moonbridge

view reference.txt @ 274:42b85f65327c

Allow "main threads" to be named; main threads also use MOONBR_PROTO_INTERVAL as listener type now
author jbe
date Tue Jun 06 11:25:07 2017 +0200 (2017-06-06)
parents 928473f7df96
children d4c82c90d244
line source
2 Moonbridge reference
3 ====================
7 Global function listen{...}
8 ---------------------------
10 This function initializes the Moonbridge Network Server. It may be called
11 multiple times. However, it is not allowed to register additional listeners by
12 calling listen{...} from a "prepare", "connect", or "finish" handler.
14 See file "example.lua" for parametrization of the listen{...} function.
16 Warning: Moonbridge will fork the Lua environment to handle parallel requests.
17 Functions provided as "prepare", "connect", and "finish" handlers may access
18 global variables, but for every child process these global variables will not
19 be shared! If you require a global state, a DBMS, cache server, or similar is
20 necessary.
24 Global function timeout(...)
25 ----------------------------
27 Calling this function with a positive number (time in seconds) sets a timer
28 that kills the current process after the selected time runs out. The remaining
29 time can be queried by calling this function without arguments.
31 Calling this function with a single argument that is the number zero will
32 disable the timeout.
34 Another mode of operation is selected by passing two arguments: a time (in
35 seconds) as first argument and a function as second argument. In this case, a
36 sub-timer will be used to limit the execution time of the function. In case of
37 timeout, the process will be killed (and the timeout function does not return).
38 If the time for the sub-timer is longer than a previously set timeout (using
39 the timeout(...) function with one argument), the shorter timeout (of the
40 previous call of timeout(...)) will have precedence.
42 Timers are also automatically reset (disabled) when a handler (prepare handler
43 or connect handler) returns. To shutdown processes after a certain time waiting
44 for a new request, use the idle_time parameter of the listen function.
48 Socket object passed to "connect" handler
49 -----------------------------------------
51 For every incoming connection, the registered "connect" handler is called with
52 a single socket object as argument, which is described below:
55 ### socket:close()
57 Closes the socket connection (input and output stream) by flushing all data and
58 sending a TCP FIN packet.
60 Returns true on success, or nil plus error message in case of an I/O error.
61 Using this method on sockets that have already been closed (or reset) will
62 throw an error.
64 Warning: Pending data on the input stream may cause connection aborts (TCP RST)
65 when network connections are used. All pending input data should have been read
66 (or drained) before calling socket:close(). Use socket:finish() to send a
67 TCP FIN packet to the peer before waiting for EOF from the peer.
69 A socket passed to the "connect" handler will be closed automatically if it was
70 not closed by the "connect" handler and if the "connect" handler returns
71 normally (i.e. without throwing an error). If the "connect" handler throws an
72 error, then the socket will be reset. See socket:reset().
75 ### socket:drain(maxlen, terminator)
77 Same as socket:read(maxlen, terminator), but discards the input and returns the
78 number of discarded bytes (as first return value) and the status code ("term",
79 "maxlen", "eof" as second return value).
81 In case of an I/O error, nil (as first return value) plus an error message (as
82 second return value) are returned.
85 ### socket:drain_call(waitfunc, maxlen, terminator)
87 Same as socket:drain(maxlen, terminator), but calls waitfunc() (in an infinite
88 loop) as long as the reading is blocked.
91 ### socket:drain_nb(maxlen, terminator)
93 Same as socket:drain(maxlen, terminator), but non-blocking. The status code
94 (which is returned as second return value) may therefore be "term", "maxlen",
95 "eof", or "block".
97 In case of an I/O error, nil (as first return value) plus an error message (as
98 second return value) are returned.
101 ### socket:drain_yield(maxlen, terminator)
103 Alias for socket:drain_call(coroutine.yield, maxlen, terminator)
106 ### socket:finish()
108 Sends a TCP FIN packet to indicate EOF on write stream. Subsequent reads are
109 still possible. When there is no more input data to be read, the connection
110 should finally be closed with socket:close().
112 In case of local sockets (Unix Domain Sockets), socket:finish() simply closes
113 the underlying socket and emulates EOF on subsequent reads. Also in this case,
114 the connection should be finally closed with socket:close().
