Merge branch 'smarter-cache-invalidation' into 'master'

Smarter cache invalidation

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/23550

See merge request !7360

app/models/project.rb

@@ -1086,7 +1086,7 @@ class Project < ActiveRecord::Base
                                         "refs/heads/#{branch}",
                                         force: true)
     repository.copy_gitattributes(branch)
-    repository.expire_avatar_cache(branch)
+    repository.expire_avatar_cache
     reload_default_branch
   end
 

app/models/repository.rb

 require 'securerandom'
 
 class Repository
+  include Gitlab::ShellAdapter
+
+  attr_accessor :path_with_namespace, :project
+
   class CommitError < StandardError; end
 
-  # Files to use as a project avatar in case no avatar was uploaded via the web
-  # UI.
-  AVATAR_FILES = %w{logo.png logo.jpg logo.gif}
+  # Methods that cache data from the Git repository.
+  #
+  # Each entry in this Array should have a corresponding method with the exact
+  # same name. The cache key used by those methods must also match method's
+  # name.
+  #
+  # For example, for entry `:readme` there's a method called `readme` which
+  # stores its data in the `readme` cache key.
+  CACHED_METHODS = %i(size commit_count readme version contribution_guide
+                      changelog license_blob license_key gitignore koding_yml
+                      gitlab_ci_yml branch_names tag_names branch_count
+                      tag_count avatar exists? empty? root_ref)
+
+  # Certain method caches should be refreshed when certain types of files are
+  # changed. This Hash maps file types (as returned by Gitlab::FileDetector) to
+  # the corresponding methods to call for refreshing caches.
+  METHOD_CACHES_FOR_FILE_TYPES = {
+    readme: :readme,
+    changelog: :changelog,
+    license: %i(license_blob license_key),
+    contributing: :contribution_guide,
+    version: :version,
+    gitignore: :gitignore,
+    koding: :koding_yml,
+    gitlab_ci: :gitlab_ci_yml,
+    avatar: :avatar
+  }
+
+  # Wraps around the given method and caches its output in Redis and an instance
+  # variable.
+  #
+  # This only works for methods that do not take any arguments.
+  def self.cache_method(name, fallback: nil)
+    original = :"_uncached_#{name}"
 
-  include Gitlab::ShellAdapter
+    alias_method(original, name)
 
-  attr_accessor :path_with_namespace, :project
+    define_method(name) do
+      cache_method_output(name, fallback: fallback) { __send__(original) }
+    end
+  end
 
   def self.storages
     Gitlab.config.repositories.storages
@@ -37,24 +75,6 @@ class Repository
     )
   end
 
-  def exists?
-    return @exists unless @exists.nil?
-
-    @exists = cache.fetch(:exists?) do
-      begin
-        raw_repository && raw_repository.rugged ? true : false
-      rescue Gitlab::Git::Repository::NoRepository
-        false
-      end
-    end
-  end
-
-  def empty?
-    return @empty unless @empty.nil?
-
-    @empty = cache.fetch(:empty?) { raw_repository.empty? }
-  end
-
   #
   # Git repository can contains some hidden refs like:
   #   /refs/notes/*
@@ -221,10 +241,6 @@ class Repository
     branch_names + tag_names
   end
 
-  def branch_names
-    @branch_names ||= cache.fetch(:branch_names) { branches.map(&:name) }
-  end
-
   def branch_exists?(branch_name)
     branch_names.include?(branch_name)
   end
@@ -274,34 +290,6 @@ class Repository
     ref_exists?(keep_around_ref_name(sha))
   end
 
-  def tag_names
-    cache.fetch(:tag_names) { raw_repository.tag_names }
-  end
-
-  def commit_count
-    cache.fetch(:commit_count) do
-      begin
-        raw_repository.commit_count(self.root_ref)
-      rescue
-        0
-      end
-    end
-  end
-
-  def branch_count
-    @branch_count ||= cache.fetch(:branch_count) { branches.size }
-  end
-
-  def tag_count
-    @tag_count ||= cache.fetch(:tag_count) { raw_repository.rugged.tags.count }
-  end
-
-  # Return repo size in megabytes
-  # Cached in redis
-  def size
-    cache.fetch(:size) { raw_repository.size }
-  end
-
   def diverging_commit_counts(branch)
     root_ref_hash = raw_repository.rev_parse_target(root_ref).oid
     cache.fetch(:"diverging_commit_counts_#{branch.name}") do
@@ -317,48 +305,55 @@ class Repository
     end
   end
 
-  # Keys for data that can be affected for any commit push.
-  def cache_keys
-    %i(size commit_count
-       readme version contribution_guide changelog
-       license_blob license_key gitignore koding_yml)
+  def expire_tags_cache
+    expire_method_caches(%i(tag_names tag_count))
+    @tags = nil
   end
 
-  # Keys for data on branch/tag operations.
-  def cache_keys_for_branches_and_tags
-    %i(branch_names tag_names branch_count tag_count)
+  def expire_branches_cache
+    expire_method_caches(%i(branch_names branch_count))
+    @local_branches = nil
   end
 
-  def build_cache
-    (cache_keys + cache_keys_for_branches_and_tags).each do |key|
-      unless cache.exist?(key)
-        send(key)
-      end
-    end
+  def expire_statistics_caches
+    expire_method_caches(%i(size commit_count))
   end
 
-  def expire_tags_cache
-    cache.expire(:tag_names)
-    @tags = nil
+  def expire_all_method_caches
+    expire_method_caches(CACHED_METHODS)
   end
 
-  def expire_branches_cache
-    cache.expire(:branch_names)
-    @branch_names = nil
-    @local_branches = nil
+  # Expires the caches of a specific set of methods
+  def expire_method_caches(methods)
+    methods.each do |key|
+      cache.expire(key)
+
+      ivar = cache_instance_variable_name(key)
+
+      remove_instance_variable(ivar) if instance_variable_defined?(ivar)
+    end
   end
 
-  def expire_cache(branch_name = nil, revision = nil)
-    cache_keys.each do |key|
-      cache.expire(key)
+  def expire_avatar_cache
+    expire_method_caches(%i(avatar))
+  end
+
+  # Refreshes the method caches of this repository.
+  #
+  # types - An Array of file types (e.g. `:readme`) used to refresh extra
+  #         caches.
+  def refresh_method_caches(types)
+    to_refresh = []
+
+    types.each do |type|
+      methods = METHOD_CACHES_FOR_FILE_TYPES[type.to_sym]
+
+      to_refresh.concat(Array(methods)) if methods
     end
 
-    expire_branch_cache(branch_name)
-    expire_avatar_cache(branch_name, revision)
+    expire_method_caches(to_refresh)
 
-    # This ensures this particular cache is flushed after the first commit to a
-    # new repository.
-    expire_emptiness_caches if empty?
+    to_refresh.each { |method| send(method) }
   end
 
   def expire_branch_cache(branch_name = nil)
@@ -377,15 +372,14 @@ class Repository
   end
 
   def expire_root_ref_cache
-    cache.expire(:root_ref)
-    @root_ref = nil
+    expire_method_caches(%i(root_ref))
   end
 
   # Expires the cache(s) used to determine if a repository is empty or not.
   def expire_emptiness_caches
-    cache.expire(:empty?)
-    @empty = nil
+    return unless empty?
 
