Class: S3DB::Database

Inherits:
Object
  • Object
show all
Defined in:
lib/s3db/database.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(backend, db_name) {|_self| ... } ⇒ Database

Create a new DB instance.

backend - S3DB::Backend subclass. Required. db_name - String name of database. Will be used in the storage path,

so make sure it's something sane. Required.

returns a new Database instance.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/s3db/database.rb', line 40

def initialize(backend, db_name)
  @backend = backend
  @name = db_name

  yield self if block_given?
end

Instance Attribute Details

#backend ⇒ Object (readonly)

Returns the value of attribute backend.



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# File 'lib/s3db/database.rb', line 3

def backend
  @backend
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/s3db/database.rb', line 3

def name
  @name
end

Class Method Details

.create(backend, db_name) ⇒ Object

Create a new database.

backend - S3DB::Backend subclass. Required. db_name - String name of the database to create. Required.

returns a new S3DB::Database on success, raises an error on failure.



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# File 'lib/s3db/database.rb', line 12

def create(backend, db_name)
  begin
    backend.write_db(db_name)
  rescue Errno::EEXIST
    raise ArgumentError, 'database exists!'
  end

  new(backend, db_name)
end

.drop(backend, db_name) ⇒ Object

Drop a database.

backend - S3DB::Backend subclass. Required. db_name - String name of database to drop. Required.

returns the String database name on success, raises an error on failure.



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# File 'lib/s3db/database.rb', line 28

def drop(backend, db_name)
  backend.delete_db(db_name)
end

Instance Method Details

#create_collection(collection, schema = {}) ⇒ Object

Create a collection under this database.

collection - String name of collection to create. Will also be used as

its filesystem path, so use something sane. Required.

schema - Hash schema for this collection. Default: {}.

returns true on success.



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# File 'lib/s3db/database.rb', line 70

def create_collection(collection, schema = {})
  Collection.create(self, collection)
end

#drop_collection(collection) ⇒ Object

Drop a collection from this database.

collection - String name of collection to drop.

returns the name of the collection on success.



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# File 'lib/s3db/database.rb', line 79

def drop_collection(collection)
  @backend.delete_collection(@name, collection)
end

#path ⇒ Object

Locate the storage location for the database.

returns a String path of the database path. Will vary by backend adapter.



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# File 'lib/s3db/database.rb', line 86

def path
  @backend.db_path(@name)
end

#save ⇒ Object

Save a DB instance to disk.

Returns a Database instance.



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# File 'lib/s3db/database.rb', line 50

def save
  @backend.write_db(@name)

  self
end

#show_collections ⇒ Object

List all available collections in the database.

returns sorted Array of Strings.



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# File 'lib/s3db/database.rb', line 59

def show_collections
  @backend.list_collections(@name).sort
end