file_sys: Add HFS/PFS helper component

src/core/file_sys/partition_filesystem.h

@@ -0,0 +1,87 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <string>
+#include <vector>
+#include "common/common_funcs.h"
+#include "common/common_types.h"
+#include "common/swap.h"
+
+namespace Loader {
+enum class ResultStatus;
+}
+
+namespace FileSys {
+
+/**
+ * Helper which implements an interface to parse PFS/HFS filesystems.
+ * Data can either be loaded from a file path or data with an offset into it.
+ */
+class PartitionFilesystem {
+public:
+    Loader::ResultStatus Load(const std::string& file_path, size_t offset = 0);
+    Loader::ResultStatus Load(const std::vector<u8> file_data, size_t offset = 0);
+
+    u32 GetNumEntries(void) const;
+    u64 GetEntryOffset(int index) const;
+    u64 GetEntrySize(int index) const;
+    std::string GetEntryName(int index) const;
+    u64 GetFileOffset(const std::string& name) const;
+    u64 GetFileSize(const std::string& name) const;
+
+    void Print() const;
+
+private:
+    struct Header {
+        std::array<char, 4> magic;
+        u32_le num_entries;
+        u32_le strtab_size;
+        INSERT_PADDING_BYTES(0x4);
+    };
+
+    static_assert(sizeof(Header) == 0x10, "PFS/HFS header structure size is wrong");
+
+#pragma pack(push, 1)
+    struct FSEntry {
+        u64_le offset;
+        u64_le size;
+        u32_le strtab_offset;
+    };
+
+    static_assert(sizeof(FSEntry) == 0x14, "FS entry structure size is wrong");
+
+    struct PFSEntry {
+        FSEntry fs_entry;
+        INSERT_PADDING_BYTES(0x4);
+    };
+
+    static_assert(sizeof(PFSEntry) == 0x18, "PFS entry structure size is wrong");
+
+    struct HFSEntry {
+        FSEntry fs_entry;
+        u32_le hash_region_size;
+        INSERT_PADDING_BYTES(0x8);
+        std::array<char, 0x20> hash;
+    };
+
+    static_assert(sizeof(HFSEntry) == 0x40, "HFS entry structure size is wrong");
+
+#pragma pack(pop)
+
+    struct FileEntry {
+        FSEntry fs_entry;
+        std::string name;
+    };
+
+    Header pfs_header;
+    bool is_hfs;
+    size_t content_offset;
+
+    std::vector<FileEntry> pfs_entries;
+};
+
+} // namespace FileSys