117 ### socket:flush(...)
119 Same as socket:write(...) but additionally flushes the socket (i.e. all pending
120 data is passed to the operating system).
122 In case of an I/O error, nil (as first return value) plus an error message (as
123 second return value) are returned. On success, the socket userdata object is
124 returned.
127 ### socket:flush_call(waitfunc, ...)
129 Same as socket:flush(...), but calls waitfunc() (in an infinite loop) as long
130 as the writing is blocked.
133 ### socket:flush_nb(...)
135 Same as socket:write_nb(...) but additionally flushes the socket (i.e. all
136 pending data is passed to the operating system). The total number of bytes that
137 could not be passed yet to the operating system is returned. Zero is returned
138 if all data could be flushed out.
140 In case of an I/O error, nil (as first return value) plus an error message (as
141 second return value) are returned.
144 ### socket:flush_yield(...)
146 Alias for socket:flush_call(coroutine.yield, ...)
149 ### socket.interval
151 Set to the name of an interval timer if the "connect" handler was called due to
152 an elapsed interval timer. Otherwise nil.
155 ### socket.local_ip4
157 Local IPv4 address used for the connection. Encoded as 4 raw bytes in form of a
158 string.
161 ### socket.local_ip6
163 Local IPv6 address used for the connection. Encoded as 16 raw bytes in form of
164 a string.
167 ### socket.local_tcpport
169 Local TCP port used for the connection.
172 ### socket:read(maxlen, terminator)
174 Reads up to maxlen bytes or until an optional termination character is
175 encountered (which is included in the result). The maxlen value may be nil, in
176 which case there is no limit on the number of bytes read.
178 In case of an I/O error, nil (as first return value) plus an error message (as
179 second return value) are returned.
181 In all other cases (including EOF), the following two values are returned:
183 - a string containing the bytes read (first return value, may be empty string)
184 - a status code equal to "term", "maxlen", or "eof" (second return value)
186 If an EOF is encountered before all data could be read, then "eof" is returned
187 as second return value. If maxlen bytes have been read and no termination
188 character has been read, then "maxlen" is returned as second return value. If
189 the termination character is the last character of the read string, the second
190 return value will be "term".
193 ### socket:read_call(waitfunc, maxlen, terminator)
195 Same as socket:read(maxlen, terminator), but calls waitfunc() (in an infinite
196 loop) as long as the reading is blocked.
199 ### socket:read_nb(maxlen, terminator)
201 Same as socket:read(maxlen, terminator), but does not block.
203 In case of an I/O error, nil (as first return value) plus an error message (as
204 second return value) are returned.
206 In all other cases (including EOF), the following two values are returned:
208 - a string containing the bytes read (first return value, may be empty string)
209 - a status code equal to "term", "maxlen", "eof", "block" (second return value)
211 The status code "block" as second return value is used if the function returned
212 prematurely because it would block otherwise. In this case, the first return
213 value is a string that contains the bytes that could be read without blocking.
216 ### socket:read_yield(maxlen, terminator)
218 Alias for socket:read_call(coroutine.yield, maxlen, terminator)
221 ### socket.remote_ip4
223 Remote IPv4 address used for the connection. Encoded as 4 raw bytes in form of
224 a string.
227 ### socket.remote_ip6
229 Remote IPv6 address used for the connection. Encoded as 16 raw bytes in form of
230 a string.
233 ### socket.remote_tcpport
235 Remote TCP port used for the connection.
238 ### socket:reset()
240 Alias for socket:close(). Closes the socket connection by sending a TCP RST
241 packet if possible to indicate error condition. This is the default operation
242 when a socket handle gets garbage collected or the process is terminated
243 abnormally.
245 Returns true on success, or nil (as first return value) plus error message (as
246 second return value) in case of an I/O error. Using this method on sockets that
247 have already been closed (or reset) will throw an error.
249 Warning: Previously sent (and flushed) data may be lost during transmission.
252 ### socket:write(...)
254 Takes a variable number of strings and sends them to the peer. The operation is
255 buffered, so to actually send out the data, it is necessary to eventually call
256 socket:flush(), socket:finish(), or socket:close().
