1 # -*- encoding: binary -*-
3 # \MogileFS file manipulation client.
5 # Create a new instance that will communicate with these trackers:
6 # hosts = %w[192.168.1.69:6001 192.168.1.70:6001]
7 # mg = MogileFS::MogileFS.new(:domain => 'test', :hosts => hosts)
9 # # Stores "A bunch of text to store" into 'some_key' with a class of 'text'.
10 # mg.store_content('some_key', 'text', "A bunch of text to store")
12 # # Retrieve data from 'some_key' as a string
13 # data = mg.get_file_data('some_key')
15 # # Store the contents of 'image.jpeg' into the key 'my_image' with a
17 # mg.store_file('my_image', 'image', 'image.jpeg')
19 # # Store the contents of 'image.jpeg' into the key 'my_image' with a
20 # # class of 'image' using an open IO object.
21 # File.open('image.jpeg') { |fp| mg.store_file('my_image', 'image', fp) }
23 # # Retrieve the contents of 'my_image' into '/path/to/huge_file'
24 # # without slurping the entire contents into memory:
25 # mg.get_file_data('my_image', '/path/to/huge_file')
27 # # Remove the key 'my_image' and 'some_key'.
28 # mg.delete('my_image')
29 # mg.delete('some_key')
31 class MogileFS::MogileFS < MogileFS::Client
32 include MogileFS::Bigfile
34 # The domain of keys for this MogileFS client.
37 # The timeout for get_file_data (per-read() system call).
38 # Defaults to five seconds.
39 attr_accessor :get_file_data_timeout
41 # The maximum allowed time for creating a new_file. Defaults to 1 hour.
42 attr_accessor :new_file_max_time
44 # Creates a new MogileFS::MogileFS instance. +args+ must include a key
45 # :domain specifying the domain of this client.
47 # Optional parameters for +args+:
49 # [:get_file_data_timeout => Numeric]
51 # See get_file_data_timeout
53 # [:new_file_max_time => Numeric]
55 # See new_file_max_time
57 # [:fail_timeout => Numeric]
59 # Delay before retrying a failed tracker backends.
60 # Defaults to 5 seconds.
62 # [:timeout => Numeric]
64 # Timeout for tracker backend responses.
65 # Defaults to 3 seconds.
67 def initialize(args = {})
68 @domain = args[:domain]
70 @get_file_data_timeout = args[:get_file_data_timeout] || 5
71 @new_file_max_time = args[:new_file_max_time] || 3600.0
73 raise ArgumentError, "you must specify a domain" unless @domain
75 if @backend = args[:db_backend]
82 # Enumerates keys, limited by optional +prefix+
83 def each_key(prefix = "", &block)
86 keys, after = list_keys(prefix, after, 1000, &block)
87 end while keys && keys[0]
91 # Enumerates keys and yields a +file_info+ hash for each key matched by
93 def each_file_info(prefix = "", args = nil)
94 # FIXME: there's a lot of duplicate code from list_keys_verbose here...
95 raise ArgumentError, "need block" unless block_given?
97 on_file_info = lambda do |info|
98 Hash === info or raise info
99 file_info_cleanup(info)
101 # deal with trackers with multiple queryworkers responding out-of-order
102 ready[info["key"]] = info
103 while info = ready.delete(ordered[-1])
110 opts = { :domain => @domain }
111 opts[:devices] = 1 if args && args[:devices]
112 after = args ? args[:after] : nil
113 limit = args ? args[:limit] : nil
116 keys, after = list_keys(prefix, after, limit || 1000)
117 return nr unless keys && keys[0]
118 ordered = keys.reverse
121 limit -= keys.size if limit
125 @backend.pipeline_dispatch(:file_info, opts, &on_file_info)
127 @backend.pipeline_wait
128 rescue MogileFS::PipelineError, SystemCallError,
129 MogileFS::RequestTruncatedError,
130 MogileFS::UnreadableSocketError,
131 MogileFS::InvalidResponseError, # truncated response
134 keys = (ordered - ready.keys).reverse!
136 end while limit == nil || limit > 0
142 # Retrieves the contents of +key+. If +dst+ is specified, +dst+
143 # should be an IO-like object capable of receiving the +write+ method
144 # or a path name. +copy_length+ may be specified to limit the number of
145 # bytes to retrieve, and +src_offset+ can be specified to specified the
146 # start position of the copy.
147 def get_file_data(key, dst = nil, copy_length = nil, src_offset = nil)
148 paths = get_paths(key)
149 sock = MogileFS::HTTPReader.first(paths, @get_file_data_timeout,
150 copy_length, src_offset)
159 sock.close if sock && ! sock.closed?
162 # Get the paths (URLs as strings) for +key+. If +args+ is specified,
164 # - :noverify -> boolean, whether or not the tracker checks (default: true)
165 # - :pathcount -> a positive integer of URLs to retrieve (default: 2)
166 # - :zone -> "alt" or nil (default: nil)
168 # :noverify defaults to true because this client library is capable of
169 # verifying paths for readability itself. It is also faster and more
170 # reliable to verify paths on the client.
