X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=lib%2Fsup%2Findex.rb;h=ff03f195f6bca74aefdb23eedecc01c2172ee39c;hb=bf30feea5c29d1aa5c1b8bbefa2bf4f4e73b1510;hp=c66a24eac428ab7256ea237db16c42e126189dd7;hpb=62957d7bd278910530d6888aefd209201b7007e6;p=sup

diff --git a/lib/sup/index.rb b/lib/sup/index.rb
index c66a24e..ff03f19 100644
--- a/lib/sup/index.rb
+++ b/lib/sup/index.rb
@@ -1,20 +1,20 @@
-## the index structure for redwood. interacts with ferret.
+## Index interface, subclassed by Ferret indexer.
 
 require 'fileutils'
-require 'ferret'
-require 'fastthread'
 
 begin
   require 'chronic'
   $have_chronic = true
 rescue LoadError => e
-  Redwood::log "optional 'chronic' library not found (run 'gem install chronic' to install)"
+  debug "optional 'chronic' library not found; date-time query restrictions disabled"
   $have_chronic = false
 end
 
 module Redwood
 
-class Index
+class BaseIndex
+  include InteractiveLock
+
   class LockError < StandardError
     def initialize h
       @h = h
@@ -25,34 +25,15 @@ class Index
 
   include Singleton
 
-  ## these two accessors should ONLY be used by single-threaded programs.
-  ## otherwise you will have a naughty ferret on your hands.
-  attr_reader :index
-  alias ferret index
-
   def initialize dir=BASE_DIR
-    @index_mutex = Monitor.new
-
     @dir = dir
-    @sources = {}
-    @sources_dirty = false
-    @source_mutex = Monitor.new
-
-    wsa = Ferret::Analysis::WhiteSpaceAnalyzer.new false
-    sa = Ferret::Analysis::StandardAnalyzer.new [], true
-    @analyzer = Ferret::Analysis::PerFieldAnalyzer.new wsa
-    @analyzer[:body] = sa
-    @analyzer[:subject] = sa
-    @qparser ||= Ferret::QueryParser.new :default_field => :body, :analyzer => @analyzer, :or_default => false
     @lock = Lockfile.new lockfile, :retries => 0, :max_age => nil
-
-    self.class.i_am_the_instance self
   end
 
   def lockfile; File.join @dir, "lock" end
 
   def lock
-    Redwood::log "locking #{lockfile}..."
+    debug "locking #{lockfile}..."
     begin
       @lock.lock
     rescue Lockfile::MaxTriesLockError
@@ -74,239 +55,60 @@ class Index
     @lock_update_thread = nil
   end
 
-  def possibly_pluralize number_of, kind
-    "#{number_of} #{kind}" +
-        if number_of == 1 then "" else "s" end
-  end
-
-  def fancy_lock_error_message_for e
-    secs = (Time.now - e.mtime).to_i
-    mins = secs / 60
-    time =
-      if mins == 0
-        possibly_pluralize secs , "second"
-      else
-        possibly_pluralize mins, "minute"
-      end
-
-    <<EOS
-Error: the sup index is locked by another process! User '#{e.user}' on
-host '#{e.host}' is running #{e.pname} with pid #{e.pid}. The process was alive
-as of #{time} ago.
-EOS
-  end
-
-  def lock_or_die
-    begin
-      lock
-    rescue LockError => e
-      $stderr.puts fancy_lock_error_message_for(e)
-      $stderr.puts <<EOS
-
-You can wait for the process to finish, or, if it crashed and left a
-stale lock file behind, you can manually delete #{@lock.path}.
-EOS
-      exit
-    end
-  end
-
   def unlock
     if @lock && @lock.locked?
-      Redwood::log "unlocking #{lockfile}..."
+      debug "unlocking #{lockfile}..."
       @lock.unlock
     end
   end
 
   def load
-    load_sources
+    SourceManager.load_sources
     load_index
   end
 
   def save
-    Redwood::log "saving index and sources..."
+    debug "saving index and sources..."
     FileUtils.mkdir_p @dir unless File.exists? @dir
-    save_sources
+    SourceManager.save_sources
     save_index
   end
 