258 In case of an I/O error, nil (as first return value) plus an error message (as
259 second return value) are returned. On success, the socket userdata object is
260 returned.
263 ### socket:write_call(waitfunc, ...)
265 Same as socket:write(...), but calls waitfunc() (in an infinite loop) as long
266 as the writing is blocked.
269 ### socket:write_nb(...)
271 Takes a variable number of strings and sends them to the peer. The operation is
272 buffered, so to actually send out the data, it is necessary to eventually call
273 socket:flush_nb(), socket:flush(), socket:finish(), or socket:close().
275 This function always returns immediately (i.e. it does not block). If all data
276 (but a small buffered portion) could be sent out, then zero is returned.
277 Otherwise, all arguments that could not be sent are stored in a buffer of
278 unlimited size (up to memory capabilities) and an integer is returned that
279 indicates the number of bytes currently in the buffer.
281 In case of an I/O error, nil (as first return value) plus an error message (as
282 second return value) are returned.
285 ### socket:write_yield(...)
287 Alias for socket:write_call(coroutine.yield, ...)
291 I/O library
292 -----------
294 The Moonbridge Network Server for Lua Applications comes with its own I/O
295 library to support blocking as well as nonblocking I/O operations.
297 All methods on an I/O handle (e.g. socket) are described in the previous
298 section regarding the "socket" object. All other functions of the library are
299 listed below.
302 ### moonbridge_io.exec(command, arg1, arg2, ...)
304 Executes the given command and returns a handle with three sockets named
305 "stdin", "stdout", and "stderr" as well as the following methods:
307 - :kill(signal)
308 - :wait()
309 - :wait_nb()
310 - :wait_call(waitfunc)
311 - :wait_yield()
313 Use :kill(signal) to terminate the process with the given signal (defaults to
314 15 for SIGTERM).
316 The :wait() method will wait for the process to terminate and return its exit
317 code. If the process was terminated by a signal, a negative integer is returned
318 which corresponds to the respective positive signal number.
320 The method :wait_nb() is the same as :wait(), except that it does not block but
321 returns false (plus a notice as second return value) if the child process has
322 not terminated yet.
324 The method :wait_call() is the same as :wait() but calls waitfunc() (in an
325 infinite loop) as long as the process is still running.
327 The method :wait_yield() is an alias for :wait_call(coroutine.yield).
329 moonbridge_io.exec(...) returns nil (as first return value) plus an error
330 message (as second return value) in case of error.
333 ### moonbridge_io.localconnect(path)
335 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
336 a socket object on success, or nil (as first return value) plus an error
337 message (as second return value) in case of error.
340 ### moonbridge_io.localconnect_nb(path)
342 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
343 a socket object on success, or nil (as first return value) plus an error
344 message (as second return value) in case of error.
346 Same as moonbridge_io.localconnect(path), except that this function does not
347 block and immediately returns a socket object.
349 In case of an I/O error, nil (as first return value) plus an error message (as
350 second return value) may be returned. However, connection errors may also be
351 reported on first read or write on the socket.
354 ### moonbridge_io.locallisten(path)
356 Attempts to create a local socket (also known as Unix Domain Socket) to accept
357 incoming connections. If the file does already exist and is a socket, then it
358 is deleted automatically before being re-created.
360 In case of an I/O error, nil (as first return value) plus an error message (as
361 second return value) may be returned. On success, a listener object is returned
362 which supports the methods :accept(), :accept_nb(), and :close().
364 The method :accept() blocks until a new incoming connection is available, in
365 which case a socket object is returned.
367 The method :accept_nb() works like :accept(), except that the call is
368 nonblocking and returns false (plus a notice as second return value) in case no
369 incoming connection is available. It is possible to wait for an incoming
370 connection by including the listener object in the input_set of the
371 moonbridge_io.poll(...) call.
373 The method :close() will close the listening socket. In case of local sockets
374 (Unix Domain Sockets), the socket will not be unlinked in the file system.
376 I/O errors by the methods of the listener object are also reported by returning
377 nil (as first return value) plus an error message (as second return value).
