Class: Gem::SourceInfoCache

Inherits:
Object
  • Object
show all
Includes:
UserInteraction
Defined in:
lib/rubygems/source_info_cache.rb

Overview

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:

  • The system cache is prefered if it is writable or can be created.

  • The user cache is used otherwise

Once a cache is selected, it will be used for all operations. SourceInfoCache will not switch between cache files dynamically.

Cache data is a Hash mapping a source URI to a SourceInfoCacheEntry.

– To keep things straight, this is how the cache objects all fit together:

Gem::SourceInfoCache
  @cache_data = {
    source_uri => Gem::SourceInfoCacheEntry
      @size => source index size
      @source_index => Gem::SourceIndex
    ...
  }

Class Method Summary collapse

Instance Method Summary collapse

Methods included from DefaultUserInteraction

#ui, ui, #ui=, ui=, #use_ui, use_ui

Constructor Details

#initialize ⇒ SourceInfoCache

:nodoc:



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# File 'lib/rubygems/source_info_cache.rb', line 52

def initialize # :nodoc:
  @cache_data = nil
  @cache_file = nil
  @dirty = false

  @system_cache_file = nil
  @user_cache_file = nil
end

Class Method Details

.cache ⇒ Object 



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# File 'lib/rubygems/source_info_cache.rb', line 36

def self.cache
  return @cache if @cache
  @cache = new
  @cache.refresh
  @cache
end

.cache_data ⇒ Object 



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# File 'lib/rubygems/source_info_cache.rb', line 43

def self.cache_data
  cache.cache_data
end

.search(pattern) ⇒ Object

Search all source indexes for pattern.



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# File 'lib/rubygems/source_info_cache.rb', line 48

def self.search(pattern)
  cache.search(pattern)
end

Instance Method Details

#cache_data ⇒ Object

The most recent cache data.



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# File 'lib/rubygems/source_info_cache.rb', line 62

def cache_data
  return @cache_data if @cache_data
  @dirty = false
  cache_file # HACK writable check
  # Marshal loads 30-40% faster from a String, and 2MB on 20061116 is small
  begin
    data = File.open cache_file, 'rb' do |fp|
      fp.read
    end
    @cache_data = Marshal.load data 
  rescue
    {}
  end
end

#cache_file ⇒ Object

The name of the cache file to be read



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# File 'lib/rubygems/source_info_cache.rb', line 78

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

#flush ⇒ Object

Write the cache to a local file (if it is dirty).



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# File 'lib/rubygems/source_info_cache.rb', line 86

def flush
  write_cache if @dirty
  @dirty = false
end

#refresh ⇒ Object

Refreshes each source in the cache from its repository.



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# File 'lib/rubygems/source_info_cache.rb', line 92

def refresh
  Gem.sources.each do |source_uri|
    cache_entry = cache_data[source_uri]
    if cache_entry.nil? then
      cache_entry = Gem::SourceInfoCacheEntry.new nil, 0
      cache_data[source_uri] = cache_entry
    end

    cache_entry.refresh source_uri
  end
  update
  flush
end

#search(pattern) ⇒ Object

Searches all source indexes for pattern.



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# File 'lib/rubygems/source_info_cache.rb', line 107

def search(pattern)
  cache_data.map do |source, sic_entry|
    sic_entry.source_index.search pattern
  end.flatten
end

#set_cache_data(hash) ⇒ Object

Set the source info cache data directly. This is mainly used for unit testing when we don’t want to read a file system for to grab the cached source index information. The hash should map a source URL into a SourceIndexCacheEntry.



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# File 'lib/rubygems/source_info_cache.rb', line 140

def set_cache_data(hash)
  @cache_data = hash
  @dirty = false
end

#system_cache_file ⇒ Object

The name of the system cache file.



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# File 'lib/rubygems/source_info_cache.rb', line 114

def system_cache_file
  @system_cache_file ||= File.join(Gem.dir, "source_cache")
end

#update ⇒ Object

Mark the cache as updated (i.e. dirty).



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# File 'lib/rubygems/source_info_cache.rb', line 119

def update
  @dirty = true
end

#user_cache_file ⇒ Object

The name of the user cache file.



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# File 'lib/rubygems/source_info_cache.rb', line 124

def user_cache_file
  @user_cache_file ||=
    ENV['GEMCACHE'] || File.join(Gem.user_home, ".gem", "source_cache")
end

#write_cache ⇒ Object

Write data to the proper cache.



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# File 'lib/rubygems/source_info_cache.rb', line 130

def write_cache
  open cache_file, "wb" do |f|
    f.write Marshal.dump(cache_data)
  end
end