-  def add_source source
-    @source_mutex.synchronize do
-      raise "duplicate source!" if @sources.include? source
-      @sources_dirty = true
-      max = @sources.max_of { |id, s| s.is_a?(DraftLoader) || s.is_a?(SentLoader) ? 0 : id }
-      source.id ||= (max || 0) + 1
-      ##source.id += 1 while @sources.member? source.id
-      @sources[source.id] = source
-    end
-  end
-
-  def sources
-    ## favour the inbox by listing non-archived sources first
-    @source_mutex.synchronize { @sources.values }.sort_by { |s| s.id }.partition { |s| !s.archived? }.flatten
+  def load_index
+    unimplemented
   end
 
-  def source_for uri; sources.find { |s| s.is_source_for? uri }; end
-  def usual_sources; sources.find_all { |s| s.usual? }; end
+  def add_message m; unimplemented end
+  def update_message m; unimplemented end
+  def update_message_state m; unimplemented end
 
-  def load_index dir=File.join(@dir, "ferret")
-    if File.exists? dir
-      Redwood::log "loading index..."
-      @index_mutex.synchronize do
-        @index = Ferret::Index::Index.new(:path => dir, :analyzer => @analyzer)
-        Redwood::log "loaded index of #{@index.size} messages"
-      end
-    else
-      Redwood::log "creating index..."
-      @index_mutex.synchronize do
-        field_infos = Ferret::Index::FieldInfos.new :store => :yes
-        field_infos.add_field :message_id, :index => :untokenized
-        field_infos.add_field :source_id
-        field_infos.add_field :source_info
-        field_infos.add_field :date, :index => :untokenized
-        field_infos.add_field :body
-        field_infos.add_field :label
-        field_infos.add_field :attachments
-        field_infos.add_field :subject
-        field_infos.add_field :from
-        field_infos.add_field :to
-        field_infos.add_field :refs
-        field_infos.add_field :snippet, :index => :no, :term_vector => :no
-        field_infos.create_index dir
-        @index = Ferret::Index::Index.new(:path => dir, :analyzer => @analyzer)
-      end
-    end
+  def save_index fn
+    unimplemented
   end
 