380 ### moonbridge_io.poll(input_set, output_set, timeout)
382 This function waits for at least one of the given file descriptors and/or
383 I/O handles to be ready for input or output. The two sets of file descriptors
384 and/or handles must contain the file descriptor or handle as a key, and a value
385 which does evaluate to true, e.g. input_set = {[socketA] = true}. If a set is
386 nil, it is treated as being empty.
388 Returns true when at least one file descriptor or handle is ready for reading
389 or writing respectively, or if a signal has been received during waiting.
390 Returns false (plus a notice as second return value) in case of timeout.
393 ### moonbridge_io.signals
395 A table mapping a string (e.g. "TERM" or "KILL") to the corresponding signal
396 number (e.g. 9 or 15, respectively).
399 ### moonbridge_io.signalsocket(signal1, signal2, ...)
401 This function installs a signal handler for the signals with the numbers passed
402 as arguments and returns a socket which receives a byte for each received
403 signal. Optionally, a string may be used instead of the signal number (e.g.
404 "KILL" instead of 9, or "TERM" instead of 15).
406 Subsequent calls of this function can extend the set of signals but will always
407 return the same socket. If the socket is closed, it is no longer possible to
408 detect signals until the process is terminated.
411 ### moonbridge_io.tcpconnect(hostname, port)
413 Tries to open a TCP connection with the given host and TCP port number. Returns
414 a socket object on success, or nil (as first return value) plus an error
415 message (as second return value) in case of error.
418 ### moonbridge_io.tcpconnect_nb(hostname, port)
420 Same as moonbridge_io.tcpconnect(hostname, port), except that this function
421 does not block and immediately returns a socket object.
423 Note: The current implementation still blocks during the DNS lookup. Use a
424 numeric IP address as hostname to be truly nonblocking.
426 In case of an I/O error, nil (as first return value) plus an error message (as
427 second return value) may be returned. However, connection errors may also be
428 reported on first read or write on the socket.
431 ### moonbridge_io.tcplisten(hostname, port)
433 Attempts to open a TCP port for listening. To listen on the loopback interface,
434 use "::1" as hostname if IPv6 shall be used, or use "127.0.0.1" as hostname if
435 IPv4 shall be used. To listen on all available interfaces, use "::" (IPv6) or
436 "0.0.0.0" (IPv4) respectively.
438 In case of an I/O error, nil (as first return value) plus an error message (as
439 second return value) may be returned. On success, a listener object is returned
440 which supports the methods :accept(), :accept_nb(), and :close(). See reference
441 for moonbridge.io_locallisten(...).
444 ### moonbridge_io.timeref(previous)
446 Helper function which returns a time reference (in SI-seconds). If a value is
447 passed as an optional argument to the function, then that value is substracted
448 from the result. A common idiom is:
450 local starttime = moonbridge_io.timeref()
451 [...]
452 while true do
453 [...]
454 if not moonbridge_io.poll(
455 input_set,
456 output_set,
457 timeout - moonbridge_io.timeref(starttime)
458 ) then
459 error("Timeout")
460 end
461 [...]
462 end
466 HTTP module
467 -----------
469 The HTTP module exports the function moonbridge_http.generate_handler(callback)
470 that converts an HTTP handler to a "connect" handler. See file "helloworld.lua"
471 for a simple example or "example_application.lua" for a more complex example of
472 invocation. A table with options may be passed either as a second argument, or
473 as a first argument preceeding the callback function (whichever is more
474 convenient).
476 The following options are supported:
478 - request_body_size_limit: maximum size of payload of HTTP request body
479 (transfer encoding is allowed to add a limited amount of extra data)
480 - chunk_size: optional default value for maximum_input_chunk_size and
481 minimum_output_chunk_size
482 - request_header_size_limit: maximum size of HTTP request headers
483 - maximum_input_chunk_size: maximum chunk size when streaming a request body or
484 certain POST fields (bigger chunks will be fragmented automatically)
485 - minimum_output_chunk_size: minimum size for a chunk when sending a response
486 body (smaller chunks will be buffered and concatenated with future data;
487 ignored when request:flush() is called)
488 - static_headers: a set of headers to be included in every HTTP response
489 (may be a string, a table or strings, or a table of key-value pairs)
491 The callback function receives a single request object as argument, which is
492 described below.
