file_sys: Cleanup to better match Switch file system constructs.

file_sys: Add factory class for RomFS file system.

src/core/file_sys/filesystem.cpp

@@ -0,0 +1,122 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstddef>
+#include <iomanip>
+#include <sstream>
+#include "common/logging/log.h"
+#include "common/string_util.h"
+#include "core/file_sys/filesystem.h"
+#include "core/memory.h"
+
+namespace FileSys {
+
+Path::Path(LowPathType type, u32 size, u32 pointer) : type(type) {
+    switch (type) {
+    case Binary: {
+        binary.resize(size);
+        Memory::ReadBlock(pointer, binary.data(), binary.size());
+        break;
+    }
+
+    case Char: {
+        string.resize(size - 1); // Data is always null-terminated.
+        Memory::ReadBlock(pointer, &string[0], string.size());
+        break;
+    }
+
+    case Wchar: {
+        u16str.resize(size / 2 - 1); // Data is always null-terminated.
+        Memory::ReadBlock(pointer, &u16str[0], u16str.size() * sizeof(char16_t));
+        break;
+    }
+
+    default:
+        break;
+    }
+}
+
+std::string Path::DebugStr() const {
+    switch (GetType()) {
+    case Invalid:
+    default:
+        return "[Invalid]";
+    case Empty:
+        return "[Empty]";
+    case Binary: {
+        std::stringstream res;
+        res << "[Binary: ";
+        for (unsigned byte : binary)
+            res << std::hex << std::setw(2) << std::setfill('0') << byte;
+        res << ']';
+        return res.str();
+    }
+    case Char:
+        return "[Char: " + AsString() + ']';
+    case Wchar:
+        return "[Wchar: " + AsString() + ']';
+    }
+}
+
+std::string Path::AsString() const {
+    switch (GetType()) {
+    case Char:
+        return string;
+    case Wchar:
+        return Common::UTF16ToUTF8(u16str);
+    case Empty:
+        return {};
+    case Invalid:
+    case Binary:
+    default:
+        // TODO(yuriks): Add assert
+        LOG_ERROR(Service_FS, "LowPathType cannot be converted to string!");
+        return {};
+    }
+}
+
+std::u16string Path::AsU16Str() const {
+    switch (GetType()) {
+    case Char:
+        return Common::UTF8ToUTF16(string);
+    case Wchar:
+        return u16str;
+    case Empty:
+        return {};
+    case Invalid:
+    case Binary:
+        // TODO(yuriks): Add assert
+        LOG_ERROR(Service_FS, "LowPathType cannot be converted to u16string!");
+        return {};
+    }
+
+    UNREACHABLE();
+}
+
+std::vector<u8> Path::AsBinary() const {
+    switch (GetType()) {
+    case Binary:
+        return binary;
+    case Char:
+        return std::vector<u8>(string.begin(), string.end());
+    case Wchar: {
+        // use two u8 for each character of u16str
+        std::vector<u8> to_return(u16str.size() * 2);
+        for (size_t i = 0; i < u16str.size(); ++i) {
+            u16 tmp_char = u16str.at(i);
+            to_return[i * 2] = (tmp_char & 0xFF00) >> 8;
+            to_return[i * 2 + 1] = (tmp_char & 0x00FF);
+        }
+        return to_return;
+    }
+    case Empty:
+        return {};
+    case Invalid:
+    default:
+        // TODO(yuriks): Add assert
+        LOG_ERROR(Service_FS, "LowPathType cannot be converted to binary!");
+        return {};
+    }
+}
+} // namespace FileSys