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Diffstat (limited to 'lib/gitlab/ci/trace/checksum.rb')
-rw-r--r-- | lib/gitlab/ci/trace/checksum.rb | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/lib/gitlab/ci/trace/checksum.rb b/lib/gitlab/ci/trace/checksum.rb new file mode 100644 index 00000000000..b01136a6d24 --- /dev/null +++ b/lib/gitlab/ci/trace/checksum.rb @@ -0,0 +1,77 @@ +# 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(:crc32) { build.pending_state&.crc32 } + end + + def chunks_crc32 + trace_chunks.reduce(0) do |crc32, chunk| + Zlib.crc32_combine(crc32, chunk.crc32, chunk_size(chunk)) + 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 + + private + + def chunk_size(chunk) + if chunk == last_chunk + chunk.size + else + ::Ci::BuildTraceChunk::CHUNK_SIZE + end + end + end + end + end +end |