Class: MergeRequestDiff

Inherits:
ApplicationRecord show all
Includes:
BulkInsertableAssociations, EachBatch, Gitlab::Utils::StrongMemoize, Importable, ManualInverseAssociation, ShaAttribute, Sortable
Defined in:
app/models/merge_request_diff.rb

Constant Summary collapse

COMMITS_SAFE_SIZE =

Don’t display more than 100 commits at once

100
BATCH_SIZE = 
1000
EXTERNAL_DIFF_CUTOFF =

Applies to closed or merged MRs when determining whether to migrate their diffs to external storage

7.days.freeze
FILES_COUNT_SENTINEL =

The files_count column is a 2-byte signed integer. Look up the true value from the database if this sentinel is seen

2**15 - 1
EXTERNAL_DIFFS_CACHE_TMPDIR =

External diff cache key used by diffs export

'project-%{project_id}-external-mr-%{mr_id}-diff-%{id}-cache'
EXTERNAL_DIFF_CACHE_CHUNK_SIZE = 
8.megabytes

Constants inherited from ApplicationRecord

ApplicationRecord::MAX_PLUCK

Constants included from ResetOnUnionError

ResetOnUnionError::MAX_RESET_PERIOD

Instance Attribute Summary

Attributes included from Importable

#imported, #importing

Class Method Summary collapse

Instance Method Summary collapse

Methods included from BulkInsertableAssociations

#bulk_insert_associations!, bulk_inserts_enabled?, with_bulk_insert

Methods inherited from ApplicationRecord

cached_column_list, #create_or_load_association, declarative_enum, default_select_columns, id_in, id_not_in, iid_in, pluck_primary_key, primary_key_in, #readable_by?, safe_ensure_unique, safe_find_or_create_by, safe_find_or_create_by!, #to_ability_name, underscore, where_exists, where_not_exists, with_fast_read_statement_timeout, without_order

Methods included from SensitiveSerializableHash

#serializable_hash

Class Method Details

.find_by_diff_refs(diff_refs) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 201

def self.find_by_diff_refs(diff_refs)
  find_by(start_commit_sha: diff_refs.start_sha, head_commit_sha: diff_refs.head_sha, base_commit_sha: diff_refs.base_sha)
end

.ids_for_external_storage_migration(limit:) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 149

def ids_for_external_storage_migration(limit:)
  return [] unless Gitlab.config.external_diffs.enabled

  case Gitlab.config.external_diffs.when
  when 'always'
    ids_for_external_storage_migration_strategy_always(limit: limit)
  when 'outdated'
    ids_for_external_storage_migration_strategy_outdated(limit: limit)
  else
    []
  end
end

.ids_for_external_storage_migration_strategy_always(limit:) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 162

def ids_for_external_storage_migration_strategy_always(limit:)
  files_in_database.limit(limit).pluck(:id)
end

.ids_for_external_storage_migration_strategy_outdated(limit:) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 166

def ids_for_external_storage_migration_strategy_outdated(limit:)
  # Outdated is too complex to be a single SQL query, so split into three
  before = EXTERNAL_DIFF_CUTOFF.ago

  ids = files_in_database
    .old_merged_diffs(before)
    .limit(limit)
    .pluck(:id)

  return ids if ids.size >= limit

  ids += files_in_database
    .old_closed_diffs(before)
    .limit(limit - ids.size)
    .pluck(:id)

  return ids if ids.size >= limit

  ids + files_in_database
    .not_latest_diffs
    .limit(limit - ids.size)
    .pluck(:id)
end

Instance Method Details

#base_commit ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 315

def base_commit
  return unless base_commit_sha

  project.commit_by(oid: base_commit_sha)
end

#cached_external_diff ⇒ Object

Yields locally cached external diff if it’s externally stored. Used during Project Export to speed up externally stored merge request diffs export



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# File 'app/models/merge_request_diff.rb', line 587

def cached_external_diff
  return yield(nil) unless stored_externally?

  cache_external_diff unless File.exist?(external_diff_cache_filepath)

  File.open(external_diff_cache_filepath) do |file|
    yield(file)
  end
end

#commit_shas(limit: nil) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 333

def commit_shas(limit: nil)
  if association(:merge_request_diff_commits).loaded?
    sorted_diff_commits = merge_request_diff_commits.sort_by { |diff_commit| [diff_commit.id, diff_commit.relative_order] }
    sorted_diff_commits = sorted_diff_commits.take(limit) if limit
    sorted_diff_commits.map(&:sha)
  else
    merge_request_diff_commits.limit(limit).pluck(:sha)
  end
end

