In Files

Parent

Included Modules

Mongo::DB

A MongoDB database.

Attributes

acceptable_latency[RW]

Read Preference

cache_time[RW]

The length of time that Collection.ensure_index should cache index calls

connection[R]

The Mongo::MongoClient instance connecting to the MongoDB server.

name[R]

The name of the database and the local write concern options.

read[RW]

Read Preference

tag_sets[RW]

Read Preference

write_concern[R]

The name of the database and the local write concern options.

Public Class Methods

new(name, client, opts={}) click to toggle source

Instances of DB are normally obtained by calling Mongo#db.

@param [String] name the database name. @param [Mongo::MongoClient] client a connection object pointing to MongoDB. Note

that databases are usually instantiated via the MongoClient class. See the examples below.

@option opts [Boolean] :strict (False) [DEPRECATED] If true, collections existence checks are performed during a number of relevant operations. See DB#collection, DB#create_collection and DB#drop_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 [String, Integer, Symbol] :w (1) Set default number of nodes to which a write

should be acknowledged

@option opts [Boolean] :j (false) Set journal acknowledgement @option opts [Integer] :wtimeout (nil) Set replica set acknowledgement timeout @option opts [Boolean] :fsync (false) Set fsync acknowledgement.

Notes on write concern:
  These write concern options are propagated to Collection objects instantiated off of this DB. If no
  options are provided, the default write concern set on this instance's MongoClient object will be used. This
  default can be overridden upon instantiation of any collection by explicitly setting write concern options
  on initialization or at the time of an operation.

@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 90
def initialize(name, client, opts={})
  @name       = Mongo::Support.validate_db_name(name)
  @connection = client
  @strict     = opts[:strict]
  @pk_factory = opts[:pk]

  @write_concern = get_write_concern(opts, client)

  @read = opts[:read] || @connection.read
  Mongo::ReadPreference::validate(@read)
  @tag_sets = opts.fetch(:tag_sets, @connection.tag_sets)
  @acceptable_latency = opts.fetch(:acceptable_latency, @connection.acceptable_latency)
  @cache_time = opts[:cache_time] || 300 #5 minutes.
end

Public Instance Methods

[](name, opts={}) click to toggle source
Alias for: collection
add_stored_function(function_name, code) click to toggle source

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 161
def add_stored_function(function_name, code)
  self[SYSTEM_JS_COLLECTION].save(
    {
      "_id" => function_name,
      :value => BSON::Code.new(code)
    }
  )
end
add_user(username, password, read_only = false) click to toggle source

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 @param [Boolean] read_only

Create a read-only user.

@return [Hash] an object representing the user.

# File lib/mongo/db.rb, line 190
def add_user(username, password, read_only = false)
  users = self[SYSTEM_USER_COLLECTION]
  user  = users.find_one({:user => username}) || {:user => username}
  user['pwd'] = Mongo::Support.hash_password(username, password)
  user['readOnly'] = true if read_only;
  begin
    users.save(user)
  rescue OperationFailure => ex
    # adding first admin user fails GLE in MongoDB 2.2
    raise ex unless ex.message =~ /login/
  end
  user
end
authenticate(username, password, save_auth=true) click to toggle source

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 client object using MongoClient#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 120
def authenticate(username, password, save_auth=true)
  if @connection.pool_size > 1 && !save_auth
    raise MongoArgumentError, "If using connection pooling, :save_auth must be set to true."
  end

  begin
    socket = @connection.checkout_reader(:mode => :primary_preferred)
    issue_authentication(username, password, save_auth, :socket => socket)
  ensure
    socket.checkin if socket
  end

  @connection.authenticate_pools
end
collection(name, opts={}) click to toggle source

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 319
def collection(name, opts={})
  if strict? && !collection_names.include?(name.to_s)
    raise MongoDBError, "Collection '#{name}' doesn't exist. (strict=true)"
  else
    opts = opts.dup
    opts.merge!(:pk => @pk_factory) unless opts[:pk]
    Collection.new(name, self, opts)
  end
end
Also aliased as: []
collection_names() click to toggle source

Get an array of collection names in this database.

@return [Array]

# File lib/mongo/db.rb, line 242
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
collections() click to toggle source

Get an array of Collection instances, one for each collection in this database.

@return [Array<Mongo::Collection>]

# File lib/mongo/db.rb, line 251
def collections
  collection_names.map do |name|
    Collection.new(name, self)
  end
end
collections_info(coll_name=nil) click to toggle source

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 specified collection only.

@return [Mongo::Cursor]

# File lib/mongo/db.rb, line 264
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
command(selector, opts={}) click to toggle source

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. @option opts [:primary, :secondary] :read Read preference for this command. See Collection#find for

more details.