+    expire_method_caches(%i(empty?))
     expire_has_visible_content_cache
   end
 
@@ -394,51 +388,22 @@ class Repository
     @has_visible_content = nil
   end
 
-  def expire_branch_count_cache
-    cache.expire(:branch_count)
-    @branch_count = nil
-  end
-
-  def expire_tag_count_cache
-    cache.expire(:tag_count)
-    @tag_count = nil
-  end
-
   def lookup_cache
     @lookup_cache ||= {}
   end
 
-  def expire_avatar_cache(branch_name = nil, revision = nil)
-    # Avatars are pulled from the default branch, thus if somebody pushes to a
-    # different branch there's no need to expire anything.
-    return if branch_name && branch_name != root_ref
-
-    # We don't want to flush the cache if the commit didn't actually make any
-    # changes to any of the possible avatar files.
-    if revision && commit = self.commit(revision)
-      return unless commit.raw_diffs(deltas_only: true).
-        any? { |diff| AVATAR_FILES.include?(diff.new_path) }
-    end
-
-    cache.expire(:avatar)
-
-    @avatar = nil
-  end
-
   def expire_exists_cache
-    cache.expire(:exists?)
-    @exists = nil
+    expire_method_caches(%i(exists?))
   end
 
   # expire cache that doesn't depend on repository data (when expiring)
   def expire_content_cache
     expire_tags_cache
-    expire_tag_count_cache
     expire_branches_cache
-    expire_branch_count_cache
     expire_root_ref_cache
     expire_emptiness_caches
     expire_exists_cache
+    expire_statistics_caches
   end
 
   # Runs code after a repository has been created.
@@ -453,9 +418,8 @@ class Repository
   # Runs code just before a repository is deleted.
   def before_delete
     expire_exists_cache
-
-    expire_cache if exists?
-
+    expire_all_method_caches
+    expire_branch_cache if exists?
     expire_content_cache
 
     repository_event(:remove_repository)
@@ -472,9 +436,9 @@ class Repository
 
   # Runs code before pushing (= creating or removing) a tag.
   def before_push_tag
-    expire_cache
+    expire_statistics_caches
+    expire_emptiness_caches
     expire_tags_cache
-    expire_tag_count_cache
 
     repository_event(:push_tag)
   end
@@ -482,7 +446,7 @@ class Repository
   # Runs code before removing a tag.
   def before_remove_tag
     expire_tags_cache
-    expire_tag_count_cache
+    expire_statistics_caches
 
     repository_event(:remove_tag)
   end
@@ -494,12 +458,14 @@ class Repository
   # Runs code after a repository has been forked/imported.
   def after_import
     expire_content_cache
-    build_cache
+    expire_tags_cache
+    expire_branches_cache
   end
 
   # Runs code after a new commit has been pushed.
-  def after_push_commit(branch_name, revision)
-    expire_cache(branch_name, revision)
+  def after_push_commit(branch_name)
+    expire_statistics_caches
+    expire_branch_cache(branch_name)
 
     repository_event(:push_commit, branch: branch_name)
   end
@@ -508,7 +474,6 @@ class Repository
   def after_create_branch
     expire_branches_cache
     expire_has_visible_content_cache
-    expire_branch_count_cache
 
     repository_event(:push_branch)
   end
@@ -523,7 +488,6 @@ class Repository
   # Runs code after an existing branch has been removed.
   def after_remove_branch
     expire_has_visible_content_cache
-    expire_branch_count_cache
     expire_branches_cache
   end
 
@@ -550,86 +514,127 @@ class Repository
     Gitlab::Git::Blob.raw(self, oid)
   end
 
+  def root_ref
+    if raw_repository
+      raw_repository.root_ref
+    else
+      # When the repo does not exist we raise this error so no data is cached.
+      raise Rugged::ReferenceError
+    end
+  end
+  cache_method :root_ref
+
+  def exists?
+    refs_directory_exists?
+  end
+  cache_method :exists?
+
+  def empty?
+    raw_repository.empty?
+  end
+  cache_method :empty?
+
+  # The size of this repository in megabytes.
+  def size
+    exists? ? raw_repository.size : 0.0
+  end
+  cache_method :size, fallback: 0.0
+
+  def commit_count
+    root_ref ? raw_repository.commit_count(root_ref) : 0
+  end
+  cache_method :commit_count, fallback: 0
+
+  def branch_names
+    branches.map(&:name)
+  end
+  cache_method :branch_names, fallback: []
+
+  def tag_names
+    raw_repository.tag_names
+  end
+  cache_method :tag_names, fallback: []
+
+  def branch_count
+    branches.size
+  end
+  cache_method :branch_count, fallback: 0
+
+  def tag_count
+    raw_repository.rugged.tags.count
+  end
+  cache_method :tag_count, fallback: 0
+
+  def avatar
+    if tree = file_on_head(:avatar)
+      tree.path
+    end
+  end
+  cache_method :avatar
+
   def readme
-    cache.fetch(:readme) { tree(:head).readme }
+    if head = tree(:head)
+      head.readme
+    end
   end
+  cache_method :readme
 
   def version
-    cache.fetch(:version) do
-      tree(:head).blobs.find do |file|
-        file.name.casecmp('version').zero?
-      end
-    end
+    file_on_head(:version)
   end
+  cache_method :version
 
   def contribution_guide
-    cache.fetch(:contribution_guide) do
-      tree(:head).blobs.find do |file|
-        file.contributing?
-      end
-    end
+    file_on_head(:contributing)
   end
+  cache_method :contribution_guide
 
   def changelog
-    cache.fetch(:changelog) do
-      file_on_head(/\A(changelog|history|changes|news)/i)
-    end
+    file_on_head(:changelog)
   end
+  cache_method :changelog
 
   def license_blob
-    return nil unless head_exists?
-
-    cache.fetch(:license_blob) do
-      file_on_head(/\A(licen[sc]e|copying)(\..+|\z)/i)
-    end
+    file_on_head(:license)
   end
+  cache_method :license_blob
 
   def license_key
-    return nil unless head_exists?
+    return unless exists?
 
-    cache.fetch(:license_key) do
-      Licensee.license(path).try(:key)
-    end
+    Licensee.license(path).try(:key)
   end
+  cache_method :license_key
 
   def gitignore
-    return nil if !exists? || empty?
-
-    cache.fetch(:gitignore) do
-      file_on_head(/\A\.gitignore\z/)
-    end
+    file_on_head(:gitignore)
   end
+  cache_method :gitignore
 
   def koding_yml
-    return nil unless head_exists?
-
-    cache.fetch(:koding_yml) do
-      file_on_head(/\A\.koding\.yml\z/)
-    end
+    file_on_head(:koding)
   end
+  cache_method :koding_yml
 
   def gitlab_ci_yml
-    return nil unless head_exists?
-
-    @gitlab_ci_yml ||= tree(:head).blobs.find do |file|
-      file.name == '.gitlab-ci.yml'
-    end
-  rescue Rugged::ReferenceError
-    # For unknow reason spinach scenario "Scenario: I change project path"
-    # lead to "Reference 'HEAD' not found" exception from Repository#empty?
-    nil
+    file_on_head(:gitlab_ci)
   end
+  cache_method :gitlab_ci_yml
 
   def head_commit
     @head_commit ||= commit(self.root_ref)
   end
 
   def head_tree
-    @head_tree ||= Tree.new(self, head_commit.sha, nil)
+    if head_commit
+      @head_tree ||= Tree.new(self, head_commit.sha, nil)
+    end
   end
 
   def tree(sha = :head, path = nil, recursive: false)
     if sha == :head
+      return unless head_commit
+
       if path.nil?
         return head_tree
       else
@@ -779,10 +784,6 @@ class Repository
     @tags ||= raw_repository.tags
   end
 
