# encoding: UTF-8 # -- # Copyright (C) 2008-2011 10gen Inc. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. module Mongo # A named collection of documents in a database. class Collection include Mongo::Logging attr_reader :db, :name, :pk_factory, :hint, :safe # Initialize a collection object. # # @param [String, Symbol] name the name of the collection. # @param [DB] db a MongoDB database instance. # # @option opts [:create_pk] :pk (BSON::ObjectId) A primary key factory to use # other than the default BSON::ObjectId. # # @option opts [Boolean, Hash] :safe (false) Set the default safe-mode options # for insert, update, and remove method called on this Collection instance. If no # value is provided, the default value set on this instance's DB will be used. This # default can be overridden for any invocation of insert, update, or remove. # @option options [:primary, :secondary] :read The default read preference for queries # initiates from this connection object. If +:secondary+ is chosen, reads will be sent # to one of the closest available secondary nodes. If a secondary node cannot be located, the # read will be sent to the primary. If this option is left unspecified, the value of the read # preference for this collection's associated Mongo::DB object will be used. # # @raise [InvalidNSName] # if collection name is empty, contains '$', or starts or ends with '.' # # @raise [TypeError] # if collection name is not a string or symbol # # @return [Collection] # # @core collections constructor_details def initialize(name, db, opts={}) if db.is_a?(String) && name.is_a?(Mongo::DB) warn "Warning: the order of parameters to initialize a collection have changed. " + "Please specify the collection name first, followed by the db. This will be made permanent" + "in v2.0." db, name = name, db end case name when Symbol, String else raise TypeError, "new_name must be a string or symbol" end name = name.to_s if name.empty? or name.include? ".." raise Mongo::InvalidNSName, "collection names cannot be empty" end if name.include? "$" raise Mongo::InvalidNSName, "collection names must not contain '$'" unless name =~ /((^\$cmd)|(oplog\.\$main))/ end if name.match(/^\./) or name.match(/\.$/) raise Mongo::InvalidNSName, "collection names must not start or end with '.'" end if opts.respond_to?(:create_pk) || !opts.is_a?(Hash) warn "The method for specifying a primary key factory on a Collection has changed.\n" + "Please specify it as an option (e.g., :pk => PkFactory)." pk_factory = opts else pk_factory = nil end @db, @name = db, name @connection = @db.connection @logger = @connection.logger @cache_time = @db.cache_time @cache = Hash.new(0) unless pk_factory @safe = opts.fetch(:safe, @db.safe) if value = opts[:read] Mongo::Support.validate_read_preference(value) else value = @db.read_preference end @read_preference = value.is_a?(Hash) ? value.dup : value end @pk_factory = pk_factory || opts[:pk] || BSON::ObjectId @hint = nil end # Indicate whether this is a capped collection. # # @raise [Mongo::OperationFailure] # if the collection doesn't exist. # # @return [Boolean] def capped? @db.command({:collstats => @name})['capped'] == 1 end # Return a sub-collection of this collection by name. If 'users' is a collection, then # 'users.comments' is a sub-collection of users. # # @param [String, Symbol] name # the collection to return # # @raise [Mongo::InvalidNSName] # if passed an invalid collection name # # @return [Collection] # the specified sub-collection def [](name) name = "#{self.name}.#{name}" return Collection.new(name, db) if !db.strict? || db.collection_names.include?