85 lines
2.4 KiB
Ruby
85 lines
2.4 KiB
Ruby
module Polecat
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# interface for searching an index
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#
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# Build on top of an Polecat::IndexReader, this class let's you search through
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# all documents stored in an index.
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class IndexSearcher
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attr_reader :reader
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attr_reader :default_field
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# creates a new Polecat::IndexSearcher
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#
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# Create a new Polecat::IndexSearcher to search documents. Either a path
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# to a directory or a Polecat::IndexReader has to be given, to make this
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# searcher work.
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# @example
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# # the following has the same meaning
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# IndexSearcher.new 'index_dir'
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# IndexSearcher.new(IndexReader.new 'index_dir')
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def initialize options
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if options.has_key? :path
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@reader = Polecat::IndexReader.new(options[:path])
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elsif options.has_key? :reader
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@reader = options[:reader]
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raise ArgumentError, 'no reader' unless @reader.kind_of?(Polecat::IndexReader)
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end
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if options.has_key? :default_field
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@default_field = options[:default_field]
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end
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end
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# returns the path of the index directory
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# @return [String] path of the index directory
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def path
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@reader.path
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end
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# searches through all documents
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#
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# Run the query against the @default_field@ of every stored document to get
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# a list of all matching documents.
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# @param [String] query a String which get's matched against the documents
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# @return [Array] a list of all matching documents
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def search query
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@reader.read.select do |doc|
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#doc.attributes.fetch(@default_field).fetch(:value) == query
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rs = []
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query.terms.each do |term|
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val = doc.send(term.field.to_sym)
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if compare val, term.operator, term.value
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rs << true
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end
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end
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if query.relation == :and
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rs.count == query.terms.count
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else
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!rs.empty?
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end
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end
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end
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# compare the document value with the searched value
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#
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# This compares the two values with the operator
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# @return [Any] trueish for matches or falsey
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# @private
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def compare ival, op, tval
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if op == :eq
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if tval.class == Regexp
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ival.match tval
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else
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ival == tval
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end
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elsif op == :gt
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ival < tval
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elsif op == :lt
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ival > tval
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else
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false
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end
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end
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private :compare
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end
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end
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