Mime-types 1.25 Released

Ruby
1

mime-types version 1.25 has been released!

This library allows for the identification of a file’s likely MIME
content
type. This is release 1.25, adding experimental caching and lazy loading
functionality.

The caching and lazy loading features were initially implemented by Greg
Brockman (gdb). As these features are experimental, they are disabled by
default and must be enabled through the use of environment variables.
The cache
is invalidated on a per-version basis; the cache for version 1.25 will
not be
reused for version 1.26.

To use lazy loading, set the environment variable
+RUBY_MIME_TYPES_LAZY_LOAD+
to any value other than ‘false’. When using lazy loading, the initial
startup
of MIME::Types is around 12–25× faster than normal startup (on my
system,
normal startup is about 90 ms; lazy startup is about 4 ms). This isn’t
generally useful, however, as the MIME::Types database has not been
loaded.
Lazy startup and load is just slightly faster—around 1 ms. The real
advantage
comes from using the cache.

To enable the cache, set the environment variable
+RUBY_MIME_TYPES_CACHE+ to a
filename where MIME::Types will have read-write access. The first time a
new
version of MIME::Types is run using this file, it will be created,
taking a
little longer than normal. Subsequent loads using the same cache file
will be
approximately 3½× faster (25 ms) than normal loads. This can be combined
with
+RUBY_MIME_TYPES_LAZY_LOAD+, but this is not recommended in a
multithreaded
or multiprocess environment where all threads or processes will be using
the
same cache file.

As the caching interface is still experimental, the only values cached
are the
default MIME::Types database, not any custom MIME::Types added by users.

MIME types are used in MIME-compliant communications, as in e-mail or
HTTP
traffic, to indicate the type of content which is transmitted.
MIME::Types
provides the ability for detailed information about MIME entities
(provided as
a set of MIME::Type objects) to be determined and used programmatically.
There
are many types defined by RFCs and vendors, so the list is long but not
complete; don’t hesitate to ask to add additional information. This
library
follows the IANA collection of MIME types (see below for reference).

MIME::Types for Ruby was originally based on MIME::Types for Perl by
Mark
Overmeer, copyright 2001 - 2009. As of version 1.15, the data format for
the
MIME::Type list has changed and the synchronization will no longer
happen.

MIME::Types is built to conform to the MIME types of RFCs 2045 and 2231.
It
tracks the {IANA registry}[Media Types]
({ftp}[ftp://ftp.iana.org/assignments/media-types]) with some unofficial
types
added from the {LTSW
collection}[http://www.ltsw.se/knbase/internet/mime.htp]
and added by the users of MIME::Types.

Changes:

1.25 / 2013-08-30

  • New Features:
    • Adding lazy loading and caching functionality to the default data
      based on
      work done by Greg B. (gdb).
  • Bugs:
    • Force the default internal application encoding to be used when
      reading the
      MIME types database. Based on a change by briangamble, found in the
      rapid7
      fork.
  • New extensions:
    • mjpeg (video/x-motion-jpeg) based on a change by punkrats, found in
      the
      vidibus fork.
  • Modernized MiniTest configuration.