(name.to_s) raise "Collection #{name} doesn't exist. Currently in strict mode." end # Set a hint field for query optimizer. Hint may be a single field # name, array of field names, or a hash (preferably an [OrderedHash]). # If using MongoDB > 1.1, you probably don't ever need to set a hint. # # @param [String, Array, OrderedHash] hint a single field, an array of # fields, or a hash specifying fields def hint=(hint=nil) @hint = normalize_hint_fields(hint) self end # Query the database. # # The +selector+ argument is a prototype document that all results must # match. For example: # # collection.find({"hello" => "world"}) # # only matches documents that have a key "hello" with value "world". # Matches can have other keys *in addition* to "hello". # # If given an optional block +find+ will yield a Cursor to that block, # close the cursor, and then return nil. This guarantees that partially # evaluated cursors will be closed. If given no block +find+ returns a # cursor. # # @param [Hash] selector # a document specifying elements which must be present for a # document to be included in the result set. Note that in rare cases, # (e.g., with $near queries), the order of keys will matter. To preserve # key order on a selector, use an instance of BSON::OrderedHash (only applies # to Ruby 1.8). # # @option opts [Array, Hash] :fields field names that should be returned in the result # set ("_id" will be included unless explicity excluded). By limiting results to a certain subset of fields, # you can cut down on network traffic and decoding time. If using a Hash, keys should be field # names and values should be either 1 or 0, depending on whether you want to include or exclude # the given field. # @option opts [:primary, :secondary] :read The default read preference for queries # initiates from this connection object. If +:secondary+ is chosen, reads will be sent # to one of the closest available secondary nodes. If a secondary node cannot be located, the # read will be sent to the primary. If this option is left unspecified, the value of the read # preference for this Collection object will be used. # @option opts [Integer] :skip number of documents to skip from the beginning of the result set # @option opts [Integer] :limit maximum number of documents to return # @option opts [Array] :sort an array of [key, direction] pairs to sort by. Direction should # be specified as Mongo::ASCENDING (or :ascending / :asc) or Mongo::DESCENDING (or :descending / :desc) # @option opts [String, Array, OrderedHash] :hint hint for query optimizer, usually not necessary if # using MongoDB > 1.1 # @option opts [Boolean] :snapshot (false) if true, snapshot mode will be used for this query. # Snapshot mode assures no duplicates are returned, or objects missed, which were preset at both the start and # end of the query's execution. # For details see http://www.mongodb.org/display/DOCS/How+to+do+Snapshotting+in+the+Mongo+Database # @option opts [Boolean] :batch_size (100) the number of documents to returned by the database per # GETMORE operation. A value of 0 will let the database server decide how many results to returns. # This option can be ignored for most use cases. # @option opts [Boolean] :timeout (true) when +true+, the returned cursor will be subject to # the normal cursor timeout behavior of the mongod process. When +false+, the returned cursor will # never timeout. Note that disabling timeout will only work when #find is invoked with a block. # This is to prevent any inadvertant failure to close the cursor, as the cursor is explicitly # closed when block code finishes. # @option opts [Integer] :max_scan (nil) Limit the number of items to scan on both collection scans and indexed queries.. # @option opts [Boolean] :show_disk_loc (false) Return the disk location of each query result (for debugging). # @option opts [Boolean] :return_key (false) Return the index key used to obtain the result (for debugging). # @option opts [Block] :transformer (nil) a block for tranforming returned documents. # This is normally used by object mappers to convert each returned document to an instance of a class. # # @raise [ArgumentError] # if timeout is set to false and find is not invoked in a block # # @raise [RuntimeError] # if given unknown options # # @core find find-instance_method def find(selector={}, opts={}) opts = opts.dup fields = opts.delete(:fields) fields = ["_id"] if fields && fields.empty? skip = opts.delete(:skip) || skip || 0 limit = opts.delete(:limit) || 0 sort = opts.delete(:sort) hint = opts.delete(:hint) snapshot = opts.delete(:snapshot) batch_size = opts.delete(:batch_size) timeout = (opts.delete(:timeout) == false) ? false : true max_scan = opts.delete(:max_scan) return_key = opts.delete(:return_key) transformer = opts.delete(:transformer) show_disk_loc = opts.delete(:show_disk_loc) read = opts.delete(:read) || @read_preference if timeout == false && !block_given? raise ArgumentError, "Collection#find must be invoked with a block when timeout is disabled." end if hint hint = normalize_hint_fields(hint) else hint = @hint # assumed to be normalized already end raise RuntimeError, "Unknown options [#{opts.inspect}]" unless opts.empty? cursor = Cursor.new(self, { :selector => selector, :fields => fields, :skip => skip, :limit => limit, :order => sort, :hint => hint, :snapshot => snapshot, :timeout => timeout, :batch_size => batch_size, :transformer => transformer, :max_scan => max_scan, :show_disk_loc => show_disk_loc, :return_key => return_key, :read => read }) if block_given? yield cursor cursor.close nil else cursor end end # Return a single object from the database. # # @return [OrderedHash, Nil] # a single document or nil if no result is found. # # @param [Hash, ObjectId, Nil] spec_or_object_id a hash specifying elements # which must be present for a document to be included in the result set or an # instance of ObjectId to be used as the value for an _id query. # If nil, an empty selector, {}, will be used. # # @option opts [Hash] # any valid options that can be send to Collection#find # # @raise [TypeError] # if the argument is of an improper type. def find_one(spec_or_object_id=nil, opts={}) spec = case spec_or_object_id when nil {} when BSON::ObjectId {:_id => spec_or_object_id} when Hash spec_or_object_id else raise TypeError, "spec_or_object_id must be an instance of ObjectId or Hash, or nil" end find(spec, opts.merge(:limit => -1)).next_document end # Save a document to this collection. # # @param [Hash] doc # the document to be saved. If the document already has an '_id' key, # then an update (upsert) operation will be performed, and any existing # document with that _id is overwritten. Otherwise an insert operation is performed. # # @return [ObjectId] the _id of the saved document. # # @option opts [Boolean, Hash] :safe (+false+) # run the operation in safe mode, which run a getlasterror command on the # database to report any assertion. In addition, a hash can be provided to # run an fsync and/or wait for replication of the save (>= 1.5.1). See the options # for DB#error. # # @raise [OperationFailure] when :safe mode fails. def save(doc, opts={}) if doc.has_key?(:_id) || doc.has_key?('_id') id = doc[:_id] || doc['_id'] update({:_id => id}, doc, :upsert => true, :safe => opts.fetch(:safe, @safe)) id else insert(doc, :safe => opts.fetch(:safe, @safe)) end end # Insert one or more documents into the collection. # # @param [Hash, Array] doc_or_docs # a document (as a hash) or array of documents to be inserted. # # @return [ObjectId, Array] # The _id of the inserted document or a list of _ids of all inserted documents. # # @option opts [Boolean, Hash] :safe (+false+) # run the operation in safe mode, which run a getlasterror command on the # database to report any assertion. In addition, a hash can be provided to # run an fsync and/or wait for replication of the insert (>= 1.5.1). Safe # options provided here will override any safe options set on this collection, # its database object, or the current connection. See the options on # for DB#get_last_error. # # @option opts [Boolean] :continue_on_error (+false+) If true, then # continue a bulk insert even if one of the documents inserted # triggers a database assertion (as in a duplicate insert, for instance). # If not using safe mode, the list of ids returned will # include the object ids of all documents attempted on insert, even # if some are rejected on error. When safe mode is # enabled, any error will raise an OperationFailure exception. # MongoDB v2.0+. # # @core insert insert-instance_method def insert(doc_or_docs, opts={}) doc_or_docs = [doc_or_docs] unless doc_or_docs.is_a?