Normalized line endings

1 files changed, 234 insertions, 234 deletions

diff --git a/byteback-snapshot b/byteback-snapshot
index daf368b..4e1be92 100755
--- a/byteback-snapshot
+++ b/byteback-snapshot
@@ -1,234 +1,234 @@
-#!/usr/bin/ruby
-#
-# Program to create a snapshot and/or rotate a directory of backup snapshots 
-# using btrfs subvolume commands.
-
-require 'trollop'
-require 'time'
-
-def error(message)
-	STDERR.print "*** #{message}\n"
-	exit 1
-end
-
-def verbose(message)
-	print "#{Time.now}: #{message}\n" if @verbose
-end
-
-# Icky way to find out free disc space on our mount
-#
-class DiskFree
-	def initialize(mount)
-		@mount = mount
-	end
-
-	def total
-		all[2]
-	end
-
-	def used
-		all[3]
-	end
-
-	def available
-		all[4]
-	end
-
-	def fraction_used
-		disk_device, disk_fs, disk_total, disk_used, disk_available, *rest = all
-		disk_used.to_f / disk_available
-	end
-
-	protected
-
-	def all
-		disk_device, disk_fs, disk_total, disk_used, disk_available, *rest = 
-			df.
-			split("\n")[1].
-			split(/\s+/).
-			map { |i| /^[0-9]+$/.match(i) ? i.to_i : i }
-	end
-
-	def df
-		`/bin/df -T -P -B1 #{@mount}`
-	end
-end
-
-# Represent a directory full of backups where "current"  is a subvolume
-# which is snapshotted to frozen backup directories called e.g. 
-# "yyyy-mm-ddThh:mm".
-#
-class BackupDirectory
-	attr_reader :dir
-
-	def initialize(dir)
-		@dir = Dir.new(dir)
-		current
-	end
-
-	# Return total amount of free space in backup directory (bytes)
-	#
-	def free
-		df = DiskFree.new(@dir.path)
-		df.total - df.used
-	end
-
-	# Return an array of Times representing the current list of 
-	# snapshots.
-	#
-	def snapshot_times
-		@dir.entries.map do |entry|
-			begin
-				Time.parse(entry)
-			rescue ArgumentError => error
-				nil
-			end
-		end.
-		compact.
-		sort
-	end
-
-	# What order to remove snapshots in to regain disk space?
-	#
-	# Order backups by their closeness to defined backup times, which are
-	# listed in a set order (i.e. today's backup is more important than yesterday's).
-	#
-	BACKUP_IMPORTANCE = [0, 1, 2, 3, 7, 14, 21, 28, 56, 112]
-	def snapshot_times_by_importance
-		now = Time.now
-		snapshot_times_unsorted = snapshot_times
-		snapshot_times_sorted = []
-		while !snapshot_times_unsorted.empty?
-			BACKUP_IMPORTANCE.each do |days|
-				target_time = now + (days*86400)
-				closest = snapshot_times_unsorted.inject(nil) do |best, time|
-					if best.nil? || (time-target_time).abs < (best-target_time).abs
-						time
-					else
-						best
-					end
-				end
-				break unless closest
-				snapshot_times_sorted << snapshot_times_unsorted.delete(closest)
-			end
-		end
-		snapshot_times_sorted
-	end
-
-	# Returns the size of the given snapshot (runs du, may be slow)
-	#
-	# Would much prefer to take advantage of this feature:
-	#   http://dustymabe.com/2013/09/22/btrfs-how-big-are-my-snapshots/
-	# but it's not currently in Debian/wheezy.
-	#
-	def snapshot_size(time=snapshot_times.latest)
-		`du -s -b #{snapshot_path(time)}`.to_i
-	end
-
-	def average_snapshot_size(number=10)
-		snapshot_times.sort[0..number].inject(0) { |time, total| snapshot_size(time) } / number
-	end
-
-	# Create a new snapshot of 'current'
-	#
-	def new_snapshot!
-		system_no_error("btrfs subvolume snapshot -r #{current.path} #{snapshot_path}")
-	end
-
-	def delete_snapshot!(time)
-		system_no_error("btrfs subvolume delete #{snapshot_path(time)}")
-	end
-
-	def current
-		Dir.new("#{dir.path}/current")
-	end
-
-	def snapshot_path(time=Time.now)
-		"#{dir.path}/#{time.strftime("%Y-%m-%dT%H:%M")}"
-	end
-
-	protected
-
-	def system_no_error(*args)
-		raise RuntimeError.new("Command failed: "+args.join(" ")) unless
-		  system(*args)
-	end
-end
-
-opts = Trollop::options do
-
-    opt :root, "Backups directory (must be a btrfs subvolume)",
-    	:type => :string
-
-    opt :snapshot, "Take a new snapshot"
-
-    opt :prune, "Prune old backups"
-    	:type => :string
-
-    opt :list, "List backups (by 'age' or 'importance')",
-    	:type => :string
-
-    opt :verbose, "Print diagnostics"
-
-end
-
-@root = opts[:root]
-@verbose = opts[:verbose]
-@do_snapshot = opts[:snapshot]
-@do_list = opts[:list]
-@do_prune = opts[:prune]
-
-error("Must specify snapshot, prune or list") unless @do_snapshot || @do_prune || @do_list
-
-error("--root not readable") unless File.directory?(@root)
-
-@backups = BackupDirectory.new(@root)
-
-def get_snapshots_by(method)
-	if method == 'importance'
-		@backups.snapshot_times_by_importance.reverse # least important first
-	elsif method == 'age'
-		@backups.snapshot_times
-	else
-		raise ArgumentError.new("Unknown snapshot sort method #{method}")
-	end
-end
-
-if @do_snapshot
-	last_snapshot_time = @backups.snapshots.last
-	error("Last snapshot was less than six hours ago") unless 
-		!last_snapshot_time || 
-		Time.now - @backups.snapshots.last >= 6*60*60 # FIXME: make configurable
-
-	verbose "Making new snapshot"
-	@backups.new_snapshot! 
-end
-
-if @do_list
-	list = get_snapshots_by(@do_list)
-	print "Backups in #{@root} by #{@do_list}:\n"
-	list.each_with_index do |time, index|
-		print "#{sprintf('% 3d',index)}: #{time}\n"
-	end
-end
-
-if @do_prune
-	verbose "Counting last 10 backups"
-	target_free_space = 1.5 * @backups.average_snapshot_size(10)
-	verbose "Want to ensure we have #{target_free_space}"
-
-	if @backups.free >= target_free_space
-		verbose "(we have #{@backups.free} so no action needed)"
-	else
-		list = get_snapshots_by(@do_prune)
-
-		while @backups.free < target_free_space && !list.empty?
-			to_delete = list.pop
-			verbose "Deleting #{to_delete}"
-			@backups.delete_snapshot!(to_delete)
-			verbose "Leaves us with #{@backups.free}"
-		end
-	end
-end
-
-verbose "Finished"
+#!/usr/bin/ruby