-  def root_ref
-    @root_ref ||= cache.fetch(:root_ref) { raw_repository.root_ref }
-  end
-
   def commit_dir(user, path, message, branch, author_email: nil, author_name: nil)
     update_branch_with_hooks(user, branch) do |ref|
       options = {
@@ -1140,28 +1141,55 @@ class Repository
     end
   end
 
-  def avatar
-    return nil unless exists?
+  # Caches the supplied block both in a cache and in an instance variable.
+  #
+  # The cache key and instance variable are named the same way as the value of
+  # the `key` argument.
+  #
+  # This method will return `nil` if the corresponding instance variable is also
+  # set to `nil`. This ensures we don't keep yielding the block when it returns
+  # `nil`.
+  #
+  # key - The name of the key to cache the data in.
+  # fallback - A value to fall back to in the event of a Git error.
+  def cache_method_output(key, fallback: nil, &block)
+    ivar = cache_instance_variable_name(key)
 
-    @avatar ||= cache.fetch(:avatar) do
-      AVATAR_FILES.find do |file|
-        blob_at_branch(root_ref, file)
+    if instance_variable_defined?(ivar)
+      instance_variable_get(ivar)
+    else
+      begin
+        instance_variable_set(ivar, cache.fetch(key, &block))
+      rescue Rugged::ReferenceError, Gitlab::Git::Repository::NoRepository
+        # if e.g. HEAD or the entire repository doesn't exist we want to
+        # gracefully handle this and not cache anything.
+        fallback
       end
     end
   end
 
-  private
+  def cache_instance_variable_name(key)
+    :"@#{key.to_s.tr('?!', '')}"
+  end
 
-  def cache
-    @cache ||= RepositoryCache.new(path_with_namespace, @project.id)
+  def file_on_head(type)
+    if head = tree(:head)
+      head.blobs.find do |file|
+        Gitlab::FileDetector.type_of(file.name) == type
+      end
+    end
   end
 
-  def head_exists?
-    exists? && !empty? && !rugged.head_unborn?
+  private
+
+  def refs_directory_exists?
+    return false unless path_with_namespace
+
+    File.exist?(File.join(path_to_repo, 'refs'))
   end
 
-  def file_on_head(regex)
-    tree(:head).blobs.find { |file| file.name =~ regex }
+  def cache
+    @cache ||= RepositoryCache.new(path_with_namespace, @project.id)
   end
 
   def tags_sorted_by_committed_date

app/models/tree.rb

@@ -18,7 +18,9 @@ class Tree
   def readme
     return @readme if defined?(@readme)
 
-    available_readmes = blobs.select(&:readme?)
+    available_readmes = blobs.select do |blob|
+      Gitlab::FileDetector.type_of(blob.name) == :readme
+    end
 
     previewable_readmes = available_readmes.select do |blob|
       previewable?(blob.name)

app/services/git_push_service.rb

@@ -18,7 +18,7 @@ class GitPushService < BaseService
   #
   def execute
     @project.repository.after_create if @project.empty_repo?
-    @project.repository.after_push_commit(branch_name, params[:newrev])
+    @project.repository.after_push_commit(branch_name)
 
     if push_remove_branch?
       @project.repository.after_remove_branch
@@ -51,12 +51,32 @@ class GitPushService < BaseService
 
     execute_related_hooks
     perform_housekeeping
+
+    update_caches
   end
 
   def update_gitattributes
     @project.repository.copy_gitattributes(params[:ref])
   end
 
+  def update_caches
+    if is_default_branch?
+      paths = Set.new
+
+      @push_commits.each do |commit|
+        commit.raw_diffs(deltas_only: true).each do |diff|
+          paths << diff.new_path
+        end
+      end
+
+      types = Gitlab::FileDetector.types_in_paths(paths.to_a)
+    else
+      types = []
+    end
+
+    ProjectCacheWorker.perform_async(@project.id, types)
+  end
+
   protected
 
   def execute_related_hooks
@@ -70,7 +90,6 @@ class GitPushService < BaseService
     @project.execute_hooks(build_push_data.dup, :push_hooks)
     @project.execute_services(build_push_data.dup, :push_hooks)
     Ci::CreatePipelineService.new(@project, current_user, build_push_data).execute
-    ProjectCacheWorker.perform_async(@project.id)
 
     if push_remove_branch?
       AfterBranchDeleteService

app/workers/project_cache_worker.rb

 # Worker for updating any project specific caches.
-#
-# This worker runs at most once every 15 minutes per project. This is to ensure
-# that multiple instances of jobs for this worker don't hammer the underlying
-# storage engine as much.
 class ProjectCacheWorker
   include Sidekiq::Worker
   include DedicatedSidekiqQueue
 
   LEASE_TIMEOUT = 15.minutes.to_i
 
-  def self.lease_for(project_id)
-    Gitlab::ExclusiveLease.
-      new("project_cache_worker:#{project_id}", timeout: LEASE_TIMEOUT)
-  end
+  # project_id - The ID of the project for which to flush the cache.
+  # refresh - An Array containing extra types of data to refresh such as
+  #           `:readme` to flush the README and `:changelog` to flush the
+  #           CHANGELOG.
+  def perform(project_id, refresh = [])
+    project = Project.find_by(id: project_id)
 
-  # Overwrite Sidekiq's implementation so we only schedule when actually needed.
-  def self.perform_async(project_id)
-    # If a lease for this project is still being held there's no point in
-    # scheduling a new job.
-    super unless lease_for(project_id).exists?
-  end
+    return unless project && project.repository.exists?
 
-  def perform(project_id)
-    if try_obtain_lease_for(project_id)
-      Rails.logger.
-        info("Obtained ProjectCacheWorker lease for project #{project_id}")
-    else
-      Rails.logger.
-        info("Could not obtain ProjectCacheWorker lease for project #{project_id}")
-
-      return
-    end
+    update_repository_size(project)
+    project.update_commit_count
 
-    update_caches(project_id)
+    project.repository.refresh_method_caches(refresh.map(&:to_sym))
   end
 
-  def update_caches(project_id)
-    project = Project.find(project_id)
+  def update_repository_size(project)
+    return unless try_obtain_lease_for(project.id, :update_repository_size)
 
-    return unless project.repository.exists?
+    Rails.logger.info("Updating repository size for project #{project.id}")
 
     project.update_repository_size
-    project.update_commit_count
-
-    if project.repository.root_ref
-      project.repository.build_cache
-    end
   end
 
