linux_wrapper.rb in ramdo-0.1.2

- old
+ new
@@ -1,7 +1,62 @@
 module Ramdo
   module Ramdisk
     class LinuxWrapper
+      def initialize
+        @shm_path = "/dev/shm"
+      end
 
+      def list
+        disks = []
+
+        found_shm = false
+        line = Cocaine::CommandLine.new("cat", "/proc/mounts")
+        line.run.each_line do |line|
+          found_shm ||= line =~ /^tmpfs \/dev\/shm tmpfs/
+        end
+        raise GeneralRamdiskException.new("#{@shm_path} not found") unless found_shm
+
+        Dir.glob(@shm_path + '/*').each do |dir|
+          if dir =~ Instance::NAME_PATTERN
+            disks << Instance.new(path: dir, device: @shm_path, size: Filesize.from("1 GB"))
+          end
+        end
+
+        disks
+      end
+
+      def create(size)
+        size = Filesize.from(size) if size.is_a? String
+        raise NotEnoughFreeRamException.new unless enough_ram? size
+
+        # Create new directory as dedicated space
+        path = [@shm_path, Instance.generate_name].join('/')
+        Dir.mkdir(path)
+
+        # Receive all disk and select just created one
+        list().select { |disk| disk.path == path }.first
+      end
+
+      def destroy(instance)
+        return false unless File.exist? instance.path
+
+        Dir.glob(instance.path + "/*").each { |file| File.delete(file) if File.file? file }
+        Dir.rmdir(instance.path)
+      end
+
+      private
+      def enough_ram?(size)
+        size = Filesize.from(size) if size.is_a? String
+        free_mem = ""
+
+        line = Cocaine::CommandLine.new("cat", "/proc/meminfo")
+        line.run.each_line do |line|
+          if line =~ /^MemFree:[\s]+([0-9]+ kB)/
+            free_mem = Regexp.last_match[1]
+          end
+        end
+
+        Filesize.from(free_mem) > size
+      end
     end
   end
-end
\ No newline at end of file
+end