Class | Mongo::DB |
In: |
lib/mongo/db.rb
|
Parent: | Object |
A MongoDB database.
SYSTEM_NAMESPACE_COLLECTION | = | "system.namespaces" |
SYSTEM_INDEX_COLLECTION | = | "system.indexes" |
SYSTEM_PROFILE_COLLECTION | = | "system.profile" |
SYSTEM_USER_COLLECTION | = | "system.users" |
SYSTEM_JS_COLLECTION | = | "system.js" |
SYSTEM_COMMAND_COLLECTION | = | "$cmd" |
cache_time | [RW] | The length of time that Collection.ensure_index should cache index calls |
connection | [R] | The Mongo::Connection instance connecting to the MongoDB server. |
name | [R] | The name of the database and the local safe option. |
safe | [R] | The name of the database and the local safe option. |
strict | [W] |
Strict mode enforces collection existence
checks. When true, asking for a collection that does not exist, or trying to
create a collection that already exists,
raises an error.
Strict mode is disabled by default, but enabled (true) at any time. |
Instances of DB are normally obtained by calling Mongo#db.
@param [String] name the database name. @param [Mongo::Connection] connection a connection object pointing to MongoDB. Note
that databases are usually instantiated via the Connection class. See the examples below.
@option opts [Boolean] :strict (False) If true, collections must exist to be accessed and must
not exist to be created. See DB#collection and DB#create_collection.
@option opts [Object, create_pk(doc)] :pk (BSON::ObjectId) A primary key factory object,
which should take a hash and return a hash which merges the original hash with any primary key fields the factory wishes to inject. (NOTE: if the object already has a primary key, the factory should not inject a new key).
@option opts [Boolean, Hash] :safe (false) Set the default safe-mode options
propagated to Collection objects instantiated off of this DB. If no value is provided, the default value set on this instance's Connection object will be used. This default can be overridden upon instantiation of any collection by explicity setting a :safe value on initialization
@option opts [Integer] :cache_time (300) Set the time that all ensure_index calls should cache the command.
@core databases constructor_details
# File lib/mongo/db.rb, line 79 def initialize(name, connection, opts={}) @name = Mongo::Support.validate_db_name(name) @connection = connection @strict = opts[:strict] @pk_factory = opts[:pk] @safe = opts.fetch(:safe, @connection.safe) if value = opts[:read] Mongo::Support.validate_read_preference(value) else value = @connection.read_preference end @read_preference = value.is_a?(Hash) ? value.dup : value @cache_time = opts[:cache_time] || 300 #5 minutes. end
Adds a stored Javascript function to the database which can executed server-side in map_reduce, db.eval and $where clauses.
@param [String] function_name @param [String] code
@return [String] the function name saved to the database
# File lib/mongo/db.rb, line 148 def add_stored_function(function_name, code) self[SYSTEM_JS_COLLECTION].save( { "_id" => function_name, :value => BSON::Code.new(code) } ) end
Adds a user to this database for use with authentication. If the user already exists in the system, the password will be updated.
@param [String] username @param [String] password
@return [Hash] an object representing the user.
# File lib/mongo/db.rb, line 178 def add_user(username, password) users = self[SYSTEM_USER_COLLECTION] user = users.find_one({:user => username}) || {:user => username} user['pwd'] = Mongo::Support.hash_password(username, password) users.save(user) return user end
Authenticate with the given username and password. Note that mongod must be started with the —auth option for authentication to be enabled.
@param [String] username @param [String] password @param [Boolean] save_auth
Save this authentication to the connection object using Connection#add_auth. This will ensure that the authentication will be applied on database reconnect. Note that this value must be true when using connection pooling.
@return [Boolean]
@raise [AuthenticationError]
@core authenticate authenticate-instance_method
# File lib/mongo/db.rb, line 109 def authenticate(username, password, save_auth=true) if @connection.pool_size > 1 if !save_auth raise MongoArgumentError, "If using connection pooling, :save_auth must be set to true." end @connection.authenticate_pools end issue_authentication(username, password, save_auth) end
Get a collection by name.
@param [String, Symbol] name the collection name. @param [Hash] opts any valid options that can be passed to Collection#new.
@raise [MongoDBError] if collection does not already exist and we‘re in
+strict+ mode.
