# encoding: UTF-8
require "nest"
require "redis"
require "securerandom"
require "scrivener"
require "ohm/transaction"
module Ohm
# All of the known errors in Ohm can be traced back to one of these
# exceptions.
#
# MissingID:
#
# Comment.new.id # => Error
# Comment.new.key # => Error
#
# Solution: you need to save your model first.
#
# IndexNotFound:
#
# Comment.find(:foo => "Bar") # => Error
#
# Solution: add an index with `Comment.index :foo`.
#
# UniqueIndexViolation:
#
# Raised when trying to save an object with a `unique` index for
# which the value already exists.
#
# Solution: rescue `Ohm::UniqueIndexViolation` during save, but
# also, do some validations even before attempting to save.
#
class Error < StandardError; end
class MissingID < Error; end
class IndexNotFound < Error; end
class UniqueIndexViolation < Error; end
# Instead of monkey patching Kernel or trying to be clever, it's
# best to confine all the helper methods in a Utils module.
module Utils
# Used by: `attribute`, `counter`, `set`, `reference`,
# `collection`.
#
# Employed as a solution to avoid `NameError` problems when trying
# to load models referring to other models not yet loaded.
#
# Example:
#
# class Comment < Ohm::Model
# reference :user, User # NameError undefined constant User.
# end
#
# Instead of relying on some clever `const_missing` hack, we can
# simply use a Symbol.
#
# class Comment < Ohm::Model
# reference :user, :User
# end
#
def self.const(context, name)
case name
when Symbol then context.const_get(name)
else name
end
end
end
class Connection
attr_accessor :context
attr_accessor :options
def initialize(context = :main, options = {})
@context = context
@options = options
end
def reset!
threaded[context] = nil
end
def start(options = {})
self.options = options
self.reset!
end
def redis
threaded[context] ||= Redis.connect(options)
end
def threaded
Thread.current[:ohm] ||= {}
end
end
def self.conn
@conn ||= Connection.new
end
# Stores the connection options for the Redis instance.
#
# Examples:
#
# Ohm.connect(:port => 6380, :db => 1, :host => "10.0.1.1")
# Ohm.connect(:url => "redis://10.0.1.1:6380/1")
#
# All of the options are simply passed on to `Redis.connect`.
#
def self.connect(options = {})
conn.start(options)
end
# Use this if you want to do quick ad hoc redis commands against the
# defined Ohm connection.
#
# Examples:
#
# Ohm.redis.keys("User:*")
# Ohm.redis.set("foo", "bar")
#
def self.redis
conn.redis
end
# Wrapper for Ohm.redis.flushdb.
def self.flush
redis.flushdb
end
# Wraps the whole pipelining functionality.
module PipelinedFetch
private
def fetch(ids)
arr = db.pipelined do
ids.each { |id| db.hgetall(namespace[id]) }
end
res = []
return res if arr.nil?
arr.each_with_index do |atts, idx|
res << model.new(Hash[*atts].update(:id => ids[idx]))
end
res
end
end
# Defines most of the methods used by `Set` and `MultiSet`.
module Collection
include PipelinedFetch
include Enumerable
# Fetch the data from Redis in one go.
def to_a
fetch(ids)
end
def each
to_a.each { |e| yield e }
end
def empty?
size == 0
end
# Allows you to sort by any field in your model.
#
# Example:
#
# class User < Ohm::Model
# attribute :name
# end
#
# User.all.sort_by(:name, :order => "ALPHA")
# User.all.sort_by(:name, :order => "ALPHA DESC")
# User.all.sort_by(:name, :order => "ALPHA DESC", :limit => [0, 10])
#
# Note: This is slower compared to just doing `sort`, specifically
# because Redis has to read each individual hash in order to sort
# them.
#
def sort_by(att, options = {})
sort(options.merge(:by => namespace["*->%s" % att]))
