Files
MosisService/src/main/cpp/sandbox/virtual_fs.cpp

707 lines
18 KiB
C++

#include "virtual_fs.h"
#include <lua.hpp>
#include <filesystem>
#include <fstream>
#include <sstream>
#include <algorithm>
#include <chrono>
namespace fs = std::filesystem;
namespace mosis {
//=============================================================================
// VIRTUALFS IMPLEMENTATION
//=============================================================================
VirtualFS::VirtualFS(const std::string& app_id,
const std::string& app_root,
const VirtualFSLimits& limits)
: m_app_id(app_id)
, m_app_root(app_root)
, m_limits(limits) {
// Ensure app root exists
std::error_code ec;
fs::create_directories(m_app_root, ec);
// Recalculate usage on startup
RecalculateUsage();
}
VirtualFS::~VirtualFS() {
}
//=============================================================================
// PATH VALIDATION
//=============================================================================
bool VirtualFS::IsValidPathChar(char c) {
// Allow alphanumeric, dash, underscore, dot, forward slash
return std::isalnum(static_cast<unsigned char>(c)) ||
c == '-' || c == '_' || c == '.' || c == '/';
}
int VirtualFS::GetPathDepth(const std::string& path) {
int depth = 0;
for (char c : path) {
if (c == '/') depth++;
}
return depth;
}
bool VirtualFS::ValidatePath(const std::string& virtual_path, std::string& error) {
// Check length
if (virtual_path.length() > m_limits.max_path_length) {
error = "path too long";
return false;
}
// Must start with /
if (virtual_path.empty() || virtual_path[0] != '/') {
error = "path must start with /";
return false;
}
// Check valid prefix
bool valid_prefix = false;
if (virtual_path.find("/data/") == 0 || virtual_path == "/data") {
valid_prefix = true;
} else if (virtual_path.find("/cache/") == 0 || virtual_path == "/cache") {
valid_prefix = true;
} else if (virtual_path.find("/temp/") == 0 || virtual_path == "/temp") {
valid_prefix = true;
} else if (virtual_path.find("/shared/") == 0 || virtual_path == "/shared") {
// Check permission for shared
if (CheckPermission && !CheckPermission("storage.shared")) {
error = "permission denied: storage.shared required";
return false;
}
valid_prefix = true;
}
if (!valid_prefix) {
error = "invalid path prefix (must be /data/, /cache/, /temp/, or /shared/)";
return false;
}
// Check for path traversal
if (virtual_path.find("..") != std::string::npos) {
error = "path traversal not allowed";
return false;
}
// Check for double slashes (except at start)
if (virtual_path.find("//") != std::string::npos) {
error = "invalid path (double slashes)";
return false;
}
// Check all characters are valid
for (char c : virtual_path) {
if (!IsValidPathChar(c)) {
error = "invalid character in path";
return false;
}
}
// Check depth
if (GetPathDepth(virtual_path) > m_limits.max_path_depth) {
error = "path too deep";
return false;
}
return true;
}
std::string VirtualFS::ResolvePath(const std::string& virtual_path) {
// Map virtual path to physical path
// /data/foo.txt -> <app_root>/data/foo.txt
// /cache/bar.txt -> <app_root>/cache/bar.txt
// /temp/baz.txt -> <app_root>/temp/baz.txt
// /shared/x.txt -> <app_root>/shared/x.txt
fs::path base(m_app_root);
// Remove leading slash and append
std::string relative = virtual_path.substr(1); // Remove leading /
return (base / relative).string();
}
//=============================================================================
// FILE OPERATIONS
//=============================================================================
bool VirtualFS::EnsureParentDir(const std::string& path) {
fs::path p(path);
fs::path parent = p.parent_path();
if (parent.empty()) return true;
std::error_code ec;
fs::create_directories(parent, ec);
return !ec;
}
void VirtualFS::UpdateUsage(int64_t delta) {
if (delta < 0 && static_cast<size_t>(-delta) > m_used_bytes) {
m_used_bytes = 0;
} else {
m_used_bytes = static_cast<size_t>(static_cast<int64_t>(m_used_bytes) + delta);
