Class: EM::Mongo::Database

Inherits:
Object
  • Object
show all
Defined in:
lib/em-mongo/database.rb

Constant Summary collapse

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"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name = DEFAULT_DB, connection = nil) ⇒ Database

Returns a new instance of Database.

Parameters:

  • name (String) (defaults to: DEFAULT_DB) —

    the database name.

  • connection (EM::Mongo::Connection) (defaults to: nil) —

    a connection object pointing to MongoDB. Note that databases are usually instantiated via the Connection class. See the examples below.



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# File 'lib/em-mongo/database.rb', line 23

def initialize(name = DEFAULT_DB, connection = nil)
  @db_name = name
  @em_connection = connection || EM::Mongo::Connection.new
  @collection = nil
  @collections = {}
  @cache_time = 300 #5 minutes.
end

Instance Attribute Details

#cache_time ⇒ Object

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



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# File 'lib/em-mongo/database.rb', line 16

def cache_time
  @cache_time
end

Instance Method Details

#add_user(username, password) ⇒ EM::Mongo::RequestResponse

Adds a user to this database for use with authentication. If the user already exists in the system, the password will be updated.

#TODO check if that works as it should with SCRAM-SHA1

Parameters:

Returns:



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# File 'lib/em-mongo/database.rb', line 363

def add_user(username, password)
  response = RequestResponse.new
  user_resp = self.collection(SYSTEM_USER_COLLECTION).first({:user => username})
  user_resp.callback do |res|
    user = res || {:user => username}
    user['pwd'] = EM::Mongo::Support.hash_password(username, password)
    response.succeed self.collection(SYSTEM_USER_COLLECTION).save(user)
  end
  user_resp.errback { |err| response.fail err }
  response
end

#authenticate(username, password, auth_method = Authentication::AuthMethod::MONGODB_CR) ⇒ EM::Mongo::RequestResponse

Authenticate with the given username and password. Note that mongod must be started with the –auth option for authentication to be enabled.

Parameters:

Returns:

Raises:



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# File 'lib/em-mongo/database.rb', line 346

def authenticate(username, password, auth_method=Authentication::AuthMethod::MONGODB_CR)
  auth = case auth_method
         when Authentication::AuthMethod::SCRAM_SHA1 then SCRAM.new self
         when Authentication::AuthMethod::MONGODB_CR then MONGODB_CR.new self
         else raise AuthenticationError.new("Authentication method #{auth_method} not supported")
         end
   return auth.authenticate(username, password)
end

#collection(name = EM::Mongo::DEFAULT_NS) ⇒ EM::Mongo::Collection

Get a collection by name.

Parameters:

  • name (String, Symbol) (defaults to: EM::Mongo::DEFAULT_NS) —

    the collection name.

Returns:



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# File 'lib/em-mongo/database.rb', line 36

def collection(name = EM::Mongo::DEFAULT_NS)
  @collections[name] ||= EM::Mongo::Collection.new(@db_name, name, @em_connection)
end

#collection_names ⇒ EM::Mongo::RequestResponse

Get an array of collection names in this database.

Returns:



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# File 'lib/em-mongo/database.rb', line 57

def collection_names
  response = RequestResponse.new
  name_resp = collections_info.defer_as_a
  name_resp.callback do |docs|
    names = docs.collect{ |doc| doc['name'] || '' }
    names = names.delete_if {|name| name.index(self.name).nil? || name.index('$')}
    names = names.map{ |name| name.sub(self.name + '.','')}
    response.succeed(names)
  end
  name_resp.errback { |err| response.fail err }
  response
end

#collections ⇒ EM::Mongo::RequestResponse

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

Returns:



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# File 'lib/em-mongo/database.rb', line 73

def collections
  response = RequestResponse.new
  name_resp = collection_names
  name_resp.callback do |names|
    collections = names.map do |name|
      EM::Mongo::Collection.new(@db_name, name, @em_connection)
    end
    response.succeed collections
  end
  name_resp.errback { |err| response.fail err }
  response
end

#collections_info(coll_name = nil) ⇒ EM::Mongo::Cursor

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.

