moonbridge
view reference.txt @ 144:e7fac0918f9c
Added new methods drain_call, drain_yield
| author | jbe |
|---|---|
| date | Sat May 02 14:31:55 2015 +0200 (2015-05-02) |
| parents | 41da87a681d6 |
| children | bd88dfa4f294 |
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.
70 ### socket:drain(maxlen, terminator)
72 Same as socket:read(maxlen, terminator), but discards the input and returns the
73 number of discarded bytes (as first return value) and the status code ("term",
74 "maxlen", "eof" as second return value).
76 In case of an I/O error, nil (as first return value) plus an error message (as
77 second return value) are returned.
80 ### socket:drain_call(waitfunc, maxlen, terminator)
82 Same as socket:drain(maxlen, terminator), but calls waitfunc(socket, "r") (in
83 an infinite loop) as long as the reading is blocked.
86 ### socket:drain_nb(maxlen, terminator)
88 Same as socket:drain(maxlen, terminator), but non-blocking. The status code
89 (which is returned as second return value) may therefore be "term", "maxlen",
90 "eof", or "block".
92 In case of an I/O error, nil (as first return value) plus an error message (as
93 second return value) are returned.
96 ### socket:drain_yield(maxlen, terminator)
98 Alias for socket:drain_call(coroutine.yield, maxlen, terminator)
101 ### socket:finish()
103 Sends a TCP FIN packet to indicate EOF on write stream. Subsequent reads are
104 still possible. When there is no more input data to be read, the connection
105 should finally be closed with socket:close().
107 In case of local sockets (Unix Domain Sockets), socket:finish() simply closes
108 the underlying socket and emulates EOF on subsequent reads. Also in this case,
109 the connection should be finally closed with socket:close().
112 ### socket:flush(...)
114 Same as socket:write(...) but additionally flushes the socket (i.e. all pending
115 data is passed to the operating system).
117 In case of an I/O error, nil (as first return value) plus an error message (as
118 second return value) are returned. On success, the socket userdata object is
119 returned.
122 ### socket:flush_nb(...)
124 Same as socket:write_nb(...) but additionally flushes the socket (i.e. all
125 pending data is passed to the operating system). The total number of bytes that
126 could not be passed yet to the operating system is returned. Zero is returned
127 if all data could be flushed out.
129 In case of an I/O error, nil (as first return value) plus an error message (as
130 second return value) are returned.
133 ### socket.interval
135 Set to the name of an interval timer if the "connect" handler was called due to
136 an elapsed interval timer. Otherwise nil.
139 ### socket.local_ip4
141 Local IPv4 address used for the connection. Encoded as 4 raw bytes in form of a
142 string.
145 ### socket.local_ip6
147 Local IPv6 address used for the connection. Encoded as 16 raw bytes in form of
148 a string.
151 ### socket.local_tcpport
153 Local TCP port used for the connection.
156 ### socket:read(maxlen, terminator)
158 Reads up to maxlen bytes or until an optional termination character is
159 encountered (which is included in the result). The maxlen value may be nil, in
160 which case there is no limit on the number of bytes read.
162 In case of an I/O error, nil (as first return value) plus an error message (as
163 second return value) are returned.
165 In all other cases (including EOF), the following two values are returned:
167 - a string containing the bytes read (first return value, may be empty string)
168 - a status code equal to "term", "maxlen", or "eof" (second return value)
170 If an EOF is encountered before all data could be read, then "eof" is returned
171 as second return value. If maxlen bytes have been read and no termination
172 character has been read, then "maxlen" is returned as second return value. If
173 the termination character is the last character of the read string, the second
174 return value will be "term".
177 ### socket:read_call(waitfunc, maxlen, terminator)
179 Same as socket:read(maxlen, terminator), but calls waitfunc(socket, "r") (in an
180 infinite loop) as long as the reading is blocked.
183 ### socket:read_nb(maxlen, terminator)
185 Same as socket:read(maxlen, terminator), but does not block.
187 In case of an I/O error, nil (as first return value) plus an error message (as
188 second return value) are returned.
190 In all other cases (including EOF), the following two values are returned:
192 - a string containing the bytes read (first return value, may be empty string)
193 - a status code equal to "term", "maxlen", "eof", "block" (second return value)
195 The status code "block" as second return value is used if the function returned
196 prematurely because it would block otherwise. In this case, the first return
197 value is a string that contains the bytes that could be read without blocking.
200 ### socket:read_yield(maxlen, terminator)
202 Alias for socket:read_call(coroutine.yield, maxlen, terminator)
205 ### socket.remote_ip4
207 Remote IPv4 address used for the connection. Encoded as 4 raw bytes in form of
208 a string.
211 ### socket.remote_ip6
213 Remote IPv6 address used for the connection. Encoded as 16 raw bytes in form of
214 a string.
217 ### socket.remote_tcpport
219 Remote TCP port used for the connection.
222 ### socket:reset()
224 Alias for socket:close(0). Closes the socket connection by sending a TCP RST
225 packet if possible to indicate error condition.
227 Returns true on success, or nil (as first return value) plus error message (as
228 second return value) in case of an I/O error. Using this method on sockets that
229 have already been closed (or reset) will throw an error.