+#

+# Program to create a snapshot and/or rotate a directory of backup snapshots 

+# using btrfs subvolume commands.

+

+require 'trollop'

+require 'time'

+

+def error(message)

+	STDERR.print "*** #{message}\n"

+	exit 1

+end

+

+def verbose(message)

+	print "#{Time.now}: #{message}\n" if @verbose

+end

+

+# Icky way to find out free disc space on our mount

+#

+class DiskFree

+	def initialize(mount)

+		@mount = mount

+	end

+

+	def total

+		all[2]

+	end

+

+	def used

+		all[3]

+	end

+

+	def available

+		all[4]

+	end

+

+	def fraction_used

+		disk_device, disk_fs, disk_total, disk_used, disk_available, *rest = all

+		disk_used.to_f / disk_available

+	end

+

+	protected

+

+	def all

+		disk_device, disk_fs, disk_total, disk_used, disk_available, *rest = 

+			df.

+			split("\n")[1].

+			split(/\s+/).

+			map { |i| /^[0-9]+$/.match(i) ? i.to_i : i }

+	end

+

+	def df

+		`/bin/df -T -P -B1 #{@mount}`

+	end

+end

+

+# Represent a directory full of backups where "current"  is a subvolume

+# which is snapshotted to frozen backup directories called e.g. 

+# "yyyy-mm-ddThh:mm".

+#

+class BackupDirectory

+	attr_reader :dir

+

+	def initialize(dir)

+		@dir = Dir.new(dir)

+		current

+	end

+

+	# Return total amount of free space in backup directory (bytes)

+	#

+	def free

+		df = DiskFree.new(@dir.path)

+		df.total - df.used

+	end

+

+	# Return an array of Times representing the current list of 

+	# snapshots.

+	#

+	def snapshot_times

+		@dir.entries.map do |entry|

+			begin

+				Time.parse(entry)

+			rescue ArgumentError => error

+				nil

+			end

+		end.

+		compact.

+		sort

+	end

+

+	# What order to remove snapshots in to regain disk space?

+	#

+	# Order backups by their closeness to defined backup times, which are

+	# listed in a set order (i.e. today's backup is more important than yesterday's).