end
# Allows you to sort your models using their IDs. This is much
# faster than `sort_by`. If you simply want to get records in
# ascending or descending order, then this is the best method to
# do that.
#
# Example:
#
# class User < Ohm::Model
# attribute :name
# end
#
# User.create(:name => "John")
# User.create(:name => "Jane")
#
# User.all.sort.map(&:id) == ["1", "2"]
# # => true
#
# User.all.sort(:order => "ASC").map(&:id) == ["1", "2"]
# # => true
#
# User.all.sort(:order => "DESC").map(&:id) == ["2", "1"]
# # => true
#
def sort(options = {})
if options.has_key?(:get)
options[:get] = namespace["*->%s" % options[:get]]
return execute { |key| db.sort(key, options) }
end
fetch(execute { |key| db.sort(key, options) })
end
# Check if a model is included in this set.
#
# Example:
#
# u = User.create
#
# User.all.include?(u)
# # => true
#
# Note: Ohm simply checks that the model's ID is included in the
# set. It doesn't do any form of type checking.
#
def include?(model)
exists?(model.id)
end
# Returns the total size of the set using SCARD.
def size
execute { |key| db.scard(key) }
end
# Syntactic sugar for `sort_by` or `sort` when you only need the
# first element.
#
# Example:
#
# User.all.first ==
# User.all.sort(:limit => [0, 1]).first
#
# User.all.first(:by => :name, "ALPHA") ==
# User.all.sort_by(:name, :order => "ALPHA", :limit => [0, 1]).first
#
def first(options = {})
opts = options.dup
opts.merge!(:limit => [0, 1])
if opts[:by]
sort_by(opts.delete(:by), opts).first
else
sort(opts).first
end
end
# Grab all the elements of this set using SMEMBERS.
def ids
execute { |key| db.smembers(key) }
end
# Retrieve a specific element using an ID from this set.
#
# Example:
#
# # Let's say we got the ID 1 from a request parameter.
# id = 1
#
# # Retrieve the post if it's included in the user's posts.
# post = user.posts[id]
#
def [](id)
model[id] if exists?(id)
end
private
def exists?(id)
execute { |key| db.sismember(key, id) }
end
end
class List < Struct.new(:key, :namespace, :model)
include PipelinedFetch
include Enumerable
# Returns the total size of the list using LLEN.
def size
db.llen(key)
end
# Returns the first element of the list using LINDEX.
def first
model[db.lindex(key, 0)]
end
# Returns the last element of the list using LINDEX.
def last
model[db.lindex(key, -1)]
end
# Checks if the model is part of this List.
#
# An important thing to note is that this method loads all of the
# elements of the List since there is no command in Redis that
# allows you to actually check the list contents efficiently.
#
# You may want to avoid doing this if your list has say, 10K entries.
def include?(model)
ids.include?(model.id.to_s)
end
# Replace all the existing elements of a list with a different
# collection of models. This happens atomically in a MULTI-EXEC
# block.
#
# Example:
#
# user = User.create
# p1 = Post.create
# user.posts.push(p1)
#
# p2, p3 = Post.create, Post.create
# user.posts.replace([p2, p3])
#
# user.posts.include?(p1)
# # => false
#
def replace(models)
ids = models.map { |model| model.id }
model.db.multi do
db.del(key)
ids.each { |id| db.rpush(key, id) }
end
end
# Fetch the data from Redis in one go.
def to_a
fetch(ids)
end
def each
to_a.each { |element| yield element }
end
def empty?
size == 0
end
# Pushes the model to the _end_ of the list using RPUSH.
def push(model)
db.rpush(key, model.id)
end
# Pushes the model to the _beginning_ of the list using LPUSH.
def unshift(model)
db.lpush(key, model.id)
end
# Delete a model from the list.
#
# Note: If your list contains the model multiple times, this method
# will delete all instances of that model in one go.
#
# Example:
#
# class Comment < Ohm::Model
# end
#
# class Post < Ohm::Model
# list :comments, Comment
# end
#
# p = Post.create
# c = Comment.create
#
# p.comments.push(c)
# p.comments.push(c)
#
# p.comments.delete(c)
#
# p.comments.size == 0
# # => true
#
def delete(model)
# LREM key 0 <id> means remove all elements matching <id>
# @see http://redis.io/commands/lrem
db.lrem(key, 0, model.id)
end
private
def ids
db.lrange(key, 0, -1)
end
def db
model.db
end
end
class Set < Struct.new(:key, :namespace, :model)
include Collection
# Chain new fiters on an existing set.
#
# Example:
#
# set = User.find(:name => "John")
# set.find(:age => 30)
#
def find(dict)
filters = model.filters(dict).push(key)
MultiSet.new(namespace, model).append(:sinterstore, filters)
