Class: FPM::Package::Python::PythonMetadata

Inherits:
Object
  • Object
show all
Defined in:
lib/fpm/package/python.rb

Defined Under Namespace

Classes: MissingField, UnexpectedContent

Constant Summary collapse

MULTIPLE_USE =

According to packaging.python.org/en/latest/specifications/core-metadata/ > Core Metadata v2.4 - August 2024

%w(Dynamic Platform Supported-Platform License-File Classifier Requires-Dist Requires-External Project-URL Provides-Extra Provides-Dist Obsoletes-Dist)
FIELD_MAP = 
{
  :@name => "Name",
  :@version => "Version",
  :@summary => "Summary",
  :@description => "Description",
  :@keywords => "Keywords",
  :@maintainer => "Author-email",

  # Note: License can also come from the deprecated "License" field
  # This is processed later in this method.
  :@license => "License-Expression",

  :@requires => "Requires-Dist",
}
REQUIRED_FIELDS = 
[ "Metadata-Version", "Name", "Version" ]

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(headers, body = nil) ⇒ PythonMetadata

headers - a Hash containing field-value pairs from headers as read from a python METADATA file. body - optional, a string containing the body text of a METADATA file



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# File 'lib/fpm/package/python.rb', line 200

def initialize(headers, body=nil)
  REQUIRED_FIELDS.each do |field|
    if !headers.include?(field)
      raise MissingField, "Missing required Python metadata field, '#{field}'. This might be a bug in the package or in fpm."
    end
  end

  FIELD_MAP.each do |attr, field|
    if headers.include?(field)
      instance_variable_set(attr, headers.fetch(field))
    end
  end

  # Do any extra processing on fields to turn them into their expected content.
  process_description(headers, body)
  process_license(headers)
  process_homepage(headers)
  process_maintainer(headers)
end

Instance Attribute Details

#description ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def description
  @description
end

#homepage ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def homepage
  @homepage
end

#keywords ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def keywords
  @keywords
end

#license ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def license
  @license
end

#maintainer ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def maintainer
  @maintainer
end

#name ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def name
  @name
end

#requires ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def requires
  @requires
end

#summary ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def summary
  @summary
end

#version ⇒ Object (readonly)

Only focusing on terms fpm may care about



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# File 'lib/fpm/package/python.rb', line 179

def version
  @version
end

Class Method Details

.from(input) ⇒ Object

self.parse



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# File 'lib/fpm/package/python.rb', line 174

def self.from(input)
  return PythonMetadata.new(*parse(input))
end

.parse(input) ⇒ Object

METADATA files are described in Python Packaging “Core Metadata”[1] and appear to have roughly RFC822 syntax.

1

packaging.python.org/en/latest/specifications/core-metadata/#core-metadata



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# File 'lib/fpm/package/python.rb', line 113

def self.parse(input)
  s = StringScanner.new(input)
  headers = {}

  # Default "Multiple use" fields to empty array instead of nil.
  MULTIPLE_USE.each do |field|
    headers[field] = []
  end

  while !s.eos? and !s.scan("\n") do 
    # Field is non-space up, but excluding the colon
    field = s.scan(/[^\s:]+/)

    # Skip colon and following whitespace
    s.scan(/:\s*/)

    # Value is text until newline, and any following lines if they have leading spaces.
    value = s.scan(/[^\n]+(?:\Z|\n(?:[ \t][^\n]+\n)*)/)
    if value.nil?
      raise "Failed parsing Python package metadata value at field #{field}, char offset #{s.pos}"
    end
    value = value.chomp

    if MULTIPLE_USE.include?(field)
      raise "Header field should be an array. This is a bug in fpm." if !headers[field].is_a?(Array)
      headers[field] << value
    else
      headers[field] = value
    end
  end # while reading headers

  # If there's more content beyond the last header, then it's a content body.
  # In Python Metadata >= 2.1, the descriptino can be written in the body.
  if !s.eos? 
    if headers["Metadata-Version"].to_f >= 2.1
      # Per Python core-metadata spec:
      # > Changed in version 2.1: This field may be specified in the message body instead.
      #return PythonMetadata.new(headers, s.string[s.pos ...])
      return headers, s.string[s.pos ... ]
    elsif headers["Metadata-Version"].to_f >= 2.0
      # dnspython v1.15.0 has a description body and Metadata-Version 2.0 
      # this seems out of spec, but let's accept it anyway.
      return headers, s.string[s.pos ... ]
    else
      raise "After reading METADATA headers, extra data is in the file but was not expected. This may be a bug in fpm."
    end
  end

  #return PythonMetadata.new(headers)
  return headers, nil # nil means no body in this metadata
rescue => e
  puts "String scan failed: #{e}"
  puts "Position: #{s.pointer}"
  puts "---"
  puts input
  puts "==="
  puts input[s.pointer...]
  puts "---"
  raise e
end