Extract history introspection from "versions" command

1 files changed, 86 insertions, 0 deletions

diff --git a/Library/Homebrew/formula_versions.rb b/Library/Homebrew/formula_versions.rb
new file mode 100644
index 000000000..d4bad4584
--- /dev/null
+++ b/Library/Homebrew/formula_versions.rb
@@ -0,0 +1,86 @@
+class FormulaVersions
+  IGNORED_EXCEPTIONS = [
+    ArgumentError, NameError, SyntaxError, TypeError,
+    FormulaSpecificationError, FormulaValidationError,
+  ]
+
+  attr_reader :f
+
+  def initialize(f)
+    @f = f
+  end
+
+  def repository
+    @repository ||= if f.path.to_s =~ HOMEBREW_TAP_DIR_REGEX
+      HOMEBREW_REPOSITORY/"Library/Taps/#$1/#$2"
+    else
+      HOMEBREW_REPOSITORY
+    end
+  end
+
+  def entry_name
+    @entry_name ||= f.path.relative_path_from(repository).to_s
+  end
+
+  def each
+    versions = Set.new
+    rev_list do |rev|
+      version = version_at_revision(rev)
+      next if version.nil?
+      yield version, rev if versions.add?(version)
+    end
+  end
+
+  def repository_path
+    Pathname.pwd == repository ? entry_name : f.path
+  end
+
+  def rev_list(branch="HEAD")
+    repository.cd do
+      IO.popen("git rev-list --abbrev-commit --remove-empty #{branch} -- #{entry_name}") do |io|
+        yield io.readline.chomp until io.eof?
+      end
+    end
+  end
+
+  def file_contents_at_revision(rev)
+    repository.cd { `git cat-file blob #{rev}:#{entry_name}` }
+  end
+
+  def version_at_revision(rev)
+    formula_at_revision(rev) { |f| f.version }
+  end
+
+  def formula_at_revision rev, &block
+    f.mktemp do
+      path = Pathname.pwd.join("#{f.name}.rb")
+      path.write file_contents_at_revision(rev)
+
+      begin
+        old_const = Formulary.unload_formula(f.name)
+        nostdout { yield Formula.factory(path.to_s) }
+      rescue *IGNORED_EXCEPTIONS => e
+        # We rescue these so that we can skip bad versions and
+        # continue walking the history
+        ohai "#{e} in #{f.name} at revision #{rev}", e.backtrace if ARGV.debug?
+      rescue FormulaUnavailableError
+        # Suppress this error
+      ensure
+        Formulary.restore_formula(f.name, old_const)
+      end
+    end
+  end
+
+  def bottle_version_map(branch="HEAD")
+    map = Hash.new { |h, k| h[k] = [] }
+    rev_list(branch) do |rev|
+      formula_at_revision(rev) do |f|
+        bottle = f.stable.bottle_specification
+        unless bottle.checksums.empty?
+          map[f.pkg_version] << bottle.revision
+        end
+      end
+    end
+    map
+  end
+end