-  ## Syncs the message to the index, replacing any previous version.  adding
-  ## either way. Index state will be determined by the message's #labels
-  ## accessor.
-  ##
-  ## if need_load is false, docid and entry are assumed to be set to the
-  ## result of load_entry_for_id (which can be nil).
-  def sync_message m, need_load=true, docid=nil, entry=nil, opts={}
-    docid, entry = load_entry_for_id m.id if need_load
-
-    raise "no source info for message #{m.id}" unless m.source && m.source_info
-    @index_mutex.synchronize do
-      raise "trying to delete non-corresponding entry #{docid} with index message-id #{@index[docid][:message_id].inspect} and parameter message id #{m.id.inspect}" if docid && @index[docid][:message_id] != m.id
-    end
-
-    source_id = if m.source.is_a? Integer
-      m.source
-    else
-      m.source.id or raise "unregistered source #{m.source} (id #{m.source.id.inspect})"
-    end
-
-    snippet = if m.snippet_contains_encrypted_content? && $config[:discard_snippets_from_encrypted_messages]
-      ""
-    else
-      m.snippet
-    end
-
-    ## write the new document to the index. if the entry already exists in the
-    ## index, reuse it (which avoids having to reload the entry from the source,
-    ## which can be quite expensive for e.g. large threads of IMAP actions.)
-    ##
-    ## exception: if the index entry belongs to an earlier version of the
-    ## message, use everything from the new message instead, but union the
-    ## flags. this allows messages sent to mailing lists to have their header
-    ## updated and to have flags set properly.
-    ##
-    ## minor hack: messages in sources with lower ids have priority over
-    ## messages in sources with higher ids. so messages in the inbox will
-    ## override everyone, and messages in the sent box will be overridden
-    ## by everyone else.
-    ##
-    ## written in this manner to support previous versions of the index which
-    ## did not keep around the entry body. upgrading is thus seamless.
-    entry ||= {}
-    labels = m.labels.uniq # override because this is the new state, unless...
-
-    ## if we are a later version of a message, ignore what's in the index,
-    ## but merge in the labels.
-    if entry[:source_id] && entry[:source_info] && entry[:label] &&
-      ((entry[:source_id].to_i > source_id) || (entry[:source_info].to_i < m.source_info))
-      labels = (entry[:label].split(/\s+/).map { |l| l.intern } + m.labels).uniq
-      #Redwood::log "found updated version of message #{m.id}: #{m.subj}"
-      #Redwood::log "previous version was at #{entry[:source_id].inspect}:#{entry[:source_info].inspect}, this version at #{source_id.inspect}:#{m.source_info.inspect}"
-      #Redwood::log "merged labels are #{labels.inspect} (index #{entry[:label].inspect}, message #{m.labels.inspect})"
-      entry = {}
-    end
-
-    ## if force_overwite is true, ignore what's in the index. this is used
-    ## primarily by sup-sync to force index updates.
-    entry = {} if opts[:force_overwrite]
-
-    d = {
-      :message_id => m.id,
-      :source_id => source_id,
-      :source_info => m.source_info,
-      :date => (entry[:date] || m.date.to_indexable_s),
-      :body => (entry[:body] || m.indexable_content),
-      :snippet => snippet, # always override
-      :label => labels.uniq.join(" "),
-      :attachments => (entry[:attachments] || m.attachments.uniq.join(" ")),
-
-      ## always override :from and :to.
-      ## older versions of Sup would often store the wrong thing in the index
-      ## (because they were canonicalizing email addresses, resulting in the
-      ## wrong name associated with each.) the correct address is read from
-      ## the original header when these messages are opened in thread-view-mode,
-      ## so this allows people to forcibly update the address in the index by
-      ## marking those threads for saving.
-      :from => (m.from ? m.from.indexable_content : ""),
-      :to => (m.to + m.cc + m.bcc).map { |x| x.indexable_content }.join(" "),
-
-      :subject => (entry[:subject] || wrap_subj(Message.normalize_subj(m.subj))),
-      :refs => (entry[:refs] || (m.refs + m.replytos).uniq.join(" ")),
-    }
-
-    @index_mutex.synchronize do
-      @index.delete docid if docid
-      @index.add_document d
-    end
-
-    ## this hasn't been triggered in a long time.
-    ## docid, entry = load_entry_for_id m.id
-    ## raise "just added message #{m.id.inspect} but couldn't find it in a search" unless docid
+  def contains_id? id
+    unimplemented
   end
 
-  def save_index fn=File.join(@dir, "ferret")
-    # don't have to do anything, apparently
-  end
+  def contains? m; contains_id? m.id end
 
-  def contains_id? id
-    @index_mutex.synchronize { @index.search(Ferret::Search::TermQuery.new(:message_id, id)).total_hits > 0 }
+  def size
+    unimplemented
   end
-  def contains? m; contains_id? m.id end
-  def size; @index_mutex.synchronize { @index.size } end
+
   def empty?; size == 0 end
 
