Class: RPM::File

Inherits:
Object
  • Object
show all
Defined in:
lib/arr-pm/file.rb,
lib/arr-pm/namespace.rb

Overview

Much of the code here is derived from knowledge gained by reading the rpm source code, but mostly it started making more sense after reading this site: www.rpm.org/max-rpm/s1-rpm-file-format-rpm-file-format.html

Defined Under Namespace

Classes: Header, Lead, Tag

Constant Summary collapse

FLAG_LESS =

RPMSENSE_LESS = (1 << 1),

(1 << 1)
FLAG_GREATER =

RPMSENSE_GREATER = (1 << 2),

(1 << 2)
FLAG_EQUAL =

RPMSENSE_EQUAL = (1 << 3),

(1 << 3)
FLAG_CONFIG_FILE =

from rpm/rpmfi.h

(1 << 0)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(file) ⇒ File 



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# File 'lib/arr-pm/file.rb', line 21

def initialize(file)
  if file.is_a?(String)
    file = File.new(file, "r")
  end
  @file = file
end

Instance Attribute Details

#file ⇒ Object (readonly)

Returns the value of attribute file.



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# File 'lib/arr-pm/file.rb', line 12

def file
  @file
end

Instance Method Details

#config_files ⇒ Object

Get an array of config files



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# File 'lib/arr-pm/file.rb', line 177

def config_files
  # this stuff seems to be in the 'enum rpmfileAttrs_e' from rpm/rpmfi.h
  results = []
  # short-circuit if there's no :fileflags tag
  return results unless tags.include?(:fileflags)
  tags[:fileflags].each_with_index do |flag, i|
    # The :fileflags (and other :file... tags) are an array, in order of
    # files in the rpm payload, we want a list of paths of config files.
    results << files[i] if mask?(flag, FLAG_CONFIG_FILE)
  end
  return results
end

#conflicts ⇒ Object

Get an array of conflicts defined in this package.



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# File 'lib/arr-pm/file.rb', line 165

def conflicts
  return relation(:conflict)
end

#extract(target) ⇒ Object

Extract this RPM to a target directory.

This should have roughly the same effect as:

% rpm2cpio blah.rpm | (cd {target}; cpio -i --make-directories)



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# File 'lib/arr-pm/file.rb', line 96

def extract(target)
  if !File.directory?(target)
    raise Errno::ENOENT.new(target)
  end
  
  extractor = IO.popen("#{tags[:payloadcompressor]} -d | (cd #{target}; cpio -i --quiet --make-directories)", "w")
  buffer = ""
  begin
      buffer.force_encoding("BINARY")
  rescue NoMethodError
      # Do Nothing
  end
  payload_fd = payload.clone
  loop do
    data = payload_fd.read(16384, buffer)
    break if data.nil? # eof
    extractor.write(data)
  end
  payload_fd.close
  extractor.close
end

#files ⇒ Object

List the files in this RPM.

This should have roughly the same effect as:

% rpm2cpio blah.rpm | cpio -it



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# File 'lib/arr-pm/file.rb', line 195

def files
  return @files unless @files.nil?

  lister = IO.popen("#{tags[:payloadcompressor]} -d | cpio -it --quiet", "r+")
  buffer = ""
  begin
      buffer.force_encoding("BINARY")
  rescue NoMethodError
      # Do Nothing
  end
  payload_fd = payload.clone
  output = ""
  loop do
    data = payload_fd.read(16384, buffer)
    break if data.nil? # listerextractor.write(data)
    lister.write(data)

    # Read output from the pipe.
    begin
      output << lister.read_nonblock(16384)
    rescue Errno::EAGAIN
      # Nothing to read, move on!
    end
  end
  lister.close_write

  # Read remaining output
  begin
    output << lister.read
  rescue Errno::EAGAIN
    # Because read_nonblock enables NONBLOCK the 'lister' fd,
    # and we may have invoked a read *before* cpio has started
    # writing, let's keep retrying this read until we get an EOF
    retry
  rescue EOFError
    # At EOF, hurray! We're done reading.
  end

  # Split output by newline and strip leading "."
  @files = output.split("\n").collect { |s| s.gsub(/^\./, "") }
  return @files
ensure
  lister.close unless lister.nil?
  payload_fd.close unless payload_fd.nil?
end

#header ⇒ Object

Return the header for this rpm.



