[rubygems/rubygems] Remove one fallback to full indexes on big gemfiles

If Gemfile has a lot of dependencies, we have an optimization that uses
the full index in that case, assuming it's going to be faster.

I think this is an old optimization that predates compact index API
times, I believe we no longer need it these days.

Also, since a few releases ago we check for circular dependencies when
resolving by looping through all versions of each name and removing
those that have circular dependencies that would trip up the resolver.

This loop becomes actually very slow when full indexes are used because
to find dependencies of a gemspec, we need to explicitly fetch the
marshaled gemspec (`gemspec.rz` endpoint) for it, so the optimization
has the opposite effect of making things very slow.

https://github.com/rubygems/rubygems/commit/2f46289bd3

lib/bundler/source/rubygems.rb

@@ -7,8 +7,6 @@ module Bundler
     class Rubygems < Source
       autoload :Remote, File.expand_path("rubygems/remote", __dir__)
 
-      # Use the API when installing less than X gems
-      API_REQUEST_LIMIT = 500
       # Ask for X gems per API request
       API_REQUEST_SIZE = 50
 
@@ -401,12 +399,11 @@ module Bundler
           # gather lists from non-api sites
           fetch_names(index_fetchers, nil, idx, false)
 
-          # because ensuring we have all the gems we need involves downloading
-          # the gemspecs of those gems, if the non-api sites contain more than
-          # about 500 gems, we treat all sites as non-api for speed.
-          allow_api = idx.size < API_REQUEST_LIMIT && dependency_names.size < API_REQUEST_LIMIT
-          Bundler.ui.debug "Need to query more than #{API_REQUEST_LIMIT} gems." \
-            " Downloading full index instead..." unless allow_api
+          # legacy multi-remote sources need special logic to figure out
+          # dependency names and that logic can be very costly if one remote
+          # uses the dependency API but others don't. So use full indexes
+          # consistently in that particular case.
+          allow_api = !multiple_remotes?
 
           fetch_names(api_fetchers, allow_api && dependency_names, idx, false)
         end

spec/bundler/install/gems/compact_index_spec.rb

@@ -406,7 +406,7 @@ The checksum of /versions does not match the checksum provided by the server! So
     expect(out).to include("Fetching source index from http://localgemserver.test/extra")
   end
 
-  it "does not fetch every spec if the index of gems is large when doing back deps" do
+  it "does not fetch every spec when doing back deps" do
     build_repo2 do
       build_gem "back_deps" do |s|
         s.add_dependency "foo"
@@ -416,9 +416,7 @@ The checksum of /versions does not match the checksum provided by the server! So
       FileUtils.rm_rf Dir[gem_repo2("gems/foo-*.gem")]
     end
 
-    api_request_limit = low_api_request_limit_for(gem_repo2)
-
-    install_gemfile <<-G, :artifice => "compact_index_extra_missing", :requires => [api_request_limit_hack_file], :env => { "BUNDLER_SPEC_API_REQUEST_LIMIT" => api_request_limit.to_s }.merge(env_for_missing_prerelease_default_gem_activation)
+    install_gemfile <<-G, :artifice => "compact_index_extra_missing", :env => env_for_missing_prerelease_default_gem_activation
       source "#{source_uri}"
       source "#{source_uri}/extra" do
         gem "back_deps"
@@ -428,7 +426,7 @@ The checksum of /versions does not match the checksum provided by the server! So
     expect(the_bundle).to include_gems "back_deps 1.0"
   end
 
-  it "does not fetch every spec if the index of gems is large when doing back deps & everything is the compact index" do
+  it "does not fetch every spec when doing back deps & everything is the compact index" do
     build_repo4 do
       build_gem "back_deps" do |s|
         s.add_dependency "foo"
@@ -438,9 +436,7 @@ The checksum of /versions does not match the checksum provided by the server! So
       FileUtils.rm_rf Dir[gem_repo4("gems/foo-*.gem")]
     end
 
