Completely re-vamped restore command. Fixes #12403

The byteback-restore command now uses the rsync xattrs to display
information about the files due to be restored.  It can handle filenames
with spaces (!) and other characters.

1 files changed, 215 insertions, 0 deletions

diff --git a/lib/byteback/restore_file.rb b/lib/byteback/restore_file.rb
new file mode 100644
index 0000000..e9282d0
--- /dev/null
+++ b/lib/byteback/restore_file.rb
@@ -0,0 +1,215 @@
+require 'ffi-xattr'
+require 'scanf'
+require 'pp'
+
+module Byteback
+  class RestoreFile
+    S_IFMT = 0170000 #  bit mask for the file type bit fields
+
+    S_IFSOCK = 0140000 #  socket
+    S_IFLNK = 0120000 #  symbolic link
+    S_IFREG = 0100000 #  regular file
+    S_IFBLK = 0060000 #  block device
+    S_IFDIR = 0040000 #  directory
+    S_IFCHR = 0020000 #  character device
+    S_IFIFO = 0010000 #  FIFO
+
+    S_ISUID = 0004000 #  set-user-ID bit
+    S_ISGID = 0002000 #  set-group-ID bit (see below)
+    S_ISVTX = 0001000 #  sticky bit (see below)
+
+    S_IRWXU = 00700 #  mask for file owner permissions
+    S_IRUSR = 00400 #  owner has read permission
+    S_IWUSR = 00200 #  owner has write permission
+    S_IXUSR = 00100 #  owner has execute permission
+
+    S_IRWXG = 00070 #  mask for group permissions
+    S_IRGRP = 00040 #  group has read permission
+    S_IWGRP = 00020 #  group has write permission
+    S_IXGRP = 00010 #  group has execute permission
+
+    S_IRWXO = 00007 #  mask for permissions for others (not in group)
+    S_IROTH = 00004 #  others have read permission
+    S_IWOTH = 00002 #  others have write permission
+    S_IXOTH = 00001 #  others have execute permission
+
+    include Comparable
+
+    def initialize(full_path, byteback_root=".", now = Time.now)
+      @full_path = full_path
+      @byteback_root = byteback_root
+      @now = now
+
+      #
+      # The snapshot is the first directory after the byteback_root
+      #
+      @snapshot = full_path.sub(%r(^#{Regexp.escape @byteback_root}),'').split("/")[1]
+
+      if @snapshot == "current"
+        @snapshot_time = @now
+      else
+        @snapshot_time = Time.parse(@snapshot)
+      end
+
+      #
+      # Restore path
+      #
+      @path = full_path.sub(%r(^#{Regexp.escape @byteback_root}/#{Regexp.escape @snapshot}),'')
+
+      @stat = @mode = @dev_major = @dev_minor = @uid = @gid = nil
+    end
+
+    def <=>(other)
+      [self.path,  self.mtime.to_i,  self.size] <=> [other.path, other.mtime.to_i, other.size]
+    end
+
+    def stat
+      @stat = ::File.lstat(@full_path) unless @stat.is_a?(File::Stat)
+      @stat
+    end
+
+    def snapshot
+      @snapshot
+    end
+
+    def snapshot_time
+      @snapshot_time
+    end
+
+    def path
+      @path
+    end
+
+    def to_s
+      sprintf("%10s %i %4i %4i %s %s %s", self.modestring, self.size, self.uid, self.gid, self.mtime.strftime("%b %2d %H:%M"), @snapshot, @path)
+    end
+
+    def read_rsync_xattrs
+      xattr = Xattr.new(@full_path, :no_follow => false)
+      rsync_xattrs = xattr["user.rsync.%stat"]
+      if rsync_xattrs