(Array) doc_or_docs.collect! { |doc| @pk_factory.create_pk(doc) } safe = opts.fetch(:safe, @safe) result = insert_documents(doc_or_docs, @name, true, safe, opts) result.size > 1 ? result : result.first end alias_method :<<, :insert # Remove all documents from this collection. # # @param [Hash] selector # If specified, only matching documents will be removed. # # @option opts [Boolean, Hash] :safe (+false+) # run the operation in safe mode, which will run a getlasterror command on the # database to report any assertion. In addition, a hash can be provided to # run an fsync and/or wait for replication of the remove (>= 1.5.1). Safe # options provided here will override any safe options set on this collection, # its database, or the current connection. See the options for DB#get_last_error for more details. # # @example remove all documents from the 'users' collection: # users.remove # users.remove({}) # # @example remove only documents that have expired: # users.remove({:expire => {"$lte" => Time.now}}) # # @return [Hash, true] Returns a Hash containing the last error object if running in safe mode. # Otherwise, returns true. # # @raise [Mongo::OperationFailure] an exception will be raised iff safe mode is enabled # and the operation fails. # # @core remove remove-instance_method def remove(selector={}, opts={}) # Initial byte is 0. safe = opts.fetch(:safe, @safe) message = BSON::ByteBuffer.new("\0\0\0\0") BSON::BSON_RUBY.serialize_cstr(message, "#{@db.name}.#{@name}") message.put_int(0) message.put_binary(BSON::BSON_CODER.serialize(selector, false, true, @connection.max_bson_size).to_s) instrument(:remove, :database => @db.name, :collection => @name, :selector => selector) do if safe @connection.send_message_with_safe_check(Mongo::Constants::OP_DELETE, message, @db.name, nil, safe) else @connection.send_message(Mongo::Constants::OP_DELETE, message) true end end end # Update one or more documents in this collection. # # @param [Hash] selector # a hash specifying elements which must be present for a document to be updated. Note: # the update command currently updates only the first document matching the # given selector. If you want all matching documents to be updated, be sure # to specify :multi => true. # @param [Hash] document # a hash specifying the fields to be changed in the selected document, # or (in the case of an upsert) the document to be inserted # # @option opts [Boolean] :upsert (+false+) if true, performs an upsert (update or insert) # @option opts [Boolean] :multi (+false+) update all documents matching the selector, as opposed to # just the first matching document. Note: only works in MongoDB 1.1.3 or later. # @option opts [Boolean] :safe (+false+) # If true, check that the save succeeded. OperationFailure # will be raised on an error. Note that a safe check requires an extra # round-trip to the database. Safe options provided here will override any safe # options set on this collection, its database object, or the current collection. # See the options for DB#get_last_error for details. # # @return [Hash, true] Returns a Hash containing the last error object if running in safe mode. # Otherwise, returns true. # # @core update update-instance_method def update(selector, document, opts={}) # Initial byte is 0. safe = opts.fetch(:safe, @safe) message = BSON::ByteBuffer.new("\0\0\0\0") BSON::BSON_RUBY.serialize_cstr(message, "#{@db.name}.#{@name}") update_options = 0 update_options += 1 if opts[:upsert] update_options += 2 if opts[:multi] message.put_int(update_options) message.put_binary(BSON::BSON_CODER.serialize(selector, false, true).to_s) message.put_binary(BSON::BSON_CODER.serialize(document, false, true, @connection.max_bson_size).to_s) instrument(:update, :database => @db.name, :collection => @name, :selector => selector, :document => document) do if safe @connection.send_message_with_safe_check(Mongo::Constants::OP_UPDATE, message, @db.name, nil, safe) else @connection.send_message(Mongo::Constants::OP_UPDATE, message) end end end # Create a new index. # # @param [String, Array] spec # should be either a single field name or an array of # [field name, direction] pairs. Directions should be specified # as Mongo::ASCENDING, Mongo::DESCENDING, or Mongo::GEO2D. # # Note that geospatial indexing only works with versions of MongoDB >= 1.3.3+. Keep in mind, too, # that in order to geo-index a given field, that field must reference either an array or a sub-object # where the first two values represent x- and y-coordinates. Examples can be seen below. # # Also note that it is permissible to create compound