Parameters:

  • coll_name (String) (defaults to: nil) —

    return info for the specified collection only.

Returns:



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# File 'lib/em-mongo/database.rb', line 93

def collections_info(coll_name=nil)
  selector = {}
  selector[:name] = full_collection_name(coll_name) if coll_name
  Cursor.new(EM::Mongo::Collection.new(@db_name, SYSTEM_NAMESPACE_COLLECTION, @em_connection), :selector => selector)
end

#command(selector, opts = {}) ⇒ EM::Mongo::RequestResponse

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.

key, specifying the command to be performed. In Ruby 1.9, OrderedHash isn’t necessary since hashes are ordered by default.

command fails.

Parameters:

  • selector (OrderedHash, Hash) —

    an OrderedHash, or a standard Hash with just one

  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :check_response (Boolean) — default: true —

    If true, raises an exception if the

  • :socket (Socket) —

    a socket to use for sending the command. This is mainly for internal use.

Returns:

Raises:



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# File 'lib/em-mongo/database.rb', line 306

def command(selector, opts={})
  check_response = opts.fetch(:check_response, true)
  raise MongoArgumentError, "command must be given a selector" unless selector.is_a?(Hash) && !selector.empty?

  if selector.size > 1 && RUBY_VERSION < '1.9' && selector.class != BSON::OrderedHash
    raise MongoArgumentError, "DB#command requires an OrderedHash when hash contains multiple keys"
  end

  response = RequestResponse.new
  cmd_resp = Cursor.new(self.collection(SYSTEM_COMMAND_COLLECTION), :limit => -1, :selector => selector).next_document

  cmd_resp.callback do |doc|
    if doc.nil?
      response.fail([OperationFailure, "Database command '#{selector.keys.first}' failed: returned null."])
    elsif (check_response && !EM::Mongo::Support.ok?(doc))
      response.fail([OperationFailure, "Database command '#{selector.keys.first}' failed: #{doc.inspect}"])
    else
      response.succeed(doc)
    end
  end

  cmd_resp.errback do |err|
    response.fail([OperationFailure, "Database command '#{selector.keys.first}' failed: #{err[1]}"])
  end

  response
end

#connection ⇒ EM::Mongo::Connection

Get the connection associated with this database

Returns:



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# File 'lib/em-mongo/database.rb', line 43

def connection
  @em_connection
end

#create_collection(name, opts = {}) ⇒ EM::Mongo::RequestResponse

Create a collection.

new collection. If strict is true, will raise an error if collection name already exists.

Parameters:

  • name (String, Symbol) —

    the name of the new collection.

  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :capped (Boolean) — default: False —

    created a capped collection.

  • :size (Integer) — default: 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.

  • :max (Integer) — default: Nil —

    If capped is true, indicates the maximum number of records in a capped collection.

Returns:

Raises:

  • (MongoDBError) —

    raised under two conditions: either we’re in strict mode and the collection already exists or collection creation fails on the server.



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# File 'lib/em-mongo/database.rb', line 121

def create_collection(name, opts = {})
  response = RequestResponse.new
  names_resp = collection_names
  names_resp.callback do |names|
    if names.include?(name.to_s)
      response.succeed EM::Mongo::Collection.new(@db_name, name, @em_connection)
    end

    # Create a new collection.
    oh = BSON::OrderedHash.new
    oh[:create] = name
    oh.merge! opts
    cmd_resp = command(oh)
    cmd_resp.callback do |doc|
      if EM::Mongo::Support.ok?(doc)
        response.succeed EM::Mongo::Collection.new(@db_name, name, @em_connection)
      else
        response.fail [MongoDBError, "Error creating collection: #{doc.inspect}"]
      end
    end
    cmd_resp.errback { |err| response.fail err }
  end
  names_resp.errback { |err| response.fail err }
  response
end

#drop_collection(name) ⇒ EM::Mongo::RequestResponse

Drop a collection by name.

