Class: MergeRequestDiff

Inherits:
ApplicationRecord show all
Includes:
BulkInsertableAssociations, EachBatch, Gitlab::Utils::StrongMemoize, Importable, ManualInverseAssociation, ObjectStorage::BackgroundMove, 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

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 included from ObjectStorage::BackgroundMove

#background_upload, #changed_mounts

Methods included from Gitlab::Utils::StrongMemoize

#clear_memoization, #strong_memoize, #strong_memoized?

Methods inherited from ApplicationRecord

at_most, id_in, id_not_in, iid_in, pluck_primary_key, primary_key_in, safe_ensure_unique, safe_find_or_create_by, safe_find_or_create_by!, underscore, without_order

Class Method Details

.find_by_diff_refs(diff_refs) ⇒ Object


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

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 110

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  when 'outdated'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 123

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 127

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_commitObject


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# File 'app/models/merge_request_diff.rb', line 264

def base_commit
  return unless base_commit_sha

  project.commit_by(oid: base_commit_sha)
end

#commit_shas(limit: nil) ⇒ Object


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

def commit_shas(limit: nil)
  merge_request_diff_commits.limit(limit).pluck(:sha)
end

#commits(limit: nil) ⇒ Object


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# File 'app/models/merge_request_diff.rb', line 246

def commits(limit: nil)
  strong_memoize(:"commits_#{limit || 'all'}") do
    load_commits(limit: limit)
  end
end

#compareObject


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# File 'app/models/merge_request_diff.rb', line 374

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 388

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_refsObject


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# File 'app/models/merge_request_diff.rb', line 302

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 296

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 335

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 349

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
      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 366

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 339

def diffs_in_batch(batch_page, batch_size, diff_options:)
  fetching_repository_diffs(diff_options) do |comparison|
    if comparison
      comparison.diffs_in_batch(batch_page, batch_size, diff_options: diff_options)
    else
      diffs_in_batch_collection(batch_page, batch_size, diff_options: diff_options)
    end
  end
end

#ensure_commit_shasObject


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# File 'app/models/merge_request_diff.rb', line 193

def ensure_commit_shas
  self.start_commit_sha ||= merge_request.target_branch_sha
  self.head_commit_sha  ||= merge_request.source_branch_sha
  self.base_commit_sha  ||= find_base_sha
end

#fallback_diff_refsObject

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 322

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_countObject


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# File 'app/models/merge_request_diff.rb', line 209

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_commitObject


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# File 'app/models/merge_request_diff.rb', line 256

def first_commit
  commits.last
end

#head_commitObject


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# File 'app/models/merge_request_diff.rb', line 276

def head_commit
  return unless head_commit_sha

  project.commit_by(oid: head_commit_sha)
end

#head_commit_shaObject

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 201

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 286

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_commitObject


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

def last_commit
  commits.first
end

#last_commit_shaObject


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

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 383

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

#lines_countObject


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# File 'app/models/merge_request_diff.rb', line 231

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 465

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
    Gitlab::Database.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 440

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
    Gitlab::Database.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 396

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_diffObject

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 424

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

#projectObject


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# File 'app/models/merge_request_diff.rb', line 370

def project
  merge_request.target_project
end

#raw_diffs(options = {}) ⇒ Object


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# File 'app/models/merge_request_diff.rb', line 237

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

#safe_start_commit_shaObject

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


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# File 'app/models/merge_request_diff.rb', line 223

def safe_start_commit_sha
  start_commit_sha || merge_request.target_branch_sha
end

#save_git_contentObject

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 172

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_diffObject


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# File 'app/models/merge_request_diff.rb', line 187

def set_as_latest_diff
  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

#sizeObject


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# File 'app/models/merge_request_diff.rb', line 227

def size
  real_size.presence || raw_diffs.size
end

#start_commitObject


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# File 'app/models/merge_request_diff.rb', line 270

def start_commit
  return unless start_commit_sha

  project.commit_by(oid: start_commit_sha)
end

#update_external_diff_storeObject


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# File 'app/models/merge_request_diff.rb', line 415

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 166

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