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Diffstat (limited to 'doc/api/ruby/example_dep_tree.rb')
| -rw-r--r-- | doc/api/ruby/example_dep_tree.rb | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/doc/api/ruby/example_dep_tree.rb b/doc/api/ruby/example_dep_tree.rb new file mode 100644 index 000000000..01bd2cdc3 --- /dev/null +++ b/doc/api/ruby/example_dep_tree.rb @@ -0,0 +1,157 @@ +#!/usr/bin/ruby +# vim: set sw=4 sts=4 et tw=100 : + +=begin description +This example demonstrates how to handle dependency specs. It looks through +all installed packages, and picks out any package whose dependencies include +'app-arch/unzip', or whose fetchable files includes any with a '.zip' +extension. +=end + +require 'Paludis' +require 'example_command_line' + +include Paludis + +# Collect dependencies upon 'app-arch/unzip' and store them in our results +# table. +def collect_dependencies env, id, spec, results, recursing_sets = {} + # We need to handle every type that could be in a dependency heirarchy. + if spec.instance_of? AllDepSpec + # For an AllDepSpec, just collect all of our children + spec.each do | child | + collect_dependencies(env, id, child, results, recursing_sets) + end + + elsif spec.instance_of? AnyDepSpec + # Same for an AnyDepSpec + spec.each do | child | + collect_dependencies(env, id, child, results, recursing_sets) + end + + elsif spec.instance_of? UseDepSpec + # Was this use flag enabled (or, if we're inverse, disabled) when we + # built this package? + if env.query_use(spec.flag(), id) ^ spec.inverse? + spec.each do | child | + collect_dependencies(env, id, child, results, recursing_sets) + end + end + + elsif spec.instance_of? PackageDepSpec + # spec.package may be a zero pointer if it's a whildcarded dep. + if spec.package and spec.package == "app-arch/unzip" + results[id.to_s][:has_dep] = true + end + + elsif spec.instance_of? NamedSetDepSpec + # For named set specs, we visit the set + set = env.set(spec.name()) + + # First complication: we might have a name referring to a set that + # doesn't exist. + if ! set + Log.instance.message(LogLevel::Warning, "Unknown set '" + spec.name() + "'") + return + end + + # Second complication: we need to handle sets that contain themselves. + # Although this shouldn't happen, user-defined sets can be made to + # include themselves, possibly with other sets inbetween (a includes b + # includes a). + if recursing_sets[set.name()] + Log.instance.message(LogLevel::Warning, "Recursively defined set '" + spec.name() + "'") + return + end + + recursing_sets[set.name()] = true + collect_dependencies(env, id, child, results, recursing_sets) + recursing_sets.delete(set.name()) + + elsif spec.instance_of? BlockDepSpec + # Do nothing + + elsif spec.instance_of? DependencyLabelsDepSpec + # Do nothing + + else + raise TypeError, "Got unexpected type '#{spec.class}'" + end +end + +# Collect files with extension '.zip' and store them in our results table. +def collect_extensions env, id, spec, results, recursing_sets = {} + # We need to handle every type that could be in a fetchable URI heirarchy. + if spec.instance_of? AllDepSpec + # For an AllDepSpec, just collect all of our children + spec.each do | child | + collect_extensions(env, id, child, results, recursing_sets) + end + + elsif spec.instance_of? UseDepSpec + # Was this use flag enabled (or, if we're inverse, disabled) when we + # built this package? + if env.query_use(spec.flag(), id) ^ spec.inverse? + spec.each do | child | + collect_extensions(env, id, child, results, recursing_sets) + end + end + + elsif spec.instance_of? FetchableURIDepSpec + # We need to be careful not to assume that the filename has an + # extension. + if spec.filename[%r/\.zip$/] + results[id.to_s][:has_ext] = true + end + + elsif spec.instance_of? URILabelsDepSpec + # Do nothing + + else + raise TypeError, "Got unexpected type '#{spec.class}'" + end + +end + +# We start with an Environment, respecting the user's '--environment' choice. +env = EnvironmentMaker.instance.make_from_spec(ExampleCommandLine.instance.environment) + +# Fetch package IDs for installed 'sys-apps/paludis' +ids = env.package_database.query( + Query::SupportsInstalledAction.new, QueryOrder::OrderByVersion) + +# Our results table, mapping the ID to { :has_dep => ?, :has_ext => ? } +results = { } + +# For each ID: +ids.each do | id | + # Ignore old-style virtuals + next if id.virtual_for_key + + # Make a default result for this ID. + results[id.to_s] = { :has_dep => false, :has_ext => false } + + # IDs can potentially have four dependency-related keys. Each of thse keys + # may return nil. If it doesn't, collect 'app-arch/unzip' dependencies. + [ :build_dependencies_key, :run_dependencies_key, :post_dependencies_key, + :suggested_dependencies_key ].each do | key | + if id.send(key) + collect_dependencies(env, id, id.send(key).value, results) + end + end + + # And the same for '.zip' file extensions + if id.fetches_key + collect_extensions(env, id, id.fetches_key.value, results) + end +end + +# Display our results +print "Package".ljust(60), "| ", "Dep".ljust(4), "| ", "Ext".ljust(4), "\n" +print "-" * 60, "+", "-" * 5, "+", "-" * 5, "\n" +results.keys.sort.each do | id | + print id.ljust(60), "| ", (results[id][:has_dep] ? "yes" : "no").ljust(4), "| ", + (results[id][:has_ext] ? "yes" : "no").ljust(4), "\n" +end +puts + |