Separate platform-specific parts of File

Similar to previous patch: Separate platform-specific parts of
IO::FileDescriptor.

src/crystal/system/file.cr

@@ -0,0 +1 @@
+require "./unix/file"

src/crystal/system/unix/file.cr

@@ -0,0 +1,230 @@
+require "c/sys/file"
+
+# :nodoc:
+module Crystal::System::File
+  def self.open(filename, mode, perm)
+    oflag = open_flag(mode) | LibC::O_CLOEXEC
+
+    fd = LibC.open(filename.check_no_null_byte, oflag, perm)
+    if fd < 0
+      raise Errno.new("Error opening file '#{filename}' with mode '#{mode}'")
+    end
+    fd
+  end
+
+  private def self.open_flag(mode)
+    if mode.size == 0
+      raise "Invalid access mode #{mode}"
+    end
+
+    m = 0
+    o = 0
+    case mode[0]
+    when 'r'
+      m = LibC::O_RDONLY
+    when 'w'
+      m = LibC::O_WRONLY
+      o = LibC::O_CREAT | LibC::O_TRUNC
+    when 'a'
+      m = LibC::O_WRONLY
+      o = LibC::O_CREAT | LibC::O_APPEND
+    else
+      raise "Invalid access mode #{mode}"
+    end
+
+    case mode.size
+    when 1
+      # Nothing
+    when 2
+      case mode[1]
+      when '+'
+        m = LibC::O_RDWR
+      when 'b'
+        # Nothing
+      else
+        raise "Invalid access mode #{mode}"
+      end
+    else
+      raise "Invalid access mode #{mode}"
+    end
+
+    oflag = m | o
+  end
+
+  def self.mktemp(name, extension)
+    tmpdir = tempdir + ::File::SEPARATOR
+    path = "#{tmpdir}#{name}.XXXXXX#{extension}"
+
+    if extension
+      fd = LibC.mkstemps(path, extension.bytesize)
+    else
+      fd = LibC.mkstemp(path)
+    end
+
+    raise Errno.new("mkstemp") if fd == -1
+    {fd, path}
+  end
+
+  def self.tempdir
+    tmpdir = ENV["TMPDIR"]? || "/tmp"
+    tmpdir.rchop(::File::SEPARATOR)
+  end
+
+  def self.stat(path)
+    if LibC.stat(path.check_no_null_byte, out stat) != 0
+      raise Errno.new("Unable to get stat for '#{path}'")
+    end
+    ::File::Stat.new(stat)
+  end
+
+  def self.lstat(path)
+    if LibC.lstat(path.check_no_null_byte, out stat) != 0
+      raise Errno.new("Unable to get lstat for '#{path}'")
+    end
+    ::File::Stat.new(stat)
+  end
+
+  def self.empty?(path)
+    begin
+      stat(path).size == 0
+    rescue Errno
+      raise Errno.new("Error determining size of '#{path}'")
+    end
+  end
+
+  def self.exists?(path)
+    accessible?(path, LibC::F_OK)
+  end
+
+  def self.readable?(path) : Bool
+    accessible?(path, LibC::R_OK)
+  end
+
+  def self.writable?(path) : Bool
+    accessible?(path, LibC::W_OK)
+  end
+
+  def self.executable?(path) : Bool
+    accessible?(path, LibC::X_OK)
+  end
+
+  private def self.accessible?(path, flag)
+    LibC.access(path.check_no_null_byte, flag) == 0
+  end
+
+  def self.file?(path) : Bool
+    if LibC.stat(path.check_no_null_byte, out stat) != 0
+      if Errno.value == Errno::ENOENT
+        return false
+      else
+        raise Errno.new("stat")
+      end
+    end
+    ::File::Stat.new(stat).file?
+  end
+
+  def self.chown(path, uid : Int, gid : Int, follow_symlinks)
+    ret = if !follow_symlinks && symlink?(path)
+            LibC.lchown(path, uid, gid)
+          else
+            LibC.chown(path, uid, gid)
+          end
+    raise Errno.new("Error changing owner of '#{path}'") if ret == -1
+  end
+
+  def self.chmod(path, mode : Int)
+    if LibC.chmod(path, mode) == -1
+      raise Errno.new("Error changing permissions of '#{path}'")
+    end
+  end
+
+  def self.delete(path)
+    err = LibC.unlink(path.check_no_null_byte)
+    if err == -1
+      raise Errno.new("Error deleting file '#{path}'")
+    end
+  end
+
+  def self.real_path(path)
+    real_path_ptr = LibC.realpath(path, nil)
+    raise Errno.new("Error resolving real path of #{path}") unless real_path_ptr
+    String.new(real_path_ptr).tap { LibC.free(real_path_ptr.as(Void*)) }
+  end
+
+  def self.link(old_path, new_path)
+    ret = LibC.link(old_path.check_no_null_byte, new_path.check_no_null_byte)
+    raise Errno.new("Error creating link from #{old_path} to #{new_path}") if ret != 0
+    ret
+  end
+
+  def self.symlink(old_path, new_path)
+    ret = LibC.symlink(old_path.check_no_null_byte, new_path.check_no_null_byte)
+    raise Errno.new("Error creating symlink from #{old_path} to #{new_path}") if ret != 0
+    ret
+  end
+
+  def self.symlink?(path)
+    if LibC.lstat(path.check_no_null_byte, out stat) != 0
+      if Errno.value == Errno::ENOENT
+        return false
+      else
+        raise Errno.new("stat")
+      end
+    end
+    (stat.st_mode & LibC::S_IFMT) == LibC::S_IFLNK
+  end
+
+  def self.rename(old_filename, new_filename)
+    code = LibC.rename(old_filename.check_no_null_byte, new_filename.check_no_null_byte)
+    if code != 0
+      raise Errno.new("Error renaming file '#{old_filename}' to '#{new_filename}'")
+    end
+  end
+
+  def self.utime(atime : ::Time, mtime : ::Time, filename : String) : Nil
+    timevals = uninitialized LibC::Timeval[2]
+    timevals[0] = to_timeval(atime)
+    timevals[1] = to_timeval(mtime)
+    ret = LibC.utimes(filename, timevals)
+    if ret != 0
+      raise Errno.new("Error setting time to file '#{filename}'")
+    end
+  end
+
+  private def self.to_timeval(time : ::Time)
+    t = uninitialized LibC::Timeval
+    t.tv_sec = typeof(t.tv_sec).new(time.to_local.epoch)
+    t.tv_usec = typeof(t.tv_usec).new(0)
+    t
+  end
+
+  private def system_truncate(size) : Nil
+    flush
+    code = LibC.ftruncate(fd, size)
+    if code != 0
+      raise Errno.new("Error truncating file '#{path}'")
+    end
+  end
+
+  private def system_flock_shared(blocking)
+    flock LibC::FlockOp::SH, blocking
+  end
+
+  private def system_flock_exclusive(blocking)
+    flock LibC::FlockOp::EX, blocking
+  end
+
+  private def system_flock_unlock
+    flock LibC::FlockOp::UN
+  end
+
+  private def flock(op : LibC::FlockOp, blocking : Bool = true)
+    op |= LibC::FlockOp::NB unless blocking
+
+    if LibC.flock(@fd, op) != 0
+      raise Errno.new("flock")
+    end
+
+    nil
+  end
+end