@return [Mongo::Collection]
# File lib/mongo/db.rb, line 306 def collection(name, opts={}) if strict? && !collection_names.include?(name.to_s) raise Mongo::MongoDBError, "Collection #{name} doesn't exist. " + "Currently in strict mode." else opts = opts.dup opts[:safe] = opts.fetch(:safe, @safe) opts.merge!(:pk => @pk_factory) unless opts[:pk] Collection.new(name, self, opts) end end
Get an array of collection names in this database.
@return [Array]
# File lib/mongo/db.rb, line 228 def collection_names names = collections_info.collect { |doc| doc['name'] || '' } names = names.delete_if {|name| name.index(@name).nil? || name.index('$')} names.map {|name| name.sub(@name + '.', '')} end
Get an array of Collection instances, one for each collection in this database.
@return [Array<Mongo::Collection>]
# File lib/mongo/db.rb, line 237 def collections collection_names.map do |name| Collection.new(name, self) end end
Get info on system namespaces (collections). This method returns a cursor which can be iterated over. For each collection, a hash will be yielded containing a ‘name’ string and, optionally, an ‘options’ hash.
@param [String] coll_name return info for the specifed collection only.
@return [Mongo::Cursor]
# File lib/mongo/db.rb, line 250 def collections_info(coll_name=nil) selector = {} selector[:name] = full_collection_name(coll_name) if coll_name Cursor.new(Collection.new(SYSTEM_NAMESPACE_COLLECTION, self), :selector => selector) end
Send a command to the database.
Note: DB commands must start with the "command" key. For this reason, any selector containing more than one key must be an OrderedHash.
Note also that a command in MongoDB is just a kind of query that occurs on the system command collection ($cmd). Examine this method‘s implementation to see how it works.
@param [OrderedHash, Hash] selector an OrderedHash, or a standard Hash with just one key, specifying the command to be performed. In Ruby 1.9, OrderedHash isn‘t necessary since hashes are ordered by default.
@option opts [Boolean] :check_response (true) If true, raises an exception if the command fails. @option opts [Socket] :socket a socket to use for sending the command. This is mainly for internal use.
@return [Hash]
@core commands command_instance-method
# File lib/mongo/db.rb, line 496 def command(selector, opts={}) check_response = opts.fetch(:check_response, true) socket = opts[:socket] raise MongoArgumentError, "command must be given a selector" unless selector.is_a?(Hash) && !selector.empty? if selector.keys.length > 1 && RUBY_VERSION < '1.9' && selector.class != BSON::OrderedHash raise MongoArgumentError, "DB#command requires an OrderedHash when hash contains multiple keys" end begin result = Cursor.new(system_command_collection, :limit => -1, :selector => selector, :socket => socket).next_document rescue OperationFailure => ex raise OperationFailure, "Database command '#{selector.keys.first}' failed: #{ex.message}" end if result.nil? raise OperationFailure, "Database command '#{selector.keys.first}' failed: returned null." elsif (check_response && !ok?(result)) message = "Database command '#{selector.keys.first}' failed: (" message << result.map do |key, value| "#{key}: '#{value}'" end.join('; ') message << ').' code = result['code'] || result['assertionCode'] raise OperationFailure.new(message, code, result) else result end end
Create a collection.
new collection. If strict is true, will raise an error if collection name already exists.
@param [String, Symbol] name the name of the new collection.
@option opts [Boolean] :capped (False) created a capped collection.
@option opts [Integer] :size (Nil) If capped is true,
specifies the maximum number of bytes for the capped collection. If +false+, specifies the number of bytes allocated for the initial extent of the collection.
@option opts [Integer] :max (Nil) If capped is true, indicates
the maximum number of records in a capped collection.
@raise [MongoDBError] raised under two conditions:
either we're in +strict+ mode and the collection already exists or collection creation fails on the server.
@return [Mongo::Collection]
# File lib/mongo/db.rb, line 278 def create_collection(name, opts={}) name = name.to_s if collection_names.include?(name) if strict? raise MongoDBError, "Collection #{name} already exists. " + "Currently in strict mode." else return Collection.new(name, self, opts) end end # Create a new collection. oh = BSON::OrderedHash.new oh[:create] = name doc = command(oh.merge(opts || {})) return Collection.new(name, self, :pk => @pk_factory) if ok?(doc) raise MongoDBError, "Error creating collection: #{doc.inspect}" end
Dereference a DBRef, returning the document it points to.
@param [Mongo::DBRef] dbref
@return [Hash] the document indicated by the db reference.
