1 files changed, 217 insertions, 95 deletions

diff --git a/lib/rubygems/source_info_cache.rb b/lib/rubygems/source_info_cache.rb
index c84868a5f5..9383f6362e 100644
--- a/lib/rubygems/source_info_cache.rb
+++ b/lib/rubygems/source_info_cache.rb
@@ -4,6 +4,7 @@ require 'rubygems'
 require 'rubygems/source_info_cache_entry'
 require 'rubygems/user_interaction'
 
+##
 # SourceInfoCache stores a copy of the gem index for each gem source.
 #
 # There are two possible cache locations, the system cache and the user cache:
@@ -25,7 +26,7 @@ require 'rubygems/user_interaction'
 #         @source_index => Gem::SourceIndex
 #       ...
 #     }
-#
+
 class Gem::SourceInfoCache
 
   include Gem::UserInteraction
@@ -37,7 +38,7 @@ class Gem::SourceInfoCache
   def self.cache
     return @cache if @cache
     @cache = new
-    @cache.refresh if Gem.configuration.update_sources
+    @cache.refresh false if Gem.configuration.update_sources
     @cache
   end
 
@@ -45,86 +46,178 @@ class Gem::SourceInfoCache
     cache.cache_data
   end
 
-  # Search all source indexes for +pattern+.
-  def self.search(pattern, platform_only = false)
-    cache.search pattern, platform_only
+  ##
+  # The name of the system cache file.
+
+  def self.latest_system_cache_file
+    File.join File.dirname(system_cache_file),
+              "latest_#{File.basename system_cache_file}"
+  end
+
+  ##
+  # The name of the latest user cache file.
+
+  def self.latest_user_cache_file
+    File.join File.dirname(user_cache_file),
+              "latest_#{File.basename user_cache_file}"
+  end
+
+  ##
+  # Search all source indexes.  See Gem::SourceInfoCache#search.
+
+  def self.search(*args)
+    cache.search(*args)
   end
 
-  # Search all source indexes for +pattern+.  Only returns gems matching
-  # Gem.platforms when +only_platform+ is true.  See #search_with_source.
-  def self.search_with_source(pattern, only_platform = false)
-    cache.search_with_source(pattern, only_platform)
+  ##
+  # Search all source indexes returning the source_uri.  See
+  # Gem::SourceInfoCache#search_with_source.
+
+  def self.search_with_source(*args)
+    cache.search_with_source(*args)
+  end
+
+  ##
+  # The name of the system cache file. (class method)
+
+  def self.system_cache_file
+    @system_cache_file ||= Gem.default_system_source_cache_dir
+  end
+
+  ##
+  # The name of the user cache file.
+
+  def self.user_cache_file
+    @user_cache_file ||=
+      ENV['GEMCACHE'] || Gem.default_user_source_cache_dir
   end
 
   def initialize # :nodoc:
     @cache_data = nil
     @cache_file = nil
     @dirty = false
+    @only_latest = true
   end
 
+  ##
   # The most recent cache data.
+
   def cache_data
     return @cache_data if @cache_data
     cache_file # HACK writable check
 
-    begin
-      # Marshal loads 30-40% faster from a String, and 2MB on 20061116 is small
-      data = File.open cache_file, 'rb' do |fp| fp.read end
-      @cache_data = Marshal.load data
-
-      @cache_data.each do |url, sice|
-        next unless sice.is_a?(Hash)
-        update
-        cache = sice['cache']
-        size  = sice['size']
-        if cache.is_a?(Gem::SourceIndex) and size.is_a?(Numeric) then
-          new_sice = Gem::SourceInfoCacheEntry.new cache, size
-          @cache_data[url] = new_sice
-        else # irreperable, force refetch.
-          reset_cache_for(url)
-        end
-      end
-      @cache_data
-    rescue => e
-      if Gem.configuration.really_verbose then
-        say "Exception during cache_data handling: #{ex.class} - #{ex}"
-        say "Cache file was: #{cache_file}"
-        say "\t#{e.backtrace.join "\n\t"}"
-      end
-      reset_cache_data
-    end
-  end
-
-  def reset_cache_for(url)
-    say "Reseting cache for #{url}" if Gem.configuration.really_verbose
+    @only_latest = true
 
-    sice = Gem::SourceInfoCacheEntry.new Gem::SourceIndex.new, 0
-    sice.refresh url # HACK may be unnecessary, see ::cache and #refresh
+    @cache_data = read_cache_data latest_cache_file
 
-    @cache_data[url] = sice
     @cache_data
   end
 
-  def reset_cache_data
-    @cache_data = {}
-  end
+  ##
+  # The name of the cache file.
 
