bsnes/nall/inode.hpp

154 lines
4.8 KiB
C++

#pragma once
//generic abstraction layer for common storage operations against both files and directories
//these functions are not recursive; use directory::create() and directory::remove() for recursion
#include <nall/platform.hpp>
#include <nall/string.hpp>
namespace nall {
struct inode {
enum class time : uint { create, modify, access };
inode() = delete;
inode(const inode&) = delete;
auto operator=(const inode&) -> inode& = delete;
static auto exists(const string& name) -> bool {
return access(name, F_OK) == 0;
}
static auto readable(const string& name) -> bool {
return access(name, R_OK) == 0;
}
static auto writable(const string& name) -> bool {
return access(name, W_OK) == 0;
}
static auto executable(const string& name) -> bool {
return access(name, X_OK) == 0;
}
static auto mode(const string& name) -> uint {
struct stat data{};
stat(name, &data);
return data.st_mode;
}
static auto uid(const string& name) -> uint {
struct stat data{};
stat(name, &data);
return data.st_uid;
}
static auto gid(const string& name) -> uint {
struct stat data{};
stat(name, &data);
return data.st_gid;
}
static auto owner(const string& name) -> string {
#if !defined(PLATFORM_WINDOWS)
struct passwd* pw = getpwuid(uid(name));
if(pw && pw->pw_name) return pw->pw_name;
#endif
return {};
}
static auto group(const string& name) -> string {
#if !defined(PLATFORM_WINDOWS)
struct group* gr = getgrgid(gid(name));
if(gr && gr->gr_name) return gr->gr_name;
#endif
return {};
}
static auto timestamp(const string& name, time mode = time::modify) -> uint64_t {
struct stat data{};
stat(name, &data);
switch(mode) {
#if defined(PLATFORM_WINDOWS)
//on Windows, the last status change time (ctime) holds the file creation time instead
case time::create: return data.st_ctime;
#elif defined(PLATFORM_BSD) || defined(PLATFORM_MACOS)
//st_birthtime may return -1 or st_atime if it is not supported by the file system
//the best that can be done in this case is to return st_mtime if it's older
case time::create: return min((uint)data.st_birthtime, (uint)data.st_mtime);
#else
//Linux simply doesn't support file creation time at all
//this is also our fallback case for unsupported operating systems
case time::create: return data.st_mtime;
#endif
case time::modify: return data.st_mtime;
//for performance reasons, last access time is usually not enabled on various filesystems
//ensure that the last access time is not older than the last modify time (eg for NTFS)
case time::access: return max((uint)data.st_atime, data.st_mtime);
}
return 0;
}
static auto setMode(const string& name, uint mode) -> bool {
#if !defined(PLATFORM_WINDOWS)
return chmod(name, mode) == 0;
#else
return _wchmod(utf16_t(name), (mode & 0400 ? _S_IREAD : 0) | (mode & 0200 ? _S_IWRITE : 0)) == 0;
#endif
}
static auto setOwner(const string& name, const string& owner) -> bool {
#if !defined(PLATFORM_WINDOWS)
struct passwd* pwd = getpwnam(owner);
if(!pwd) return false;
return chown(name, pwd->pw_uid, inode::gid(name)) == 0;
#else
return true;
#endif
}
static auto setGroup(const string& name, const string& group) -> bool {
#if !defined(PLATFORM_WINDOWS)
struct group* grp = getgrnam(group);
if(!grp) return false;
return chown(name, inode::uid(name), grp->gr_gid) == 0;
#else
return true;
#endif
}
static auto setTimestamp(const string& name, uint64_t value, time mode = time::modify) -> bool {
struct utimbuf timeBuffer;
timeBuffer.modtime = mode == time::modify ? value : inode::timestamp(name, time::modify);
timeBuffer.actime = mode == time::access ? value : inode::timestamp(name, time::access);
return utime(name, &timeBuffer) == 0;
}
//returns true if 'name' already exists
static auto create(const string& name, uint permissions = 0755) -> bool {
if(exists(name)) return true;
if(name.endsWith("/")) return mkdir(name, permissions) == 0;
int fd = open(name, O_CREAT | O_EXCL, permissions);
if(fd < 0) return false;
return close(fd), true;
}
//returns false if 'name' and 'targetname' are on different file systems (requires copy)
static auto rename(const string& name, const string& targetname) -> bool {
return ::rename(name, targetname) == 0;
}
//returns false if 'name' is a directory that is not empty
static auto remove(const string& name) -> bool {
#if defined(PLATFORM_WINDOWS)
if(name.endsWith("/")) return _wrmdir(utf16_t(name)) == 0;
return _wunlink(utf16_t(name)) == 0;
#else
if(name.endsWith("/")) return rmdir(name) == 0;
return unlink(name) == 0;
#endif
}
};
}