}
}
bool VirtualFS::CheckQuota(size_t additional_bytes, std::string& error) {
if (m_used_bytes + additional_bytes > m_limits.max_quota_bytes) {
error = "quota exceeded";
return false;
}
return true;
}
std::optional<std::string> VirtualFS::Read(const std::string& path, std::string& error) {
if (!ValidatePath(path, error)) {
return std::nullopt;
}
std::string physical_path = ResolvePath(path);
std::ifstream file(physical_path, std::ios::binary);
if (!file) {
error = "file not found";
return std::nullopt;
}
std::ostringstream ss;
ss << file.rdbuf();
return ss.str();
}
bool VirtualFS::Write(const std::string& path, const std::string& data, std::string& error) {
if (!ValidatePath(path, error)) {
return false;
}
// Check file size limit
if (data.size() > m_limits.max_file_size) {
error = "file size limit exceeded";
return false;
}
std::string physical_path = ResolvePath(path);
// Get current file size if exists (for quota calculation)
size_t old_size = 0;
std::error_code ec;
if (fs::exists(physical_path, ec)) {
old_size = static_cast<size_t>(fs::file_size(physical_path, ec));
}
// Check quota for net change
int64_t delta = static_cast<int64_t>(data.size()) - static_cast<int64_t>(old_size);
if (delta > 0 && !CheckQuota(static_cast<size_t>(delta), error)) {
return false;
}
// Ensure parent directory exists
if (!EnsureParentDir(physical_path)) {
error = "failed to create parent directory";
return false;
}
std::ofstream file(physical_path, std::ios::binary | std::ios::trunc);
if (!file) {
error = "failed to open file for writing";
return false;
}
file.write(data.data(), data.size());
if (!file) {
error = "failed to write data";
return false;
}
file.close();
UpdateUsage(delta);
return true;
}
bool VirtualFS::Append(const std::string& path, const std::string& data, std::string& error) {
if (!ValidatePath(path, error)) {
return false;
}
std::string physical_path = ResolvePath(path);
// Get current file size
size_t current_size = 0;
std::error_code ec;
if (fs::exists(physical_path, ec)) {
current_size = static_cast<size_t>(fs::file_size(physical_path, ec));
}
// Check file size limit
if (current_size + data.size() > m_limits.max_file_size) {
error = "file size limit exceeded";
return false;
}
// Check quota
if (!CheckQuota(data.size(), error)) {
return false;
}
// Ensure parent directory exists
if (!EnsureParentDir(physical_path)) {
error = "failed to create parent directory";
return false;
}
std::ofstream file(physical_path, std::ios::binary | std::ios::app);
if (!file) {
error = "failed to open file for appending";
return false;
}
file.write(data.data(), data.size());
if (!file) {
error = "failed to append data";
return false;
}
file.close();
UpdateUsage(static_cast<int64_t>(data.size()));
return true;
}
bool VirtualFS::Delete(const std::string& path, std::string& error) {
if (!ValidatePath(path, error)) {
return false;
}
std::string physical_path = ResolvePath(path);
std::error_code ec;
if (!fs::exists(physical_path, ec)) {
error = "file not found";
return false;
}
// Get size before deletion
size_t file_size = 0;
if (fs::is_regular_file(physical_path, ec)) {
file_size = static_cast<size_t>(fs::file_size(physical_path, ec));
}
if (!fs::remove(physical_path, ec)) {
error = "failed to delete";
return false;
}
UpdateUsage(-static_cast<int64_t>(file_size));
return true;
}
bool VirtualFS::Exists(const std::string& path) {
std::string error;
if (!ValidatePath(path, error)) {
return false;
}
std::string physical_path = ResolvePath(path);
std::error_code ec;
return fs::exists(physical_path, ec);
}
std::optional<std::vector<std::string>> VirtualFS::List(const std::string& path, std::string& error) {
if (!ValidatePath(path, error)) {
return std::nullopt;
}
std::string physical_path = ResolvePath(path);
std::error_code ec;
if (!fs::exists(physical_path, ec) || !fs::is_directory(physical_path, ec)) {
error = "directory not found";
return std::nullopt;
}
std::vector<std::string> entries;