end
# Reduce the set using any number of filters.
#
# Example:
#
# set = User.find(:name => "John")
# set.except(:country => "US")
#
# # You can also do it in one line.
# User.find(:name => "John").except(:country => "US")
#
def except(dict)
MultiSet.new(namespace, model).append(:sinterstore, key).except(dict)
end
# Do a union to the existing set using any number of filters.
#
# Example:
#
# set = User.find(:name => "John")
# set.union(:name => "Jane")
#
# # You can also do it in one line.
# User.find(:name => "John").union(:name => "Jane")
#
def union(dict)
MultiSet.new(namespace, model).append(:sinterstore, key).union(dict)
end
private
def execute
yield key
end
def db
model.db
end
end
class MutableSet < Set
# Add a model directly to the set.
#
# Example:
#
# user = User.create
# post = Post.create
#
# user.posts.add(post)
#
def add(model)
db.sadd(key, model.id)
end
# Remove a model directly from the set.
#
# Example:
#
# user = User.create
# post = Post.create
#
# user.posts.delete(post)
#
def delete(model)
db.srem(key, model.id)
end
# Replace all the existing elements of a set with a different
# collection of models. This happens atomically in a MULTI-EXEC
# block.
#
# Example:
#
# user = User.create
# p1 = Post.create
# user.posts.add(p1)
#
# p2, p3 = Post.create, Post.create
# user.posts.replace([p2, p3])
#
# user.posts.include?(p1)
# # => false
#
def replace(models)
ids = models.map { |model| model.id }
key.redis.multi do
db.del(key)
ids.each { |id| db.sadd(key, id) }
end
end
end
# Anytime you filter a set with more than one requirement, you
# internally use a `MultiSet`. `MutiSet` is a bit slower than just
# a `Set` because it has to `SINTERSTORE` all the keys prior to
# retrieving the members, size, etc.
#
# Example:
#
# User.all.kind_of?(Ohm::Set)
# # => true
#
# User.find(:name => "John").kind_of?(Ohm::Set)
# # => true
#
# User.find(:name => "John", :age => 30).kind_of?(Ohm::MultiSet)
# # => true
#
class MultiSet < Struct.new(:namespace, :model)
include Collection
def append(operation, list)
filters.push([operation, list])
return self
end
# Chain new fiters on an existing set.
#
# Example:
#
# set = User.find(:name => "John", :age => 30)
# set.find(:status => 'pending')
#
def find(dict)
filters.push([:sinterstore, model.filters(dict)])
return self
end
# Reduce the set using any number of filters.
#
# Example:
#
# set = User.find(:name => "John")
# set.except(:country => "US")
#
# # You can also do it in one line.
# User.find(:name => "John").except(:country => "US")
#
def except(dict)
filters.push([:sdiffstore, model.filters(dict)])
return self
end
# Do a union to the existing set using any number of filters.
#
# Example:
#
# set = User.find(:name => "John")
# set.union(:name => "Jane")
#
# # You can also do it in one line.
# User.find(:name => "John").union(:name => "Jane")
#
def union(dict)
filters.push([:sunionstore, model.filters(dict)])
return self
end
private
def db
model.db
end
def filters
@filters ||= []
end
def temp_keys
@temp_keys ||= []
end
def clean_temp_keys
db.del(*temp_keys)
temp_keys.clear
end
def generate_temp_key
key = namespace[:temp][SecureRandom.hex(32)]
temp_keys << key
key
end
def execute
# Hold the final result key for this MultiSet.
main = nil
filters.each do |operation, list|
# Operation can be sinterstore, sdiffstore, or sunionstore.
# each operation we do, i.e. `.union(...)`, will be considered
# one intersected set, hence we need to `sinterstore` all
# the filters in a temporary set.
temp = generate_temp_key
db.sinterstore(temp, *list)
# If this is the first set, we simply assign the generated
# set to main, which could possibly be the return value
# for simple filters like one `.find(...)`.
if main.nil?