495 ### request.body
497 The request body (without headers) as a string. Accessing this value makes
498 further access to request.post_params and request.post_params_list, or
499 invocation of request:stream_request_body(...) impossible.
502 ### request:close_after_finish()
504 Closes the connection after answering the request.
506 This method can only be called before the HTTP response header section has been
507 finished (i.e. before request:finish_headers(), request:send_data(...), or
508 request:finish() were called), but it may be called before a status code has
509 been sent using request:send_status(...).
511 A corresponding "Connection: close" header is automatically sent.
513 See also request:monologue().
516 ### request:consume_input()
518 Starts processing the request body (if existent) to set the values
519 request.post_params, request.post_params_list, request.post_metadata, and
520 and request.post_metadata_list and/or to call POST field stream handlers that
521 have been previously registered with request:stream_post_param(...) or
522 request:stream_post_params(...), or to call a previously registered request
523 body stream handler that was set with request:set_request_body_streamer().
525 This method gets invoked automatically when the POST param tables
526 (request.post_params, etc.) are accessed or if request.body is accessed.
529 ### request.cookies
531 A table with all cookies sent by the client.
534 ### request.faulty
536 Normally set to false. In case of a write error on the client connection or
537 certain other unexpected errors, this value is set to true before a Lua error
538 is raised.
540 A faulty request handle must not be used, or another Lua error will be raised.
543 ### request:finish()
545 Finishes and flushes a HTTP response. An HTTP status, all headers, and the
546 response body (if applicable) must have been previously sent. May be called
547 multiple times (performs no operation if called on a finished request handle).
548 Gets automatically invoked when the callback handler returns. After calling
549 this method explicitly, no further data may be written.
552 ### request:finish_headers()
554 Finishes and flushes the HTTP response header section. May be called multiple
555 times, as long as the request is not finished completely. This method is
556 automatically invoked if the application is beginning to send a response body.
557 After calling this method, no further headers may be sent.
560 ### request:flush()
562 Flushes any pending output data. Note: In order to mark the end of a response
563 body, it is required to call request:finish().
566 ### request.fresh
568 Set to false whenever the request object has been used (e.g. data has been read
569 or sent out, or a stream handler was installed); true otherwise.
572 ### request.get_params
574 A table that maps field names to their corresponding GET value. If there are
575 several GET values with the given field name, then the first value is used.
577 Note: May be implemented through metamethods, but does support iteration
578 through pairs(...).
581 ### request.get_params_list
583 A table that maps field names to a sequence of their corresponding GET values.
585 Note: May be implemented through metamethods, but does support iteration
586 through pairs(...).
589 ### request.headers
591 A table that maps (case-insensitively) a HTTP header field name to a sequence
592 of values. For each occurrence of the respective header line, a string entry is
593 created in that sequence. Non-existent headers are mapped to an empty table.
596 ### request.headers_csv_string
598 A table that maps (case-insensitively) a HTTP header field name to a comma
599 separated string. Multiple occurrences of the header with the given field name
600 are automatically merged into the comma separated string.
603 ### request.headers_csv_table
605 A table that maps (case-insensitively) a HTTP header field name to a sequence
606 of values. One entry is created in that sequence for every comma separated
607 value of each header with the given field name.
610 ### request.headers_flags
612 A table that maps (case-insensitively) a HTTP header field name to another
613 table which (again case-insensitively) maps a string to a boolean, depending on
614 whether this string occurred in the list of comma separated values of one
615 header line with the given field name that was the key in the first table.
618 ### request.headers_value
620 A table that maps (case-insensitively) a HTTP header field name to a value. If
621 multiple header lines with the given field name have been received, false is
622 used as value.
625 ### request.method
627 The HTTP request method, e.g. "HEAD", "GET", or "POST".
630 ### request:monologue()
632 Same as request:close_after_finish() but additionally discards all input data
633 immediately.
636 ### request.path
638 The requested path without a leading slash and without the query part (e.g.
639 "index.html" if "/index.html?a=b&c=d" has been requested). For the query part,
640 see request.query.
