Implement Crystal::System::FileDescriptor for windows

Author: RX14

src/crystal/system/file_descriptor.cr

@@ -1 +1,5 @@
-require "./unix/file_descriptor"
+{% if flag?(:win32) %}
+  require "./win32/file_descriptor"
+{% else %}
+  require "./unix/file_descriptor"
+{% end %}

src/crystal/system/win32/file_descriptor.cr

@@ -0,0 +1,98 @@
+require "file/stat"
+require "c/io"
+
+module Crystal::System::FileDescriptor
+  @fd : LibC::Int
+
+  private def unbuffered_read(slice : Bytes)
+    bytes_read = LibC._read(@fd, slice, slice.size)
+    if bytes_read == -1
+      raise Errno.new("Error reading file")
+    end
+    bytes_read
+  end
+
+  private def unbuffered_write(slice : Bytes)
+    loop do
+      bytes_written = LibC._write(@fd, slice, slice.size)
+      if bytes_written == -1
+        raise Errno.new("Error writing file")
+      end
+
+      slice += bytes_written
+      return if slice.size == 0
+    end
+  end
+
+  private def system_blocking?
+    true
+  end
+
+  private def system_blocking=(blocking)
+    raise NotImplementedError.new("Crystal::System::FileDescriptor#system_blocking=") unless blocking
+  end
+
+  private def system_close_on_exec?
+    false
+  end
+
+  private def system_close_on_exec=(close_on_exec)
+    raise NotImplementedError.new("Crystal::System::FileDescriptor#system_close_on_exec=") if close_on_exec
+  end
+
+  private def system_stat
+    if LibC._fstat64(@fd, out stat) != 0
+      raise Errno.new("Unable to get stat")
+    end
+    ::File::Stat.new(stat)
+  end
+
+  private def system_seek(offset, whence : IO::Seek) : Nil
+    seek_value = LibC._lseek(@fd, offset, whence)
+
+    if seek_value == -1
+      raise Errno.new "Unable to seek"
+    end
+  end
+
+  private def system_pos
+    pos = LibC._lseek(@fd, 0, IO::Seek::Current)
+    raise Errno.new "Unable to tell" if pos == -1
+    pos
+  end
+
+  private def system_tty?
+    LibC._isatty(@fd) != 0
+  end
+
+  private def system_reopen(other : IO::FileDescriptor)
+    {% if LibC.methods.includes? "dup3".id %}
+      # dup doesn't copy the CLOEXEC flag, so copy it manually using dup3
+      flags = other.close_on_exec? ? LibC::O_CLOEXEC : 0
+      if LibC.dup3(other.fd, self.fd, flags) == -1
+        raise Errno.new("Could not reopen file descriptor")
+      end
+    {% else %}
+      # dup doesn't copy the CLOEXEC flag, copy it manually to the new
+      if LibC.dup2(other.fd, self.fd) == -1
+        raise Errno.new("Could not reopen file descriptor")
+      end
+
+      if other.close_on_exec?
+        self.close_on_exec = true
+      end
+    {% end %}
+  end
+
+  private def system_close
+    err = nil
+    if LibC._close(@fd) != 0
+      case Errno.value
+      when Errno::EINTR
+        # ignore
+      else
+        raise Errno.new("Error closing file")
+      end
+    end
+  end
+end

src/file/stat.cr

@@ -2,34 +2,51 @@ require "c/sys/stat"
 
 class File
   struct Stat
-    def initialize(filename : String)
-      if LibC.stat(filename, out @stat) != 0
-        raise Errno.new("Unable to get stat for '#{filename}'")
-      end
+    def self.new(filename : String)
+      File.stat(filename)
     end
 
-    def initialize(@stat : LibC::Stat)
-    end
+    {% if flag?(:win32) %}
+      # :nodoc:
+      def initialize(@stat : LibC::Stat64)
+      end
+    {% else %}
+      # :nodoc:
+      def initialize(@stat : LibC::Stat)
+      end
+    {% end %}
 
     def atime
       {% if flag?(:darwin) %}
         time @stat.st_atimespec
+      {% elsif flag?(:win32) %}
+        time @stat.st_atime
       {% else %}
         time @stat.st_atim
       {% end %}
     end
 
     def blksize
-      @stat.st_blksize
+      {% if flag?(:win32) %}
+        raise NotImplementedError.new("File::Stat#blksize")
+      {% else %}
+        @stat.st_blksize
+      {% end %}
     end
 
     def blocks
-      @stat.st_blocks
+      {% if flag?(:win32) %}
+        raise NotImplementedError.new("File::Stat#blocks")
+      {% else %}
+        @stat.st_blocks
+      {% end %}
     end
 
     def ctime
       {% if flag?(:darwin) %}
         time @stat.st_ctimespec
+      {% elsif flag?(:win32) %}
+        time @stat.st_ctime
       {% else %}
         time @stat.st_ctim
       {% end %}
@@ -59,6 +76,8 @@ class File
     def mtime
       {% if flag?(:darwin) %}
         time @stat.st_mtimespec
+      {% elsif flag?(:win32) %}
+        time @stat.st_mtime
       {% else %}
         time @stat.st_mtim
       {% end %}
@@ -93,8 +112,11 @@ class File
       io << ", rdev=0x"
       rdev.to_s(16, io)
       io << ", size=" << size
-      io << ", blksize=" << blksize
-      io << ", blocks=" << blocks
+      {% unless flag?(:win32) %}
+        # These two getters raise NotImplementedError on windows.
+        io << ", blksize=" << blksize
+        io << ", blocks=" << blocks
+      {% end %}
       io << ", atime=" << atime
       io << ", mtime=" << mtime
       io << ", ctime=" << ctime
@@ -119,10 +141,13 @@ class File
         pp.comma
         pp.text "size=#{size}"
         pp.comma
-        pp.text "blksize=#{blksize}"
-        pp.comma
-        pp.text "blocks=#{blocks}"
-        pp.comma
+        {% unless flag?(:win32) %}
+          # These two getters raise NotImplementedError on windows.
+          pp.text "blksize=#{blksize}"
+          pp.comma
+          pp.text "blocks=#{blocks}"
+          pp.comma
+        {% end %}
         pp.text "atime=#{atime}"
         pp.comma
         pp.text "mtime=#{mtime}"
@@ -171,8 +196,14 @@ class File
       (@stat.st_mode & LibC::S_IFMT) == LibC::S_ISVTX
     end
 
-    private def time(value)
-      Time.new value, Time::Kind::Utc
-    end
+    {% if flag?(:win32) %}
+      private def time(value)
+        Time.epoch(value)
+      end
+    {% else %}
+      private def time(value)
+        Time.new value, Time::Kind::Utc
+      end
+    {% end %}
   end
 end