gitlab-org--gitlab-foss/app/models/merge_request_diff.rb
2019-05-06 11:35:03 +01:00

577 lines
17 KiB
Ruby

# frozen_string_literal: true
class MergeRequestDiff < ApplicationRecord
include Sortable
include Importable
include ManualInverseAssociation
include IgnorableColumn
include EachBatch
include Gitlab::Utils::StrongMemoize
include ObjectStorage::BackgroundMove
# Don't display more than 100 commits at once
COMMITS_SAFE_SIZE = 100
# Applies to closed or merged MRs when determining whether to migrate their
# diffs to external storage
EXTERNAL_DIFF_CUTOFF = 7.days.freeze
belongs_to :merge_request
manual_inverse_association :merge_request, :merge_request_diff
has_many :merge_request_diff_files,
-> { order(:merge_request_diff_id, :relative_order) },
inverse_of: :merge_request_diff
has_many :merge_request_diff_commits, -> { order(:merge_request_diff_id, :relative_order) }
validates :base_commit_sha, :head_commit_sha, :start_commit_sha, sha: true
state_machine :state, initial: :empty do
event :clean do
transition any => :without_files
end
state :collected
state :overflow
# Diff files have been deleted by the system
state :without_files
# Deprecated states: these are no longer used but these values may still occur
# in the database.
state :timeout
state :overflow_commits_safe_size
state :overflow_diff_files_limit
state :overflow_diff_lines_limit
end
scope :with_files, -> { without_states(:without_files, :empty) }
scope :viewable, -> { without_state(:empty) }
scope :by_commit_sha, ->(sha) do
joins(:merge_request_diff_commits).where(merge_request_diff_commits: { sha: sha }).reorder(nil)
end
scope :by_project_id, -> (project_id) do
joins(:merge_request).where(merge_requests: { target_project_id: project_id })
end
scope :recent, -> { order(id: :desc).limit(100) }
scope :files_in_database, -> { where(stored_externally: [false, nil]) }
scope :not_latest_diffs, -> do
merge_requests = MergeRequest.arel_table
mr_diffs = arel_table
join_condition = merge_requests[:id].eq(mr_diffs[:merge_request_id])
.and(mr_diffs[:id].not_eq(merge_requests[:latest_merge_request_diff_id]))
arel_join = mr_diffs.join(merge_requests).on(join_condition)
joins(arel_join.join_sources)
end
scope :old_merged_diffs, -> (before) do
merge_requests = MergeRequest.arel_table
mr_metrics = MergeRequest::Metrics.arel_table
mr_diffs = arel_table
mr_join = mr_diffs
.join(merge_requests)
.on(mr_diffs[:merge_request_id].eq(merge_requests[:id]))
metrics_join_condition = mr_diffs[:merge_request_id]
.eq(mr_metrics[:merge_request_id])
.and(mr_metrics[:merged_at].not_eq(nil))
metrics_join = mr_diffs.join(mr_metrics).on(metrics_join_condition)
condition = MergeRequest.arel_table[:state].eq(:merged)
.and(MergeRequest::Metrics.arel_table[:merged_at].lteq(before))
.and(MergeRequest::Metrics.arel_table[:merged_at].not_eq(nil))
joins(metrics_join.join_sources, mr_join.join_sources).where(condition)
end
scope :old_closed_diffs, -> (before) do
condition = MergeRequest.arel_table[:state].eq(:closed)
.and(MergeRequest::Metrics.arel_table[:latest_closed_at].lteq(before))
joins(merge_request: :metrics).where(condition)
end
def self.ids_for_external_storage_migration(limit:)
# No point doing any work unless the feature is enabled
return [] unless Gitlab.config.external_diffs.enabled
case Gitlab.config.external_diffs.when
when 'always'
files_in_database.limit(limit).pluck(:id)
when 'outdated'
# 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)
else
[]
end
end
mount_uploader :external_diff, ExternalDiffUploader
# All diff information is collected from repository after object is created.
# It allows you to override variables like head_commit_sha before getting diff.
after_create :save_git_content, unless: :importing?
