Class: Sprockets::Utils::Gzip

Inherits:
Object
  • Object
show all
Defined in:
lib/sprockets/utils/gzip.rb

Defined Under Namespace

Modules: ZlibArchiver, ZopfliArchiver

Constant Summary collapse

COMPRESSABLE_MIME_TYPES =

What non-text mime types should we compress? This list comes from: www.fastly.com/blog/new-gzip-settings-and-deciding-what-compress

{
  "application/vnd.ms-fontobject" => true,
  "application/x-font-opentype" => true,
  "application/x-font-ttf" => true,
  "image/x-icon" => true,
  "image/svg+xml" => true
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(asset, archiver: ZlibArchiver) ⇒ Gzip

Private: Generates a gzipped file based off of reference file.


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# File 'lib/sprockets/utils/gzip.rb', line 43

def initialize(asset, archiver: ZlibArchiver)
  @content_type  = asset.content_type
  @source        = asset.source
  @charset       = asset.charset
  @archiver      = archiver
end

Instance Attribute Details

#archiverObject (readonly)

Returns the value of attribute archiver


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# File 'lib/sprockets/utils/gzip.rb', line 40

def archiver
  @archiver
end

#charsetObject (readonly)

Returns the value of attribute charset


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# File 'lib/sprockets/utils/gzip.rb', line 40

def charset
  @charset
end

#content_typeObject (readonly)

Returns the value of attribute content_type


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# File 'lib/sprockets/utils/gzip.rb', line 40

def content_type
  @content_type
end

#sourceObject (readonly)

Returns the value of attribute source


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# File 'lib/sprockets/utils/gzip.rb', line 40

def source
  @source
end

Instance Method Details

#can_compress?Boolean

Private: Returns whether or not an asset can be compressed.

We want to compress any file that is text based. You do not want to compress binary files as they may already be compressed and running them through a compression algorithm would make them larger.

Return Boolean.

Returns:

  • (Boolean)

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# File 'lib/sprockets/utils/gzip.rb', line 68

def can_compress?  # The "charset" of a mime type is present if the value is
  # encoded text. We can check this value to see if the asset
  # can be compressed.
  #
  # We also check against our list of non-text compressible mime types

  @charset || COMPRESSABLE_MIME_TYPES.include?(@content_type)
end

#cannot_compress?Boolean

Private: Opposite of `can_compress?`.

Returns Boolean.

Returns:

  • (Boolean)

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# File 'lib/sprockets/utils/gzip.rb', line 80

def cannot_compress?
  !can_compress?
end

#compress(file, target) ⇒ Object

Private: Generates a gzipped file based off of reference asset.

Compresses the target asset's contents and puts it into a file with the same name plus a `.gz` extension in the same folder as the original. Does not modify the target asset.

Returns nothing.


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# File 'lib/sprockets/utils/gzip.rb', line 91

def compress(file, target)
  mtime = Sprockets::PathUtils.stat(target).mtime
  archiver.call(file, source, mtime)

  nil
end