Class: RedisLoad::Loader

Inherits:
Object
  • Object
show all
Defined in:
lib/redis-load/loader.rb

Overview

Exposes support for loading and saving different types of redis data structures to and from files

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(redis) ⇒ Loader

Returns a new instance of Loader.



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# File 'lib/redis-load/loader.rb', line 9

def initialize(redis)
  @redis = redis      
end

Instance Attribute Details

#redis ⇒ Object (readonly)

Returns the value of attribute redis.



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# File 'lib/redis-load/loader.rb', line 7

def redis
  @redis
end

Instance Method Details

#load_json(file, path = nil) ⇒ Object

Load the contents of a JSON file into Redis

Each key in the JSON file becomes a redis key. If the value is a literal then this is added as a redis key-value pair. If an array, then a List. If a hash, then a Hash.

Nested objects will be flattened.

file:: json file
path:: optional, path in the json file indicating the subsection to load



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# File 'lib/redis-load/loader.rb', line 54

def load_json(file, path=nil)
  f = File.new( file )
  json = JSON.parse( f.read )
  if path != nil
    json = Siren.query(query, json)
  end
  counter = 0
  #TODO could support proper results, not just hash?
  if json != nil
    json.each_pair do |key,value|
      if value.class() == Array
        value.each do |v|
          @redis.lpush( key, v )
        end          
      elsif value.class == Hash
        value.each_pair do |field, v|
          #TODO better handling of nesting?
          #E.g. convert hash or array back into JSON?
          @redis.hset(key, field, v)
        end
      else
        @redis.set(key, value)
      end
      counter = counter + 1      
    end        
  end
  return counter
end

#load_keys(file) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 35

def load_keys(file)
  f = File.new( file )
  counter = process_lines(f) do |redis,line|
    line = line.chomp
    parts = line.split(",")
    redis.set( parts[0], parts[1] )
  end
  return counter
end

#load_list(key, file) ⇒ Object

Load the contents of a file into a Redis list

key:: name of the list
file:: name of file (string)



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# File 'lib/redis-load/loader.rb', line 87

def load_list(key, file)
  f = File.new( file )
  counter = process_lines(f) do |redis,line|
    redis.lpush( key , line.chomp)
  end
  return counter            
end

#load_set(key, file) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 95

def load_set(key, file)
  f = File.new( file )
  counter = process_lines(f) do |redis,line|
    redis.sadd( key , line.chomp)
  end
  return counter
end

#load_zset(key, file) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 103

def load_zset(key, file)
  f = File.new( file )
  counter = process_lines(f) do |redis,line|
    line = line.chomp
    parts = line.split(",")
    redis.set( key , parts[1], parts[0] )
  end
  return counter
end

#process_lines(io) ⇒ Object

Process lines

io:: IO Object



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# File 'lib/redis-load/loader.rb', line 158

def process_lines(io)
  counter = 0
  io.each_line do |line|
    yield @redis, line
    counter = counter + 1
  end
  return counter      
end

#save_json(file, pattern = "*", limit = -1,, opts = nil) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 113

def save_json(file, pattern="*", limit=-1, opts=nil)
  counter = 0
  File.open( file, "w" ) do |file|
    json, count = to_json(pattern, limit, opts)
    file.write( json )
    counter = count
  end
  return counter
end

#save_list(key, file) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 123

def save_list(key, file)
  size = @redis.llen( key )
  count = 0
  File.open( file , "w") do |file|
    while (count < size)
      file.puts( @redis.lindex(key , count) )
      count = count + 1
    end
  end
  return size      
end

#save_set(key, file) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 135

def save_set(key, file)
  members = @redis.smembers( key )
  File.open( file , "w") do |file|
    members.each do |m|
      file.puts(m)
    end
  end
  return members.length      
end

#save_zset(key, file) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 145

def save_zset(key, file)
  members = @redis.zrange( key , 0, -1, :with_scores => true)
  File.open( file , "w") do |file|
    members.each_slice(2) do |member,value|
      file.puts("#{member},#{value}")
    end
  end
  return members.length/2  
end

#to_json(pattern = "*", limit = -1,, opts = nil) ⇒ Object 



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# File 'lib/redis-load/loader.rb', line 13

def to_json( pattern="*", limit=-1, opts=nil )
  keys = @redis.keys(pattern)
  h = Hash.new
  counter = 0
  keys.each do |key|
    counter = counter + 1
    type = @redis.type(key)
    if type == "hash"
      h[key] = @redis.hgetall(key)
    elsif type == "list"
      h[key] = @redis.lrange(key, 0, limit)
    elsif type == "set"
      h[key] = @redis.smembers(key)
    elsif type == "zset"
      h[key] = @redis.zrange(key, 0, limit)
    else
      h[key] = @redis.get(key)
    end  
  end     
  return JSON.fast_generate(h, opts), counter
end