-  ## you should probably not call this on a block that doesn't break
+  ## Yields a message-id and message-building lambda for each
+  ## message that matches the given query, in descending date order.
+  ## You should probably not call this on a block that doesn't break
   ## rather quickly because the results can be very large.
-  EACH_BY_DATE_NUM = 100
-  def each_id_by_date opts={}
-    return if empty? # otherwise ferret barfs ###TODO: remove this once my ferret patch is accepted
-    query = build_query opts
-    offset = 0
-    while true
-      limit = (opts[:limit])? [EACH_BY_DATE_NUM, opts[:limit] - offset].min : EACH_BY_DATE_NUM
-      results = @index_mutex.synchronize { @index.search query, :sort => "date DESC", :limit => limit, :offset => offset }
-      Redwood::log "got #{results.total_hits} results for query (offset #{offset}) #{query.inspect}"
-      results.hits.each do |hit|
-        yield @index_mutex.synchronize { @index[hit.doc][:message_id] }, lambda { build_message hit.doc }
-      end
-      break if opts[:limit] and offset >= opts[:limit] - limit
-      break if offset >= results.total_hits - limit
-      offset += limit
-    end
+  def each_id_by_date query={}
+    unimplemented
   end
 
-  def num_results_for opts={}
-    return 0 if empty? # otherwise ferret barfs ###TODO: remove this once my ferret patch is accepted
-
-    q = build_query opts
-    @index_mutex.synchronize { @index.search(q, :limit => 1).total_hits }
+  ## Return the number of matches for query in the index
+  def num_results_for query={}
+    unimplemented
   end
 
   ## yield all messages in the thread containing 'm' by repeatedly
@@ -317,316 +119,68 @@ EOS
   ## only two options, :limit and :skip_killed. if :skip_killed is
   ## true, stops loading any thread if a message with a :killed flag
   ## is found.
-  SAME_SUBJECT_DATE_LIMIT = 7
-  MAX_CLAUSES = 1000
   def each_message_in_thread_for m, opts={}
-    #Redwood::log "Building thread for #{m.id}: #{m.subj}"
-    messages = {}
-    searched = {}
-    num_queries = 0
-
-    pending = [m.id]
-    if $config[:thread_by_subject] # do subject queries
-      date_min = m.date - (SAME_SUBJECT_DATE_LIMIT * 12 * 3600)
-      date_max = m.date + (SAME_SUBJECT_DATE_LIMIT * 12 * 3600)
-
-      q = Ferret::Search::BooleanQuery.new true
-      sq = Ferret::Search::PhraseQuery.new(:subject)
-      wrap_subj(Message.normalize_subj(m.subj)).split(/\s+/).each do |t|
-        sq.add_term t
-      end
-      q.add_query sq, :must
-      q.add_query Ferret::Search::RangeQuery.new(:date, :>= => date_min.to_indexable_s, :<= => date_max.to_indexable_s), :must
-
-      q = build_query :qobj => q
-
-      p1 = @index_mutex.synchronize { @index.search(q).hits.map { |hit| @index[hit.doc][:message_id] } }
-      Redwood::log "found #{p1.size} results for subject query #{q}"
-
-      p2 = @index_mutex.synchronize { @index.search(q.to_s, :limit => :all).hits.map { |hit| @index[hit.doc][:message_id] } }
-      Redwood::log "found #{p2.size} results in string form"
-
-      pending = (pending + p1 + p2).uniq
-    end
-
-    until pending.empty? || (opts[:limit] && messages.size >= opts[:limit])
-      q = Ferret::Search::BooleanQuery.new true
-      # this disappeared in newer ferrets... wtf.
-      # q.max_clause_count = 2048
-
-      lim = [MAX_CLAUSES / 2, pending.length].min
-      pending[0 ... lim].each do |id|
-        searched[id] = true
-        q.add_query Ferret::Search::TermQuery.new(:message_id, id), :should
-        q.add_query Ferret::Search::TermQuery.new(:refs, id), :should
-      end
-      pending = pending[lim .. -1]
-
-      q = build_query :qobj => q
-
-      num_queries += 1
-      killed = false
-      @index_mutex.synchronize do
-        @index.search_each(q, :limit => :all) do |docid, score|
-          break if opts[:limit] && messages.size >= opts[:limit]
-          if @index[docid][:label].split(/\s+/).include?("killed") && opts[:skip_killed]
-            killed = true
-            break
-          end
-          mid = @index[docid][:message_id]
-          unless messages.member?(mid)
-            #Redwood::log "got #{mid} as a child of #{id}"
-            messages[mid] ||= lambda { build_message docid }
-            refs = @index[docid][:refs].split(" ")
-            pending += refs.select { |id| !searched[id] }
-          end
-        end
-      end
-    end
-
-    if killed
-      Redwood::log "thread for #{m.id} is killed, ignoring"
-      false
-    else
-      Redwood::log "ran #{num_queries} queries to build thread of #{messages.size + 1} messages for #{m.id}: #{m.subj}" if num_queries > 0
-      messages.each { |mid, builder| yield mid, builder }
-      true
-    end
+    unimplemented
   end
 