642 This value will be nil if (and only if) the request method is "OPTIONS" with a
643 request target equal to "*" (see also asterisk-form of request-target in
644 section 5.3.4 in RFC 7230).
647 ### request.post_metadata
649 Only set for multipart/form-data POST requests. A table that maps field names
650 to their corresponding POST metadata table which contains two entries:
651 "file_name" and "content_type". If there are several POST values with the given
652 field name, then the first value/file is used.
654 Note: May be implemented through metamethods, but does support iteration
655 through pairs(...).
658 ### request.post_metadata_list
660 Only set for multipart/form-data POST requests. A table that maps field names
661 to a sequence with their corresponding POST metadata tables. Needed if multiple
662 files are uploaded with the same field name.
664 Note: May be implemented through metamethods, but does support iteration
665 through pairs(...).
668 ### request.post_params
670 A table that maps field names to their corresponding POST value. If there are
671 several POST values with the given field name, then the first value is used.
673 Note: May be implemented through metamethods, but does support iteration
674 through pairs(...).
677 ### request.post_params_list
679 A table that maps field names to a sequence of their corresponding POST values.
681 Note: May be implemented through metamethods, but does support iteration
682 through pairs(...).
685 ### request.query
687 Query part of the request target including the leading question mark, e.g.
688 "?a=b&c=d" if the requested target is "/index.html?a=b&c=d". The data is
689 automatically parsed and made available through request.get_params and
690 request.get_params_list.
692 If there is no query part given in the request target, then this string is
693 the empty string. This value will be nil if (and only if) the request method
694 is "OPTIONS" with a request target equal to "*" (see also asterisk-form of
695 request-target in section 5.3.4 in RFC 7230).
698 ### request:send_data(...)
700 Sends data as response body. All arguments are converted via tostring(...) and
701 concatenated. May be called multiple times until the request has been finished
702 by calling request:finish().
704 If the request method (see request.method) is "HEAD", then calls to
705 request:send_data(...) are automatically ignored.
708 ### request:send_header(key, value)
710 Sends a HTTP response header that consists of the given key and the given
711 value. Note: Key and value must be provided as separate arguments. Before any
712 headers can be sent, a HTTP status must have been set with
713 request:send_status(status_string).
716 ### request:send_status(status_string)
718 Sends a HTTP response status that is given as a string consisting of a 3-digit
719 number and an explanatory string, e.g. "200 OK" or "404 Not Found". This
720 function must be called once before any headers or response body data may be
721 sent.
724 ### request.socket
726 The underlaying socket. Can be used to force a TCP RST, etc.
729 ### request:stream_post_param(field_name, callback)
731 Registers a stream handler for the given POST parameter. The callback function
732 will be called in the following manner:
734 - For the initial chunk, the first chunk gets passed as first argument while a
735 table with metadata ("field_name" and "content_type") gets passed as second
736 argument. In case of an immediate EOF (i.e. an empty file), the passed
737 chunk is the empty string. In all other cases the chunk has a length greater
738 than zero.
739 - For any remaining chunks, the respective chunk gets passed as first and only
740 argument (no metadata). Here, the chunk has always a length greater than
741 zero.
742 - To indicate the end of the stream, the callback function is called without
743 arguments. This also happens in case of an immediate EOF (see above).
745 In case of an immediate EOF (i.e. an empty file), the callback function is thus
746 called as follows:
748 - The first time with an empty string as first argument, and with the metadata
749 as second argument.
750 - The second time without any arguments.
752 Note that request:consume_input() needs to be called to enforce streaming to
753 finish.
756 ### request:stream_post_params(pattern, callback)
758 Same as request:stream_post_param(...) but providing a string pattern to match
759 multiple field names (e.g. "^file_[0-9]+$").
762 ### request:stream_request_body(callback)
764 Registeres a stream handler for the whole request body. For each chunk of the
765 request body, the callback function is called with the corresponding chunk. End
766 of data is indicated by passing a nil value to the callback functuion.
768 Note that request:consume_input() needs to be called to enforce streaming to
769 finish.
772 ### request:stream_request_body_now(callback)
774 Start streaming of request body immediately. On EOF the function returns and
775 the callback function is *not* called with nil as argument.

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