@option opts [String] :comment (nil) a comment to include in profiling logs

@return [Hash]

@core commands command_instance-method

# File lib/mongo/db.rb, line 510
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

  if read_pref = opts[:read]
    Mongo::ReadPreference::validate(read_pref)
    unless read_pref == :primary || Mongo::Support::secondary_ok?(selector)
      raise MongoArgumentError, "Command is not supported on secondaries: #{selector.keys.first}"
    end
  end

  begin
    result = Cursor.new(
      system_command_collection,
      :limit => -1,
      :selector => selector,
      :socket => socket,
      :read => read_pref,
      :comment => opts[:comment]).next_document
  rescue OperationFailure => ex
    raise OperationFailure, "Database command '#{selector.keys.first}' failed: #{ex.message}"
  end

  raise OperationFailure,
    "Database command '#{selector.keys.first}' failed: returned null." unless result

  if 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)
  end

  result
end
create_collection(name, opts={}) click to toggle source

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 292
def create_collection(name, opts={})
  name = name.to_s
  if strict? && collection_names.include?(name)
    raise MongoDBError, "Collection '#{name}' already exists. (strict=true)"
  end

  begin
    cmd = BSON::OrderedHash.new
    cmd[:create] = name
    doc = command(cmd.merge(opts || {}))
    return Collection.new(name, self, :pk => @pk_factory) if ok?(doc)
  rescue OperationFailure => e
    return Collection.new(name, self, :pk => @pk_factory) if e.message =~ /exists/
    raise e
  end
  raise MongoDBError, "Error creating collection: #{doc.inspect}"
end
dereference(dbref) click to toggle source

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 399
def dereference(dbref)
  collection(dbref.namespace).find_one("_id" => dbref.object_id)
end
drop_collection(name) click to toggle source

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 335
def drop_collection(name)
  return false if strict? && !collection_names.include?(name.to_s)
  begin
    ok?(command(:drop => name))
  rescue OperationFailure => e
    false
  end
end
drop_index(collection_name, index_name) click to toggle source

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 dropping the index.

# File lib/mongo/db.rb, line 447
def drop_index(collection_name, index_name)
  cmd = BSON::OrderedHash.new
  cmd[:deleteIndexes] = collection_name
  cmd[:index] = index_name.to_s
  doc = command(cmd, :check_response => false)
  ok?(doc) || raise(MongoDBError, "Error with drop_index command: #{doc.inspect}")
end
error?() click to toggle source

Return true if an error was caused by the most recently executed database operation.

@return [Boolean]

# File lib/mongo/db.rb, line 367
def error?
  get_last_error['err'] != nil
end
eval(code, *args) click to toggle source

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 410
def eval(code, *args)
  unless code.is_a?(BSON::Code)
    code = BSON::Code.new(code)
  end

  cmd = BSON::OrderedHash.new
  cmd[:$eval] = code
  cmd[:args] = args
  doc = command(cmd)
  doc['retval']
end
full_collection_name(collection_name) click to toggle source

A shortcut returning db plus dot plus collection name.

@param [String] collection_name

@return [String]

# File lib/mongo/db.rb, line 559
def full_collection_name(collection_name)
  "#{@name}.#{collection_name}"
end
get_last_error(opts={}) click to toggle source

Run the getlasterror command with the specified replication options.

@option opts [Boolean] :fsync (false) @option opts [Integer] :w (nil) @option opts [Integer] :wtimeout (nil) @option opts [Boolean] :j (false)

@return [Hash] the entire response to getlasterror.

@raise [MongoDBError] if the operation fails.

# File lib/mongo/db.rb, line 354
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
index_information(collection_name) click to toggle source

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, type] pairs

defining the index.
# File lib/mongo/db.rb, line 462
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
issue_authentication(username, password, save_auth=true, opts={}) click to toggle source
# File lib/mongo/db.rb, line 135
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]))
    @connection.add_auth(@name, username, password) if save_auth
  else
    message = "Failed to authenticate user '#{username}' on db '#{self.name}'"
    raise Mongo::AuthenticationError.new(message, doc['code'], doc)
  end
  true
end
issue_logout(opts={}) click to toggle source
# File lib/mongo/db.rb, line 230
def issue_logout(opts={})
  if ok?(doc = command({:logout => 1}, :socket => opts[:socket]))
    @connection.remove_auth(@name)
  else
    raise MongoDBError, "Error logging out: #{doc.inspect}"
  end
  true
end
logout(opts={}) click to toggle source

Deauthorizes use for this database for this client connection. Also removes any saved authentication in the MongoClient class associated with this database.