-  ## builds a message object from a ferret result
-  def build_message docid
-    @index_mutex.synchronize do
-      doc = @index[docid]
-
-      source = @source_mutex.synchronize { @sources[doc[:source_id].to_i] }
-      raise "invalid source #{doc[:source_id]}" unless source
-
-      #puts "building message #{doc[:message_id]} (#{source}##{doc[:source_info]})"
-
-      fake_header = {
-        "date" => Time.at(doc[:date].to_i),
-        "subject" => unwrap_subj(doc[:subject]),
-        "from" => doc[:from],
-        "to" => doc[:to].split(/\s+/).join(", "), # reformat
-        "message-id" => doc[:message_id],
-        "references" => doc[:refs].split(/\s+/).map { |x| "<#{x}>" }.join(" "),
-      }
-
-      m = Message.new :source => source, :source_info => doc[:source_info].to_i,
-                  :labels => doc[:label].split(" ").map { |s| s.intern },
-                  :snippet => doc[:snippet]
-      m.parse_header fake_header
-      m
-    end
+  ## Load message with the given message-id from the index
+  def build_message id
+    unimplemented
   end
 
-  def fresh_thread_id; @next_thread_id += 1; end
-  def wrap_subj subj; "__START_SUBJECT__ #{subj} __END_SUBJECT__"; end
-  def unwrap_subj subj; subj =~ /__START_SUBJECT__ (.*?) __END_SUBJECT__/ && $1; end
-
-  def drop_entry docno; @index_mutex.synchronize { @index.delete docno } end
-
-  def load_entry_for_id mid
-    @index_mutex.synchronize do
-      results = @index.search Ferret::Search::TermQuery.new(:message_id, mid)
-      return if results.total_hits == 0
-      docid = results.hits[0].doc
-      entry = @index[docid]
-      entry_dup = entry.fields.inject({}) { |h, f| h[f] = entry[f]; h }
-      [docid, entry_dup]
-    end
+  ## Delete message with the given message-id from the index
+  def delete id
+    unimplemented
   end
 
-  def load_contacts emails, h={}
-    q = Ferret::Search::BooleanQuery.new true
-    emails.each do |e|
-      qq = Ferret::Search::BooleanQuery.new true
-      qq.add_query Ferret::Search::TermQuery.new(:from, e), :should
-      qq.add_query Ferret::Search::TermQuery.new(:to, e), :should
-      q.add_query qq
-    end
-    q.add_query Ferret::Search::TermQuery.new(:label, "spam"), :must_not
-    
-    Redwood::log "contact search: #{q}"
-    contacts = {}
-    num = h[:num] || 20
-    @index_mutex.synchronize do
-      @index.search_each q, :sort => "date DESC", :limit => :all do |docid, score|
-        break if contacts.size >= num
-        #Redwood::log "got message #{docid} to: #{@index[docid][:to].inspect} and from: #{@index[docid][:from].inspect}"
-        f = @index[docid][:from]
-        t = @index[docid][:to]
-
-        if AccountManager.is_account_email? f
-          t.split(" ").each { |e| contacts[Person.from_address(e)] = true }
-        else
-          contacts[Person.from_address(f)] = true
-        end
-      end
-    end
+  ## Given an array of email addresses, return an array of Person objects that
+  ## have sent mail to or received mail from any of the given addresses.
+  def load_contacts email_addresses, h={}
+    unimplemented
+  end
 