for (const auto& entry : fs::directory_iterator(physical_path, ec)) {
entries.push_back(entry.path().filename().string());
}
if (ec) {
error = "failed to list directory";
return std::nullopt;
}
return entries;
}
bool VirtualFS::MakeDir(const std::string& path, std::string& error) {
if (!ValidatePath(path, error)) {
return false;
}
std::string physical_path = ResolvePath(path);
std::error_code ec;
if (!fs::create_directories(physical_path, ec) && ec) {
error = "failed to create directory";
return false;
}
return true;
}
std::optional<FileStat> VirtualFS::Stat(const std::string& path, std::string& error) {
if (!ValidatePath(path, error)) {
return std::nullopt;
}
std::string physical_path = ResolvePath(path);
std::error_code ec;
if (!fs::exists(physical_path, ec)) {
error = "file not found";
return std::nullopt;
}
FileStat stat;
stat.is_dir = fs::is_directory(physical_path, ec);
if (stat.is_dir) {
stat.size = 0;
} else {
stat.size = static_cast<size_t>(fs::file_size(physical_path, ec));
}
auto ftime = fs::last_write_time(physical_path, ec);
// Convert file_time_type to system_clock (portable workaround for clock_cast)
auto file_time_ns = ftime.time_since_epoch();
auto sys_time_ns = std::chrono::duration_cast<std::chrono::seconds>(file_time_ns);
stat.modified = sys_time_ns.count();
return stat;
}
//=============================================================================
// CLEANUP
//=============================================================================
void VirtualFS::DeleteDirectoryRecursive(const std::string& path) {
std::error_code ec;
fs::remove_all(path, ec);
}
size_t VirtualFS::CalculateDirectorySize(const std::string& path) {
size_t total = 0;
std::error_code ec;
if (!fs::exists(path, ec)) {
return 0;
}
for (const auto& entry : fs::recursive_directory_iterator(path, ec)) {
if (fs::is_regular_file(entry, ec)) {
total += static_cast<size_t>(fs::file_size(entry, ec));
}
}
return total;
}
void VirtualFS::RecalculateUsage() {
m_used_bytes = CalculateDirectorySize(m_app_root);
}
void VirtualFS::ClearTemp() {
fs::path temp_path = fs::path(m_app_root) / "temp";
std::error_code ec;
if (fs::exists(temp_path, ec)) {
size_t temp_size = CalculateDirectorySize(temp_path.string());
DeleteDirectoryRecursive(temp_path.string());
UpdateUsage(-static_cast<int64_t>(temp_size));
}
}
void VirtualFS::ClearAll() {
DeleteDirectoryRecursive(m_app_root);
m_used_bytes = 0;
}
//=============================================================================
// LUA API
//=============================================================================
static const char* VFS_KEY = "__mosis_vfs";
static VirtualFS* GetVFS(lua_State* L) {
lua_getfield(L, LUA_REGISTRYINDEX, VFS_KEY);
if (lua_islightuserdata(L, -1)) {
VirtualFS* vfs = static_cast<VirtualFS*>(lua_touserdata(L, -1));
lua_pop(L, 1);
return vfs;
}
lua_pop(L, 1);
return nullptr;
}
// fs.read(path) -> content|nil, error
static int lua_fs_read(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushnil(L);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
std::string error;
auto content = vfs->Read(path, error);
if (content) {
lua_pushlstring(L, content->data(), content->size());
return 1;
} else {
lua_pushnil(L);
lua_pushstring(L, error.c_str());
return 2;
}
}
// fs.write(path, data) -> bool, error
static int lua_fs_write(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushboolean(L, 0);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
size_t len;
const char* data = luaL_checklstring(L, 2, &len);
std::string error;
if (vfs->Write(path, std::string(data, len), error)) {
lua_pushboolean(L, 1);
return 1;
} else {
lua_pushboolean(L, 0);
lua_pushstring(L, error.c_str());
return 2;
}
}
// fs.append(path, data) -> bool, error
static int lua_fs_append(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushboolean(L, 0);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
size_t len;
const char* data = luaL_checklstring(L, 2, &len);