#commits(limit: nil, load_from_gitaly: false, page: nil) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 297

def commits(limit: nil, load_from_gitaly: false, page: nil)
  strong_memoize(:"commits_#{limit || 'all'}_#{load_from_gitaly}_page_#{page}") do
    load_commits(limit: limit, load_from_gitaly: load_from_gitaly, page: page)
  end
end

#compare ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 475

def compare
  @compare ||=
    Gitlab::Git::Compare.new(
      repository.raw_repository,
      safe_start_commit_sha,
      head_commit_sha
    )
end

#compare_with(sha) ⇒ Object

rubocop: disable CodeReuse/ServiceClass



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# File 'app/models/merge_request_diff.rb', line 489

def compare_with(sha)
  # When compare merge request versions we want diff A..B instead of A...B
  # so we handle cases when user does squash and rebase of the commits between versions.
  # For this reason we set straight to true by default.
  CompareService.new(project, head_commit_sha).execute(project, sha, straight: true)
end

#diff_refs ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 359

def diff_refs
  return unless start_commit_sha || base_commit_sha

  Gitlab::Diff::DiffRefs.new(
    base_sha: base_commit_sha,
    start_sha: start_commit_sha,
    head_sha: head_commit_sha
  )
end

#diff_refs=(new_diff_refs) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 353

def diff_refs=(new_diff_refs)
  self.base_commit_sha = new_diff_refs&.base_sha
  self.start_commit_sha = new_diff_refs&.start_sha
  self.head_commit_sha = new_diff_refs&.head_sha
end

#diff_refs_by_sha? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/merge_request_diff.rb', line 392

def diff_refs_by_sha?
  base_commit_sha? && head_commit_sha? && start_commit_sha?
end

#diffs(diff_options = nil) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 449

def diffs(diff_options = nil)
  fetching_repository_diffs(diff_options) do |comparison|
    # It should fetch the repository when diffs are cleaned by the system.
    # We don't keep these for storage overload purposes.
    # See https://gitlab.com/gitlab-org/gitlab-foss/issues/37639
    if comparison
      comparison.diffs(diff_options)
    else
      reorder_diff_files!
      diffs_collection(diff_options)
    end
  end
end

#diffs_collection(diff_options = nil) ⇒ Object

Should always return the DB persisted diffs collection (e.g. Gitlab::Diff::FileCollection::MergeRequestDiff. It’s useful when trying to invalidate old caches through FileCollection::MergeRequestDiff#clear_cache!



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# File 'app/models/merge_request_diff.rb', line 467

def diffs_collection(diff_options = nil)
  Gitlab::Diff::FileCollection::MergeRequestDiff.new(self, diff_options: diff_options)
end

#diffs_in_batch(batch_page, batch_size, diff_options:) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 396

def diffs_in_batch(batch_page, batch_size, diff_options:)
  fetching_repository_diffs(diff_options) do |comparison|
    Gitlab::Metrics.measure(:diffs_reorder) do
      reorder_diff_files!
    end

    diffs_batch = Gitlab::Metrics.measure(:diffs_collection) do
      diffs_in_batch_collection(batch_page, batch_size, diff_options: diff_options)
    end

    if comparison
      if diff_options[:paths].blank? && !without_files?
        # Return the empty MergeRequestDiffBatch for an out of bound batch request
        break diffs_batch if diffs_batch.diff_paths.blank?

        diff_options.merge!(
          paths: diffs_batch.diff_paths,
          pagination_data: diffs_batch.pagination_data
        )
      end

      Gitlab::Metrics.measure(:diffs_comparison) do
        comparison.diffs(diff_options)
      end
    else
      diffs_batch
    end
  end
end

#ensure_commit_shas ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 236

def ensure_commit_shas
  self.start_commit_sha ||= merge_request.target_branch_sha

  if merge_head? && merge_request.merge_ref_head.present?
    diff_refs = merge_request.merge_ref_head.diff_refs

    self.head_commit_sha  ||= diff_refs.head_sha
    self.base_commit_sha  ||= diff_refs.base_sha
  else
    self.head_commit_sha  ||= merge_request.source_branch_sha
    self.base_commit_sha  ||= find_base_sha
  end
end

#fallback_diff_refs ⇒ Object

MRs created before 8.4 don’t store their true diff refs (start and base), but we need to get a commit SHA for the “View file @ …” link by a file, so we use an approximation of the diff refs if we can’t get the actual one.

