Class: Moneta::Adapters::Sqlite

Inherits:
Object
  • Object
show all
Includes:
Defaults, IncrementSupport
Defined in:
lib/moneta/adapters/sqlite.rb

Overview

Sqlite3 backend

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from IncrementSupport

included

Methods included from Defaults

#[], #[]=, #decrement, #each_key, #features, #fetch, #fetch_values, included, #merge!, #slice, #supports?, #values_at

Methods included from OptionSupport

#expires, #prefix, #raw, #with

Constructor Details

#initialize(options = {}) ⇒ Sqlite

Returns a new instance of Sqlite

Options Hash (options):

  • :file (String) —

    Database file

  • :table (String) — default: 'moneta' —

    Table name

  • :busy_timeout (Integer) — default: 1000 —

    Sqlite timeout if database is busy

  • :backend (::Sqlite3::Database) —

    Use existing backend instance

  • :journal_mode (String, Symbol) —

    Set the journal mode for the connection


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# File 'lib/moneta/adapters/sqlite.rb', line 20

def initialize(options = {})
  table = options[:table] || 'moneta'
  @backend = options[:backend] ||
    begin
      raise ArgumentError, 'Option :file is required' unless options[:file]
      ::SQLite3::Database.new(options[:file])
    end
  @backend.busy_timeout(options[:busy_timeout] || 1000)
  @backend.execute("create table if not exists #{table} (k blob not null primary key, v blob)")
  if journal_mode = options[:journal_mode]
    @backend.journal_mode = journal_mode.to_s
  end
  @stmts =
    [@exists  = @backend.prepare("select exists(select 1 from #{table} where k = ?)"),
     @select  = @backend.prepare("select v from #{table} where k = ?"),
     @replace = @backend.prepare("replace into #{table} values (?, ?)"),
     @delete  = @backend.prepare("delete from #{table} where k = ?"),
     @clear   = @backend.prepare("delete from #{table}"),
     @create  = @backend.prepare("insert into #{table} values (?, ?)")]
end

Instance Attribute Details

#backend ⇒ Object (readonly) 


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# File 'lib/moneta/adapters/sqlite.rb', line 12

def backend
  @backend
end

Instance Method Details

#clear(options = {}) ⇒ void

This method returns an undefined value.

Clear all keys in this store


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# File 'lib/moneta/adapters/sqlite.rb', line 71

def clear(options = {})
  @clear.execute!
  self
end

#close ⇒ Object

Explicitly close the store


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# File 'lib/moneta/adapters/sqlite.rb', line 88

def close
  @stmts.each {|s| s.close }
  @backend.close
  nil
end

#create(key, value, options = {}) ⇒ Object 


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# File 'lib/moneta/adapters/sqlite.rb', line 77

def create(key, value, options = {})
  @create.execute!(key,value)
  true
rescue SQLite3::ConstraintException
  # If you know a better way to detect whether an insert-ignore
  # suceeded, please tell me.
  @create.reset!
  false
end

#delete(key, options = {}) ⇒ Object

Delete the key from the store and return the current value

Options Hash (options):

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware


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# File 'lib/moneta/adapters/sqlite.rb', line 59

def delete(key, options = {})
  value = load(key, options)
  @delete.execute!(key)
  value
end

#increment(key, amount = 1, options = {}) ⇒ Object

Note:

Not every Moneta store implements this method, a NotImplementedError is raised if it is not supported.

Atomically increment integer value with key

This method also accepts negative amounts.

Options Hash (options):

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware


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# File 'lib/moneta/adapters/sqlite.rb', line 66

def increment(key, amount = 1, options = {})
  @backend.transaction(:exclusive) { return super }
end

#key?(key, options = {}) ⇒ Boolean

Exists the value with key

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware


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# File 'lib/moneta/adapters/sqlite.rb', line 42

def key?(key, options = {})
  @exists.execute!(key).first.first.to_i == 1
end

#load(key, options = {}) ⇒ Object

Fetch value with key. Return nil if the key doesn't exist

Options Hash (options):

  • :expires (Integer) —

    Update expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • :sync (Boolean) —

    Synchronized load (Cache reloads from adapter, Daybreak syncs with file)

  • Other (Object) —

    options as defined by the adapters or middleware


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# File 'lib/moneta/adapters/sqlite.rb', line 47

def load(key, options = {})
  rows = @select.execute!(key)
  rows.empty? ? nil : rows.first.first
end

#store(key, value, options = {}) ⇒ Object

Store value with key

Options Hash (options):

  • :expires (Integer) —

    Set expiration time (See Expires)

  • :raw (Boolean) —

    Raw access without value transformation (See Transformer)

  • :prefix (String) —

    Prefix key (See Transformer)

  • Other (Object) —

    options as defined by the adapters or middleware


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# File 'lib/moneta/adapters/sqlite.rb', line 53

def store(key, value, options = {})
  @replace.execute!(key, value)
  value
end