std::string error;
if (vfs->Append(path, std::string(data, len), error)) {
lua_pushboolean(L, 1);
return 1;
} else {
lua_pushboolean(L, 0);
lua_pushstring(L, error.c_str());
return 2;
}
}
// fs.delete(path) -> bool, error
static int lua_fs_delete(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushboolean(L, 0);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
std::string error;
if (vfs->Delete(path, error)) {
lua_pushboolean(L, 1);
return 1;
} else {
lua_pushboolean(L, 0);
lua_pushstring(L, error.c_str());
return 2;
}
}
// fs.exists(path) -> bool
static int lua_fs_exists(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushboolean(L, 0);
return 1;
}
const char* path = luaL_checkstring(L, 1);
lua_pushboolean(L, vfs->Exists(path) ? 1 : 0);
return 1;
}
// fs.list(path) -> array|nil, error
static int lua_fs_list(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushnil(L);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
std::string error;
auto entries = vfs->List(path, error);
if (entries) {
lua_createtable(L, static_cast<int>(entries->size()), 0);
int i = 1;
for (const auto& name : *entries) {
lua_pushlstring(L, name.c_str(), name.size());
lua_rawseti(L, -2, i++);
}
return 1;
} else {
lua_pushnil(L);
lua_pushstring(L, error.c_str());
return 2;
}
}
// fs.mkdir(path) -> bool, error
static int lua_fs_mkdir(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushboolean(L, 0);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
std::string error;
if (vfs->MakeDir(path, error)) {
lua_pushboolean(L, 1);
return 1;
} else {
lua_pushboolean(L, 0);
lua_pushstring(L, error.c_str());
return 2;
}
}
// fs.stat(path) -> {size, modified, isDir}|nil, error
static int lua_fs_stat(lua_State* L) {
VirtualFS* vfs = GetVFS(L);
if (!vfs) {
lua_pushnil(L);
lua_pushstring(L, "VirtualFS not initialized");
return 2;
}
const char* path = luaL_checkstring(L, 1);
std::string error;
auto stat = vfs->Stat(path, error);
if (stat) {
lua_createtable(L, 0, 3);
lua_pushinteger(L, static_cast<lua_Integer>(stat->size));
lua_setfield(L, -2, "size");
lua_pushinteger(L, static_cast<lua_Integer>(stat->modified));
lua_setfield(L, -2, "modified");
lua_pushboolean(L, stat->is_dir ? 1 : 0);
lua_setfield(L, -2, "isDir");
return 1;
} else {
lua_pushnil(L);
lua_pushstring(L, error.c_str());
return 2;
}
}
// Helper to set a global in the real _G (bypassing any proxy)
static void SetGlobalInRealG(lua_State* L, const char* name) {
// Stack: value to set as global
// Get _G (might be a proxy)
lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS);
// Check if it has a metatable with __index (proxy pattern)
if (lua_getmetatable(L, -1)) {
lua_getfield(L, -1, "__index");
if (lua_istable(L, -1)) {
// Found real _G through proxy's __index
// Stack: value, proxy, mt, real_G
lua_pushvalue(L, -4); // Copy value
lua_setfield(L, -2, name); // real_G[name] = value
lua_pop(L, 4); // pop real_G, mt, proxy, original value
return;
}
lua_pop(L, 2); // pop __index, metatable
}
// No proxy, set directly in _G
// Stack: value, _G
lua_pushvalue(L, -2); // Copy value
lua_setfield(L, -2, name); // _G[name] = value
lua_pop(L, 2); // pop _G, original value
}
void RegisterVirtualFS(lua_State* L, VirtualFS* vfs) {
// Store VFS in registry
lua_pushlightuserdata(L, vfs);
lua_setfield(L, LUA_REGISTRYINDEX, VFS_KEY);
// Create fs table
lua_newtable(L);
lua_pushcfunction(L, lua_fs_read);
lua_setfield(L, -2, "read");
lua_pushcfunction(L, lua_fs_write);
lua_setfield(L, -2, "write");
lua_pushcfunction(L, lua_fs_append);
lua_setfield(L, -2, "append");
lua_pushcfunction(L, lua_fs_delete);
lua_setfield(L, -2, "delete");
lua_pushcfunction(L, lua_fs_exists);
lua_setfield(L, -2, "exists");
lua_pushcfunction(L, lua_fs_list);
lua_setfield(L, -2, "list");
lua_pushcfunction(L, lua_fs_mkdir);
lua_setfield(L, -2, "mkdir");
lua_pushcfunction(L, lua_fs_stat);
lua_setfield(L, -2, "stat");
// Set as global (bypassing proxy)
SetGlobalInRealG(L, "fs");
}
} // namespace mosis