diff options
| -rw-r--r-- | vendor/plugins/acts_as_xapian/README | 1 | ||||
| -rw-r--r-- | vendor/plugins/acts_as_xapian/lib/acts_as_xapian.rb | 120 |
2 files changed, 83 insertions, 38 deletions
diff --git a/vendor/plugins/acts_as_xapian/README b/vendor/plugins/acts_as_xapian/README new file mode 100644 index 000000000..eae6a9ae3 --- /dev/null +++ b/vendor/plugins/acts_as_xapian/README @@ -0,0 +1 @@ +See lib/acts_as_xapian.rb for documentation. diff --git a/vendor/plugins/acts_as_xapian/lib/acts_as_xapian.rb b/vendor/plugins/acts_as_xapian/lib/acts_as_xapian.rb index b72293d27..d8ea2a06f 100644 --- a/vendor/plugins/acts_as_xapian/lib/acts_as_xapian.rb +++ b/vendor/plugins/acts_as_xapian/lib/acts_as_xapian.rb @@ -4,9 +4,11 @@ # Copyright (c) 2008 UK Citizens Online Democracy. All rights reserved. # Email: francis@mysociety.org; WWW: http://www.mysociety.org/ # -# $Id: acts_as_xapian.rb,v 1.2 2008-04-23 14:58:11 francis Exp $ - +# $Id: acts_as_xapian.rb,v 1.3 2008-04-23 16:00:00 francis Exp $ +# # TODO: + + # Cope with making acts_as_xapian get called before search by preloading classes somewhere # Make all indexing offline - have a table where what needs doing is stored @@ -16,6 +18,55 @@ # Eager loading # Boost particular fields? +# Documentation +# ============= +# +# Xapian is a search engine library, which has Ruby bindings. acts_as_xapian +# adds support for it to Rails. +# +# Xapian is an *offline indexing* search library - only one process can have +# the database open for writing at once, and others that try meanwhile are +# unceremoniously kicked off. For this reason, acts_as_xapian does not support +# automatic writing to the database when your models change. You need to +# update indices in a separate batch job (cron or a daemon) which there is +# only one of. +# +# Indexing +# ======== +# +# Put acts_as_xapian in your models that need search indexing. +# +# Options must include: +# :texts, an array of fields for indexing with full text search +# e.g. :texts => [ :title, :body ] +# :values, things which have a range of values for indexing, or for collapsing. +# Specify an array quadruple of [ field, index, prefix, type ] where +# - :index is an arbitary numeric identifier for use in the Xapian database +# - :prefix is the part to use in search queries that goes before the : +# - :type can be any of :string, :number or :date +# e.g. :values => [ [ :created_at, 0, "created_at" ], [ :size, 1, "size"] ] +# :terms, things which come after a : in search queries. Specify an array +# triple of [ field, char, prefix ] where +# - :char is an arbitary single upper case char used in the Xapian database +# - :prefix is the part to use in search queries that goes before the : +# e.g. :terms => [ [ :variety, 'V', "variety" ] ] +# A field is a symbol referring to either an attribute or a name +# +# Then call xapian_index and/or xapian_destroy on the model. +# +# Querying +# ======== +# +# To perform a query call ActsAsXapian.search. This takes in turn: +# query_string - Google like syntax, as described in http://www.xapian.org/docs/queryparser.html +# first_result - Offset of first result +# results_per_page - Number of results per page +# sort_by_prefix - Optionally, prefix of value to sort by +# collapse_by_prefix - Optionally, prefix of value to collapse by (i.e. only return most relevant result from group) +# +# Returns an object. The count and results methods are the two useful ones. +# + require 'xapian' module ActsAsXapian @@ -28,6 +79,10 @@ module ActsAsXapian def ActsAsXapian.db @@db end + @@writable_db = nil + def ActsAsXapian.writable_db + @@writable_db + end def ActsAsXapian.stemmer @@stemmer end @@ -51,14 +106,8 @@ module ActsAsXapian # basic Xapian objects @@db_path = File.join(db_parent_path, ENV['RAILS_ENV']) - @@db = Xapian::WritableDatabase.new(@@db_path, Xapian::DB_CREATE_OR_OPEN) + @@db = Xapian::Database.new(@@db_path) @@stemmer = Xapian::Stem.new('english') - - # for indexing - @@term_generator = Xapian::TermGenerator.new() - @@term_generator.set_flags(Xapian::TermGenerator::FLAG_SPELLING, 