@see www.mongodb.org/display/DOCS/DB+Ref MongoDB DBRef spec.
# File lib/mongo/db.rb, line 388 def dereference(dbref) collection(dbref.namespace).find_one("_id" => dbref.object_id) end
Drop a collection by name.
@param [String, Symbol] name
@return [Boolean] true on success or false if the collection name doesn‘t exist.
# File lib/mongo/db.rb, line 324 def drop_collection(name) return true unless collection_names.include?(name.to_s) ok?(command(:drop => name)) end
Drop an index from a given collection. Normally called from Collection#drop_index or Collection#drop_indexes.
@param [String] collection_name @param [String] index_name
@return [True] returns true on success.
@raise MongoDBError if there‘s an error renaming the collection.
# File lib/mongo/db.rb, line 436 def drop_index(collection_name, index_name) oh = BSON::OrderedHash.new oh[:deleteIndexes] = collection_name oh[:index] = index_name.to_s doc = command(oh, :check_response => false) ok?(doc) || raise(MongoDBError, "Error with drop_index command: #{doc.inspect}") end
Return true if an error was caused by the most recently executed database operation.
@return [Boolean]
# File lib/mongo/db.rb, line 352 def error? get_last_error['err'] != nil end
Evaluate a JavaScript expression in MongoDB.
@param [String, Code] code a JavaScript expression to evaluate server-side. @param [Integer, Hash] args any additional argument to be passed to the code expression when
it's run on the server.
@return [String] the return value of the function.
# File lib/mongo/db.rb, line 399 def eval(code, *args) if not code.is_a? BSON::Code code = BSON::Code.new(code) end oh = BSON::OrderedHash.new oh[:$eval] = code oh[:args] = args doc = command(oh) doc['retval'] end
A shortcut returning db plus dot plus collection name.
@param [String] collection_name
@return [String]
# File lib/mongo/db.rb, line 531 def full_collection_name(collection_name) "#{@name}.#{collection_name}" end
Run the getlasterror command with the specified replication options.
@option opts [Boolean] :fsync (false) @option opts [Integer] :w (nil) @option opts [Integer] :wtimeout (nil)
@return [Hash] the entire response to getlasterror.
@raise [MongoDBError] if the operation fails.
# File lib/mongo/db.rb, line 339 def get_last_error(opts={}) cmd = BSON::OrderedHash.new cmd[:getlasterror] = 1 cmd.merge!(opts) doc = command(cmd, :check_response => false) raise MongoDBError, "error retrieving last error: #{doc.inspect}" unless ok?(doc) doc end
Get information on the indexes for the given collection. Normally called by Collection#index_information.
@param [String] collection_name
@return [Hash] keys are index names and the values are lists of [key, direction] pairs
defining the index.
# File lib/mongo/db.rb, line 451 def index_information(collection_name) sel = {:ns => full_collection_name(collection_name)} info = {} Cursor.new(Collection.new(SYSTEM_INDEX_COLLECTION, self), :selector => sel).each do |index| info[index['name']] = index end info end
# File lib/mongo/db.rb, line 120 def issue_authentication(username, password, save_auth=true, opts={}) doc = command({:getnonce => 1}, :check_response => false, :socket => opts[:socket]) raise MongoDBError, "Error retrieving nonce: #{doc}" unless ok?(doc) nonce = doc['nonce'] auth = BSON::OrderedHash.new auth['authenticate'] = 1 auth['user'] = username auth['nonce'] = nonce auth['key'] = Mongo::Support.auth_key(username, password, nonce) if ok?(doc = self.command(auth, :check_response => false, :socket => opts[:socket])) if save_auth @connection.add_auth(@name, username, password) end true else message = "Failed to authenticate user '#{username}' on db '#{self.name}'" raise Mongo::AuthenticationError.new(message, doc['code'], doc) end end
# File lib/mongo/db.rb, line 215 def issue_logout(opts={}) doc = command({:logout => 1}, :socket => opts[:socket]) if ok?(doc) @connection.remove_auth(@name) true else raise MongoDBError, "error logging out: #{doc.inspect}" end end
Deauthorizes use for this database for this connection. Also removes any saved authentication in the connection class associated with this database.
@raise [MongoDBError] if logging out fails.
@return [Boolean]
# File lib/mongo/db.rb, line 207 def logout(opts={}) if @connection.pool_size > 1 @connection.logout_pools(@name) end issue_logout(opts) end
Specify a primary key factory if not already set.
