56 lines
1.9 KiB
Ruby
56 lines
1.9 KiB
Ruby
# frozen_string_literal: true
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module Gitlab
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module Git
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class CrossRepoComparer
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attr_reader :source_repo, :target_repo
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def initialize(source_repo, target_repo)
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@source_repo = source_repo
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@target_repo = target_repo
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end
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def compare(source_ref, target_ref, straight:)
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ensuring_ref_in_source(target_ref) do |target_commit_id|
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Gitlab::Git::Compare.new(
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source_repo,
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target_commit_id,
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source_ref,
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straight: straight
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)
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end
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end
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private
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def ensuring_ref_in_source(ref, &blk)
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return yield ref if source_repo == target_repo
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# If the commit doesn't exist in the target, there's nothing we can do
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commit_id = target_repo.commit(ref)&.sha
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return unless commit_id
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# The commit pointed to by ref may exist in the source even when they
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# are different repositories. This is particularly true of close forks,
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# but may also be the case if a temporary ref for this comparison has
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# already been created in the past, and the result hasn't been GC'd yet.
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return yield commit_id if source_repo.commit(commit_id)
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# Worst case: the commit is not in the source repo so we need to fetch
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# it. Use a temporary ref and clean up afterwards
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with_commit_in_source_tmp(commit_id, &blk)
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end
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# Fetch the ref into source_repo from target_repo, using a temporary ref
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# name that will be deleted once the method completes. This is a no-op if
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# fetching the source branch fails
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def with_commit_in_source_tmp(commit_id, &blk)
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tmp_ref = "refs/#{::Repository::REF_TMP}/#{SecureRandom.hex}"
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yield commit_id if source_repo.fetch_source_branch!(target_repo, commit_id, tmp_ref)
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ensure
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source_repo.delete_refs(tmp_ref) # best-effort
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end
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end
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end
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end
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