src/crystal/system/unix/file_descriptor.cr

@@ -61,7 +61,7 @@ module Crystal::System::FileDescriptor
     if LibC.fstat(@fd, out stat) != 0
       raise Errno.new("Unable to get stat")
     end
-    File::Stat.new(stat)
+    ::File::Stat.new(stat)
   end
 
   private def system_seek(offset, whence : IO::Seek) : Nil

src/crystal/system/unix/getrandom.cr

@@ -6,15 +6,15 @@ require "c/sys/syscall"
 module Crystal::System::Random
   @@initialized = false
   @@getrandom_available = false
-  @@urandom : File?
+  @@urandom : ::File?
 
   private def self.init
     @@initialized = true
 
     if sys_getrandom(Bytes.new(16)) >= 0
       @@getrandom_available = true
     else
-      urandom = File.open("/dev/urandom", "r")
+      urandom = ::File.open("/dev/urandom", "r")
       return unless urandom.stat.chardev?
 
       urandom.close_on_exec = true

src/crystal/system/unix/urandom.cr

@@ -3,12 +3,12 @@
 
 module Crystal::System::Random
   @@initialized = false
-  @@urandom : File?
+  @@urandom : ::File?
 
   private def self.init
     @@initialized = true
 
-    urandom = File.open("/dev/urandom", "r")
+    urandom = ::File.open("/dev/urandom", "r")
     return unless urandom.stat.chardev?
 
     urandom.close_on_exec = true