Add fancy hashing

src/utils/hash.cpp

@@ -0,0 +1,99 @@
+#include "hash.hpp"
+#include <fstream>
+#include <filesystem>
+#include <iostream>
+
+namespace dropshell {
+
+XXH64_hash_t hash_file(const std::string &path) {
+    // Create hash state
+    XXH64_state_t* const state = XXH64_createState();
+    if (state == nullptr) {
+        std::cerr << "Failed to create hash state" << std::endl;
+        return 0;
+    }
+
+    // Initialize state with seed 0
+    if (XXH64_reset(state, 0) == XXH_ERROR) {
+        std::cerr << "Failed to reset hash state" << std::endl;
+        XXH64_freeState(state);
+        return 0;
+    }
+
+    // Open file
+    std::ifstream file(path, std::ios::binary);
+    if (!file.is_open()) {
+        std::cerr << "Failed to open file: " << path << std::endl;
+        XXH64_freeState(state);
+        return 0;
+    }
+
+    // Read file in chunks and update hash
+    const size_t buffer_size = 4096;
+    char buffer[buffer_size];
+    while (file.read(buffer, buffer_size)) {
+        if (XXH64_update(state, buffer, file.gcount()) == XXH_ERROR) {
+            std::cerr << "Failed to update hash" << std::endl;
+            XXH64_freeState(state);
+            return 0;
+        }
+    }
+
+    // Handle any remaining bytes
+    if (file.gcount() > 0) {
+        if (XXH64_update(state, buffer, file.gcount()) == XXH_ERROR) {
+            std::cerr << "Failed to update hash" << std::endl;
+            XXH64_freeState(state);
+            return 0;
+        }
+    }
+
+    // Get final hash
+    XXH64_hash_t hash = XXH64_digest(state);
+    XXH64_freeState(state);
+    return hash;
+}
+
+XXH64_hash_t hash_directory_recursive(const std::string &path) {
+    // Create hash state
+    XXH64_state_t* const state = XXH64_createState();
+    if (state == nullptr) {
+        std::cerr << "Failed to create hash state" << std::endl;
+        return 0;
+    }
+
+    // Initialize state with seed 0
+    if (XXH64_reset(state, 0) == XXH_ERROR) {
+        std::cerr << "Failed to reset hash state" << std::endl;
+        XXH64_freeState(state);
+        return 0;
+    }
+
+    try {
+        // Iterate through all files in directory recursively
+        for (const auto& entry : std::filesystem::recursive_directory_iterator(path)) {
+            if (entry.is_regular_file()) {
+                // Get file hash
+                XXH64_hash_t file_hash = hash_file(entry.path().string());
+                
+                // Update directory hash with file hash
+                if (XXH64_update(state, &file_hash, sizeof(file_hash)) == XXH_ERROR) {
+                    std::cerr << "Failed to update hash" << std::endl;
+                    XXH64_freeState(state);
+                    return 0;
+                }
+            }
+        }
+    } catch (const std::filesystem::filesystem_error& e) {
+        std::cerr << "Filesystem error: " << e.what() << std::endl;
+        XXH64_freeState(state);
+        return 0;
+    }
+
+    // Get final hash
+    XXH64_hash_t hash = XXH64_digest(state);
+    XXH64_freeState(state);
+    return hash;
+}
+
+} // namespace dropshell

src/utils/hash.hpp

@@ -0,0 +1,16 @@
+#ifndef HASH_HPP
+#define HASH_HPP
+
+#include <xxhash.h>
+#include <string>
+
+namespace dropshell {
+
+    XXH64_hash_t hash_file(const std::string &path);
+
+    XXH64_hash_t hash_directory_recursive(const std::string &path);
+
+} // namespace dropshell
+
+
+#endif