-    api_request_limit = low_api_request_limit_for(gem_repo4)
-
-    install_gemfile <<-G, :artifice => "compact_index_extra_api_missing", :requires => [api_request_limit_hack_file], :env => { "BUNDLER_SPEC_API_REQUEST_LIMIT" => api_request_limit.to_s }.merge(env_for_missing_prerelease_default_gem_activation)
+    install_gemfile <<-G, :artifice => "compact_index_extra_api_missing", :env => env_for_missing_prerelease_default_gem_activation
       source "#{source_uri}"
       source "#{source_uri}/extra" do
         gem "back_deps"

spec/bundler/install/gems/dependency_api_spec.rb

@@ -359,7 +359,7 @@ RSpec.describe "gemcutter's dependency API" do
     expect(out).to include("Fetching source index from http://localgemserver.test/extra")
   end
 
-  it "does not fetch every spec if the index of gems is large when doing back deps", :bundler => "< 3" do
+  it "does not fetch every spec when doing back deps", :bundler => "< 3" do
     build_repo2 do
       build_gem "back_deps" do |s|
         s.add_dependency "foo"
@@ -369,9 +369,7 @@ RSpec.describe "gemcutter's dependency API" do
       FileUtils.rm_rf Dir[gem_repo2("gems/foo-*.gem")]
     end
 
-    api_request_limit = low_api_request_limit_for(gem_repo2)
-
-    install_gemfile <<-G, :artifice => "endpoint_extra_missing", :requires => [api_request_limit_hack_file], :env => { "BUNDLER_SPEC_API_REQUEST_LIMIT" => api_request_limit.to_s }.merge(env_for_missing_prerelease_default_gem_activation)
+    install_gemfile <<-G, :artifice => "endpoint_extra_missing", :env => env_for_missing_prerelease_default_gem_activation
       source "#{source_uri}"
       source "#{source_uri}/extra"
       gem "back_deps"
@@ -380,7 +378,7 @@ RSpec.describe "gemcutter's dependency API" do
     expect(the_bundle).to include_gems "back_deps 1.0"
   end
 
-  it "does not fetch every spec if the index of gems is large when doing back deps using blocks" do
+  it "does not fetch every spec when doing back deps using blocks" do
     build_repo2 do
       build_gem "back_deps" do |s|
         s.add_dependency "foo"
@@ -390,9 +388,7 @@ RSpec.describe "gemcutter's dependency API" do
       FileUtils.rm_rf Dir[gem_repo2("gems/foo-*.gem")]
     end
 
-    api_request_limit = low_api_request_limit_for(gem_repo2)
-
-    install_gemfile <<-G, :artifice => "endpoint_extra_missing", :requires => [api_request_limit_hack_file], :env => { "BUNDLER_SPEC_API_REQUEST_LIMIT" => api_request_limit.to_s }.merge(env_for_missing_prerelease_default_gem_activation)
+    install_gemfile <<-G, :artifice => "endpoint_extra_missing", :env => env_for_missing_prerelease_default_gem_activation
       source "#{source_uri}"
       source "#{source_uri}/extra" do
         gem "back_deps"

spec/bundler/support/builders.rb

@@ -17,18 +17,6 @@ module Spec
       Gem::Platform.new(platform)
     end
 
-    # Returns a number smaller than the size of the index. Useful for specs that
-    # need the API request limit to be reached for some reason.
-    def low_api_request_limit_for(gem_repo)
-      all_gems = Dir[gem_repo.join("gems/*.gem")]
-
-      all_gem_names = all_gems.map do |file|
-        File.basename(file, ".gem").match(/\A(?<gem_name>[^-]+)-.*\z/)[:gem_name]
-      end.uniq
-
-      (all_gem_names - ["bundler"]).size
-    end
-
     def build_repo1
       rake_path = Dir["#{Path.base_system_gems}/**/rake*.gem"].first
 

spec/bundler/support/path.rb

@@ -71,10 +71,6 @@ module Spec
       @spec_dir ||= source_root.join(ruby_core? ? "spec/bundler" : "spec")
     end
 
-    def api_request_limit_hack_file
-      spec_dir.join("support/api_request_limit_hax.rb")
-    end
-
     def man_dir
       @man_dir ||= lib_dir.join("bundler/man")
     end