main = temp
else
# Append the generated temporary set using the operation.
# i.e. if we have (mood=happy & book=1) and we have an
# `sunionstore`, we do (mood=happy & book=1) | (mood=sad & book=1)
#
# Here we dynamically call the stored command, e.g.
#
# SUNIONSTORE main main temp
#
db.send(operation, main, main, temp)
end
end
begin
# At this point, we have the final aggregated set, which we yield
# to the caller. the caller can do all the normal set operations,
# i.e. SCARD, SMEMBERS, etc.
yield main
ensure
# We have to make sure we clean up the temporary keys to avoid
# memory leaks and the unintended explosion of memory usage.
clean_temp_keys
end
end
end
# The base class for all your models. In order to better understand
# it, here is a semi-realtime explanation of the details involved
# when creating a User instance.
#
# Example:
#
# class User < Ohm::Model
# attribute :name
# index :name
#
# attribute :email
# unique :email
#
# counter :points
#
# set :posts, :Post
# end
#
# u = User.create(:name => "John", :email => "foo@bar.com")
# u.incr :points
# u.posts.add(Post.create)
#
# When you execute `User.create(...)`, you run the following Redis
# commands:
#
# # Generate an ID
# INCR User:id
#
# # Add the newly generated ID, (let's assume the ID is 1).
# SADD User:all 1
#
# # Store the unique index
# HSET User:uniques:email foo@bar.com 1
#
# # Store the name index
# SADD User:indices:name:John 1
#
# # Store the HASH
# HMSET User:1 name John email foo@bar.com
#
# Next we increment points:
#
# HINCR User:1:counters points 1
#
# And then we add a Post to the `posts` set.
# (For brevity, let's assume the Post created has an ID of 1).
#
# SADD User:1:posts 1
#
class Model
include Scrivener::Validations
def self.conn
@conn ||= Connection.new(name, Ohm.conn.options)
end
def self.connect(options)
@key = nil
@lua = nil
conn.start(options)
end
def self.db
conn.redis
end
def self.lua
@lua ||= Lua.new(File.join(Dir.pwd, "lua"), db)
end
# The namespace for all the keys generated using this model.
#
# Example:
#
# class User < Ohm::Model
#
# User.key == "User"
# User.key.kind_of?(String)
# # => true
#
# User.key.kind_of?(Nest)
# # => true
#
# To find out more about Nest, see:
# http://github.com/soveran/nest
#
def self.key
@key ||= Nest.new(self.name, db)
end
# Retrieve a record by ID.
#
# Example:
#
# u = User.create
# u == User[u.id]
# # => true
#
def self.[](id)
new(:id => id).load! if id && exists?(id)
end
# Retrieve a set of models given an array of IDs.
#
# Example:
#
# ids = [1, 2, 3]
# ids.map(&User)
#
# Note: The use of this should be a last resort for your actual
# application runtime, or for simply debugging in your console. If
# you care about performance, you should pipeline your reads. For
# more information checkout the implementation of Ohm::Set#fetch.
#
def self.to_proc
lambda { |id| self[id] }
end
# Check if the ID exists within <Model>:all.
def self.exists?(id)
db.sismember(key[:all], id)
end
# Find values in `unique` indices.
#
# Example:
#
# class User < Ohm::Model
# unique :email
# end
#
# u = User.create(:email => "foo@bar.com")
# u == User.with(:email, "foo@bar.com")
# # => true
#
def self.with(att, val)
id = db.hget(key[:uniques][att], val)
id && self[id]
end
# Find values in indexed fields.
#
# Example:
#
# class User < Ohm::Model
# attribute :email
#
# attribute :name
# index :name
#
# attribute :status
# index :status
#
# index :provider
# index :tag
#
# def provider
# email[/@(.*?).com/, 1]
# end
#
# def tag
# ["ruby", "python"]
# end
# end
#
# u = User.create(name: "John", status: "pending", email: "foo@me.com")
# User.find(provider: "me", name: "John", status: "pending").include?(u)
# # => true
#
# User.find(:tag => "ruby").include?(u)
# # => true
#
# User.find(:tag => "python").include?(u)
# # => true
#
# User.find(:tag => ["ruby", "python"]).include?(u)
# # => true
#
def self.find(dict)
keys = filters(dict)
if keys.size == 1
Ohm::Set.new(keys.first, key, self)
else
Ohm::MultiSet.new(key, self).append(:sinterstore, keys)
end
end
# Index any method on your model. Once you index a method, you can
# use it in `find` statements.
def self.index(attribute)
indices << attribute unless indices.include?(attribute)