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# File 'lib/arr-pm/file.rb', line 67

def header
  signature

  if @header.nil?
    @header = ::RPM::File::Header.new(@file)
    @header.read
  end
  return @header
end

#lead ⇒ Object

Return the lead for this rpm

This ‘lead’ structure is almost entirely deprecated in the RPM file format.



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# File 'lib/arr-pm/file.rb', line 31

def lead
  if @lead.nil?
    # Make sure we're at the beginning of the file.
    @file.seek(0, IO::SEEK_SET)
    @lead = ::RPM::File::Lead.new(@file)

    # TODO(sissel): have 'read' return number of bytes read?
    @lead.read
  end
  return @lead
end

#mask?(value, mask) ⇒ Boolean

def files



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# File 'lib/arr-pm/file.rb', line 241

def mask?(value, mask)
  return (value & mask) == mask
end

#operator(flag) ⇒ Object

def mask?



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# File 'lib/arr-pm/file.rb', line 245

def operator(flag)
  return "<=" if mask?(flag, FLAG_LESS | FLAG_EQUAL)
  return ">=" if mask?(flag, FLAG_GREATER | FLAG_EQUAL)
  return "=" if mask?(flag, FLAG_EQUAL)
  return "<" if mask?(flag, FLAG_LESS)
  return ">" if mask?(flag, FLAG_GREATER)
end

#payload ⇒ Object

Returns a file descriptor for the payload. On first invocation, it seeks to the start of the payload



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# File 'lib/arr-pm/file.rb', line 79

def payload
  header
  if @payload.nil?
    @payload = @file.clone
    # The payload starts after the lead, signature, and header. Remember the signature has an
    # 8-byte boundary-rounding.
  end

  @payload.seek(@lead.length + @signature.length + @signature.length % 8 + @header.length, IO::SEEK_SET)
  return @payload
end

#provides ⇒ Object

Get an array of provides defined in this package.



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# File 'lib/arr-pm/file.rb', line 172

def provides
  return relation(:provide)
end

#relation(type) ⇒ Object

Get all relations of a given type to this package.

Examples:

rpm.relation(:require)
rpm.relation(:conflict)
rpm.relation(:provide)

In the return array-of-arrays, the elements are:

name (string), operator (string), version (string)

operator will be “>=”, “>”, “=”, “<”, or “<=”



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# File 'lib/arr-pm/file.rb', line 142

def relation(type)
  name = "#{type}name".to_sym
  flags = "#{type}flags".to_sym
  version = "#{type}version".to_sym
  # There is no data if we are missing all 3 tag types (name/flags/version)
  # FYI: 'tags.keys' is an array, Array#& does set intersection. 
  return [] if (tags.keys & [name, flags, version]).size != 3
  # Find tags <type>name, <type>flags, and <type>version, and return
  # an array of "name operator version"
  return tags[name].zip(tags[flags], tags[version]) \
    .reduce([]) { |memo, (n,o,v)| memo << [n, operator(o), v] }
end

#requires ⇒ Object

Get an array of requires defined in this package.



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# File 'lib/arr-pm/file.rb', line 158

def requires
  return relation(:require)
end

#signature ⇒ Object

Return the signature header for this rpm



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# File 'lib/arr-pm/file.rb', line 44

def signature
  lead # Make sure we've parsed the lead...

  # If signature_type is not 5 (HEADER_SIGNED_TYPE), no signature.
  if @lead.signature_type != Header::HEADER_SIGNED_TYPE
    @signature = false
    return
  end

  if @signature.nil?
    @signature = ::RPM::File::Header.new(@file)
    @signature.read

    # signature headers are padded up to an 8-byte boundar, details here:
    # http://rpm.org/gitweb?p=rpm.git;a=blob;f=lib/signature.c;h=63e59c00f255a538e48cbc8b0cf3b9bd4a4dbd56;hb=HEAD#l204
    # Throw away the pad.
    @file.read(@signature.length % 8)
  end

  return @signature
end

#tags ⇒ Object

def extract



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# File 'lib/arr-pm/file.rb', line 118

def tags
  if @tags.nil?
    @tags = {}
    header.tags.each do |tag|
      tags[tag.tag] = tag.value
    end
  end
  @tags
end