gitlab-org--gitlab-foss/lib/gitlab/git/diff_collection.rb
2017-01-04 19:09:28 -05:00

129 lines
3.2 KiB
Ruby

module Gitlab
module Git
class DiffCollection
include Enumerable
DEFAULT_LIMITS = { max_files: 100, max_lines: 5000 }.freeze
def initialize(iterator, options = {})
@iterator = iterator
@max_files = options.fetch(:max_files, DEFAULT_LIMITS[:max_files])
@max_lines = options.fetch(:max_lines, DEFAULT_LIMITS[:max_lines])
@max_bytes = @max_files * 5120 # Average 5 KB per file
@safe_max_files = [@max_files, DEFAULT_LIMITS[:max_files]].min
@safe_max_lines = [@max_lines, DEFAULT_LIMITS[:max_lines]].min
@safe_max_bytes = @safe_max_files * 5120 # Average 5 KB per file
@all_diffs = !!options.fetch(:all_diffs, false)
@no_collapse = !!options.fetch(:no_collapse, true)
@deltas_only = !!options.fetch(:deltas_only, false)
@line_count = 0
@byte_count = 0
@overflow = false
@array = Array.new
end
def each(&block)
if @populated
# @iterator.each is slower than just iterating the array in place
@array.each(&block)
elsif @deltas_only
each_delta(&block)
else
each_patch(&block)
end
end
def empty?
!@iterator.any?
end
def overflow?
populate!
!!@overflow
end
def size
@size ||= count # forces a loop using each method
end
def real_size
populate!
if @overflow
"#{size}+"
else
size.to_s
end
end
def decorate!
collection = each_with_index do |element, i|
@array[i] = yield(element)
end
@populated = true
collection
end
private
def populate!
return if @populated
each { nil } # force a loop through all diffs
@populated = true
nil
end
def over_safe_limits?(files)
files >= @safe_max_files || @line_count > @safe_max_lines || @byte_count >= @safe_max_bytes
end
def each_delta
@iterator.each_delta.with_index do |delta, i|
diff = Gitlab::Git::Diff.new(delta)
yield @array[i] = diff
end
end
def each_patch
@iterator.each_with_index do |raw, i|
# First yield cached Diff instances from @array
if @array[i]
yield @array[i]
next
end
# We have exhausted @array, time to create new Diff instances or stop.
break if @overflow
if !@all_diffs && i >= @max_files
@overflow = true
break
end
collapse = !@all_diffs && !@no_collapse
diff = Gitlab::Git::Diff.new(raw, collapse: collapse)
if collapse && over_safe_limits?(i)
diff.prune_collapsed_diff!
end
@line_count += diff.line_count
@byte_count += diff.diff.bytesize
if !@all_diffs && (@line_count >= @max_lines || @byte_count >= @max_bytes)
# This last Diff instance pushes us over the lines limit. We stop and
# discard it.
@overflow = true
break
end
yield @array[i] = diff
end
end
end
end
end