These will not be the actual diff refs if the target branch was merged into the source branch after the merge request was created, but it is good enough for the specific purpose of linking to a commit.

It is not good enough for highlighting diffs, so we can’t simply pass these as ‘diff_refs.`



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# File 'app/models/merge_request_diff.rb', line 379

def fallback_diff_refs
  real_refs = diff_refs
  return real_refs if real_refs

  likely_base_commit_sha = (first_commit&.parent || first_commit)&.sha

  Gitlab::Diff::DiffRefs.new(
    base_sha: likely_base_commit_sha,
    start_sha: safe_start_commit_sha,
    head_sha: head_commit_sha
  )
end

#files_count ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 260

def files_count
  db_value = read_attribute(:files_count)

  case db_value
  when nil, FILES_COUNT_SENTINEL
    merge_request_diff_files.count
  else
    db_value
  end
end

#first_commit ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 307

def first_commit
  commits.last
end

#head_commit ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 327

def head_commit
  return unless head_commit_sha

  project.commit_by(oid: head_commit_sha)
end

#head_commit_sha ⇒ Object

Override head_commit_sha to keep compatibility with merge request diff created before version 8.4 that does not store head_commit_sha in separate db field.



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# File 'app/models/merge_request_diff.rb', line 252

def head_commit_sha
  if persisted? && super.nil?
    last_commit_sha
  else
    super
  end
end

#includes_any_commits?(shas) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/merge_request_diff.rb', line 343

def includes_any_commits?(shas)
  return false if shas.blank?

  # when the number of shas is huge (1000+) we don't want
  # to pass them all as an SQL param, let's pass them in batches
  shas.each_slice(BATCH_SIZE).any? do |batched_shas|
    merge_request_diff_commits.where(sha: batched_shas).exists?
  end
end

#last_commit ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 311

def last_commit
  commits.first
end

#last_commit_sha ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 303

def last_commit_sha
  commit_shas(limit: 1).first
end

#latest? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/merge_request_diff.rb', line 484

def latest?
  self.id == merge_request.latest_merge_request_diff_id
end

#lines_count ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 282

def lines_count
  strong_memoize(:lines_count) do
    raw_diffs(limits: false).line_count
  end
end

#migrate_files_to_database! ⇒ Object

Transactionally migrate the current merge_request_diff_files entries from external storage, back to the database. This is the rollback operation for migrate_files_to_external_storage!

If this diff isn’t in external storage, the method is a no-op.



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# File 'app/models/merge_request_diff.rb', line 566

def migrate_files_to_database!
  return unless stored_externally?
  return if files_count == 0

  rows = convert_external_diffs_to_database

  transaction do
    MergeRequestDiffFile.where(merge_request_diff_id: id).delete_all
    ApplicationRecord.legacy_bulk_insert('merge_request_diff_files', rows) # rubocop:disable Gitlab/BulkInsert
    update!(stored_externally: false)
  end

  # Only delete the external diff file after the contents have been saved to
  # the database
  remove_external_diff!
  merge_request_diff_files.reset
end

#migrate_files_to_external_storage! ⇒ Object

Transactionally migrate the current merge_request_diff_files entries to external storage. If external storage isn’t an option for this diff, the method is a no-op.



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# File 'app/models/merge_request_diff.rb', line 541

def migrate_files_to_external_storage!
  return if stored_externally? || !use_external_diff? || files_count == 0

  rows = build_merge_request_diff_files(merge_request_diff_files)
  rows = build_external_merge_request_diff_files(rows)

  # Perform carrierwave activity before entering the database transaction.
  # This is safe as until the `external_diff_store` column is changed, we will
  # continue to consult the in-database content.
  self.external_diff.store!