indexes that include a geospatial index as # long as the geospatial index comes first. # # If your code calls create_index frequently, you can use Collection#ensure_index to cache these calls # and thereby prevent excessive round trips to the database. # # @option opts [Boolean] :unique (false) if true, this index will enforce a uniqueness constraint. # @option opts [Boolean] :background (false) indicate that the index should be built in the background. This # feature is only available in MongoDB >= 1.3.2. # @option opts [Boolean] :drop_dups (nil) If creating a unique index on a collection with pre-existing records, # this option will keep the first document the database indexes and drop all subsequent with duplicate values. # @option opts [Integer] :min (nil) specify the minimum longitude and latitude for a geo index. # @option opts [Integer] :max (nil) specify the maximum longitude and latitude for a geo index. # # @example Creating a compound index: # @posts.create_index([['subject', Mongo::ASCENDING], ['created_at', Mongo::DESCENDING]]) # # @example Creating a geospatial index: # @restaurants.create_index([['location', Mongo::GEO2D]]) # # # Note that this will work only if 'location' represents x,y coordinates: # {'location': [0, 50]} # {'location': {'x' => 0, 'y' => 50}} # {'location': {'latitude' => 0, 'longitude' => 50}} # # @example A geospatial index with alternate longitude and latitude: # @restaurants.create_index([['location', Mongo::GEO2D]], :min => 500, :max => 500) # # @return [String] the name of the index created. # # @core indexes create_index-instance_method def create_index(spec, opts={}) opts[:dropDups] = opts[:drop_dups] if opts[:drop_dups] field_spec = parse_index_spec(spec) opts = opts.dup name = opts.delete(:name) || generate_index_name(field_spec) name = name.to_s if name generate_indexes(field_spec, name, opts) name end # Calls create_index and sets a flag to not do so again for another X minutes. # this time can be specified as an option when initializing a Mongo::DB object as options[:cache_time] # Any changes to an index will be propogated through regardless of cache time (e.g., a change of index direction) # # The parameters and options for this methods are the same as those for Collection#create_index. # # @example Call sequence: # Time t: @posts.ensure_index([['subject', Mongo::ASCENDING]) -- calls create_index and # sets the 5 minute cache # Time t+2min : @posts.ensure_index([['subject', Mongo::ASCENDING]) -- doesn't do anything # Time t+3min : @posts.ensure_index([['something_else', Mongo::ASCENDING]) -- calls create_index # and sets 5 minute cache # Time t+10min : @posts.ensure_index([['subject', Mongo::ASCENDING]) -- calls create_index and # resets the 5 minute counter # # @return [String] the name of the index. def ensure_index(spec, opts={}) now = Time.now.utc.to_i opts[:dropDups] = opts[:drop_dups] if opts[:drop_dups] field_spec = parse_index_spec(spec) name = opts[:name] || generate_index_name(field_spec) name = name.to_s if name if !@cache[name] || @cache[name] <= now generate_indexes(field_spec, name, opts) end # Reset the cache here in case there are any errors inserting. Best to be safe. @cache[name] = now + @cache_time name end # Drop a specified index. # # @param [String] name # # @core indexes def drop_index(name) if name.is_a?(Array) return drop_index(index_name(name)) end @cache[name.to_s] = nil @db.drop_index(@name, name) end # Drop all indexes. # # @core indexes def drop_indexes @cache = {} # Note: calling drop_indexes with no args will drop them all. @db.drop_index(@name, '*') end # Drop the entire collection. USE WITH CAUTION. def drop @db.drop_collection(@name) end # Atomically update and return a document using MongoDB's findAndModify command. (MongoDB > 1.3.0) # # @option opts [Hash] :query ({}) a query selector document for matching the desired document. # @option opts [Hash] :update (nil) the update operation to perform on the matched document. # @option opts [Array, String, OrderedHash] :sort ({}) specify a sort option for the query using any # of the sort options available for Cursor#sort. Sort order is important if the query will be matching # multiple documents since only the first matching document will be updated and returned. # @option opts [Boolean] :remove (false) If true, removes the the returned document from the collection. # @option opts [Boolean] :new (false) If true, returns the updated document; otherwise, returns the document # prior to update. # # @return [Hash] the matched document. # # @core findandmodify find_and_modify-instance_method def find_and_modify(opts={}) cmd = BSON::OrderedHash.new cmd[:findandmodify] = @name cmd.merge!