module Sprockets::Digest

def digest

its assets.
digests. Any change in the environment digest will affect all of
The value also provides a seed digest for all `Asset`

cached assets.
than in the same. Two equal `Environment`s can share the same
useful for comparing environment states between processes rather
same digest value they can be treated as equal. This is more
This value serves two purposes. If two `Environment`s have the

Returns a `Digest` instance for the `Environment`. 
def digest
  # Compute the initial digest using the implementation class. The
  # Sprockets release version and custom environment version are
  # mixed in. So any new releases will affect all your assets.
  @digest ||= digest_class.new.update(VERSION).update(version.to_s)
  # Returned a dupped copy so the caller can safely mutate it with `.update`
  @digest.dup
end

def digest_class

Defaults to `Digest::MD5`.

Returns a `Digest` implementation class. 
def digest_class
  @digest_class
end

def digest_class=(klass)


environment.digest_class = Digest::SHA1

`Digest::SHA1`.
`Digest::` implementation such as `Digest::MD5` or
Assign a `Digest` implementation class. This maybe any Ruby 
def digest_class=(klass)
  expire_index!
  @digest_class = klass
end

def version

configuration change to the `Environment` object.
It would be wise to increment this value anytime you make a

into the `Context`.
impossible to know when any custom helpers change that you mix
will take care of expiring the cache for you. However, its
Sprockets is able to track most file and directory changes and

expiring all asset caches.
The `Environment#version` is a custom value used for manually 
def version
  @version
end

def version=(version)


environment.version = '2.0'

Assign an environment version. 
def version=(version)
  expire_index!
  @version = version
end