0) - @@term_generator.database = @@db - @@term_generator.stemmer = @@stemmer # for queries @@enquire = Xapian::Enquire.new(@@db) @@ -108,6 +157,16 @@ module ActsAsXapian end end + def ActsAsXapian.writable_init + if @@writable_db.nil? + # for indexing + @@writable_db = Xapian::WritableDatabase.new(@@db_path, Xapian::DB_CREATE_OR_OPEN) + @@term_generator = Xapian::TermGenerator.new() + @@term_generator.set_flags(Xapian::TermGenerator::FLAG_SPELLING, 0) + @@term_generator.database = @@writable_db + @@term_generator.stemmer = @@stemmer + end + end # Search for a query string, returns an array of hashes in result order. # Each hash contains the actual Rails object in :model, and other detail @@ -120,6 +179,10 @@ module ActsAsXapian attr_accessor :matches def initialize(query_string, first_result, results_per_page, sort_by_prefix = nil, collapse_by_prefix = nil) + if ActsAsXapian.db.nil? + raise "ActsAsXapian not initialized" + end + self.query = ActsAsXapian.query_parser.parse_query(query_string, Xapian::QueryParser::FLAG_BOOLEAN | Xapian::QueryParser::FLAG_PHRASE | Xapian::QueryParser::FLAG_LOVEHATE | Xapian::QueryParser::FLAG_WILDCARD | @@ -127,10 +190,10 @@ module ActsAsXapian ActsAsXapian.enquire.query = self.query if not sort_by_prefix.nil? - enquire->sort_by_value(ActsAsXapian.values_by_prefix[sort_by_prefix]) + enquire.sort_by_value(ActsAsXapian.values_by_prefix[sort_by_prefix]) end if not collapse_by_prefix.nil? - enquire->set_collapse_key(ActsAsXapian.values_by_prefix[collapse_by_prefix]) + enquire.set_collapse_key(ActsAsXapian.values_by_prefix[collapse_by_prefix]) end self.matches = ActsAsXapian.enquire.mset(first_result, results_per_page, 100) @@ -147,7 +210,6 @@ module ActsAsXapian end # Return array of models found - # XXX currently only returns all types of models def results # Pull out all the results docs = [] @@ -198,8 +260,8 @@ module ActsAsXapian end # Store record in the Xapian database - def xapian_save - ActsAsXapian.db.begin_transaction # XXX hoping this will lock/unlock on disk too? + def xapian_index + ActsAsXapian.writable_init doc = Xapian::Document.new ActsAsXapian.term_generator.document = doc @@ -219,46 +281,28 @@ module ActsAsXapian ActsAsXapian.term_generator.index_text(xapian_value(text)) end - ActsAsXapian.db.replace_document("I" + doc.data, doc) - ActsAsXapian.db.commit_transaction + ActsAsXapian.writable_db.replace_document("I" + doc.data, doc) end # Delete record from the Xapian database def xapian_destroy - raise "xapian_destroy" + ActsAsXapian.writable_init + + ActsAsXapian.writable_db.delete_document("I" + self.class.to_s + "-" + self.id.to_s) end end # Main entry point module ActsMethods - - # Put acts_as_xapian in your models that need search indexing. - # - # Options must include: - # :texts, an array of fields for indexing with full text search - # e.g. :texts => [ :title, :body ] - # :values, things which have a range of values for indexing, or for collapsing. - # Specify an array quadruple of [ field, index, prefix, type ] where - # - :index is an arbitary numeric identifier for use in the Xapian database - # - :prefix is the part to use in search queries that goes before the : - # - :type can be any of :string, :number or :date - # e.g. :values => [ [ :created_at, 0, "created_at" ], [ :size, 1, "size"] ] - # :terms, things which come after a : in search queries. Specify an array - # triple of [ field, char, prefix ] where - # - :char is an arbitary single upper case char used in the Xapian database - # - :prefix is the part to use in search queries that goes before the : - # e.g. :terms => [ [ :variety, 'V', "variety" ] ] - # A field is a symbol referring to either an attribute or a name + # See top of this file for docs def acts_as_xapian(options) + STDERR.puts("acts_as_xapian") include InstanceMethods cattr_accessor :xapian_options self.xapian_options = options ActsAsXapian.init(self.class.to_s, options) - - after_save :xapian_save - after_destroy :xapian_destroy end end |