(opts) cmd[:sort] = Mongo::Support.format_order_clause(opts[:sort]) if opts[:sort] @db.command(cmd)['value'] end # Perform a map-reduce operation on the current collection. # # @param [String, BSON::Code] map a map function, written in JavaScript. # @param [String, BSON::Code] reduce a reduce function, written in JavaScript. # # @option opts [Hash] :query ({}) a query selector document, like what's passed to #find, to limit # the operation to a subset of the collection. # @option opts [Array] :sort ([]) an array of [key, direction] pairs to sort by. Direction should # be specified as Mongo::ASCENDING (or :ascending / :asc) or Mongo::DESCENDING (or :descending / :desc) # @option opts [Integer] :limit (nil) if passing a query, number of objects to return from the collection. # @option opts [String, BSON::Code] :finalize (nil) a javascript function to apply to the result set after the # map/reduce operation has finished. # @option opts [String] :out (nil) a valid output type. In versions of MongoDB prior to v1.7.6, # this option takes the name of a collection for the output results. In versions 1.7.6 and later, # this option specifies the output type. See the core docs for available output types. # @option opts [Boolean] :keeptemp (false) if true, the generated collection will be persisted. The defualt # is false. Note that this option has no effect is versions of MongoDB > v1.7.6. # @option opts [Boolean ] :verbose (false) if true, provides statistics on job execution time. # @option opts [Boolean] :raw (false) if true, return the raw result object from the map_reduce command, and not # the instantiated collection that's returned by default. Note if a collection name isn't returned in the # map-reduce output (as, for example, when using :out => { :inline => 1 }), then you must specify this option # or an ArgumentError will be raised. # # @return [Collection, Hash] a Mongo::Collection object or a Hash with the map-reduce command's results. # # @raise ArgumentError if you specify { :out => { :inline => true }} but don't specify :raw => true. # # @see http://www.mongodb.org/display/DOCS/MapReduce Offical MongoDB map/reduce documentation. # # @core mapreduce map_reduce-instance_method def map_reduce(map, reduce, opts={}) map = BSON::Code.new(map) unless map.is_a?(BSON::Code) reduce = BSON::Code.new(reduce) unless reduce.is_a?(BSON::Code) raw = opts.delete(:raw) hash = BSON::OrderedHash.new hash['mapreduce'] = self.name hash['map'] = map hash['reduce'] = reduce hash.merge! opts if hash[:sort] hash[:sort] = Mongo::Support.format_order_clause(hash[:sort]) end result = @db.command(hash) unless Mongo::Support.ok?(result) raise Mongo::OperationFailure, "map-reduce failed: #{result['errmsg']}" end if raw result elsif result["result"] if result['result'].is_a? BSON::OrderedHash and result['result'].has_key? 'db' and result['result'].has_key? 'collection' otherdb = @db.connection[result['result']['db']] otherdb[result['result']['collection']] else @db[result["result"]] end else raise ArgumentError, "Could not instantiate collection from result. If you specified " + "{:out => {:inline => true}}, then you must also specify :raw => true to get the results." end end alias :mapreduce :map_reduce # Perform a group aggregation. # # @param [Hash] opts the options for this group operation. The minimum required are :initial # and :reduce. # # @option opts [Array, String, Symbol] :key (nil) Either the name of a field or a list of fields to group by (optional). # @option opts [String, BSON::Code] :keyf (nil) A JavaScript function to be used to generate the grouping keys (optional). # @option opts [String, BSON::Code] :cond ({}) A document specifying a query for filtering the documents over # which the aggregation is run (optional). # @option opts [Hash] :initial the initial value of the aggregation counter object (required). # @option opts [String, BSON::Code] :reduce (nil) a JavaScript aggregation function (required). # @option opts [String, BSON::Code] :finalize (nil) a JavaScript function that receives and modifies # each of the resultant grouped objects. Available only when group is run with command # set to true. # # @return [Array] the command response consisting of grouped items. def group(opts, condition={}, initial={}, reduce=nil, finalize=nil) if opts.is_a?