end
# Create a unique index for any method on your model. Once you add
# a unique index, you can use it in `with` statements.
#
# Note: if there is a conflict while saving, an
# `Ohm::UniqueIndexViolation` violation is raised.
#
def self.unique(attribute)
uniques << attribute unless uniques.include?(attribute)
end
# Declare an Ohm::Set with the given name.
#
# Example:
#
# class User < Ohm::Model
# set :posts, :Post
# end
#
# u = User.create
# u.posts.empty?
# # => true
#
# Note: You can't use the set until you save the model. If you try
# to do it, you'll receive an Ohm::MissingID error.
#
def self.set(name, model)
collections << name unless collections.include?(name)
define_method name do
model = Utils.const(self.class, model)
Ohm::MutableSet.new(key[name], model.key, model)
end
end
# Declare an Ohm::List with the given name.
#
# Example:
#
# class Comment < Ohm::Model
# end
#
# class Post < Ohm::Model
# list :comments, :Comment
# end
#
# p = Post.create
# p.comments.push(Comment.create)
# p.comments.unshift(Comment.create)
# p.comments.size == 2
# # => true
#
# Note: You can't use the list until you save the model. If you try
# to do it, you'll receive an Ohm::MissingID error.
#
def self.list(name, model)
collections << name unless collections.include?(name)
define_method name do
model = Utils.const(self.class, model)
Ohm::List.new(key[name], model.key, model)
end
end
# A macro for defining a method which basically does a find.
#
# Example:
# class Post < Ohm::Model
# reference :user, :User
# end
#
# class User < Ohm::Model
# collection :posts, :Post
# end
#
# # is the same as
#
# class User < Ohm::Model
# def posts
# Post.find(:user_id => self.id)
# end
# end
#
def self.collection(name, model, reference = to_reference)
define_method name do
model = Utils.const(self.class, model)
model.find(:"#{reference}_id" => id)
end
end
# A macro for defining an attribute, an index, and an accessor
# for a given model.
#
# Example:
#
# class Post < Ohm::Model
# reference :user, :User
# end
#
# # It's the same as:
#
# class Post < Ohm::Model
# attribute :user_id
# index :user_id
#
# def user
# @_memo[:user] ||= User[user_id]
# end
#
# def user=(user)
# self.user_id = user.id
# @_memo[:user] = user
# end
#
# def user_id=(user_id)
# @_memo.delete(:user_id)
# self.user_id = user_id
# end
# end
#
def self.reference(name, model)
reader = :"#{name}_id"
writer = :"#{name}_id="
index reader
define_method(reader) do
@attributes[reader]
end
define_method(writer) do |value|
@_memo.delete(name)
@attributes[reader] = value
end
define_method(:"#{name}=") do |value|
@_memo.delete(name)
send(writer, value ? value.id : nil)
end
define_method(name) do
@_memo[name] ||= begin
model = Utils.const(self.class, model)
model[send(reader)]
end
end
end
# The bread and butter macro of all models. Basically declares
# persisted attributes. All attributes are stored on the Redis
# hash.
#
# Example:
# class User < Ohm::Model
# attribute :name
# end
#
# # It's the same as:
#
# class User < Ohm::Model
# def name
# @attributes[:name]
# end
#
# def name=(name)
# @attributes[:name] = name
# end
# end
#
def self.attribute(name, cast = nil)
if cast
define_method(name) do
cast[@attributes[name]]
end
else
define_method(name) do
@attributes[name]
end
end
define_method(:"#{name}=") do |value|
@attributes[name] = value
end
end
# Declare a counter. All the counters are internally stored in
# a different Redis hash, independent from the one that stores
# the model attributes. Counters are updated with the `incr` and
# `decr` methods, which interact directly with Redis. Their value
# can't be assigned as with regular attributes.
#
# Example:
#
# class User < Ohm::Model
# counter :points
# end
#
# u = User.create
# u.incr :points
#
# Ohm.redis.hget "User:1:counters", "points"
# # => 1
#
# Note: You can't use counters until you save the model. If you
# try to do it, you'll receive an Ohm::MissingID error.
#
def self.counter(name)
define_method(name) do
return 0 if new?