+	#

+	BACKUP_IMPORTANCE = [0, 1, 2, 3, 7, 14, 21, 28, 56, 112]

+	def snapshot_times_by_importance

+		now = Time.now

+		snapshot_times_unsorted = snapshot_times

+		snapshot_times_sorted = []

+		while !snapshot_times_unsorted.empty?

+			BACKUP_IMPORTANCE.each do |days|

+				target_time = now + (days*86400)

+				closest = snapshot_times_unsorted.inject(nil) do |best, time|

+					if best.nil? || (time-target_time).abs < (best-target_time).abs

+						time

+					else

+						best

+					end

+				end

+				break unless closest

+				snapshot_times_sorted << snapshot_times_unsorted.delete(closest)

+			end

+		end

+		snapshot_times_sorted

+	end

+

+	# Returns the size of the given snapshot (runs du, may be slow)

+	#

+	# Would much prefer to take advantage of this feature:

+	#   http://dustymabe.com/2013/09/22/btrfs-how-big-are-my-snapshots/

+	# but it's not currently in Debian/wheezy.

+	#

+	def snapshot_size(time=snapshot_times.latest)

+		`du -s -b #{snapshot_path(time)}`.to_i

+	end

+

+	def average_snapshot_size(number=10)

+		snapshot_times.sort[0..number].inject(0) { |time, total| snapshot_size(time) } / number

+	end

+

+	# Create a new snapshot of 'current'

+	#

+	def new_snapshot!

+		system_no_error("btrfs subvolume snapshot -r #{current.path} #{snapshot_path}")

+	end

+

+	def delete_snapshot!(time)

+		system_no_error("btrfs subvolume delete #{snapshot_path(time)}")

+	end

+

+	def current

+		Dir.new("#{dir.path}/current")

+	end

+

+	def snapshot_path(time=Time.now)

+		"#{dir.path}/#{time.strftime("%Y-%m-%dT%H:%M")}"

+	end

+

+	protected

+

+	def system_no_error(*args)

+		raise RuntimeError.new("Command failed: "+args.join(" ")) unless

+		  system(*args)

+	end

+end

+

+opts = Trollop::options do

+

+    opt :root, "Backups directory (must be a btrfs subvolume)",

+    	:type => :string

+

+    opt :snapshot, "Take a new snapshot"

+

+    opt :prune, "Prune old backups"

+    	:type => :string

+

+    opt :list, "List backups (by 'age' or 'importance')",

+    	:type => :string

+

+    opt :verbose, "Print diagnostics"

+

+end

+

+@root = opts[:root]

+@verbose = opts[:verbose]

+@do_snapshot = opts[:snapshot]

+@do_list = opts[:list]

+@do_prune = opts[:prune]

+

+error("Must specify snapshot, prune or list") unless @do_snapshot || @do_prune || @do_list

+

+error("--root not readable") unless File.directory?(@root)

+

+@backups = BackupDirectory.new(@root)

+

+def get_snapshots_by(method)

+	if method == 'importance'

+		@backups.snapshot_times_by_importance.reverse # least important first

+	elsif method == 'age'

+		@backups.snapshot_times

+	else

+		raise ArgumentError.new("Unknown snapshot sort method #{method}")

+	end

+end

+

+if @do_snapshot

+	last_snapshot_time = @backups.snapshots.last

+	error("Last snapshot was less than six hours ago") unless 

+		!last_snapshot_time || 

+		Time.now - @backups.snapshots.last >= 6*60*60 # FIXME: make configurable

+

+	verbose "Making new snapshot"

+	@backups.new_snapshot! 

+end

+

+if @do_list

+	list = get_snapshots_by(@do_list)

+	print "Backups in #{@root} by #{@do_list}:\n"

+	list.each_with_index do |time, index|

+		print "#{sprintf('% 3d',index)}: #{time}\n"

+	end

+end

+

+if @do_prune

+	verbose "Counting last 10 backups"

+	target_free_space = 1.5 * @backups.average_snapshot_size(10)

+	verbose "Want to ensure we have #{target_free_space}"

+

+	if @backups.free >= target_free_space

+		verbose "(we have #{@backups.free} so no action needed)"

+	else

+		list = get_snapshots_by(@do_prune)

+

+		while @backups.free < target_free_space && !list.empty?

+			to_delete = list.pop

+			verbose "Deleting #{to_delete}"

+			@backups.delete_snapshot!(to_delete)

+			verbose "Leaves us with #{@backups.free}"

+		end

+	end

+end

+

+verbose "Finished"