(Hash) return new_group(opts) else warn "Collection#group no longer take a list of parameters. This usage is deprecated and will be remove in v2.0." + "Check out the new API at http://api.mongodb.org/ruby/current/Mongo/Collection.html#group-instance_method" end reduce = BSON::Code.new(reduce) unless reduce.is_a?(BSON::Code) group_command = { "group" => { "ns" => @name, "$reduce" => reduce, "cond" => condition, "initial" => initial } } if opts.is_a?(Symbol) raise MongoArgumentError, "Group takes either an array of fields to group by or a JavaScript function" + "in the form of a String or BSON::Code." end unless opts.nil? if opts.is_a? Array key_type = "key" key_value = {} opts.each { |k| key_value[k] = 1 } else key_type = "$keyf" key_value = opts.is_a?(BSON::Code) ? opts : BSON::Code.new(opts) end group_command["group"][key_type] = key_value end finalize = BSON::Code.new(finalize) if finalize.is_a?(String) if finalize.is_a?(BSON::Code) group_command['group']['finalize'] = finalize end result = @db.command(group_command) if Mongo::Support.ok?(result) result["retval"] else raise OperationFailure, "group command failed: #{result['errmsg']}" end end # The value of the read preference. This will be # either +:primary+, +:secondary+, or an object # representing the tags to be read from. def read_preference @read_preference end private def new_group(opts={}) reduce = opts[:reduce] finalize = opts[:finalize] cond = opts.fetch(:cond, {}) initial = opts[:initial] if !(reduce && initial) raise MongoArgumentError, "Group requires at minimum values for initial and reduce." end cmd = { "group" => { "ns" => @name, "$reduce" => reduce.to_bson_code, "cond" => cond, "initial" => initial } } if finalize cmd['group']['finalize'] = finalize.to_bson_code end if key = opts[:key] if key.is_a?(String) || key.is_a?(Symbol) key = [key] end key_value = {} key.each { |k| key_value[k] = 1 } cmd["group"]["key"] = key_value elsif keyf = opts[:keyf] cmd["group"]["$keyf"] = keyf.to_bson_code end result = @db.command(cmd) result["retval"] end public # Return a list of distinct values for +key+ across all # documents in the collection. The key may use dot notation # to reach into an embedded object. # # @param [String, Symbol, OrderedHash] key or hash to group by. # @param [Hash] query a selector for limiting the result set over which to group. # # @example Saving zip codes and ages and returning distinct results. # @collection.save({:zip => 10010, :name => {:age => 27}}) # @collection.save({:zip => 94108, :name => {:age => 24}}) # @collection.save({:zip => 10010, :name => {:age => 27}}) # @collection.save({:zip => 99701, :name => {:age => 24}}) # @collection.save({:zip => 94108, :name => {:age => 27}}) # # @collection.distinct(:zip) # [10010, 94108, 99701] # @collection.distinct("name.age") # [27, 24] # # # You may also pass a document selector as the second parameter # # to limit the documents over which distinct is run: # @collection.distinct("name.age", {"name.age" => {"$gt" => 24}}) # [27] # # @return [Array] an array of distinct values. def distinct(key, query=nil) raise MongoArgumentError unless [String, Symbol].include?(key.class) command = BSON::OrderedHash.new command[:distinct] = @name command[:key] = key.to_s command[:query] = query @db.command(command)["values"] end # Rename this collection. # # Note: If operating in auth mode, the client must be authorized as an admin to # perform this operation. # # @param [String] new_name the new name for this collection # # @return [String] the name of the new collection. # # @raise [Mongo::InvalidNSName] if +new_name+ is an invalid collection name. def rename(new_name) case new_name when Symbol, String else raise TypeError, "new_name must be a string or symbol" end new_name = new_name.to_s if new_name.empty? or new_name.include? ".." raise Mongo::InvalidNSName, "collection names cannot be empty" end if new_name.include? "$" raise Mongo::InvalidNSName, "collection names must not contain '$'" end if new_name.match(/^\./) or new_name.match(/\.