@raise [MongoDBError] if logging out fails.

@return [Boolean]

# File lib/mongo/db.rb, line 225
def logout(opts={})
  @connection.logout_pools(@name) if @connection.pool_size > 1
  issue_logout(opts)
end
ok?(doc) click to toggle source

Return true if the supplied doc contains an 'ok' field with the value 1.

@param [Hash] doc

@return [Boolean]

# File lib/mongo/db.rb, line 483
def ok?(doc)
  Mongo::Support.ok?(doc)
end
pk_factory() click to toggle source

The primary key factory object (or nil).

@return [Object, Nil]

# File lib/mongo/db.rb, line 566
def pk_factory
  @pk_factory
end
pk_factory=(pk_factory) click to toggle source

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 573
def pk_factory=(pk_factory)
  raise MongoArgumentError,
    "Cannot change primary key factory once it's been set" if @pk_factory

  @pk_factory = pk_factory
end
previous_error() click to toggle source

Get the most recent error to have occurred on this database.

This command only returns errors that have occurred 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 377
def previous_error
  error = command(:getpreverror => 1)
  error["err"] ? error : nil
end
profiling_info() click to toggle source

Get the current profiling information.

@return [Array] a list of documents containing profiling information.

# File lib/mongo/db.rb, line 612
def profiling_info
  Cursor.new(Collection.new(SYSTEM_PROFILE_COLLECTION, self), :selector => {}).to_a
end
profiling_level() click to toggle source

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 586
def profiling_level
  cmd = BSON::OrderedHash.new
  cmd[:profile] = -1
  doc = command(cmd, :check_response => false)

  raise "Error with profile command: #{doc.inspect}" unless ok?(doc)

  level_sym = PROFILE_LEVEL.invert[doc['was'].to_i]
  raise "Error: illegal profiling level value #{doc['was']}" unless level_sym
  level_sym
end
profiling_level=(level) click to toggle source

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 602
def profiling_level=(level)
  cmd = BSON::OrderedHash.new
  cmd[:profile] = PROFILE_LEVEL[level]
  doc = command(cmd, :check_response => false)
  ok?(doc) || raise(MongoDBError, "Error with profile command: #{doc.inspect}")
end
remove_stored_function(function_name) click to toggle source

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 176
def remove_stored_function(function_name)
  return false unless self[SYSTEM_JS_COLLECTION].find_one({"_id" => function_name})
  self[SYSTEM_JS_COLLECTION].remove({"_id" => function_name}, :w => 1)
end
remove_user(username) click to toggle source

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 210
def remove_user(username)
  if self[SYSTEM_USER_COLLECTION].find_one({:user => username})
    self[SYSTEM_USER_COLLECTION].remove({:user => username}, :w => 1)
  else
    false
  end
end
rename_collection(from, to) click to toggle source

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 430
def rename_collection(from, to)
  cmd = BSON::OrderedHash.new
  cmd[:renameCollection] = "#{@name}.#{from}"
  cmd[:to] = "#{@name}.#{to}"
  doc = DB.new('admin', @connection).command(cmd, :check_response => false)
  ok?(doc) || raise(MongoDBError, "Error renaming collection: #{doc.inspect}")
end
reset_error_history() click to toggle source

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 388
def reset_error_history
  command(:reseterror => 1)
end
stats() click to toggle source

Return stats on this database. Uses MongoDB's dbstats command.

@return [Hash]

# File lib/mongo/db.rb, line 474
def stats
  self.command({:dbstats => 1})
end
strict=(value) click to toggle source

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.

@deprecated Support for strict will be removed in version 2.0 of the driver.

# File lib/mongo/db.rb, line 33
def strict=(value)
  unless ENV['TEST_MODE']
    warn "Support for strict mode has been deprecated and will be " +
         "removed in version 2.0 of the driver."
  end
  @strict = value
end
strict?() click to toggle source

Returns the value of the strict flag.

@deprecated Support for strict will be removed in version 2.0 of the driver.

# File lib/mongo/db.rb, line 44
def strict?
  @strict
end
validate_collection(name) click to toggle source

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 624
def validate_collection(name)
  cmd = BSON::OrderedHash.new
  cmd[:validate] = name
  cmd[:full] = true
  doc = command(cmd, :check_response => false)

  raise MongoDBError, "Error with validate command: #{doc.inspect}" unless ok?(doc)

  if (doc.has_key?('valid') && !doc['valid']) || (doc['result'] =~ /\b(exception|corrupt)\b/)
    raise MongoDBError, "Error: invalid collection #{name}: #{doc.inspect}"
  end
  doc
end

[Validate]

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