after_save :update_external_diff_store, if: -> { !importing? && saved_change_to_external_diff? }
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
def viewable?
collected? || without_files? || overflow?
end
# Collect information about commits and diff from repository
# and save it to the database as serialized data
def save_git_content
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)
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
end
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
# 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.
def head_commit_sha
if persisted? && super.nil?
last_commit_sha
else
super
end
end
# 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
def safe_start_commit_sha
start_commit_sha || merge_request.target_branch_sha
end
def size
real_size.presence || raw_diffs.size
end
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
def commits
@commits ||= load_commits
end
def last_commit_sha
commit_shas.first
end
def first_commit
commits.last
end
def base_commit
return unless base_commit_sha
project.commit_by(oid: base_commit_sha)
end
def start_commit
return unless start_commit_sha
project.commit_by(oid: start_commit_sha)
end
def head_commit
return unless head_commit_sha
project.commit_by(oid: head_commit_sha)
end
def commit_shas
merge_request_diff_commits.map(&:sha)
end
def commits_by_shas(shas)
return MergeRequestDiffCommit.none unless shas.present?
merge_request_diff_commits.where(sha: shas)
end
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
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
# 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.`
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
def diff_refs_by_sha?
base_commit_sha? && head_commit_sha? && start_commit_sha?
end
def diffs(diff_options = nil)
if without_files? && comparison = diff_refs&.compare_in(project)
# 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-ce/issues/37639
comparison.diffs(diff_options)
else
diffs_collection(diff_options)
end
end
# 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!
def diffs_collection(diff_options = nil)
Gitlab::Diff::FileCollection::MergeRequestDiff.new(self, diff_options: diff_options)
end
def project
merge_request.target_project
end
def compare
@compare ||=
Gitlab::Git::Compare.new(
repository.raw_repository,
safe_start_commit_sha,
head_commit_sha
)
end
def latest?
self.id == merge_request.latest_merge_request_diff_id
end
# rubocop: disable CodeReuse/ServiceClass
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
# rubocop: enable CodeReuse/ServiceClass
def modified_paths
strong_memoize(:modified_paths) do
merge_request_diff_files.pluck(:new_path, :old_path).flatten.uniq
end
end
# Carrierwave defines `write_uploader` dynamically on this class, so `super`
# does not work. Alias the carrierwave method so we can call it when needed
alias_method :carrierwave_write_uploader, :write_uploader
# The `external_diff`, `external_diff_store`, and `stored_externally`
# columns were introduced in GitLab 11.8, but some background migration specs
# use factories that rely on current code with an old schema. Without these
# `has_attribute?` guards, they fail with a `MissingAttributeError`.
#
# For more details, see: https://gitlab.com/gitlab-org/gitlab-ce/issues/44990
def write_uploader(column, identifier)
carrierwave_write_uploader(column, identifier) if has_attribute?(column)
end
def update_external_diff_store
update_column(:external_diff_store, external_diff.object_store) if
has_attribute?(:external_diff_store)
end
def saved_change_to_external_diff?
super if has_attribute?(:external_diff)
end
def stored_externally
super if has_attribute?(:stored_externally)
end
alias_method :stored_externally?, :stored_externally
# 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
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
# 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.
def migrate_files_to_external_storage!
return if stored_externally? || !use_external_diff? || merge_request_diff_files.count == 0
rows = build_merge_request_diff_files(merge_request_diff_files)
transaction do
MergeRequestDiffFile.where(merge_request_diff_id: id).delete_all
create_merge_request_diff_files(rows)
save!
end
merge_request_diff_files.reset
end
private
def encode_in_base64?(diff_text)
(diff_text.encoding == Encoding::BINARY && !diff_text.ascii_only?) ||
diff_text.include?("\0")
end
def build_external_merge_request_diff_files(rows)
tempfile = build_external_diff_tempfile(rows)
self.external_diff = tempfile
self.stored_externally = true
rows
ensure
tempfile&.unlink
end
def create_merge_request_diff_files(rows)
rows = build_external_merge_request_diff_files(rows) if use_external_diff?
