Add functions to compress/decompress vector of bytes

components/misc/compression.cpp

@@ -0,0 +1,48 @@
+#include "compression.hpp"
+
+#include <lz4.h>
+
+#include <cstddef>
+#include <cstring>
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+namespace Misc
+{
+    std::vector<std::byte> compress(const std::vector<std::byte>& data)
+    {
+        const std::size_t originalSize = data.size();
+        std::vector<std::byte> result(static_cast<std::size_t>(LZ4_compressBound(static_cast<int>(originalSize)) + sizeof(originalSize)));
+        const int size = LZ4_compress_default(
+            reinterpret_cast<const char*>(data.data()),
+            reinterpret_cast<char*>(result.data()) + sizeof(originalSize),
+            static_cast<int>(data.size()),
+            static_cast<int>(result.size() - sizeof(originalSize))
+        );
+        if (size == 0)
+            throw std::runtime_error("Failed to compress");
+        std::memcpy(result.data(), &originalSize, sizeof(originalSize));
+        result.resize(static_cast<std::size_t>(size) + sizeof(originalSize));
+        return result;
+    }
+
+    std::vector<std::byte> decompress(const std::vector<std::byte>& data)
+    {
+        std::size_t originalSize;
+        std::memcpy(&originalSize, data.data(), sizeof(originalSize));
+        std::vector<std::byte> result(originalSize);
+        const int size = LZ4_decompress_safe(
+            reinterpret_cast<const char*>(data.data()) + sizeof(originalSize),
+            reinterpret_cast<char*>(result.data()),
+            static_cast<int>(data.size() - sizeof(originalSize)),
+            static_cast<int>(result.size())
+        );
+        if (size < 0)
+            throw std::runtime_error("Failed to decompress");
+        if (originalSize != static_cast<std::size_t>(size))
+            throw std::runtime_error("Size of decompressed data (" + std::to_string(size)
+                                     + ") doesn't match stored (" + std::to_string(originalSize) + ")");
+        return result;
+    }
+}