  transaction do
    MergeRequestDiffFile.where(merge_request_diff_id: id).delete_all
    ApplicationRecord.legacy_bulk_insert('merge_request_diff_files', rows) # rubocop:disable Gitlab/BulkInsert
    save!
  end

  merge_request_diff_files.reset
end

#modified_paths(fallback_on_overflow: false) ⇒ Object

rubocop: enable CodeReuse/ServiceClass



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# File 'app/models/merge_request_diff.rb', line 497

def modified_paths(fallback_on_overflow: false)
  if fallback_on_overflow && overflow?
    # This is an extremely slow means to find the modified paths for a given
    #   MergeRequestDiff. This should be avoided, except where the limit of
    #   1_000 (as of %12.10) entries returned by the default behavior is an
    #   issue.
    strong_memoize(:overflowed_modified_paths) do
      project.repository.diff_stats(
        base_commit_sha,
        head_commit_sha
      ).paths
    end
  else
    strong_memoize(:modified_paths) do
      merge_request_diff_files.pluck(:new_path, :old_path).flatten.uniq
    end
  end
end

#opening_external_diff ⇒ Object

If enabled, yields the external file containing the diff. Otherwise, yields nil. This method is not thread-safe, but it is re-entrant, which allows multiple merge_request_diff_files to load their data efficiently



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# File 'app/models/merge_request_diff.rb', line 525

def opening_external_diff
  return yield(nil) unless stored_externally?
  return yield(@external_diff_file) if @external_diff_file

  external_diff.open do |file|
    @external_diff_file = file

    yield(@external_diff_file)
  ensure
    @external_diff_file = nil
  end
end

#paginated_diffs(page, per_page) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 426

def paginated_diffs(page, per_page)
  fetching_repository_diffs({}) do |comparison|
    reorder_diff_files!

    collection = Gitlab::Diff::FileCollection::PaginatedMergeRequestDiff.new(
      self,
      page,
      per_page
    )

    if comparison
      comparison.diffs(
        paths: collection.diff_paths,
        page: collection.current_page,
        per_page: collection.limit_value,
        count: collection.total_count
      )
    else
      collection
    end
  end
end

#project ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 471

def project
  merge_request.target_project
end

#raw_diffs(options = {}) ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 288

def raw_diffs(options = {})
  if options[:ignore_whitespace_change]
    @diffs_no_whitespace ||= compare.diffs(options)
  else
    @raw_diffs ||= {}
    @raw_diffs[options] ||= load_diffs(options)
  end
end

#remove_cached_external_diff ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 597

def remove_cached_external_diff
  Gitlab::PathTraversal.check_path_traversal!(external_diff_cache_dir)
  Gitlab::PathTraversal.check_allowed_absolute_path!(external_diff_cache_dir, [Dir.tmpdir])

  return unless Dir.exist?(external_diff_cache_dir)

  FileUtils.rm_rf(external_diff_cache_dir)
end

#safe_start_commit_sha ⇒ Object

This method will rely on repository branch sha in case start_commit_sha is nil. It’s necessary for old merge request diff created before version 8.4 to work



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# File 'app/models/merge_request_diff.rb', line 274

def safe_start_commit_sha
  start_commit_sha || merge_request.target_branch_sha
end

#save_git_content ⇒ Object

Collect information about commits and diff from repository and save it to the database as serialized data



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# File 'app/models/merge_request_diff.rb', line 211

def save_git_content
  ensure_commit_shas
  save_commits
  save_diffs

  # Another set of `after_save` hooks will be called here when we update the record
  save
  # We need to reset so that dirty tracking is reset when running the original set
  # of `after_save` hooks that come after this `after_create` hook. Otherwise, the
  # hooks that run when an attribute was changed are run twice.
  reset

  keep_around_commits unless importing?
end

#set_as_latest_diff ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 226

def set_as_latest_diff
  # Don't set merge_head diff as latest so it won't get considered as the
  # MergeRequest#merge_request_diff.
  return if merge_head?

  MergeRequest
    .where('id = ? AND COALESCE(latest_merge_request_diff_id, 0) < ?', self.merge_request_id, self.id)
    .update_all(latest_merge_request_diff_id: self.id)
end

#size ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 278

def size
  real_size.presence || raw_diffs.size
end

#start_commit ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 321

def start_commit
  return unless start_commit_sha

  project.commit_by(oid: start_commit_sha)
end

#update_external_diff_store ⇒ Object 



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# File 'app/models/merge_request_diff.rb', line 516

def update_external_diff_store
  return unless saved_change_to_external_diff? || saved_change_to_stored_externally?

  update_column(:external_diff_store, external_diff.object_store)
end

#viewable? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/merge_request_diff.rb', line 205

def viewable?
  collected? || without_files? || overflow?
end