# Faster inserts
Gitlab::Database.bulk_insert('merge_request_diff_files', rows)
end
def build_external_diff_tempfile(rows)
Tempfile.open(external_diff.filename) do |file|
rows.each do |row|
data = row.delete(:diff)
row[:external_diff_offset] = file.pos
row[:external_diff_size] = data.bytesize
file.write(data)
end
file
end
end
def build_merge_request_diff_files(diffs)
diffs.map.with_index do |diff, index|
diff_hash = diff.to_hash.merge(
binary: false,
merge_request_diff_id: self.id,
relative_order: index
)
# Compatibility with old diffs created with Psych.
diff_hash.tap do |hash|
diff_text = hash[:diff]
if encode_in_base64?(diff_text)
hash[:binary] = true
hash[:diff] = [diff_text].pack('m0')
end
end
end
end
def use_external_diff?
return false unless has_attribute?(:external_diff)
return false unless Gitlab.config.external_diffs.enabled
case Gitlab.config.external_diffs.when
when 'always'
true
when 'outdated'
outdated_by_merge? || outdated_by_closure? || old_version?
else
false # Disable external diffs if misconfigured
end
end
def outdated_by_merge?
return false unless merge_request&.metrics&.merged_at
merge_request.merged? && merge_request.metrics.merged_at < EXTERNAL_DIFF_CUTOFF.ago
end
def outdated_by_closure?
return false unless merge_request&.metrics&.latest_closed_at
merge_request.closed? && merge_request.metrics.latest_closed_at < EXTERNAL_DIFF_CUTOFF.ago
end
# We can't rely on `merge_request.latest_merge_request_diff_id` because that
# may have been changed in `save_git_content` without being reflected in
# the association's instance. This query is always subject to races, but
# the worst case is that we *don't* make a diff external when we could. The
# background worker will make it external at a later date.
def old_version?
latest_id = MergeRequest
.where(id: merge_request_id)
.limit(1)
.pluck(:latest_merge_request_diff_id)
.first
self.id != latest_id
end
def load_diffs(options)
# Ensure all diff files operate on the same external diff file instance if
# present. This reduces file open/close overhead.
opening_external_diff do
collection = merge_request_diff_files
if paths = options[:paths]
collection = collection.where('old_path IN (?) OR new_path IN (?)', paths, paths)
end
Gitlab::Git::DiffCollection.new(collection.map(&:to_hash), options)
end
end
def load_commits
commits = merge_request_diff_commits.map { |commit| Commit.from_hash(commit.to_hash, project) }
CommitCollection
.new(merge_request.source_project, commits, merge_request.source_branch)
end
def save_diffs
new_attributes = {}
if compare.commits.size.zero?
new_attributes[:state] = :empty
else
diff_collection = compare.diffs(Commit.max_diff_options)
new_attributes[:real_size] = diff_collection.real_size
if diff_collection.any?
new_attributes[:state] = :collected
rows = build_merge_request_diff_files(diff_collection)
create_merge_request_diff_files(rows)
end
# Set our state to 'overflow' to make the #empty? and #collected?
# methods (generated by StateMachine) return false.
#
# This attribution has to come at the end of the method so 'overflow'
# state does not get overridden by 'collected'.
new_attributes[:state] = :overflow if diff_collection.overflow?
end
assign_attributes(new_attributes)
end
def save_commits
MergeRequestDiffCommit.create_bulk(self.id, compare.commits.reverse)
# merge_request_diff_commits.reset is preferred way to reload associated
# objects but it returns cached result for some reason in this case
# we can circumvent that by specifying that we need an uncached reload
commits = self.class.uncached { merge_request_diff_commits.reset }
self.commits_count = commits.size
end
def repository
project.repository
end
def find_base_sha
return unless head_commit_sha && start_commit_sha
project.merge_base_commit(head_commit_sha, start_commit_sha).try(:sha)
end
def keep_around_commits
[repository, merge_request.source_project.repository].uniq.each do |repo|
repo.keep_around(start_commit_sha, head_commit_sha, base_commit_sha)
end
end
end