Parameters:

Returns:



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# File 'lib/em-mongo/database.rb', line 152

def drop_collection(name)
  response = RequestResponse.new
  names_resp = collection_names
  names_resp.callback do |names|
    if names.include?(name.to_s)
      cmd_resp = command(:drop=>name)
      cmd_resp.callback do |doc|
        response.succeed EM::Mongo::Support.ok?(doc)
      end
      cmd_resp.errback { |err| response.fail err }
    else
      response.succeed false
    end
  end
  names_resp.errback { |err| response.fail err }
  response
end

#drop_index(collection_name, index_name) ⇒ EM::Mongo::RequestResponse

Drop an index from a given collection. Normally called from Collection#drop_index or Collection#drop_indexes.

Parameters:

Returns:

Raises:

  • MongoDBError if there’s an error renaming the collection.



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# File 'lib/em-mongo/database.rb', line 179

def drop_index(collection_name, index_name)
  response = RequestResponse.new
  oh = BSON::OrderedHash.new
  oh[:deleteIndexes] = collection_name
  oh[:index] = index_name.to_s
  cmd_resp = command(oh, :check_response => false)
  cmd_resp.callback do |doc|
    if EM::Mongo::Support.ok?(doc)
      response.succeed(true)
    else
      response.fail [MongoDBError, "Error with drop_index command: #{doc.inspect}"]
    end
  end
  cmd_resp.errback do |err|
    response.fail err
  end
  response
end

#error? ⇒ EM::Mongo::RequestResponse

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

Returns:



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# File 'lib/em-mongo/database.rb', line 252

def error?
  response = RequestResponse.new
  err_resp = get_last_error
  err_resp.callback do |doc|
    response.succeed doc['err'] != nil
  end
  err_resp.errback do |err|
    response.fail err
  end
  response
end

#full_collection_name(collection_name) ⇒ String

A shortcut returning db plus dot plus collection name.

Parameters:

Returns:



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# File 'lib/em-mongo/database.rb', line 280

def full_collection_name(collection_name)
  "#{name}.#{collection_name}"
end

#get_last_error(opts = {}) ⇒ EM::Mongo::RequestResponse

Run the getlasterror command with the specified replication options.

Parameters:

  • opts (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (opts):

  • :fsync (Boolean) — default: false
  • :w (Integer) — default: nil
  • :wtimeout (Integer) — default: nil

Returns:

Raises:



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# File 'lib/em-mongo/database.rb', line 231

def get_last_error(opts={})
  response = RequestResponse.new
  cmd = BSON::OrderedHash.new
  cmd[:getlasterror] = 1
  cmd.merge!(opts)
  cmd_resp = command(cmd, :check_response => false)
  cmd_resp.callback do |doc|
    if EM::Mongo::Support.ok?(doc)
      response.succeed doc
    else
      response.fail [MongoDBError, "error retrieving last error: #{doc.inspect}"]
    end
  end
  cmd_resp.errback { |err| response.fail err }
  response
end

#index_information(collection_name) ⇒ EM::Mongo::RequestResponse

Get information on the indexes for the given collection. Normally called by Collection#index_information.

Parameters:

Returns:

  • (EM::Mongo::RequestResponse) —

    Calls back with a hash where keys are index names and the values are lists of [key, direction] pairs defining the index.



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# File 'lib/em-mongo/database.rb', line 205

def index_information(collection_name)
  response = RequestResponse.new
  sel  = {:ns => full_collection_name(collection_name)}
  idx_resp = Cursor.new(self.collection(SYSTEM_INDEX_COLLECTION), :selector => sel).defer_as_a
  idx_resp.callback do |indexes|
    info = indexes.inject({}) do |info, index|
      info[index['name']] = index
      info
    end
    response.succeed info
  end
  idx_resp.errback do |err|
    fail err
  end
  response
end

#name ⇒ String

Get the name of this database

Returns:



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# File 'lib/em-mongo/database.rb', line 50

def name
  @db_name
end

#reset_error_history ⇒ EM::Mongo::RequestResponse

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.

Returns:



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# File 'lib/em-mongo/database.rb', line 270

def reset_error_history
  command(:reseterror => 1)
end