1 files changed, 180 insertions, 0 deletions
diff --git a/trunk/lib/rubygems/package/tar_writer.rb b/trunk/lib/rubygems/package/tar_writer.rb
new file mode 100644
index 0000000000..6e11440e22
--- /dev/null
+++ b/trunk/lib/rubygems/package/tar_writer.rb
@@ -0,0 +1,180 @@
+#++
+# Copyright (C) 2004 Mauricio Julio Fernández Pradier
+# See LICENSE.txt for additional licensing information.
+#--
+
+require 'rubygems/package'
+
+class Gem::Package::TarWriter
+
+  class FileOverflow < StandardError; end
+
+  class BoundedStream
+
+    attr_reader :limit, :written
+
+    def initialize(io, limit)
+      @io = io
+      @limit = limit
+      @written = 0
+    end
+
+    def write(data)
+      if data.size + @written > @limit
+        raise FileOverflow, "You tried to feed more data than fits in the file."
+      end
+      @io.write data
+      @written += data.size
+      data.size
+    end
+
+  end
+
+  class RestrictedStream
+
+    def initialize(io)
+      @io = io
+    end
+
+    def write(data)
+      @io.write data
+    end
+
+  end
+
+  def self.new(io)
+    writer = super
+
+    return writer unless block_given?
+
+    begin
+      yield writer
+    ensure
+      writer.close
+    end
+
+    nil
+  end
+
+  def initialize(io)
+    @io = io
+    @closed = false
+  end
+
+  def add_file(name, mode)
+    check_closed
+
+    raise Gem::Package::NonSeekableIO unless @io.respond_to? :pos=
+
+    name, prefix = split_name name
+
+    init_pos = @io.pos
+    @io.write "\0" * 512 # placeholder for the header
+
+    yield RestrictedStream.new(@io) if block_given?
+
+    size = @io.pos - init_pos - 512
+
+    remainder = (512 - (size % 512)) % 512
+    @io.write "\0" * remainder
+
+    final_pos = @io.pos
+    @io.pos = init_pos
+
+    header = Gem::Package::TarHeader.new :name => name, :mode => mode,
+                                         :size => size, :prefix => prefix
+
+    @io.write header
+    @io.pos = final_pos
+
+    self
+  end
+
+  def add_file_simple(name, mode, size)
+    check_closed
+
+    name, prefix = split_name name
+
+    header = Gem::Package::TarHeader.new(:name => name, :mode => mode,
+                                         :size => size, :prefix => prefix).to_s
+
+    @io.write header
+    os = BoundedStream.new @io, size
+
+    yield os if block_given?
+
+    min_padding = size - os.written
+    @io.write("\0" * min_padding)
+
+    remainder = (512 - (size % 512)) % 512
+    @io.write("\0" * remainder)
+
+    self
+  end
+
+  def check_closed
+    raise IOError, "closed #{self.class}" if closed?
+  end
+
+  def close
+    check_closed
+
+    @io.write "\0" * 1024
+    flush
+
+    @closed = true
+  end
+
+  def closed?
+    @closed
+  end
+
+  def flush
+    check_closed
+
+    @io.flush if @io.respond_to? :flush
+  end
+
+  def mkdir(name, mode)
+    check_closed
+
+    name, prefix = split_name(name)
+
+    header = Gem::Package::TarHeader.new :name => name, :mode => mode,
+                                         :typeflag => "5", :size => 0,
+                                         :prefix => prefix
+
+    @io.write header
+
+    self
+  end
+
+  def split_name(name) # :nodoc:
+    raise Gem::Package::TooLongFileName if name.size > 256
+
+    if name.size <= 100 then
+      prefix = ""
+    else
+      parts = name.split(/\//)
+      newname = parts.pop
+      nxt = ""
+
+      loop do
+        nxt = parts.pop
+        break if newname.size + 1 + nxt.size > 100
+        newname = nxt + "/" + newname
+      end
+
+      prefix = (parts + [nxt]).join "/"
+      name = newname
+
+      if name.size > 100 or prefix.size > 155 then
+        raise Gem::Package::TooLongFileName 
+      end
+    end
+
+    return name, prefix
+  end
+
+end
+