-  # The name of the cache file to be read
   def cache_file
     return @cache_file if @cache_file
     @cache_file = (try_file(system_cache_file) or
       try_file(user_cache_file) or
       raise "unable to locate a writable cache file")
   end
+  
+  ##
+  # Force cache file to be reset, useful for integration testing of rubygems
+  
+  def reset_cache_file
+    @cache_file = nil
+  end
 
+  ##
   # Write the cache to a local file (if it is dirty).
+
   def flush
     write_cache if @dirty
     @dirty = false
   end
 
-  # Refreshes each source in the cache from its repository.
-  def refresh
+  def latest_cache_data
+    latest_cache_data = {}
+
+    cache_data.each do |repo, sice|
+      latest = sice.source_index.latest_specs
+
+      new_si = Gem::SourceIndex.new
+      new_si.add_specs(*latest)
+
+      latest_sice = Gem::SourceInfoCacheEntry.new new_si, sice.size
+      latest_cache_data[repo] = latest_sice
+    end
+
+    latest_cache_data
+  end
+
+  ##
+  # The name of the latest cache file.
+
+  def latest_cache_file
+    File.join File.dirname(cache_file), "latest_#{File.basename cache_file}"
+  end
+
+  ##
+  # The name of the latest system cache file.
+
+  def latest_system_cache_file
+    self.class.latest_system_cache_file
+  end
+
+  ##
+  # The name of the latest user cache file.
+
+  def latest_user_cache_file
+    self.class.latest_user_cache_file
+  end
+
+  def read_all_cache_data
+    if @only_latest then
+      @only_latest = false
+      @cache_data = read_cache_data cache_file
+    end
+  end
+
+  def read_cache_data(file)
+    # Marshal loads 30-40% faster from a String, and 2MB on 20061116 is small
+    data = open file, 'rb' do |fp| fp.read end
+    cache_data = Marshal.load data
+
+    cache_data.each do |url, sice|
+      next unless sice.is_a?(Hash)
+      update
+
+      cache = sice['cache']
+      size  = sice['size']
+
+      if cache.is_a?(Gem::SourceIndex) and size.is_a?(Numeric) then
+        new_sice = Gem::SourceInfoCacheEntry.new cache, size
+        cache_data[url] = new_sice
+      else # irreperable, force refetch.
+        reset_cache_for url, cache_data
+      end
+    end
+
+    cache_data
+  rescue => e
+    if Gem.configuration.really_verbose then
+      say "Exception during cache_data handling: #{e.class} - #{e}"
+      say "Cache file was: #{file}"
+      say "\t#{e.backtrace.join "\n\t"}"
+    end
+
+    {}
+  end
+
+  ##
+  # Refreshes each source in the cache from its repository.  If +all+ is
+  # false, only latest gems are updated.
+
+  def refresh(all)
     Gem.sources.each do |source_uri|
       cache_entry = cache_data[source_uri]
       if cache_entry.nil? then
@@ -132,14 +225,34 @@ class Gem::SourceInfoCache
         cache_data[source_uri] = cache_entry
       end
 
