lib/filemagic.rb in ruby-filemagic-0.2.2 vs lib/filemagic.rb in ruby-filemagic-0.3.0

@@ -1,11 +1,11 @@
 require 'filemagic.so'
 
 class FileMagic
 
-  # Map abbreviated flag names to their values (:name => Constant).
-  MAGIC_FLAGS = [
+  # Map flag names to their values (:name => Integer).
+  FLAGS_BY_SYM = [
     :none,               # No flags
     :debug,              # Turn on debugging
     :symlink,            # Follow symlinks
     :compress,           # Check inside compressed files
     :devices,            # Look at the contents of devices
@@ -29,11 +29,13 @@
   ].inject({}) { |flags, flag|
     const = "MAGIC_#{flag.to_s.upcase}"
     flags.update(flag => const_defined?(const) && const_get(const))
   }
 
-  attr_reader :flags
+  # Map flag values to their names (Integer => :name).
+  FLAGS_BY_INT = FLAGS_BY_SYM.invert.update(0 => :none)
+
   attr_writer :simplified
 
   @fm = Hash.new { |fm, flags|
     fm.has_key?(key = flags.to_s) ? fm[key] : fm[key] = new(*flags)
   }
@@ -91,34 +93,35 @@
       open(:mime, *flags, &block)
     end
 
     # Build the actual flags from the named flags passed as arguments.
     def build_flags(*flags)
-      _flags = *flags
+      int_flags = *flags
 
-      unless _flags.is_a?(Integer)
-        _flags = MAGIC_NONE
+      unless int_flags.is_a?(Integer)
+        int_flags = MAGIC_NONE
 
         flags.flatten.each { |flag|
-          if value = flag.is_a?(Integer) ? flag : MAGIC_FLAGS[flag.to_sym]
-            _flags |= value
+          if value = flag.is_a?(Integer) ? flag : FLAGS_BY_SYM[flag.to_sym]
+            int_flags |= value
           else
-            raise ArgumentError, "#{value.nil? ? 'no such flag' : 'flag not available'}: #{flag}"
+            err = value.nil? ? 'no such flag' : 'flag not available'
+            raise ArgumentError, "#{err}: #{flag}"
           end
         }
       end
 
-      _flags
+      int_flags
     end
 
   end
 
   # The actual processing happens in #new.
   def initialize(*flags)
     fm_initialize(*flags)
 
-    @flags  = *flags
+    @flags  = flags
     @closed = false
   end
 
   def close
     return if closed?
@@ -130,25 +133,42 @@
   # Optionally cut off additional information after mime-type.
   def file(file, simplified = simplified?)
     simplify_mime(fm_file(file), simplified)
   end
 
+  # Returns the flags as integer.
+  def int_flags
+    @flags.first
+  end
+
+  # Returns the flags as array of symbols.
+  def flags
+    int, flags, log2 = int_flags, [], Math.log(2)
+
+    while int > 0
+      flags << FLAGS_BY_INT[flag = 2 ** Math.log(int).div(log2)]
+      int -= flag
+    end
+
+    flags.reverse
+  end
+
   # Optionally cut off additional information after mime-type.
   def buffer(buffer, simplified = simplified?)
     simplify_mime(fm_buffer(buffer), simplified)
   end
 
   def setflags(*flags)
-    previous_flags, @flags = @flags, self.class.build_flags(*flags)
-    fm_setflags(@flags)
-
-    previous_flags
+    @flags = [self.class.build_flags(*flags)]
+    fm_setflags(int_flags)
   end
+
   alias_method :flags=, :setflags
 
   def check(file = "\0")
     fm_check(file)
   end
+
   alias_method :valid?, :check
 
   def compile(file)
     fm_compile(file)
   end