Class: Makura::Server

Inherits:
Object
  • Object
show all
Includes:
HTTPMethods
Defined in:
lib/makura/server.rb

Constant Summary collapse

COUCHDB_URI = 
'http://localhost:5984'
CACHE_TTL = 
5
CACHE_TRIES = 
2
JSON_PARAMS = 
%w[key startkey endkey]

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from HTTPMethods

#delete, #get, #post, #put

Constructor Details

#initialize(uri = COUCHDB_URI, cache_ttl = CACHE_TTL, cache_tries = CACHE_TRIES) ⇒ Server

Usage:

server = Makura::Server.new
#<URI::HTTP:0xb778ce38 URL:http://localhost:5984>
server.info
{"couchdb"=>"Welcome", "version"=>"0.9.0a718650-incubating"}



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# File 'lib/makura/server.rb', line 16

def initialize(uri = COUCHDB_URI, cache_ttl = CACHE_TTL, cache_tries = CACHE_TRIES)
  @uri = URI(uri.to_s)
  @cache_ttl = cache_ttl
  @cache_tries = cache_tries
  @uuids = UUIDCache.new(self)
end

Instance Attribute Details

#cache_tries ⇒ Object

Returns the value of attribute cache_tries.



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# File 'lib/makura/server.rb', line 4

def cache_tries
  @cache_tries
end

#cache_ttl ⇒ Object

Returns the value of attribute cache_ttl.



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# File 'lib/makura/server.rb', line 4

def cache_ttl
  @cache_ttl
end

#uri(path = '/', params = {}) ⇒ Object

Returns the value of attribute uri.



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# File 'lib/makura/server.rb', line 4

def uri
  @uri
end

Instance Method Details

#appropriate_error(exception) ⇒ Object

Raises:



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# File 'lib/makura/server.rb', line 158

def appropriate_error(exception)
  body = exception.response.body if exception.respond_to?(:response)
  backtrace = exception.backtrace

  raise(Error::RequestFailed, exception.message, backtrace) unless body
  raise(Error::RequestFailed, exception.message, backtrace) if body.empty?

  json = JSON.parse(body)
  error, reason = json['error'], json['reason']

  case error
  when 'bad_request'
    raise(Error::BadRequest, reason, backtrace)
  when 'authorization'
    raise(Error::Authorization, reason, backtrace)
  when 'not_found'
    raise(Error::NotFound, reason, backtrace)
  when 'file_exists'
    raise(Error::FileExists, reason, backtrace)
  when 'missing_rev'
    raise(Error::MissingRevision, reason, backtrace)
  when 'conflict'
    raise(Error::Conflict, reason, backtrace)
  else
    raise(Error::RequestFailed, json.inspect, backtrace)
  end
end

#cached(request, ttl = cache_ttl, tries = cache_tries) ⇒ Object 



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# File 'lib/makura/server.rb', line 96

def cached(request, ttl = cache_ttl, tries = cache_tries)
  key = request[:url]

  unless response = @cache.get(key)
    response = execute(request)
    @cache.add(key, response, ttl)
  end

  return response
rescue MemCache::MemCacheError => error
  servers = @cache.servers.map{|s| "#{s.host}:#{s.port}"}
  start_cache(@cache.namespace, *servers)
  tries -= 1
  retry if tries > 0
  warn "[makura caching disabled] #{error.message}"
  @cache = nil
  execute(request)
end

#config ⇒ Object

Answers with configuration info.

Usage:

server.config



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# File 'lib/makura/server.rb', line 43

def config
  get('/_config')
end

#database(name) ⇒ Object

Return new database instance using this server instance.

Usage:

foo = server.database('foo')
# #<Makura::Database 'http://localhost:5984/foo'>
server.databases
# ["another", "blog", "foo", "makura-spec"]



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# File 'lib/makura/server.rb', line 73

def database(name)
  Database.new(self, name)
end

#databases ⇒ Object

Array of names of databases on the server

Usage:

server.databases
# ["another", "blog", "makura-spec"]



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# File 'lib/makura/server.rb', line 61

def databases
  get('/_all_dbs')
end

#execute(request) ⇒ Object 



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# File 'lib/makura/server.rb', line 154

def execute(request)
  RestClient::Request.execute(request)
end

#info ⇒ Object

Answers with general couchdb info, looks like:

Usage:

server.info
# {'couchdb' => 'Welcome', 'version' => '0.9.0a718650-incubating'}



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# File 'lib/makura/server.rb', line 34

def info
  get('/')
end

#inspect ⇒ Object 



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# File 'lib/makura/server.rb', line 23

def inspect
  @uri.inspect
end

#next_uuid ⇒ Object

Answers with an uuid from the UUIDCache.

Usage:

server.next_uuid
# "55fdca746fa5a5b56f5270875477a2cc"



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# File 'lib/makura/server.rb', line 83

def next_uuid
  @uuids.next
end

#paramify(hash) ⇒ Object 



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# File 'lib/makura/server.rb', line 188

def paramify(hash)
  hash.map{|k,v|
    k = k.to_s
    v = v.to_json if JSON_PARAMS.include?(k)
    "#{Makura.escape(k)}=#{Makura.escape(v)}"
  }.join('&')
end

#request(method, path, params = {}) ⇒ Object

Helpers



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# File 'lib/makura/server.rb', line 117

def request(method, path, params = {})
  keep_raw = params.delete(:raw)
  payload = params.delete(:payload)
  payload = payload.to_json if payload and not keep_raw
  headers = {}

  if content_type = params.delete('Content-Type')
    headers['Content-Type'] = content_type
  end

  params.delete_if{|k,v| v.nil? }
  uri = uri(path, params).to_s

  request = {
    :method => method,
    :url => uri,
    :payload => payload,
    :headers => headers}

  if @cache and request[:method] == :get
    raw = cached(request)
  else
    raw = execute(request)
  end

  return raw if keep_raw
  json = JSON.parse(raw)
rescue JSON::ParserError
  return raw
rescue RestClient::RequestFailed => ex
  raise appropriate_error(ex)
rescue RestClient::ResourceNotFound => ex
  raise Error::ResourceNotFound, request[:url], ex.backtrace
rescue Errno::ECONNREFUSED
  raise Error::ConnectionRefused, "Is CouchDB running at #{@uri}?"
end

#restart ⇒ Object

Issue restart of the CouchDB daemon.

Usage:

server.restart
# {'ok' => true}



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# File 'lib/makura/server.rb', line 52

def restart
  post('/_restart')
end

#start_cache(namespace = 'makura', *servers) ⇒ Object 



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# File 'lib/makura/server.rb', line 87

def start_cache(namespace = 'makura', *servers)
  servers << 'localhost:11211' if servers.empty?
  @cache = MemCache.new(servers, :namespace => namespace, :multithread => true)
end

#stop_cache ⇒ Object 



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# File 'lib/makura/server.rb', line 92

def stop_cache
  @cache = nil
end