-    contacts.keys.compact
+  ## Yield each message-id matching query
+  def each_id query={}
+    unimplemented
   end
 
-  def load_sources fn=Redwood::SOURCE_FN
-    source_array = (Redwood::load_yaml_obj(fn) || []).map { |o| Recoverable.new o }
-    @source_mutex.synchronize do
-      @sources = Hash[*(source_array).map { |s| [s.id, s] }.flatten]
-      @sources_dirty = false
+  ## Yield each message matching query
+  def each_message query={}, &b
+    each_id query do |id|
+      yield build_message(id)
     end
   end
 
-  def has_any_from_source_with_label? source, label
-    q = Ferret::Search::BooleanQuery.new
-    q.add_query Ferret::Search::TermQuery.new("source_id", source.id.to_s), :must
-    q.add_query Ferret::Search::TermQuery.new("label", label.to_s), :must
-    @index_mutex.synchronize { @index.search(q, :limit => 1).total_hits > 0 }
+  ## Implementation-specific optimization step
+  def optimize
+    unimplemented
   end
 
-protected
-
-  ## do any specialized parsing
-  ## returns nil and flashes error message if parsing failed
-  def parse_user_query_string s
-    extraopts = {}
-
-    subs = s.gsub(/\b(to|from):(\S+)\b/) do
-      field, name = $1, $2
-      if(p = ContactManager.contact_for(name))
-        [field, p.email]
-      elsif name == "me"
-        [field, "(" + AccountManager.user_emails.join("||") + ")"]
-      else
-        [field, name]
-      end.join(":")
-    end
-
-    ## if we see a label:deleted or a label:spam term anywhere in the query
-    ## string, we set the extra load_spam or load_deleted options to true.
-    ## bizarre? well, because the query allows arbitrary parenthesized boolean
-    ## expressions, without fully parsing the query, we can't tell whether
-    ## the user is explicitly directing us to search spam messages or not.
-    ## e.g. if the string is -(-(-(-(-label:spam)))), does the user want to
-    ## search spam messages or not?
-    ##
-    ## so, we rely on the fact that turning these extra options ON turns OFF
-    ## the adding of "-label:deleted" or "-label:spam" terms at the very
-    ## final stage of query processing. if the user wants to search spam
-    ## messages, not adding that is the right thing; if he doesn't want to
-    ## search spam messages, then not adding it won't have any effect.
-    extraopts[:load_spam] = true if subs =~ /\blabel:spam\b/
-    extraopts[:load_deleted] = true if subs =~ /\blabel:deleted\b/
-
-    ## gmail style "is" operator
-    subs = subs.gsub(/\b(is|has):(\S+)\b/) do
-      field, label = $1, $2
-      case label
-      when "read"
-        "-label:unread"
-      when "spam"
-        extraopts[:load_spam] = true
-        "label:spam"
-      when "deleted"
-        extraopts[:load_deleted] = true
-        "label:deleted"
-      else
-        "label:#{$2}"
-      end
-    end
-
-    ## gmail style attachments "filename" and "filetype" searches
-    subs = subs.gsub(/\b(filename|filetype):(\((.+?)\)\B|(\S+)\b)/) do
-      field, name = $1, ($3 || $4)
-      case field
-      when "filename"
-        Redwood::log "filename - translated #{field}:#{name} to attachments:(#{name.downcase})"
-        "attachments:(#{name.downcase})"
-      when "filetype"
-        Redwood::log "filetype - translated #{field}:#{name} to attachments:(*.#{name.downcase})"
-        "attachments:(*.#{name.downcase})"
-      end
-    end
-
-    if $have_chronic
-      chronic_failure = false
-      subs = subs.gsub(/\b(before|on|in|during|after):(\((.+?)\)\B|(\S+)\b)/) do
-        break if chronic_failure
-        field, datestr = $1, ($3 || $4)
-        realdate = Chronic.parse(datestr, :guess => false, :context => :none)
-        if realdate
-          case field
-          when "after"
-            Redwood::log "chronic: translated #{field}:#{datestr} to #{realdate.end}"
-            "date:(>= #{sprintf "%012d", realdate.end.to_i})"
-          when "before"
-            Redwood::log "chronic: translated #{field}:#{datestr} to #{realdate.begin}"
-            "date:(<= #{sprintf "%012d", realdate.begin.to_i})"
-          else
-            Redwood::log "chronic: translated #{field}:#{datestr} to #{realdate}"
-            "date:(<= #{sprintf "%012d", realdate.end.to_i}) date:(>= #{sprintf "%012d", realdate.begin.to_i})"
-          end
-        else
-          BufferManager.flash "Can't understand date #{datestr.inspect}!"
-          chronic_failure = true
-        end
-      end
-      subs = nil if chronic_failure
-    end
-
-    ## limit:42 restrict the search to 42 results
-    subs = subs.gsub(/\blimit:(\S+)\b/) do
-      lim = $1
-      if lim =~ /^\d+$/
-        extraopts[:limit] = lim.to_i
-        ''
-      else
-        BufferManager.flash "Can't understand limit #{lim.inspect}!"
-        subs = nil
-      end
-    end
-    
-    if subs
-      [@qparser.parse(subs), extraopts]
-    else
-      nil
-    end
+  ## Return the id source of the source the message with the given message-id
+  ## was synced from
+  def source_for_id id
+    unimplemented
   end
 
