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# This program is free software. It comes without any warranty, to
# the extent permitted by applicable law. You can redistribute it
# and/or modify it under the terms of the Do What The Fuck You Want
# To Public License, Version 2, as published by Sam Hocevar. See
# http://sam.zoy.org/wtfpl/COPYING for more details.
# Setup configuration
# This tells python-apt that we've seen the warning about the API not being
# stable yet, and we don't want to see every time we run the program
require 'xapian'
# Setup configuration
XAPIANDBPATH = '/var/lib/apt-xapian-index'
XAPIANDB = XAPIANDBPATH + '/index'
XAPIANDBVALUES = XAPIANDBPATH + '/values'
# This is our little database of simple Debtags filters we provide: the name
# entered by the user in "--type" maps to a piece of Xapian query
FILTER_DB = {
# We can do simple AND queries...
:game => Xapian::Query.new(Xapian::Query::OP_AND, ['XTuse::gameplaying', 'XTrole::program']),
# Or we can do complicate binary expressions...
:gui => Xapian::Query.new(
Xapian::Query::OP_AND, Xapian::Query.new('XTrole::program'),
Xapian::Query.new(Xapian::Query::OP_OR, 'XTinterface::x11', 'XTinterface::3d')),
:cmdline => Xapian::Query.new(Xapian::Query::OP_AND, 'XTrole::program', 'XTinterface::commandline'),
:editor => Xapian::Query.new(Xapian::Query::OP_AND, 'XTrole::program', 'XTuse::editing')
# Feel free to invent more
}
=begin
Given a list of user-supplied keywords, build the list of terms that will
go in a simple Xapian query.
If a term is lowercase and contains '::', then it's considered to be a
Debtags tag.
=end
def terms_for_simple_query keywords
stemmer = Xapian::Stem.new("english")
terms = []
keywords.each do |word|
if not word.downcase! and word['::']
# FIXME: A better way could be to look up arguments in
# /var/lib/debtags/vocabulary
#
# According to /var/lib/apt-xapian-index/README, Debtags tags are
# indexed with the 'XT' prefix.
terms << ( "XT" << word )
else
# If it is not a Debtags tag, then we consider it a normal keyword.
terms << word
# If the word has a stemmed version, add it to the query.
# /var/lib/apt-xapian-index/README tells us that stemmed terms have a
# 'Z' prefix.
stem = stemmer.call(word)
terms << ( 'Z' << stem ) unless stem == word
end
end
terms
end
=begin
If filtername is not None, lookup the simple filter database for the name
and add its filter to the query. Returns the enhanced query.
=end
def add_simple_filter_to_query query, filtername
# See if the user wants to use one of the result filters
if filtername
if FILTER_DB.include? filtername
# If a filter was requested, AND it with the query
Xapian::Query.new(Xapian::Query::OP_AND, FILTER_DB[filtername], query)
else
raise RuntimeError("Invalid filter type. Try one of %s" % FILTER_DB.keys.join(', '))
end
else
query
end
end
# Show a Xapian result mset as a list of packages and their short descriptions
def show_mset mset
# Display the top 20 results, sorted by how well they match
puts "%i results found." % mset.matches_estimated
puts "Results 1-%i:" % mset.size
mset.matches.each do |m|
# /var/lib/apt-xapian-index/README tells us that the Xapian document data
# is the package name.
name = m.document.data
# Print the match, together with the short description
puts "%i%% %s - %s" % [m.percent, name, 'summary not available']
end
end
# Read the "/etc/services"-style database of value indices
def read_value_db pathname
begin
rmcomments = /\s*(#.*)?$/
splitter = /\s+/
values = {}
File.open pathname, 'r' do |io|
while line = io.gets
# Remove comments and trailing spaces
line = rmcomments.sub("", line)
# Skip empty lines
next if line.empty?
# Split the line
fields = splitter.split(line)
if fields.length < 2
stderr.puts "Ignoring line %s:%d: only 1 value found when I need at least the value name and number" % [pathname, io.lineno + 1]
next
end
# Parse the number
begin
number = fields[1].to_i
rescue NoMethodError
$stderr.puts "Ignoring line %s:%d: the second column (\"%s\") must be a number" % [pathname, io.lineno + 1, fields[1]]
next
end
values[fields[0]] = number
fields[2..-1].each do |a|
values[a] = number
end
end
end
rescue => e
# If we can't read the database, fallback to defaults
$stderr.puts "Cannot read %s: %s. Using a minimal default configuration" % [pathname, e]
values = {
:installedsize => 1,
:packagesize => 2
}
end
values
end
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