-  def try_obtain_lease_for(project_id)
-    self.class.lease_for(project_id).try_obtain
+  private
+
+  def try_obtain_lease_for(project_id, section)
+    Gitlab::ExclusiveLease.
+      new("project_cache_worker:#{project_id}:#{section}", timeout: LEASE_TIMEOUT).
+      try_obtain
   end
 end

changelogs/unreleased/smarter-cache-invalidation.yml

+---
+title: Rework cache invalidation so only changed data is refreshed
+merge_request: 7360
+author: 

lib/gitlab/file_detector.rb

+require 'set'
+
+module Gitlab
+  # Module that can be used to detect if a path points to a special file such as
+  # a README or a CONTRIBUTING file.
+  module FileDetector
+    PATTERNS = {
+      readme: /\Areadme/i,
+      changelog: /\A(changelog|history|changes|news)/i,
+      license: /\A(licen[sc]e|copying)(\..+|\z)/i,
+      contributing: /\Acontributing/i,
+      version: 'version',
+      gitignore: '.gitignore',
+      koding: '.koding.yml',
+      gitlab_ci: '.gitlab-ci.yml',
+      avatar: /\Alogo\.(png|jpg|gif)\z/
+    }
+
+    # Returns an Array of file types based on the given paths.
+    #
+    # This method can be used to check if a list of file paths (e.g. of changed
+    # files) involve any special files such as a README or a LICENSE file.
+    #
+    # Example:
+    #
+    #     types_in_paths(%w{README.md foo/bar.txt}) # => [:readme]
+    def self.types_in_paths(paths)
+      types = Set.new
+
+      paths.each do |path|
+        type = type_of(path)
+
+        types << type if type
+      end
+
+      types.to_a
+    end
+
+    # Returns the type of a file path, or nil if none could be detected.
+    #
+    # Returned types are Symbols such as `:readme`, `:version`, etc.
+    #
+    # Example:
+    #
+    #     type_of('README.md') # => :readme
+    #     type_of('VERSION') # => :version
+    def self.type_of(path)
+      name = File.basename(path)
+
+      PATTERNS.each do |type, search|
+        did_match = if search.is_a?(Regexp)
+                      name =~ search
+                    else
+                      name.casecmp(search) == 0
+                    end
+
+        return type if did_match
+      end
+
+      nil
+    end
+  end
+end

spec/lib/gitlab/file_detector_spec.rb

+require 'spec_helper'
+
+describe Gitlab::FileDetector do
+  describe '.types_in_paths' do
+    it 'returns the file types for the given paths' do
+      expect(described_class.types_in_paths(%w(README.md CHANGELOG VERSION VERSION))).
+        to eq(%i{readme changelog version})
+    end
+
+    it 'does not include unrecognized file paths' do
+      expect(described_class.types_in_paths(%w(README.md foo.txt))).
+        to eq(%i{readme})
+    end
+  end
+
+  describe '.type_of' do
+    it 'returns the type of a README file' do
+      expect(described_class.type_of('README.md')).to eq(:readme)
+    end
+
+    it 'returns the type of a changelog file' do
+      %w(CHANGELOG HISTORY CHANGES NEWS).each do |file|
+        expect(described_class.type_of(file)).to eq(:changelog)
+      end
+    end
+
+    it 'returns the type of a license file' do
+      %w(LICENSE LICENCE COPYING).each do |file|
+        expect(described_class.type_of(file)).to eq(:license)
+      end
+    end
+
+    it 'returns the type of a version file' do
+      expect(described_class.type_of('VERSION')).to eq(:version)
+    end
+
+    it 'returns the type of a .gitignore file' do
+      expect(described_class.type_of('.gitignore')).to eq(:gitignore)
+    end
+
+    it 'returns the type of a Koding config file' do
+      expect(described_class.type_of('.koding.yml')).to eq(:koding)
+    end
+
+    it 'returns the type of a GitLab CI config file' do
+      expect(described_class.type_of('.gitlab-ci.yml')).to eq(:gitlab_ci)
+    end
+
+    it 'returns the type of an avatar' do
+      %w(logo.gif logo.png logo.jpg).each do |file|
+        expect(described_class.type_of(file)).to eq(:avatar)
+      end
+    end
+
+    it 'returns nil for an unknown file' do
+      expect(described_class.type_of('foo.txt')).to be_nil
+    end
+  end
+end

spec/models/project_spec.rb

@@ -1572,7 +1572,7 @@ describe Project, models: true do
     end
 
     it 'expires the avatar cache' do
-      expect(project.repository).to receive(:expire_avatar_cache).with(project.default_branch)
+      expect(project.repository).to receive(:expire_avatar_cache)
       project.change_head(project.default_branch)
     end
 

spec/models/repository_spec.rb

@@ -464,11 +464,7 @@ describe Repository, models: true do
     end
   end
 
-  describe "#changelog" do
-    before do
-      repository.send(:cache).expire(:changelog)
-    end
-
+  describe "#changelog", caching: true do
     it 'accepts changelog' do
       expect(repository.tree).to receive(:blobs).and_return([TestBlob.new('changelog')])
 
@@ -500,17 +496,16 @@ describe Repository, models: true do
     end
   end
 
-  describe "#license_blob" do
+  describe "#license_blob", caching: true do
     before do
-      repository.send(:cache).expire(:license_blob)
       repository.remove_file(user, 'LICENSE', 'Remove LICENSE', 'master')
     end
 
     it 'handles when HEAD points to non-existent ref' do
       repository.commit_file(user, 'LICENSE', 'Copyright!', 'Add LICENSE', 'master', false)
-      rugged = double('rugged')
-      expect(rugged).to receive(:head_unborn?).and_return(true)
-      expect(repository).to receive(:rugged).and_return(rugged)
+
+      allow(repository).to receive(:file_on_head).
+        and_raise(Rugged::ReferenceError)
 
       expect(repository.license_blob).to be_nil
     end
@@ -537,22 +532,18 @@ describe Repository, models: true do
     end
   end
 
-  describe '#license_key' do
+  describe '#license_key', caching: true do
     before do
-      repository.send(:cache).expire(:license_key)
       repository.remove_file(user, 'LICENSE', 'Remove LICENSE', 'master')
     end
 
-    it 'handles when HEAD points to non-existent ref' do
-      repository.commit_file(user, 'LICENSE', 'Copyright!', 'Add LICENSE', 'master', false)
-      rugged = double('rugged')
-      expect(rugged).to receive(:head_unborn?).and_return(true)
-      expect(repository).to receive(:rugged).and_return(rugged)
-
+    it 'returns nil when no license is detected' do
       expect(repository.license_key).to be_nil
     end
 
-    it 'returns nil when no license is detected' do
+    it 'returns nil when the repository does not exist' do
+      expect(repository).to receive(:exists?).and_return(false)
+
       expect(repository.license_key).to be_nil
     end
 
