🆕 Add circular bit stream

src/kyut/circular_bit_stream.hpp

+#ifndef INCLUDE_kyut_circular_bit_stream_hpp
+#define INCLUDE_kyut_circular_bit_stream_hpp
+
+#include <cassert>
+#include <cstdint>
+
+#include <memory>
+#include <string_view>
+#include <vector>
+
+namespace kyut {
+    class CircularBitStream {
+    public:
+        explicit CircularBitStream(const std::uint8_t *data, std::size_t size_bytes) noexcept
+            : bytes_(data, data + size_bytes)
+            , pos_bits_(0) {
+            assert(data != nullptr || size_bytes == 0);
+        }
+
+        CircularBitStream(const CircularBitStream &) = delete;
+        CircularBitStream(CircularBitStream &&) = delete;
+
+        CircularBitStream &operator=(const CircularBitStream &) = delete;
+        CircularBitStream &operator=(CircularBitStream &&) = delete;
+
+        ~CircularBitStream() noexcept = default;
+
+        [[nodiscard]] const std::vector<std::uint8_t> &bytes() const noexcept {
+            return bytes_;
+        }
+
+        [[nodiscard]] std::size_t size_bytes() const noexcept {
+            return bytes_.size();
+        }
+
+        [[nodiscard]] std::size_t size_bits() const noexcept {
+            return size_bytes() * 8;
+        }
+
+        bool read_bit() noexcept {
+            if (size_bits() == 0) {
+                return false;
+            }
+
+            const auto value = bytes_[pos_bits_ >> 3] >> (pos_bits_ & 0x7);
+
+            if (++pos_bits_ >= size_bits()) {
+                pos_bits_ = 0;
+            }
+
+            return value;
+        }
+
+        std::uint64_t read(std::size_t size_bits) {
+            assert(size_bits <= 64);
+
+            std::uint64_t value = 0;
+
+            for (size_t i = 0; i < size_bits; i++) {
+                if (read_bit()) {
+                    value |= std::uint64_t{1} << i;
+                }
+            }
+
+            return value;
+        }
+
+        static std::unique_ptr<CircularBitStream> from_string(std::string_view s) {
+            return std::make_unique<CircularBitStream>(reinterpret_cast<const std::uint8_t *>(s.data()), s.length());
+        }
+
+    private:
+        std::vector<std::uint8_t> bytes_;
+        std::size_t pos_bits_;
+    };
+} // namespace kyut
+
+#endif // INCLUDE_kyut_circular_bit_stream_hpp