debian-mirror-gitlab/lib/gitlab/ci/trace/checksum.rb
2021-01-03 14:25:43 +05:30

83 lines
2.2 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Ci
class Trace
##
# Trace::Checksum class is responsible for calculating a CRC32 checksum
# of an entire build trace using partial build trace chunks stored in a
# database.
#
# CRC32 checksum can be easily calculated by combining partial checksums
# in a right order.
#
# Then we compare CRC32 checksum provided by a GitLab Runner and expect
# it to be the same as the CRC32 checksum derived from partial chunks.
#
class Checksum
include Gitlab::Utils::StrongMemoize
attr_reader :build
def initialize(build)
@build = build
end
def valid?
return false unless state_crc32.present?
state_crc32 == chunks_crc32
end
def state_crc32
strong_memoize(:state_crc32) { build.pending_state&.crc32 }
end
def chunks_crc32
strong_memoize(:chunks_crc32) do
trace_chunks.reduce(0) do |crc32, chunk|
Zlib.crc32_combine(crc32, chunk.crc32, chunk_size(chunk))
end
end
end
def last_chunk
strong_memoize(:last_chunk) { trace_chunks.max }
end
##
# Trace chunks will be persisted in a database if an object store is
# not configured - in that case we do not want to load entire raw data
# of all the chunks into memory.
#
# We ignore `raw_data` attribute instead, and rely on internal build
# trace chunk database adapter to handle
# `ActiveModel::MissingAttributeError` exception.
#
# Alternative solution would be separating chunk data from chunk
# metadata on the database level too.
#
def trace_chunks
strong_memoize(:trace_chunks) do
build.trace_chunks.persisted
.select(::Ci::BuildTraceChunk.metadata_attributes)
end
end
def chunks_count
trace_chunks.to_a.size
end
private
def chunk_size(chunk)
if chunk == last_chunk
chunk.size
else
::Ci::BuildTraceChunk::CHUNK_SIZE
end
end
end
end
end
end