Made DatabaseCache.new private, and changes instances in code that call it to use DatabaseCache.use instead.

Library/Homebrew/cache_store.rb

@@ -12,8 +12,13 @@ class DatabaseCache
   #   https://docs.oracle.com/cd/E17276_01/html/api_reference/C/envopen.html
   DATABASE_MODE = 0664
 
-  # Returned value from `initialize` block
-  attr_reader :return_value
+  def self.use(type)
+    return_value = nil
+    DatabaseCache.new(type) { |db| return_value = yield(db) }
+    return_value
+  end
+
+  private
 
   # Opens and yields a database in read/write mode. Closes the database after use
   #
@@ -22,15 +27,9 @@ class DatabaseCache
   def initialize(name)
     # DBM::WRCREAT: Creates the database if it does not already exist
     @db = DBM.open("#{HOMEBREW_CACHE}/#{name}.db", DATABASE_MODE, DBM::WRCREAT)
-    @return_value = yield(@db)
+    yield(@db)
     @db.close
   end
-
-  def self.use(type)
-    return_value = nil
-    DatabaseCache.new(type) { |db| return_value = yield(db) }
-    return_value
-  end
 end
 
 #

Library/Homebrew/dev-cmd/linkage.rb

@@ -20,7 +20,7 @@ module Homebrew
   module_function
 
   def linkage
-    DatabaseCache.new(:linkage) do |database_cache|
+    DatabaseCache.use(:linkage) do |database_cache|
       ARGV.kegs.each do |keg|
         ohai "Checking #{keg.name} linkage" if ARGV.kegs.size > 1
 

Library/Homebrew/extend/os/mac/formula_cellar_checks.rb

@@ -66,7 +66,7 @@ module FormulaCellarChecks
     return unless formula.prefix.directory?
     keg = Keg.new(formula.prefix)
 
-    DatabaseCache.new(:linkage) do |database_cache|
+    DatabaseCache.use(:linkage) do |database_cache|
       use_cache = !ENV["HOMEBREW_LINKAGE_CACHE"].nil?
       checker = LinkageChecker.new(keg, database_cache, use_cache, formula)
 

Library/Homebrew/formula_installer.rb

@@ -611,7 +611,7 @@ class FormulaInstaller
     puts summary
 
     # Updates the cache for a particular formula after doing an install
-    DatabaseCache.new(:linkage) do |database_cache|
+    DatabaseCache.use(:linkage) do |database_cache|
       break if database_cache.empty?
       LinkageChecker.new(keg, database_cache, false, formula)
     end