From 51e831cbfec54299ca80b6eb6b3bea8edd1e74be Mon Sep 17 00:00:00 2001
From: Caball <Caball009@al.al>
Date: Mon, 30 Dec 2024 23:26:29 +0100
Subject: [PATCH] Added helper util functions for (de)compression.

---
 src/common/utils/compression.cpp | 80 ++++++++++++++++++++++++++++++++
 src/common/utils/compression.hpp |  5 ++
 2 files changed, 85 insertions(+)

diff --git a/src/common/utils/compression.cpp b/src/common/utils/compression.cpp
index 1688cee..9c50a4a 100644
--- a/src/common/utils/compression.cpp
+++ b/src/common/utils/compression.cpp
@@ -109,6 +109,86 @@ namespace utils::compression
 			result.resize(length);
 			return result;
 		}
+
+		std::vector<std::uint8_t> decompress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate)
+		{
+			auto decompress_internal = [](std::uint8_t* output, uLong* output_size, const std::uint8_t* input, uLong* input_size)
+			{
+				return uncompress2(
+					reinterpret_cast<Bytef*>(output), output_size,
+					reinterpret_cast<const Bytef*>(input), input_size
+				);
+			};
+
+			auto output_size = static_cast<uLong>(std::max(exp_output_size, std::size_t(256)));
+			std::vector<std::uint8_t> output(output_size);
+
+			auto input_size = static_cast<uLong>(input.size());
+			auto status = decompress_internal(output.data(), &output_size, input.data(), &input_size);
+
+			if (status == Z_BUF_ERROR)
+			{
+				const auto decompression_ratio = (input_size / static_cast<double>(output.size())) - 0.04;
+				output_size = static_cast<uLong>(std::max(input.size() / decompression_ratio, static_cast<double>(output_size)));
+				output.resize(output_size);
+
+				input_size = static_cast<uLong>(input.size());
+				status = decompress_internal(output.data(), &output_size, input.data(), &input_size);
+			}
+
+			for (growth_rate = std::max(growth_rate, 1.0); status == Z_BUF_ERROR;)
+			{
+				output_size = 4 + static_cast<uLong>(growth_rate * output.size());
+				output.resize(output_size);
+
+				input_size = static_cast<uLong>(input.size());
+				status = decompress_internal(output.data(), &output_size, input.data(), &input_size);
+			}
+
+			if (status != Z_OK)
+			{
+				output.clear();
+				return output;
+			}
+
+			output.resize(output_size);
+			return output;
+		}
+
+		std::vector<std::uint8_t> compress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate)
+		{
+			auto compress_internal = [](std::uint8_t* output, uLong* output_size, const std::uint8_t* input, uLong input_size)
+			{
+				return compress2(
+					reinterpret_cast<Bytef*>(output), output_size,
+					reinterpret_cast<const Bytef*>(input), input_size,
+					Z_BEST_COMPRESSION
+				);
+			};
+
+			auto output_size = static_cast<uLong>(std::max(exp_output_size, std::size_t(256)));
+			std::vector<std::uint8_t> output(output_size);
+
+			const auto input_size = static_cast<uLong>(input.size());
+			auto status = compress_internal(output.data(), &output_size, input.data(), input_size);
+
+			for (growth_rate = std::max(growth_rate, 1.0); status == Z_BUF_ERROR;)
+			{
+				output_size = 4 + static_cast<uLong>(growth_rate * output.size());
+				output.resize(output_size);
+
+				status = compress_internal(output.data(), &output_size, input.data(), input_size);
+			}
+
+			if (status != Z_OK)
+			{
+				output.clear();
+				return output;
+			}
+
+			output.resize(output_size);
+			return output;
+		}
 	}
 
 	namespace zip
diff --git a/src/common/utils/compression.hpp b/src/common/utils/compression.hpp
index dfe36ad..d1a2a37 100644
--- a/src/common/utils/compression.hpp
+++ b/src/common/utils/compression.hpp
@@ -1,7 +1,9 @@
 #pragma once
 
+#include <span>
 #include <string>
 #include <unordered_map>
+#include <vector>
 
 #define CHUNK 16384u
 
@@ -11,6 +13,9 @@ namespace utils::compression
 	{
 		std::string compress(const std::string& data);
 		std::string decompress(const std::string& data);
+
+		std::vector<std::uint8_t> compress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate = 2.0);
+		std::vector<std::uint8_t> decompress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate = 2.0);
 	}
 
 	namespace zip