db.hget(key[:counters], name).to_i
end
end
# An Ohm::Set wrapper for Model.key[:all].
def self.all
Set.new(key[:all], key, self)
end
# Syntactic sugar for Model.new(atts).save
def self.create(atts = {})
new(atts).save
end
# Manipulate the Redis hash of attributes directly.
#
# Example:
#
# class User < Ohm::Model
# attribute :name
# end
#
# u = User.create(:name => "John")
# u.key.hget(:name)
# # => John
#
# For more details see
# http://github.com/soveran/nest
#
def key
model.key[id]
end
# Initialize a model using a dictionary of attributes.
#
# Example:
#
# u = User.new(:name => "John")
#
def initialize(atts = {})
@attributes = {}
@_memo = {}
update_attributes(atts)
end
# Access the ID used to store this model. The ID is used together
# with the name of the class in order to form the Redis key.
#
# Example:
#
# class User < Ohm::Model; end
#
# u = User.create
# u.id
# # => 1
#
# u.key
# # => User:1
#
def id
raise MissingID if not defined?(@id)
@id
end
# Check for equality by doing the following assertions:
#
# 1. That the passed model is of the same type.
# 2. That they represent the same Redis key.
#
def ==(other)
other.kind_of?(model) && other.key == key
rescue MissingID
false
end
# Preload all the attributes of this model from Redis. Used
# internally by `Model::[]`.
def load!
update_attributes(db.hgetall(key)) unless new?
return self
end
# Read an attribute remotly from Redis. Useful if you want to get
# the most recent value of the attribute and not rely on locally
# cached value.
#
# Example:
#
# User.create(:name => "A")
#
# Session 1 | Session 2
# --------------|------------------------
# u = User[1] | u = User[1]
# u.name = "B" |
# u.save |
# | u.name == "A"
# | u.get(:name) == "B"
#
def get(att)
@attributes[att] = db.hget(key, att)
end
# Update an attribute value atomically. The best usecase for this
# is when you simply want to update one value.
#
# Note: This method is dangerous because it doesn't update indices
# and uniques. Use it wisely. The safe equivalent is `update`.
#
def set(att, val)
val.to_s.empty? ? db.hdel(key, att) : db.hset(key, att, val)
@attributes[att] = val
end
def new?
!defined?(@id)
end
# Increment a counter atomically. Internally uses HINCRBY.
def incr(att, count = 1)
db.hincrby(key[:counters], att, count)
end
# Decrement a counter atomically. Internally uses HINCRBY.
def decr(att, count = 1)
incr(att, -count)
end
# Return a value that allows the use of models as hash keys.
#
# Example:
#
# h = {}
#
# u = User.new
#
# h[:u] = u
# h[:u] == u
# # => true
#
def hash
new? ? super : key.hash
end
alias :eql? :==
def attributes
@attributes
end
# Export the ID and the errors of the model. The approach of Ohm
# is to whitelist public attributes, as opposed to exporting each
# (possibly sensitive) attribute.
#
# Example:
#
# class User < Ohm::Model
# attribute :name
# end
#
# u = User.create(:name => "John")
# u.to_hash
# # => { :id => "1" }
#
# In order to add additional attributes, you can override `to_hash`:
#
# class User < Ohm::Model
# attribute :name
#
# def to_hash
# super.merge(:name => name)
# end
# end
#
# u = User.create(:name => "John")
# u.to_hash
# # => { :id => "1", :name => "John" }
#
def to_hash
attrs = {}
attrs[:id] = id unless new?
attrs[:errors] = errors if errors.any?
return attrs
end
# Persist the model attributes and update indices and unique
# indices. The `counter`s and `set`s are not touched during save.
#
# If the model is not valid, nil is returned. Otherwise, the
# persisted model is returned.
#
# Example:
#
# class User < Ohm::Model
# attribute :name
#
# def validate
# assert_present :name
# end
# end
#
# User.new(:name => nil).save
# # => nil
#
# u = User.new(:name => "John").save
# u.kind_of?(User)
# # => true
#
def save(&block)
return if not valid?
save!(&block)
end
# Saves the model without checking for validity. Refer to
# `Model#save` for more details.
def save!
t = __save__
yield t if block_given?
t.commit(db)
return self
end
def __save__
Transaction.new do |t|
t.watch(*_unique_keys)
t.watch(key) if not new?
t.before do
_initialize_id if new?
