add: Add bit stream reader

example/add.wast

@@ -16,4 +16,10 @@
             (local.get $c)
         )
     )
+    (func $inc (param $a i32) (result i32)
+        (i32.add
+            (local.get $a)
+            (i32.const 1)
+        )
+    )
 )

src/kyut/BitStreamReader.hpp

+#ifndef INCLUDE_kyut_BitStreamReader_hpp
+#define INCLUDE_kyut_BitStreamReader_hpp
+
+#include <cstdint>
+#include <memory>
+#include <string_view>
+#include <vector>
+
+namespace kyut {
+    class BitStreamReader {
+    public:
+        explicit BitStreamReader(std::vector<std::uint8_t> data)
+            : data_(std::move(data))
+            , pos_read_(0) {}
+
+        template <typename Iterator>
+        explicit BitStreamReader(Iterator begin, Iterator end)
+            : BitStreamReader({begin, end}) {}
+
+        BitStreamReader(const BitStreamReader &) = delete;
+        BitStreamReader(BitStreamReader &&) = delete;
+
+        BitStreamReader &operator=(const BitStreamReader &) = delete;
+        BitStreamReader &operator=(BitStreamReader &&) = delete;
+
+        ~BitStreamReader() noexcept = default;
+
+        static std::unique_ptr<BitStreamReader> fromString(std::string_view s) {
+            return std::make_unique<BitStreamReader>(reinterpret_cast<const std::uint8_t *>(s.data()),
+                                                     reinterpret_cast<const std::uint8_t *>(s.data() + s.size()));
+        }
+
+        [[nodiscard]] std::size_t tell() const noexcept {
+            return pos_read_;
+        }
+
+        bool readBit() {
+            if (data_.empty()) {
+                return false;
+            }
+
+            const auto pos = pos_read_;
+            pos_read_ = (pos_read_ + 1) % data_.size();
+
+            return (data_[pos / 8] >> (pos % 8)) & 1;
+        }
+
+        std::uint64_t read(std::size_t countBits) {
+            std::uint64_t value = 0;
+
+            for (std::size_t i = 0; i < countBits; i++) {
+                value <<= 1;
+                value |= readBit();
+            }
+
+            return value;
+        }
+
+    private:
+        std::vector<std::uint8_t> data_;
+        std::size_t pos_read_;
+    };
+} // namespace kyut
+
+#endif // INCLUDE_kyut_BitStreamReader_hpp

src/snpi.cpp

@@ -2,21 +2,27 @@
 
 #include <wasm-io.h>
 
+#include "kyut/BitStreamReader.hpp"
+
 int main(int argc, char *argv[]) {
     // Parse command line options
-    if (argc != 2) {
-        fmt::print(std::cerr, "{} <input file>\n", argv[0]);
+    if (argc != 3) {
+        fmt::print(std::cerr, "{} <input file> <watermark>\n", argv[0]);
 
         return 1;
     }
 
     const std::string inputFile = argv[1];
+    const std::string watermark = argv[2];
 
     try {
         // Read the input module
         wasm::Module module;
         wasm::ModuleReader{}.read(inputFile, module);
 
+        // Embed watermarks
+        const auto stream = kyut::BitStreamReader::fromString(watermark);
+
         // Output the result
         wasm::ModuleWriter{}.writeText(module, "");
     } catch (const wasm::ParseException &e) {