-  def build_query opts
-    query = Ferret::Search::BooleanQuery.new
-    query.add_query opts[:qobj], :must if opts[:qobj]
-    labels = ([opts[:label]] + (opts[:labels] || [])).compact
-    labels.each { |t| query.add_query Ferret::Search::TermQuery.new("label", t.to_s), :must }
-    if opts[:participants]
-      q2 = Ferret::Search::BooleanQuery.new
-      opts[:participants].each do |p|
-        q2.add_query Ferret::Search::TermQuery.new("from", p.email), :should
-        q2.add_query Ferret::Search::TermQuery.new("to", p.email), :should
-      end
-      query.add_query q2, :must
-    end
-        
-    query.add_query Ferret::Search::TermQuery.new("label", "spam"), :must_not unless opts[:load_spam] || labels.include?(:spam)
-    query.add_query Ferret::Search::TermQuery.new("label", "deleted"), :must_not unless opts[:load_deleted] || labels.include?(:deleted)
-    query.add_query Ferret::Search::TermQuery.new("label", "killed"), :must_not if opts[:skip_killed]
-    query
-  end
+  class ParseError < StandardError; end
 
-  def save_sources fn=Redwood::SOURCE_FN
-    @source_mutex.synchronize do
-      if @sources_dirty || @sources.any? { |id, s| s.dirty? }
-        bakfn = fn + ".bak"
-        if File.exists? fn
-          File.chmod 0600, fn
-          FileUtils.mv fn, bakfn, :force => true unless File.exists?(bakfn) && File.size(fn) == 0
-        end
-        Redwood::save_yaml_obj sources.sort_by { |s| s.id.to_i }, fn, true
-        File.chmod 0600, fn
-      end
-      @sources_dirty = false
-    end
+  ## parse a query string from the user. returns a query object
+  ## that can be passed to any index method with a 'query'
+  ## argument.
+  ##
+  ## raises a ParseError if something went wrong.
+  def parse_query s
+    unimplemented
   end
 end
 
+index_name = ENV['SUP_INDEX'] || $config[:index] || DEFAULT_INDEX
+case index_name
+  when "xapian"; require "sup/xapian_index"
+  when "ferret"; require "sup/ferret_index"
+  else fail "unknown index type #{index_name.inspect}"
+end
+Index = Redwood.const_get "#{index_name.capitalize}Index"
+debug "using index #{Index.name}"
+
 end