@@ -569,7 +560,7 @@ describe Repository, models: true do
     end
   end
 
-  describe "#gitlab_ci_yml" do
+  describe "#gitlab_ci_yml", caching: true do
     it 'returns valid file' do
       files = [TestBlob.new('file'), TestBlob.new('.gitlab-ci.yml'), TestBlob.new('copying')]
       expect(repository.tree).to receive(:blobs).and_return(files)
@@ -583,7 +574,7 @@ describe Repository, models: true do
     end
 
     it 'returns nil for empty repository' do
-      expect(repository).to receive(:empty?).and_return(true)
+      allow(repository).to receive(:file_on_head).and_raise(Rugged::ReferenceError)
       expect(repository.gitlab_ci_yml).to be_nil
     end
   end
@@ -778,7 +769,6 @@ describe Repository, models: true do
         expect(repository).not_to receive(:expire_emptiness_caches)
         expect(repository).to     receive(:expire_branches_cache)
         expect(repository).to     receive(:expire_has_visible_content_cache)
-        expect(repository).to     receive(:expire_branch_count_cache)
 
         repository.update_branch_with_hooks(user, 'new-feature') { new_rev }
       end
@@ -797,7 +787,6 @@ describe Repository, models: true do
         expect(empty_repository).to receive(:expire_emptiness_caches)
         expect(empty_repository).to receive(:expire_branches_cache)
         expect(empty_repository).to receive(:expire_has_visible_content_cache)
-        expect(empty_repository).to receive(:expire_branch_count_cache)
 
         empty_repository.commit_file(user, 'CHANGELOG', 'Changelog!',
                                      'Updates file content', 'master', false)
@@ -811,8 +800,7 @@ describe Repository, models: true do
     end
 
     it 'returns false when a repository does not exist' do
-      expect(repository.raw_repository).to receive(:rugged).
-        and_raise(Gitlab::Git::Repository::NoRepository)
+      allow(repository).to receive(:refs_directory_exists?).and_return(false)
 
       expect(repository.exists?).to eq(false)
     end
@@ -916,34 +904,6 @@ describe Repository, models: true do
     end
   end
 
-  describe '#expire_cache' do
-    it 'expires all caches' do
-      expect(repository).to receive(:expire_branch_cache)
-
-      repository.expire_cache
-    end
-
-    it 'expires the caches for a specific branch' do
-      expect(repository).to receive(:expire_branch_cache).with('master')
-
-      repository.expire_cache('master')
-    end
-
-    it 'expires the emptiness caches for an empty repository' do
-      expect(repository).to receive(:empty?).and_return(true)
-      expect(repository).to receive(:expire_emptiness_caches)
-
-      repository.expire_cache
-    end
-
-    it 'does not expire the emptiness caches for a non-empty repository' do
-      expect(repository).to receive(:empty?).and_return(false)
-      expect(repository).not_to receive(:expire_emptiness_caches)
-
-      repository.expire_cache
-    end
-  end
-
   describe '#expire_root_ref_cache' do
     it 'expires the root reference cache' do
       repository.root_ref
@@ -1003,12 +963,23 @@ describe Repository, models: true do
   describe '#expire_emptiness_caches' do
     let(:cache) { repository.send(:cache) }
 
-    it 'expires the caches' do
+    it 'expires the caches for an empty repository' do
+      allow(repository).to receive(:empty?).and_return(true)
+
       expect(cache).to receive(:expire).with(:empty?)
       expect(repository).to receive(:expire_has_visible_content_cache)
 
       repository.expire_emptiness_caches
     end
+
+    it 'does not expire the cache for a non-empty repository' do
+      allow(repository).to receive(:empty?).and_return(false)
+
+      expect(cache).not_to receive(:expire).with(:empty?)
+      expect(repository).not_to receive(:expire_has_visible_content_cache)
+
+      repository.expire_emptiness_caches
+    end
   end
 
   describe :skip_merged_commit do
@@ -1120,24 +1091,12 @@ describe Repository, models: true do
         repository.before_delete
       end
 
-      it 'flushes the tag count cache' do
-        expect(repository).to receive(:expire_tag_count_cache)
-
-        repository.before_delete
-      end
-
       it 'flushes the branches cache' do
         expect(repository).to receive(:expire_branches_cache)
 
         repository.before_delete
       end
 
-      it 'flushes the branch count cache' do
-        expect(repository).to receive(:expire_branch_count_cache)
-
-        repository.before_delete
-      end
-
       it 'flushes the root ref cache' do
         expect(repository).to receive(:expire_root_ref_cache)
 
@@ -1162,36 +1121,18 @@ describe Repository, models: true do
         allow(repository).to receive(:exists?).and_return(true)
       end
 
-      it 'flushes the caches that depend on repository data' do
-        expect(repository).to receive(:expire_cache)
-
-        repository.before_delete
-      end
-
       it 'flushes the tags cache' do
         expect(repository).to receive(:expire_tags_cache)
 
         repository.before_delete
       end
 
-      it 'flushes the tag count cache' do
-        expect(repository).to receive(:expire_tag_count_cache)
-
-        repository.before_delete
-      end
-
       it 'flushes the branches cache' do
         expect(repository).to receive(:expire_branches_cache)
 
         repository.before_delete
       end
 
-      it 'flushes the branch count cache' do
-        expect(repository).to receive(:expire_branch_count_cache)
-
-        repository.before_delete
-      end
-
       it 'flushes the root ref cache' do
         expect(repository).to receive(:expire_root_ref_cache)
 
@@ -1222,8 +1163,9 @@ describe Repository, models: true do
 
   describe '#before_push_tag' do
     it 'flushes the cache' do
-      expect(repository).to receive(:expire_cache)
-      expect(repository).to receive(:expire_tag_count_cache)
+      expect(repository).to receive(:expire_statistics_caches)
+      expect(repository).to receive(:expire_emptiness_caches)
+      expect(repository).to receive(:expire_tags_cache)
 
       repository.before_push_tag
     end
@@ -1240,17 +1182,23 @@ describe Repository, models: true do
   describe '#after_import' do
     it 'flushes and builds the cache' do
       expect(repository).to receive(:expire_content_cache)
-      expect(repository).to receive(:build_cache)
+      expect(repository).to receive(:expire_tags_cache)
+      expect(repository).to receive(:expire_branches_cache)
 
       repository.after_import
     end
   end
 
   describe '#after_push_commit' do
-    it 'flushes the cache' do
-      expect(repository).to receive(:expire_cache).with('master', '123')
+    it 'expires statistics caches' do
+      expect(repository).to receive(:expire_statistics_caches).
+        and_call_original
 
-      repository.after_push_commit('master', '123')
+      expect(repository).to receive(:expire_branch_cache).
+        with('master').
+        and_call_original
+
+      repository.after_push_commit('master')
     end
   end
 
@@ -1302,7 +1250,8 @@ describe Repository, models: true do
 
   describe '#before_remove_tag' do
     it 'flushes the tag cache' do
-      expect(repository).to receive(:expire_tag_count_cache)
+      expect(repository).to receive(:expire_tags_cache).and_call_original
+      expect(repository).to receive(:expire_statistics_caches).and_call_original
 
       repository.before_remove_tag
     end
@@ -1320,23 +1269,23 @@ describe Repository, models: true do
     end
   end
 
-  describe '#expire_branch_count_cache' do
-    let(:cache) { repository.send(:cache) }
-
+  describe '#expire_branches_cache' do
     it 'expires the cache' do
-      expect(cache).to receive(:expire).with(:branch_count)
+      expect(repository).to receive(:expire_method_caches).
+        with(%i(branch_names branch_count)).
+        and_call_original
 
-      repository.expire_branch_count_cache
+      repository.expire_branches_cache
     end
   end
 
-  describe '#expire_tag_count_cache' do
-    let(:cache) { repository.send(:cache) }
-
+  describe '#expire_tags_cache' do
     it 'expires the cache' do
-      expect(cache).to receive(:expire).with(:tag_count)
+      expect(repository).to receive(:expire_method_caches).
+        with(%i(tag_names tag_count)).
+        and_call_original
 
-      repository.expire_tag_count_cache
+      repository.expire_tags_cache
     end
   end
 