$/) raise Mongo::InvalidNSName, "collection names must not start or end with '.'" end @db.rename_collection(@name, new_name) @name = new_name end # Get information on the indexes for this collection. # # @return [Hash] a hash where the keys are index names. # # @core indexes def index_information @db.index_information(@name) end # Return a hash containing options that apply to this collection. # For all possible keys and values, see DB#create_collection. # # @return [Hash] options that apply to this collection. def options @db.collections_info(@name).next_document['options'] end # Return stats on the collection. Uses MongoDB's collstats command. # # @return [Hash] def stats @db.command({:collstats => @name}) end # Get the number of documents in this collection. # # @option opts [Hash] :query ({}) A query selector for filtering the documents counted. # @option opts [Integer] :skip (nil) The number of documents to skip. # @option opts [Integer] :limit (nil) The number of documents to limit. # # @return [Integer] def count(opts={}) find(opts[:query], :skip => opts[:skip], :limit => opts[:limit]).count(true) end alias :size :count protected def normalize_hint_fields(hint) case hint when String {hint => 1} when Hash hint when nil nil else h = BSON::OrderedHash.new hint.to_a.each { |k| h[k] = 1 } h end end private def index_name(spec) field_spec = parse_index_spec(spec) index_information.each do |index| return index[0] if index[1]['key'] == field_spec end nil end def parse_index_spec(spec) field_spec = BSON::OrderedHash.new if spec.is_a?(String) || spec.is_a?(Symbol) field_spec[spec.to_s] = 1 elsif spec.is_a?(Array) && spec.all? {|field| field.is_a?(Array) } spec.each do |f| if [Mongo::ASCENDING, Mongo::DESCENDING, Mongo::GEO2D, Mongo::GEOHAYSTACK].include?(f[1]) field_spec[f[0].to_s] = f[1] else raise MongoArgumentError, "Invalid index field #{f[1].inspect}; " + "should be one of Mongo::ASCENDING (1), Mongo::DESCENDING (-1) or Mongo::GEO2D ('2d')." end end else raise MongoArgumentError, "Invalid index specification #{spec.inspect}; " + "should be either a string, symbol, or an array of arrays." end field_spec end def generate_indexes(field_spec, name, opts) selector = { :name => name, :ns => "#{@db.name}.#{@name}", :key => field_spec } selector.merge!(opts) begin insert_documents([selector], Mongo::DB::SYSTEM_INDEX_COLLECTION, false, true) rescue Mongo::OperationFailure => e if selector[:dropDups] && e.message =~ /^11000/ # NOP. If the user is intentionally dropping dups, we can ignore duplicate key errors. else raise Mongo::OperationFailure, "Failed to create index #{selector.inspect} with the following error: " + "#{e.message}" end end nil end # Sends a Mongo::Constants::OP_INSERT message to the database. # Takes an array of +documents+, an optional +collection_name+, and a # +check_keys+ setting. def insert_documents(documents, collection_name=@name, check_keys=true, safe=false, flags={}) if flags[:continue_on_error] message = BSON::ByteBuffer.new message.put_int(1) else message = BSON::ByteBuffer.new("\0\0\0\0") end BSON::BSON_RUBY.serialize_cstr(message, "#{@db.name}.#{collection_name}") documents.each do |doc| message.put_binary(BSON::BSON_CODER.serialize(doc, check_keys, true, @connection.max_bson_size).to_s) end raise InvalidOperation, "Exceded maximum insert size of 16,000,000 bytes" if message.size > 16_000_000 instrument(:insert, :database => @db.name, :collection => collection_name, :documents => documents) do if safe @connection.send_message_with_safe_check(Mongo::Constants::OP_INSERT, message, @db.name, nil, safe) else @connection.send_message(Mongo::Constants::OP_INSERT, message) end end documents.collect { |o| o[:_id] || o['_id'] } end def generate_index_name(spec) indexes = [] spec.each_pair do |field, direction| indexes.push("#{field}_#{direction}") end indexes.join("_") end end end