte[size_]);  // NOLINT
+  Byte* pos = buffer_.get();
+  for (const auto& byte_data : byte_data_vector) {
+    size_t bytes_written = WriteBytes(byte_data, pos);
+    if (bytes_written == 0 && byte_data.GetByteCount() != 0) {
+      size_ = 0;
+      buffer_.reset(nullptr);
+    }
+    pos += bytes_written;
+  }
+}
+
+bool ByteBuffer::SetBigEndianValue(size_t location, std::uint16_t value) {
+  if (location + 1 >= size_) {
+    return false;
+  }
+  buffer_[location] = static_cast<Byte>(value >> 8);
+  buffer_[location + 1] = static_cast<Byte>(value & 0xFF);
+  return true;
+}
+
+Byte* ByteBuffer::Release() {
+  size_ = 0;
+  return buffer_.release();
+}
+
+}  // namespace image_io
+}  // namespace photos_editing_formats