@raise [MongoArgumentError] if the primary key factory has already been set.
# File lib/mongo/db.rb, line 545 def pk_factory=(pk_factory) if @pk_factory raise MongoArgumentError, "Cannot change primary key factory once it's been set" end @pk_factory = pk_factory end
Get the most recent error to have occured on this database.
This command only returns errors that have occured since the last call to DB#reset_error_history - returns nil if there is no such error.
@return [String, Nil] the text of the error or nil if no error has occurred.
# File lib/mongo/db.rb, line 362 def previous_error error = command(:getpreverror => 1) if error["err"] error else nil end end
Get the current profiling information.
@return [Array] a list of documents containing profiling information.
# File lib/mongo/db.rb, line 599 def profiling_info Cursor.new(Collection.new(SYSTEM_PROFILE_COLLECTION, self), :selector => {}).to_a end
Return the current database profiling level. If profiling is enabled, you can get the results using DB#profiling_info.
@return [Symbol] :off, :slow_only, or :all
@core profiling profiling_level-instance_method
# File lib/mongo/db.rb, line 559 def profiling_level oh = BSON::OrderedHash.new oh[:profile] = -1 doc = command(oh, :check_response => false) raise "Error with profile command: #{doc.inspect}" unless ok?(doc) && doc['was'].kind_of?(Numeric) case doc['was'].to_i when 0 :off when 1 :slow_only when 2 :all else raise "Error: illegal profiling level value #{doc['was']}" end end
Set this database‘s profiling level. If profiling is enabled, you can get the results using DB#profiling_info.
@param [Symbol] level acceptable options are +:off+, +:slow_only+, or +:all+.
# File lib/mongo/db.rb, line 580 def profiling_level=(level) oh = BSON::OrderedHash.new oh[:profile] = case level when :off 0 when :slow_only 1 when :all 2 else raise "Error: illegal profiling level value #{level}" end doc = command(oh, :check_response => false) ok?(doc) || raise(MongoDBError, "Error with profile command: #{doc.inspect}") end
The value of the read preference. This will be either +:primary+, +:secondary+, or an object representing the tags to be read from.
# File lib/mongo/db.rb, line 628 def read_preference @read_preference end
Removes stored Javascript function from the database. Returns false if the function does not exist
@param [String] function_name
@return [Boolean]
# File lib/mongo/db.rb, line 163 def remove_stored_function(function_name) if self[SYSTEM_JS_COLLECTION].find_one({"_id" => function_name}) self[SYSTEM_JS_COLLECTION].remove({"_id" => function_name}, :safe => true) else return false end end
Remove the given user from this database. Returns false if the user doesn‘t exist in the system.
@param [String] username
@return [Boolean]
# File lib/mongo/db.rb, line 192 def remove_user(username) if self[SYSTEM_USER_COLLECTION].find_one({:user => username}) self[SYSTEM_USER_COLLECTION].remove({:user => username}, :safe => true) else return false end end
Rename a collection.
@param [String] from original collection name. @param [String] to new collection name.
@return [True] returns true on success.
@raise MongoDBError if there‘s an error renaming the collection.
# File lib/mongo/db.rb, line 419 def rename_collection(from, to) oh = BSON::OrderedHash.new oh[:renameCollection] = "#{@name}.#{from}" oh[:to] = "#{@name}.#{to}" doc = DB.new('admin', @connection).command(oh, :check_response => false) ok?(doc) || raise(MongoDBError, "Error renaming collection: #{doc.inspect}") end
Reset the error history of this database
Calls to DB#previous_error will only return errors that have occurred since the most recent call to this method.
@return [Hash]
# File lib/mongo/db.rb, line 377 def reset_error_history command(:reseterror => 1) end
Validate a named collection.
@param [String] name the collection name.
@return [Hash] validation information.
@raise [MongoDBError] if the command fails or there‘s a problem with the validation
data, or if the collection is invalid.
# File lib/mongo/db.rb, line 611 def validate_collection(name) cmd = BSON::OrderedHash.new cmd[:validate] = name cmd[:full] = true doc = command(cmd, :check_response => false) if !ok?(doc) raise MongoDBError, "Error with validate command: #{doc.inspect}" end if (doc.has_key?('valid') && !doc['valid']) || (doc['result'] =~ /\b(exception|corrupt)\b/i) raise MongoDBError, "Error: invalid collection #{name}: #{doc.inspect}" end doc end