end
existing = nil
uniques = nil
indices = nil
t.read do
_verify_uniques
existing = db.hgetall(key)
uniques = _read_index_type(:uniques)
indices = _read_index_type(:indices)
end
t.write do
db.sadd(model.key[:all], id)
_delete_uniques(existing)
_delete_indices(existing)
_save
_save_indices(indices)
_save_uniques(uniques)
end
end
end
# Delete the model, including all the following keys:
#
# - <Model>:<id>
# - <Model>:<id>:counters
# - <Model>:<id>:<set name>
#
# If the model has uniques or indices, they're also cleaned up.
#
def delete
transaction do |t|
t.read do |store|
store[:existing] = db.hgetall(key)
end
t.write do |store|
_delete_uniques(store[:existing])
_delete_indices(store[:existing])
model.collections.each { |e| db.del(key[e]) }
db.srem(model.key[:all], id)
db.del(key[:counters])
db.del(key)
end
yield t if block_given?
end
end
# Update the model attributes and call save.
#
# Example:
#
# User[1].update(:name => "John")
#
# # It's the same as:
#
# u = User[1]
# u.update_attributes(:name => "John")
# u.save
#
def update(attributes)
update_attributes(attributes)
save
end
# Write the dictionary of key-value pairs to the model.
def update_attributes(atts)
atts.each { |att, val| send(:"#{att}=", val) }
end
protected
def self.to_reference
name.to_s.
match(/^(?:.*::)*(.*)$/)[1].
gsub(/([a-z\d])([A-Z])/, '\1_\2').
downcase.to_sym
end
def self.indices
@indices ||= []
end
def self.uniques
@uniques ||= []
end
def self.collections
@collections ||= []
end
def self.filters(dict)
unless dict.kind_of?(Hash)
raise ArgumentError,
"You need to supply a hash with filters. " +
"If you want to find by ID, use #{self}[id] instead."
end
dict.map { |k, v| toindices(k, v) }.flatten
end
def self.toindices(att, val)
raise IndexNotFound unless indices.include?(att)
if val.kind_of?(Enumerable)
val.map { |v| key[:indices][att][v] }
else
[key[:indices][att][val]]
end
end
def self.new_id
db.incr(key[:id])
end
attr_writer :id
def transaction
txn = Transaction.new { |t| yield t }
txn.commit(db)
end
def model
self.class
end
def db
model.db
end
def _initialize_id
@id = model.new_id.to_s
end
def _skip_empty(atts)
{}.tap do |ret|
atts.each do |att, val|
ret[att] = send(att).to_s unless val.to_s.empty?
end
throw :empty if ret.empty?
end
end
def _unique_keys
model.uniques.map { |att| model.key[:uniques][att] }
end
def _save
catch :empty do
db.del(key)
db.hmset(key, *_skip_empty(attributes).to_a.flatten)
end
end
def _verify_uniques
if att = _detect_duplicate
raise UniqueIndexViolation, "#{att} is not unique."
end
end
def _detect_duplicate
model.uniques.detect do |att|
id = db.hget(model.key[:uniques][att], send(att))
id && id != self.id.to_s
end
end
def _read_index_type(type)
{}.tap do |ret|
model.send(type).each do |att|
ret[att] = send(att)
end
end
end
def _save_uniques(uniques)
uniques.each do |att, val|
db.hset(model.key[:uniques][att], val, id)
end
end
def _delete_uniques(atts)
model.uniques.each do |att|
db.hdel(model.key[:uniques][att], atts[att.to_s])
end
end
def _delete_indices(atts)
model.indices.each do |att|
val = atts[att.to_s]
db.srem(model.key[:indices][att][val], id)
end
end
def _save_indices(indices)
indices.each do |att, val|
model.toindices(att, val).each do |index|
db.sadd(index, id)
end
end
end
end
class Lua
attr :dir
attr :redis
attr :files
attr :scripts
def initialize(dir, redis)
@dir = dir
@redis = redis
@files = Hash.new { |h, cmd| h[cmd] = read(cmd) }
@scripts = {}
end
def run_file(file, options)
run(files[file], options)
end
def run(script, options)
keys = options[:keys]
argv = options[:argv]
params = keys + argv
begin
redis.evalsha(sha(script), keys.size, *params)
rescue RuntimeError
redis.eval(script, keys.size, *params)
end
end
private
def read(file)
File.read("%s/%s.lua" % [dir, file])
end
def sha(script)
Digest::SHA1.hexdigest(script)
end
end
end