171 def get_paths(key, *args)
175 :noverify => args[0],
180 opts[:noverify] = args[:noverify]
181 opts[:zone] = args[:zone]
182 pathcount = args[:pathcount] and opts[:pathcount] = pathcount.to_i
185 opts[:noverify] = false == opts[:noverify] ? 0 : 1
186 @backend.respond_to?(:_get_paths) and return @backend._get_paths(opts)
187 res = @backend.get_paths(opts)
188 (1..res['paths'].to_i).map { |i| res["path#{i}"] }
191 # Returns +true+ if +key+ exists, +false+ if not
193 args = { :key => key, :domain => @domain , :ruby_no_raise => true}
194 case rv = @backend.get_paths(args)
197 when MogileFS::Backend::UnknownKeyError
204 # Get the URIs for +key+ (paths) as URI::HTTP objects
205 def get_uris(key, *args)
206 get_paths(key, *args).map! { |path| URI.parse(path) }
209 # Creates a new file +key+ in the domain of this object.
211 # +bytes+ is the expected size of the file if known in advance
213 # It operates like File.open(..., "w") and may take an optional
214 # block, yielding an IO-like object with support for the methods
215 # documented in MogileFS::NewFile::Writer.
217 # This atomically replaces existing data stored as +key+
218 # when the block exits or when the returned object is closed.
220 # +args+ may contain the following options:
222 # [:content_length => Integer]
224 # This has the same effect as the (deprecated) +bytes+ parameter.
226 # [ :largefile => :stream, :content_range or :tempfile ]
228 # See MogileFS::NewFile for more information on this
230 # [ :class => String]
232 # The MogileFS storage class of the object.
234 # [:content_md5 => String, Proc, or :trailer]
236 # This can either be a Base64-encoded String, a Proc object, or
237 # the :trailer symbol. If given a String, it will be used as the
238 # Content-MD5 HTTP header. If given the :trailer symbol, this library
239 # will automatically generate an Content-MD5 HTTP trailer. If given
240 # a Proc object, this Proc object should give a Base64-encoded string
241 # which can be used as the Content-MD5 HTTP trailer when called at the
242 # end of the request.
244 # Keep in mind most HTTP servers do not support HTTP trailers, so
245 # passing a String is usually the safest way to use this.
247 def new_file(key, args = nil, bytes = nil) # :yields: file
248 raise MogileFS::ReadOnlyError if readonly?
249 opts = { :key => key, :multi_dest => 1 }
252 opts[:domain] = args[:domain]
253 klass = args[:class] and "default" != klass and opts[:class] = klass
255 opts[:class] = args if "default" != args
257 opts[:domain] ||= @domain
258 res = @backend.create_open(opts)
260 dests = if dev_count = res['dev_count'] # multi_dest succeeded
261 (1..dev_count.to_i).map { |i| [res["devid_#{i}"], res["path_#{i}"]] }
262 else # single destination returned
263 # 0x0040: d0e4 4f4b 2064 6576 6964 3d31 2666 6964 ..OK.devid=1&fid
264 # 0x0050: 3d33 2670 6174 683d 6874 7470 3a2f 2f31 =3&path=http://1
265 # 0x0060: 3932 2e31 3638 2e31 2e37 323a 3735 3030 92.168.1.72:7500
266 # 0x0070: 2f64 6576 312f 302f 3030 302f 3030 302f /dev1/0/000/000/
267 # 0x0080: 3030 3030 3030 3030 3033 2e66 6964 0d0a 0000000003.fid..
269 [[res['devid'], res['path']]]
272 opts.merge!(args) if Hash === args
273 opts[:backend] = @backend
274 opts[:fid] = res['fid']
275 opts[:content_length] ||= bytes if bytes
276 opts[:new_file_max_time] ||= @new_file_max_time
277 opts[:start_time] = Time.now
279 case (dests[0][1] rescue nil)
281 http_file = MogileFS::NewFile.new(dests, opts)
284 return http_file.commit # calls create_close
289 raise MogileFS::EmptyPathError,
290 "Empty path for mogile upload res=#{res.inspect}"
292 raise MogileFS::UnsupportedPathError,
293 "paths '#{dests.inspect}' returned by backend is not supported"
297 # Copies the contents of +file+ into +key+ in class +klass+. +file+ can be
298 # either a path name (String or Pathname object) or an IO-like object that
299 # responds to #read or #readpartial. Returns size of +file+ stored.
300 # This atomically replaces existing data stored as +key+
301 def store_file(key, klass, file, opts = nil)
302 raise MogileFS::ReadOnlyError if readonly?
303 (opts ||= {})[:class] = klass if String === klass
305 new_file(key, opts) { |mfp| mfp.big_io = file }
308 # Stores +content+ into +key+ in class +klass+, where +content+ is a String
309 # This atomically replaces existing data stored as +key+
310 def store_content(key, klass, content, opts = nil)
311 raise MogileFS::ReadOnlyError if readonly?