-      update if cache_entry.refresh source_uri
+      update if cache_entry.refresh source_uri, all
     end
 
     flush
   end
 
-  # Searches all source indexes for +pattern+.
-  def search(pattern, platform_only = false)
+  def reset_cache_for(url, cache_data)
+    say "Reseting cache for #{url}" if Gem.configuration.really_verbose
+
+    sice = Gem::SourceInfoCacheEntry.new Gem::SourceIndex.new, 0
+    sice.refresh url, false # HACK may be unnecessary, see ::cache and #refresh
+
+    cache_data[url] = sice
+    cache_data
+  end
+
+  def reset_cache_data
+    @cache_data = nil
+  end
+
+  ##
+  # Searches all source indexes.  See Gem::SourceIndex#search for details on
+  # +pattern+ and +platform_only+.  If +all+ is set to true, the full index
+  # will be loaded before searching.
+
+  def search(pattern, platform_only = false, all = false)
+    read_all_cache_data if all
+
     cache_data.map do |source_uri, sic_entry|
       next unless Gem.sources.include? source_uri
       sic_entry.source_index.search pattern, platform_only
@@ -150,7 +263,9 @@ class Gem::SourceInfoCache
   # only gems matching Gem.platforms will be selected.  Returns an Array of
   # pairs containing the Gem::Specification found and the source_uri it was
   # found at.
-  def search_with_source(pattern, only_platform = false)
+  def search_with_source(pattern, only_platform = false, all = false)
+    read_all_cache_data if all
+
     results = []
 
     cache_data.map do |source_uri, sic_entry|
@@ -164,68 +279,75 @@ class Gem::SourceInfoCache
     results
   end
 
-  # Mark the cache as updated (i.e. dirty).
-  def update
-    @dirty = true
+  ##
+  # Set the source info cache data directly.  This is mainly used for unit
+  # testing when we don't want to read a file system to grab the cached source
+  # index information.  The +hash+ should map a source URL into a
+  # SourceInfoCacheEntry.
+
+  def set_cache_data(hash)
+    @cache_data = hash
+    update
   end
 
+  ##
   # The name of the system cache file.
+
   def system_cache_file
     self.class.system_cache_file
   end
 
-  # The name of the system cache file. (class method)
-  def self.system_cache_file
-    @system_cache_file ||= Gem.default_system_source_cache_dir
+  ##
+  # Determine if +path+ is a candidate for a cache file.  Returns +path+ if
+  # it is, nil if not.
+
+  def try_file(path)
+    return path if File.writable? path
+    return nil if File.exist? path
+
+    dir = File.dirname path
+
+    unless File.exist? dir then
+      begin
+        FileUtils.mkdir_p dir
+      rescue RuntimeError, SystemCallError
+        return nil
+      end
+    end
+
+    if File.writable? dir then
+      open path, "wb" do |io| io.write Marshal.dump({}) end
+      return path
+    end
+
+    nil
+  end
+
+  ##
+  # Mark the cache as updated (i.e. dirty).
+
+  def update
+    @dirty = true
   end
 
+  ##
   # The name of the user cache file.
+
   def user_cache_file
     self.class.user_cache_file
   end
 
-  # The name of the user cache file. (class method)
-  def self.user_cache_file
-    @user_cache_file ||=
-      ENV['GEMCACHE'] || Gem.default_user_source_cache_dir
-  end
-
+  ##
   # Write data to the proper cache.
+
   def write_cache
-    open cache_file, "wb" do |f|
-      f.write Marshal.dump(cache_data)
+    open cache_file, 'wb' do |io|
+      io.write Marshal.dump(cache_data)
     end
-  end
 
-  # Set the source info cache data directly.  This is mainly used for unit
-  # testing when we don't want to read a file system to grab the cached source
-  # index information.  The +hash+ should map a source URL into a
-  # SourceInfoCacheEntry.
-  def set_cache_data(hash)
-    @cache_data = hash
-    update
-  end
-
-  private
-
-  # Determine if +fn+ is a candidate for a cache file.  Return fn if
-  # it is.  Return nil if it is not.
-  def try_file(fn)
-    return fn if File.writable?(fn)
-    return nil if File.exist?(fn)
-    dir = File.dirname(fn)
-    unless File.exist? dir then
-      begin
-        FileUtils.mkdir_p(dir)
-      rescue RuntimeError, SystemCallError
-        return nil
-      end
+    open latest_cache_file, 'wb' do |io|
+      io.write Marshal.dump(latest_cache_data)
     end
-    if File.writable?(dir)
-      File.open(fn, "wb") { |f| f << Marshal.dump({}) }
-      return fn
-    end
-    nil
   end
 
 end