@@ -1412,170 +1361,316 @@ describe Repository, models: true do
 
   describe '#avatar' do
     it 'returns nil if repo does not exist' do
-      expect(repository).to receive(:exists?).and_return(false)
+      expect(repository).to receive(:file_on_head).
+        and_raise(Rugged::ReferenceError)
 
       expect(repository.avatar).to eq(nil)
     end
 
     it 'returns the first avatar file found in the repository' do
-      expect(repository).to receive(:blob_at_branch).
-        with('master', 'logo.png').
-        and_return(true)
+      expect(repository).to receive(:file_on_head).
+        with(:avatar).
+        and_return(double(:tree, path: 'logo.png'))
 
       expect(repository.avatar).to eq('logo.png')
     end
 
     it 'caches the output' do
-      allow(repository).to receive(:blob_at_branch).
-        with('master', 'logo.png').
-        and_return(true)
-
-      expect(repository.avatar).to eq('logo.png')
+      expect(repository).to receive(:file_on_head).
+        with(:avatar).
+        once.
+        and_return(double(:tree, path: 'logo.png'))
 
-      expect(repository).not_to receive(:blob_at_branch)
-      expect(repository.avatar).to eq('logo.png')
+      2.times { expect(repository.avatar).to eq('logo.png') }
     end
   end
 
-  describe '#expire_avatar_cache' do
+  describe '#expire_exists_cache' do
     let(:cache) { repository.send(:cache) }
 
-    before do
-      allow(repository).to receive(:cache).and_return(cache)
+    it 'expires the cache' do
+      expect(cache).to receive(:expire).with(:exists?)
+
+      repository.expire_exists_cache
     end
+  end
 
-    context 'without a branch or revision' do
-      it 'flushes the cache' do
-        expect(cache).to receive(:expire).with(:avatar)
+  describe "#keep_around" do
+    it "does not fail if we attempt to reference bad commit" do
+      expect(repository.kept_around?('abc1234')).to be_falsey
+    end
 
-        repository.expire_avatar_cache
-      end
+    it "stores a reference to the specified commit sha so it isn't garbage collected" do
+      repository.keep_around(sample_commit.id)
+
+      expect(repository.kept_around?(sample_commit.id)).to be_truthy
+    end
+
+    it "attempting to call keep_around on truncated ref does not fail" do
+      repository.keep_around(sample_commit.id)
+      ref = repository.send(:keep_around_ref_name, sample_commit.id)
+      path = File.join(repository.path, ref)
+      # Corrupt the reference
+      File.truncate(path, 0)
+
+      expect(repository.kept_around?(sample_commit.id)).to be_falsey
+
+      repository.keep_around(sample_commit.id)
+
+      expect(repository.kept_around?(sample_commit.id)).to be_falsey
+
+      File.delete(path)
+    end
+  end
+
+  describe '#update_ref!' do
+    it 'can create a ref' do
+      repository.update_ref!('refs/heads/foobar', 'refs/heads/master', Gitlab::Git::BLANK_SHA)
+
+      expect(repository.find_branch('foobar')).not_to be_nil
     end
 
-    context 'with a branch' do
-      it 'does not flush the cache if the branch is not the default branch' do
-        expect(cache).not_to receive(:expire)
+    it 'raises CommitError when the ref update fails' do
+      expect do
+        repository.update_ref!('refs/heads/master', 'refs/heads/master', Gitlab::Git::BLANK_SHA)
+      end.to raise_error(Repository::CommitError)
+    end
+  end
+
+  describe '#contribution_guide', caching: true do
+    it 'returns and caches the output' do
+      expect(repository).to receive(:file_on_head).
+        with(:contributing).
+        and_return(Gitlab::Git::Tree.new(path: 'CONTRIBUTING.md')).
+        once
 
-        repository.expire_avatar_cache('cats')
+      2.times do
+        expect(repository.contribution_guide).
+          to be_an_instance_of(Gitlab::Git::Tree)
       end
+    end
+  end
 
-      it 'flushes the cache if the branch equals the default branch' do
-        expect(cache).to receive(:expire).with(:avatar)
+  describe '#gitignore', caching: true do
+    it 'returns and caches the output' do
+      expect(repository).to receive(:file_on_head).
+        with(:gitignore).
+        and_return(Gitlab::Git::Tree.new(path: '.gitignore')).
+        once
 
-        repository.expire_avatar_cache(repository.root_ref)
+      2.times do
+        expect(repository.gitignore).to be_an_instance_of(Gitlab::Git::Tree)
       end
     end
+  end
 
-    context 'with a branch and revision' do
-      let(:commit) { double(:commit) }
+  describe '#koding_yml', caching: true do
+    it 'returns and caches the output' do
+      expect(repository).to receive(:file_on_head).
+        with(:koding).
+        and_return(Gitlab::Git::Tree.new(path: '.koding.yml')).
+        once
 
-      before do
-        allow(repository).to receive(:commit).and_return(commit)
+      2.times do
+        expect(repository.koding_yml).to be_an_instance_of(Gitlab::Git::Tree)
       end
+    end
+  end
 
-      it 'does not flush the cache if the commit does not change any logos' do
-        diff = double(:diff, new_path: 'test.txt')
+  describe '#readme', caching: true do
+    context 'with a non-existing repository' do
+      it 'returns nil' do
+        expect(repository).to receive(:tree).with(:head).and_return(nil)
 
-        expect(commit).to receive(:raw_diffs).and_return([diff])
-        expect(cache).not_to receive(:expire)
+        expect(repository.readme).to be_nil
+      end
+    end
 
-        repository.expire_avatar_cache(repository.root_ref, '123')
+    context 'with an existing repository' do
+      it 'returns the README' do
+        expect(repository.readme).to be_an_instance_of(Gitlab::Git::Blob)
       end
+    end
+  end
 
-      it 'flushes the cache if the commit changes any of the logos' do
-        diff = double(:diff, new_path: Repository::AVATAR_FILES[0])
+  describe '#expire_statistics_caches' do
+    it 'expires the caches' do
+      expect(repository).to receive(:expire_method_caches).
+        with(%i(size commit_count))
+
+      repository.expire_statistics_caches
+    end
+  end
 
-        expect(commit).to receive(:raw_diffs).and_return([diff])
-        expect(cache).to receive(:expire).with(:avatar)
+  describe '#expire_method_caches' do
+    it 'expires the caches of the given methods' do
+      expect_any_instance_of(RepositoryCache).to receive(:expire).with(:readme)
+      expect_any_instance_of(RepositoryCache).to receive(:expire).with(:gitignore)
 
-        repository.expire_avatar_cache(repository.root_ref, '123')
-      end
+      repository.expire_method_caches(%i(readme gitignore))
     end
   end
 
-  describe '#expire_exists_cache' do
-    let(:cache) { repository.send(:cache) }
+  describe '#expire_all_method_caches' do
+    it 'expires the caches of all methods' do
+      expect(repository).to receive(:expire_method_caches).
+        with(Repository::CACHED_METHODS)
+
+      repository.expire_all_method_caches
+    end
+  end
 
+  describe '#expire_avatar_cache' do
     it 'expires the cache' do
-      expect(cache).to receive(:expire).with(:exists?)
+      expect(repository).to receive(:expire_method_caches).with(%i(avatar))
 
-      repository.expire_exists_cache
+      repository.expire_avatar_cache
     end
   end
 
-  describe '#build_cache' do
-    let(:cache) { repository.send(:cache) }
+  describe '#file_on_head' do
+    context 'with a non-existing repository' do
+      it 'returns nil' do
+        expect(repository).to receive(:tree).with(:head).and_return(nil)
 
