sys: Cleanup libmagic mess

plugins/libimhex/source/helpers/magic.cpp

@@ -0,0 +1,94 @@
+#include <hex/helpers/magic.hpp>
+
+#include <hex/helpers/utils.hpp>
+#include <hex/helpers/paths.hpp>
+
+#include <hex/providers/provider.hpp>
+
+#include <filesystem>
+#include <optional>
+#include <string>
+
+#include <magic.h>
+
+#if defined(OS_WINDOWS)
+    #define MAGIC_PATH_SEPARATOR ";"
+#else
+    #define MAGIC_PATH_SEPARATOR ":"
+#endif
+
+
+namespace hex::magic {
+
+    static std::optional<std::string> getMagicFiles(bool sourceFiles = false) {
+        std::string magicFiles;
+
+        std::error_code error;
+        for (const auto &dir : hex::getPath(ImHexPath::Magic)) {
+            for (const auto &entry : std::filesystem::directory_iterator(dir, error)) {
+                if (entry.is_regular_file() && ((sourceFiles && entry.path().extension().empty()) || (!sourceFiles && entry.path().extension() == ".mgc")))
+                    magicFiles += entry.path().string() + MAGIC_PATH_SEPARATOR;
+            }
+        }
+
+        if (error)
+            return { };
+        else
+            return magicFiles;
+    }
+
+    bool compile() {
+        magic_t ctx = magic_open(MAGIC_NONE);
+        ON_SCOPE_EXIT { magic_close(ctx); };
+
+        auto magicFiles = getMagicFiles(true);
+
+        if (!magicFiles.has_value())
+            return false;
+
+        return magic_compile(ctx, magicFiles->c_str()) == 0;
+    }
+
+    std::string getDescription(const std::vector<u8> &data) {
+        auto magicFiles = getMagicFiles();
+
+        if (magicFiles.has_value()) {
+            magic_t ctx = magic_open(MAGIC_NONE);
+            ON_SCOPE_EXIT { magic_close(ctx); };
+
+            if (magic_load(ctx, magicFiles->c_str()))
+                return magic_buffer(ctx, data.data(), data.size()) ?: "";
+        }
+
+        return "";
+    }
+
+    std::string getDescription(prv::Provider *provider, size_t size) {
+        std::vector<u8> buffer(std::min(provider->getSize(), size), 0x00);
+        provider->readRelative(0x00, buffer.data(), buffer.size());
+
+        return getDescription(buffer);
+    }
+
+    std::string getMIMEType(const std::vector<u8> &data){
+        auto magicFiles = getMagicFiles();
+
+        if (magicFiles.has_value()) {
+            magic_t ctx = magic_open(MAGIC_MIME);
+            ON_SCOPE_EXIT { magic_close(ctx); };
+
+            if (magic_load(ctx, magicFiles->c_str()))
+                return magic_buffer(ctx, data.data(), data.size()) ?: "";
+        }
+
+        return "";
+    }
+
+    std::string getMIMEType(prv::Provider *provider, size_t size) {
+        std::vector<u8> buffer(std::min(provider->getSize(), size), 0x00);
+        provider->readRelative(0x00, buffer.data(), buffer.size());
+
+        return getMIMEType(buffer);
+    }
+
+}