+        @mode, @dev_major, @dev_minor, @uid, @gid = rsync_xattrs.scanf("%o %d,%d %d:%d")
+        raise ArgumentError, "Corrupt rsync stat xattr found for #{@full_path} (#{rsync_xattrs})" unless [@mode, @dev_major, @dev_minor, @uid, @gid].all?{|i| i.is_a?(Integer)}
+      else
+        warn "No rsync stat xattr found for #{@full_path}" 
+        @mode, @dev_major, @dev_minor, @uid, @gid = %w(mode dev_major dev_minor uid gid).collect{|m| self.stat.__send__(m.to_sym)}
+      end
+    end
+
+    def mode
+      return self.stat.mode if self.stat.symlink?
+      read_rsync_xattrs unless @mode
+      @mode
+    end
+
+    def dev_minor
+      read_rsync_xattrs unless @dev_minor
+      @dev_minor
+    end
+
+    def dev_major
+      read_rsync_xattrs unless @dev_major
+      @dev_major
+    end
+
+    def uid
+      read_rsync_xattrs unless @uid
+      @uid
+    end
+
+    def gid
+      read_rsync_xattrs unless @gid
+      @gid
+    end
+
+    #
+    # This returns the type of file as a single character.
+    #
+    def ftypelet
+      if file?
+        "-"
+      elsif directory?
+        "d"
+      elsif blockdev?
+        "b"
+      elsif chardev?
+        "c"
+      elsif symlink?
+        "l"
+      elsif fifo?
+        "p"
+      elsif socket?
+        "s" 
+      else
+        "?"
+      end 
+    end
+
+    #
+    # This returns a modestring from the octal, like drwxr-xr-x.
+    # This has mostly been copied from strmode from filemode.h in coreutils.
+    #
+    def modestring
+      str = ""
+      str << ftypelet
+      str << ((mode & S_IRUSR == S_IRUSR) ? 'r' : '-')
+      str << ((mode & S_IWUSR == S_IWUSR) ? 'w' : '-')
+      str << ((mode & S_ISUID == S_ISUID) ?
+                ((mode & S_IXUSR == S_IXUSR) ? 's' : 'S') :
+                ((mode & S_IXUSR == S_IXUSR) ? 'x' : '-'))
+      str << ((mode & S_IRGRP == S_IRGRP) ? 'r' : '-')
+      str << ((mode & S_IWGRP == S_IWGRP) ? 'w' : '-')
+      str << ((mode & S_ISGID == S_ISGID) ?
+                ((mode & S_IXGRP == S_IXGRP) ? 's' : 'S') :
+                ((mode & S_IXGRP == S_IXGRP) ? 'x' : '-'))
+      str << ((mode & S_IROTH == S_IROTH) ? 'r' : '-')
+      str << ((mode & S_IWOTH == S_IWOTH) ? 'w' : '-')
+      str << ((mode & S_ISVTX == S_ISVTX) ?
+                ((mode & S_IXOTH == S_IXOTH) ? 't' : 'T') :
+                ((mode & S_IXOTH == S_IXOTH) ? 'x' : '-'))
+      return str
+    end
+
+    def socket?
+      (mode & S_IFMT) == S_IFSOCK
+    end
+
+    def symlink?
+      self.stat.symlink? || (mode & S_IFMT) == S_IFLNK
+    end
+
+    def file?
+      (mode & S_IFMT) == S_IFREG
+    end
+
+    def blockdev?
+      (mode & S_IFMT) == S_IFBLK
+    end
+
+    def directory?
+      (mode & S_IFMT) == S_IFDIR
+    end
+
+    def chardev?
+      (mode & S_IFMT) == S_IFCHR
+    end
+
+    def fifo?
+      (mode & S_IFMT) == S_IFIFO
+    end
+
+    def readlink
+      if self.stat.symlink?
+        File.readlink(@full_path)
+      else
+        File.read(@full_path).chomp
+      end
+    end
+
+    def method_missing(m, *args, &blk)
+      return self.stat.__send__(m) if self.stat.respond_to?(m)
+
+      raise NoMethodError, m
+    end 
+  end
+end