-    it 'builds the caches if they do not already exist' do
-      cache_keys = repository.cache_keys + repository.cache_keys_for_branches_and_tags
+        expect(repository.file_on_head(:readme)).to be_nil
+      end
+    end
 
-      expect(cache).to receive(:exist?).
-        exactly(cache_keys.length).
-        times.
-        and_return(false)
+    context 'with a repository that has no blobs' do
+      it 'returns nil' do
+        expect_any_instance_of(Tree).to receive(:blobs).and_return([])
+
+        expect(repository.file_on_head(:readme)).to be_nil
+      end
+    end
+
+    context 'with an existing repository' do
+      it 'returns a Gitlab::Git::Tree' do
+        expect(repository.file_on_head(:readme)).
+          to be_an_instance_of(Gitlab::Git::Tree)
+      end
+    end
+  end
+
+  describe '#head_tree' do
+    context 'with an existing repository' do
+      it 'returns a Tree' do
+        expect(repository.head_tree).to be_an_instance_of(Tree)
+      end
+    end
+
+    context 'with a non-existing repository' do
+      it 'returns nil' do
+        expect(repository).to receive(:head_commit).and_return(nil)
+
+        expect(repository.head_tree).to be_nil
+      end
+    end
+  end
 
-      cache_keys.each do |key|
-        expect(repository).to receive(key)
+  describe '#tree' do
+    context 'using a non-existing repository' do
+      before do
+        allow(repository).to receive(:head_commit).and_return(nil)
+      end
+
+      it 'returns nil' do
+        expect(repository.tree(:head)).to be_nil
       end
 
-      repository.build_cache
+      it 'returns nil when using a path' do
+        expect(repository.tree(:head, 'README.md')).to be_nil
+      end
     end
 
-    it 'does not build any caches that already exist' do
-      cache_keys = repository.cache_keys + repository.cache_keys_for_branches_and_tags
+    context 'using an existing repository' do
+      it 'returns a Tree' do
+        expect(repository.tree(:head)).to be_an_instance_of(Tree)
+      end
+    end
+  end
 
-      expect(cache).to receive(:exist?).
-        exactly(cache_keys.length).
-        times.
-        and_return(true)
+  describe '#size' do
+    context 'with a non-existing repository' do
+      it 'returns 0' do
+        expect(repository).to receive(:exists?).and_return(false)
 
-      cache_keys.each do |key|
-        expect(repository).not_to receive(key)
+        expect(repository.size).to eq(0.0)
       end
+    end
 
-      repository.build_cache
+    context 'with an existing repository' do
+      it 'returns the repository size as a Float' do
+        expect(repository.size).to be_an_instance_of(Float)
+      end
     end
   end
 
-  describe "#keep_around" do
-    it "does not fail if we attempt to reference bad commit" do
-      expect(repository.kept_around?('abc1234')).to be_falsey
+  describe '#commit_count' do
+    context 'with a non-existing repository' do
+      it 'returns 0' do
+        expect(repository).to receive(:root_ref).and_return(nil)
+
+        expect(repository.commit_count).to eq(0)
+      end
     end
 
-    it "stores a reference to the specified commit sha so it isn't garbage collected" do
-      repository.keep_around(sample_commit.id)
+    context 'with an existing repository' do
+      it 'returns the commit count' do
+        expect(repository.commit_count).to be_an_instance_of(Fixnum)
+      end
+    end
+  end
 
-      expect(repository.kept_around?(sample_commit.id)).to be_truthy
+  describe '#cache_method_output', caching: true do
+    context 'with a non-existing repository' do
+      let(:value) do
+        repository.cache_method_output(:cats, fallback: 10) do
+          raise Rugged::ReferenceError
+        end
+      end
+
+      it 'returns a fallback value' do
+        expect(value).to eq(10)
+      end
+
+      it 'does not cache the data' do
+        value
+
+        expect(repository.instance_variable_defined?(:@cats)).to eq(false)
+        expect(repository.send(:cache).exist?(:cats)).to eq(false)
+      end
     end
 
-    it "attempting to call keep_around on truncated ref does not fail" do
-      repository.keep_around(sample_commit.id)
-      ref = repository.send(:keep_around_ref_name, sample_commit.id)
-      path = File.join(repository.path, ref)
-      # Corrupt the reference
-      File.truncate(path, 0)
+    context 'with an existing repository' do
+      it 'caches the output' do
+        object = double
 
-      expect(repository.kept_around?(sample_commit.id)).to be_falsey
+        expect(object).to receive(:number).once.and_return(10)
 
-      repository.keep_around(sample_commit.id)
+        2.times do
+          val = repository.cache_method_output(:cats) { object.number }
 
-      expect(repository.kept_around?(sample_commit.id)).to be_falsey
+          expect(val).to eq(10)
+        end
 
-      File.delete(path)
+        expect(repository.send(:cache).exist?(:cats)).to eq(true)
+        expect(repository.instance_variable_get(:@cats)).to eq(10)
+      end
     end
   end
 
-  describe '#update_ref!' do
-    it 'can create a ref' do
-      repository.update_ref!('refs/heads/foobar', 'refs/heads/master', Gitlab::Git::BLANK_SHA)
+  describe '#refresh_method_caches' do
+    it 'refreshes the caches of the given types' do
+      expect(repository).to receive(:expire_method_caches).
+        with(%i(readme license_blob license_key))
 
-      expect(repository.find_branch('foobar')).not_to be_nil
-    end
+      expect(repository).to receive(:readme)
+      expect(repository).to receive(:license_blob)
+      expect(repository).to receive(:license_key)
 
-    it 'raises CommitError when the ref update fails' do
-      expect do
-        repository.update_ref!('refs/heads/master', 'refs/heads/master', Gitlab::Git::BLANK_SHA)
-      end.to raise_error(Repository::CommitError)
+      repository.refresh_method_caches(%i(readme license))
     end
   end
 end

spec/requests/api/branches_spec.rb

@@ -14,7 +14,7 @@ describe API::API, api: true  do
 
   describe "GET /projects/:id/repository/branches" do
     it "returns an array of project branches" do
-      project.repository.expire_cache
+      project.repository.expire_all_method_caches
 
       get api("/projects/#{project.id}/repository/branches", user)
       expect(response).to have_http_status(200)

spec/services/git_push_service_spec.rb

@@ -27,27 +27,14 @@ describe GitPushService, services: true do
 
       it { is_expected.to be_truthy }
 
-      it 'flushes general cached data' do
-        expect(project.repository).to receive(:expire_cache).
-          with('master', newrev)
+      it 'calls the after_push_commit hook' do
+        expect(project.repository).to receive(:after_push_commit).with('master')
 
         subject
       end
 
-      it 'flushes the visible content cache' do
-        expect(project.repository).to receive(:expire_has_visible_content_cache)
-
-        subject
-      end
-
-      it 'flushes the branches cache' do
-        expect(project.repository).to receive(:expire_branches_cache)
-
-        subject
-      end
-
-      it 'flushes the branch count cache' do
-        expect(project.repository).to receive(:expire_branch_count_cache)
+      it 'calls the after_create_branch hook' do
+        expect(project.repository).to receive(:after_create_branch)
 
         subject
       end
@@ -56,21 +43,8 @@ describe GitPushService, services: true do
     context 'existing branch' do
       it { is_expected.to be_truthy }
 