312 (opts ||= {})[:class] = klass if String === klass
314 new_file(key, opts) do |mfp|
315 if content.is_a?(MogileFS::Util::StoreContent)
316 mfp.streaming_io = content
325 raise MogileFS::ReadOnlyError if readonly?
327 @backend.delete :domain => @domain, :key => key
331 # Updates +key+ to +newclass+
332 def updateclass(key, newclass)
333 raise MogileFS::ReadOnlyError if readonly?
335 @backend.updateclass(:domain => @domain, :key => key, :class => newclass)
339 # Sleeps +duration+, only used for testing
340 def sleep(duration) # :nodoc:
341 @backend.sleep :duration => duration
344 # Renames a key +from+ to key +to+.
346 raise MogileFS::ReadOnlyError if readonly?
348 @backend.rename :domain => @domain, :from_key => from, :to_key => to
352 # Returns the size of +key+.
354 @backend.respond_to?(:_size) and return @backend._size(domain, key)
356 file_info(key)["length"].to_i
357 rescue MogileFS::Backend::UnknownCommandError
358 paths_size(get_paths(key))
362 def paths_size(paths) # :nodoc:
363 require "mogilefs/paths_size"
364 MogileFS::PathsSize.call(paths)
367 # Lists keys starting with +prefix+ following +after+ up to +limit+. If
368 # +after+ is nil the list starts at the beginning.
369 def list_keys(prefix = "", after = nil, limit = 1000, &block)
370 @backend.respond_to?(:_list_keys) and
371 return @backend._list_keys(domain, prefix, after, limit, &block)
373 res = @backend.list_keys(:domain => domain, :prefix => prefix,
374 :after => after, :limit => limit,
375 :ruby_no_raise => true)
376 MogileFS::Backend::NoneMatchError === res and return
377 raise res if MogileFS::Error === res
379 keys = (1..res['key_count'].to_i).map { |i| res["key_#{i}"] }
382 keys.each { |key| block.call(key) }
384 list_keys_verbose(keys, block)
388 [ keys, res['next_after'] ]
391 def list_keys_verbose(keys, block) # :nodoc:
392 # emulate the MogileFS::Mysql interface, slowly...
393 ordered = keys.reverse
395 on_file_info = lambda do |info|
396 Hash === info or raise info
397 file_info_cleanup(info)
399 # deal with trackers with multiple queryworkers responding out-of-order
400 ready[info["key"]] = info
401 while info = ready.delete(ordered[-1])
402 block.call(ordered.pop, info["length"], info["devcount"])
405 opts = { :domain => @domain }
409 @backend.pipeline_dispatch(:file_info, opts, &on_file_info)
411 @backend.pipeline_wait
412 rescue MogileFS::Backend::UnknownCommandError # MogileFS < 2.45
413 @backend.shutdown # reset the socket
414 args = { :pathcount => 0x7fffffff }
416 paths = get_paths(key, args)
417 block.call(key, paths_size(paths), paths.size)
419 rescue MogileFS::PipelineError, SystemCallError,
420 MogileFS::RequestTruncatedError,
421 MogileFS::UnreadableSocketError,
422 MogileFS::InvalidResponseError, # truncated response
425 keys = (ordered - ready.keys).reverse!
433 # Return metadata about a file as a hash.
434 # Returns the domain, class, length, devcount, etc. as keys.
435 # Optionally, device ids (not paths) can be returned as
436 # well if :devices is specified and +true+.
438 # This should only be used for informational purposes, and not usually
439 # for dynamically serving files.
441 # mg.file_info("bar")
448 # "class" => "default",
452 def file_info(key, args = nil)
453 opts = { :domain => @domain, :key => key }
454 args and devices = args[:devices] and opts[:devices] = devices ? 1 : 0
455 file_info_cleanup(@backend.file_info(opts))
458 def file_info_cleanup(rv) # :nodoc:
459 %w(fid length devcount).each { |f| rv[f] = rv[f].to_i }
460 devids = rv["devids"] and
461 rv["devids"] = devids.split(/,/).map! { |x| x.to_i }
465 # Given an Integer +fid+ or String +key+ and domain, thorougly search
466 # the database for all occurences of a particular fid.
468 # Use this sparingly, this command hits the master database numerous
469 # times and is very expensive. This is not for production use, only
470 # troubleshooting and debugging.
472 # Searches for fid=666:
474 # client.file_debug(666)
476 # Search for key=foo using the default domain for this object:
478 # client.file_debug("foo")
480 # Search for key=foo in domain="bar":
482 # client.file_debug(:key => "foo", :domain => "bar")
486 when Integer then args = { "fid" => args }
487 when String then args = { "key" => args }
489 opts = { :domain => args[:domain] || @domain }.merge!(args)
491 rv = @backend.file_debug(opts)
494 when /_(?:classid|devcount|dmid|fid|length|
495 nexttry|fromdevid|failcount|flags|devid|type)\z/x
498 rv[k] = v.split(/,/).map! { |x| x.to_i }