-      it 'flushes general cached data' do
-        expect(project.repository).to receive(:expire_cache).
-          with('master', newrev)
-
-        subject
-      end
-
-      it 'does not flush the branches cache' do
-        expect(project.repository).not_to receive(:expire_branches_cache)
-
-        subject
-      end
-
-      it 'does not flush the branch count cache' do
-        expect(project.repository).not_to receive(:expire_branch_count_cache)
+      it 'calls the after_push_commit hook' do
+        expect(project.repository).to receive(:after_push_commit).with('master')
 
         subject
       end
@@ -81,27 +55,14 @@ describe GitPushService, services: true do
 
       it { is_expected.to be_truthy }
 
-      it 'flushes the visible content cache' do
-        expect(project.repository).to receive(:expire_has_visible_content_cache)
-
-        subject
-      end
-
-      it 'flushes the branches cache' do
-        expect(project.repository).to receive(:expire_branches_cache)
-
-        subject
-      end
-
-      it 'flushes the branch count cache' do
-        expect(project.repository).to receive(:expire_branch_count_cache)
+      it 'calls the after_push_commit hook' do
+        expect(project.repository).to receive(:after_push_commit).with('master')
 
         subject
       end
 
-      it 'flushes general cached data' do
-        expect(project.repository).to receive(:expire_cache).
-          with('master', newrev)
+      it 'calls the after_remove_branch hook' do
+        expect(project.repository).to receive(:after_remove_branch)
 
         subject
       end
@@ -588,6 +549,51 @@ describe GitPushService, services: true do
     end
   end
 
+  describe '#update_caches' do
+    let(:service) do
+      described_class.new(project,
+                          user,
+                          oldrev: sample_commit.parent_id,
+                          newrev: sample_commit.id,
+                          ref: 'refs/heads/master')
+    end
+
+    context 'on the default branch' do
+      before do
+        allow(service).to receive(:is_default_branch?).and_return(true)
+      end
+
+      it 'flushes the caches of any special files that have been changed' do
+        commit = double(:commit)
+        diff = double(:diff, new_path: 'README.md')
+
+        expect(commit).to receive(:raw_diffs).with(deltas_only: true).
+          and_return([diff])
+
+        service.push_commits = [commit]
+
+        expect(ProjectCacheWorker).to receive(:perform_async).
+          with(project.id, %i(readme))
+
+        service.update_caches
+      end
+    end
+
+    context 'on a non-default branch' do
+      before do
+        allow(service).to receive(:is_default_branch?).and_return(false)
+      end
+
+      it 'does not flush any conditional caches' do
+        expect(ProjectCacheWorker).to receive(:perform_async).
+          with(project.id, []).
+          and_call_original
+
+        service.update_caches
+      end
+    end
+  end
+
   def execute_service(project, user, oldrev, newrev, ref)
     service = described_class.new(project, user, oldrev: oldrev, newrev: newrev, ref: ref )
     service.execute

spec/services/git_tag_push_service_spec.rb

@@ -18,7 +18,7 @@ describe GitTagPushService, services: true do
     end
 
     it 'flushes general cached data' do
-      expect(project.repository).to receive(:expire_cache)
+      expect(project.repository).to receive(:before_push_tag)
 
       subject
     end
@@ -28,12 +28,6 @@ describe GitTagPushService, services: true do
 
       subject
     end
-
-    it 'flushes the tag count cache' do
-      expect(project.repository).to receive(:expire_tag_count_cache)
-
-      subject
-    end
   end
 
   describe "Git Tag Push Data" do

spec/workers/project_cache_worker_spec.rb

@@ -2,62 +2,78 @@ require 'spec_helper'
 
 describe ProjectCacheWorker do
   let(:project) { create(:project) }
+  let(:worker) { described_class.new }
 
-  subject { described_class.new }
-
-  describe '.perform_async' do
-    it 'schedules the job when no lease exists' do
-      allow_any_instance_of(Gitlab::ExclusiveLease).to receive(:exists?).
-        and_return(false)
+  describe '#perform' do
+    before do
+      allow_any_instance_of(Gitlab::ExclusiveLease).to receive(:try_obtain).
+        and_return(true)
+    end
 
-      expect_any_instance_of(described_class).to receive(:perform)
+    context 'with a non-existing project' do
+      it 'does nothing' do
+        expect(worker).not_to receive(:update_repository_size)
 
-      described_class.perform_async(project.id)
+        worker.perform(-1)
+      end
     end
 
-    it 'does not schedule the job when a lease exists' do
-      allow_any_instance_of(Gitlab::ExclusiveLease).to receive(:exists?).
-        and_return(true)
+    context 'with an existing project without a repository' do
+      it 'does nothing' do
+        allow_any_instance_of(Repository).to receive(:exists?).and_return(false)
 
-      expect_any_instance_of(described_class).not_to receive(:perform)
+        expect(worker).not_to receive(:update_repository_size)
 
-      described_class.perform_async(project.id)
+        worker.perform(project.id)
+      end
     end
-  end
 
-  describe '#perform' do
-    context 'when an exclusive lease can be obtained' do
-      before do
-        allow(subject).to receive(:try_obtain_lease_for).with(project.id).
-          and_return(true)
-      end
+    context 'with an existing project' do
+      it 'updates the repository size' do
+        expect(worker).to receive(:update_repository_size).and_call_original
 
-      it 'updates project cache data' do
-        expect_any_instance_of(Repository).to receive(:size)
-        expect_any_instance_of(Repository).to receive(:commit_count)
+        worker.perform(project.id)
+      end
 
-        expect_any_instance_of(Project).to receive(:update_repository_size)
-        expect_any_instance_of(Project).to receive(:update_commit_count)
+      it 'updates the commit count' do
+        expect_any_instance_of(Project).to receive(:update_commit_count).
+          and_call_original
 
-        subject.perform(project.id)
+        worker.perform(project.id)
       end
 
-      it 'handles missing repository data' do
-        expect_any_instance_of(Repository).to receive(:exists?).and_return(false)
-        expect_any_instance_of(Repository).not_to receive(:size)
+      it 'refreshes the method caches' do
+        expect_any_instance_of(Repository).to receive(:refresh_method_caches).
+          with(%i(readme)).
+          and_call_original
 
-        subject.perform(project.id)
+        worker.perform(project.id, %i(readme))
       end
     end
+  end
 
-    context 'when an exclusive lease can not be obtained' do
-      it 'does nothing' do
-        allow(subject).to receive(:try_obtain_lease_for).with(project.id).
+  describe '#update_repository_size' do
+    context 'when a lease could not be obtained' do
+      it 'does not update the repository size' do
+        allow(worker).to receive(:try_obtain_lease_for).
+          with(project.id, :update_repository_size).
           and_return(false)
 
-        expect(subject).not_to receive(:update_caches)
+        expect(project).not_to receive(:update_repository_size)
+
+        worker.update_repository_size(project)
+      end
+    end
+
+    context 'when a lease could be obtained' do
+      it 'updates the repository size' do
+        allow(worker).to receive(:try_obtain_lease_for).
+          with(project.id, :update_repository_size).
+          and_return(true)
+
+        expect(project).to receive(:update_repository_size).and_call_original
 
-        subject.perform(project.id)
+        worker.update_repository_size(project)
       end
     end
   end