231 Warning: Previously sent (and flushed) data may be lost during transmission.
234 ### socket:write(...)
236 Takes a variable number of strings and sends them to the peer. The operation is
237 buffered, so to actually send out the data, it is necessary to eventually call
238 socket:flush(), socket:finish(), or socket:close().
240 In case of an I/O error, nil (as first return value) plus an error message (as
241 second return value) are returned. On success, the socket userdata object is
242 returned.
245 ### socket:write_nb(...)
247 Takes a variable number of strings and sends them to the peer. The operation is
248 buffered, so to actually send out the data, it is necessary to eventually call
249 socket:flush_nb(), socket:flush(), socket:finish(), or socket:close().
251 This function always returns immediately (i.e. it does not block). If all data
252 (but a small buffered portion) could be sent out, then zero is returned.
253 Otherwise, all arguments that could not be sent are stored in a buffer of
254 unlimited size (up to memory capabilities) and an integer is returned that
255 indicates the number of bytes currently in the buffer.
257 In case of an I/O error, nil (as first return value) plus an error message (as
258 second return value) are returned.
262 I/O library
263 -----------
265 The Moonbridge Network Server for Lua Applications comes with its own I/O
266 library to support blocking as well as nonblocking I/O operations.
268 All methods on an I/O handle (e.g. socket) are described in the previous
269 section regarding the "socket" object. All other functions of the library are
270 listed below.
273 ### moonbridge_io.localconnect(path)
275 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
276 a socket object on success, or nil (as first return value) plus an error
277 message (as second return value) in case of error.
280 ### moonbridge_io.localconnect_nb(path)
282 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
283 a socket object on success, or nil (as first return value) plus an error
284 message (as second return value) in case of error.
286 Same as moonbridge_io.localconnect(path), except that this function does not
287 block and immediately returns a socket object.
289 In case of an I/O error, nil (as first return value) plus an error message (as
290 second return value) may be returned. However, connection errors may also be
291 reported on first read or write on the socket.
294 ### moonbridge_io.locallisten(path)
296 Attempts to create a local socket (also known as Unix Domain Socket) to accept
297 incoming connections. If the file does already exist and is a socket, then it
298 is deleted automatically before being re-created.
300 In case of an I/O error, nil (as first return value) plus an error message (as
301 second return value) may be returned.On success, a listener object is returned
302 which supports the methods :accept(), :accept_nb(), and :close().
304 The method :accept() blocks until a new incoming connection is available in
305 which case a socket object is returned.
307 The method :accept_nb() works like :accept(), except that the call is
308 nonblocking and returns false (plus a notice as second return value) in case no
309 incoming connection is available. It is possible to wait for an incoming
310 connection by including the listener object in the input_set of the
311 moonbridge_io.poll(...) call.
313 The method :close() will close the listening socket. In case of local sockets
314 (Unix Domain Sockets), the socket will not be unlinked in the file system.
316 I/O errors by the methods of the listener object are also reported by returning
317 nil (as first return value) plus an error message (as second return value).
320 ### moonbridge_io.poll(input_set, output_set, timeout)
322 This function waits for at least one of the given file descriptors and/or
323 I/O handles to be ready for input or output. The two sets of file descriptors
324 and/or handles must contain the file descriptor or handle as a key, and a value
325 which does evaluate to true. If a set is nil, it is treated as being empty.
327 Returns true when at least one file descriptor or handle is ready for reading
328 or writing respectively. Returns false (as first return value) plus a status
329 message (as second return value) in case of timeout or when a signal was
330 received.
333 ### moonbridge_io.tcpconnect(hostname, port)
335 Tries to open a TCP connection with the given host and TCP port number. 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.tcpconnect_nb(hostname, port)
342 Same as moonbridge_io.tcpconnect(hostname, port), except that this function
343 does not block and immediately returns a socket object.
345 Note: The current implementation still blocks during the DNS lookup. Use a
346 numeric IP address as hostname to be truly nonblocking.
348 In case of an I/O error, nil (as first return value) plus an error message (as
349 second return value) may be returned. However, connection errors may also be
350 reported on first read or write on the socket.
353 ### moonbridge_io.tcplisten(hostname, port)
355 Attempts to open a TCP port for listening. To listen on the loopback interface,
356 use "::1" as hostname if IPv6 shall be used, or use "127.0.0.1" as hostname if
357 IPv4 shall be used. To listen on all available interfaces, use "::" (IPv6) or
358 "0.0.0.0" (IPv4) respectively.
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(). See reference
363 for moonbridge.io_locallisten(...).
367 HTTP module
368 -----------
370 The http module exports the function http.generate_handler(callback) that
371 converts an HTTP handler to a "connect" handler. See file "example.lua" for an
372 example of invocation. A table with options may be passed either as a second
373 argument, or as a first argument preceeding the callback function (whichever is
374 more convenient).
376 The following options are supported:
378 - request_body_size_limit: maximum size of payload of HTTP request body
379 (transfer encoding is allowed to add a limited amount of extra data)
380 - chunk_size: optional default value for maximum_input_chunk_size and
381 minimum_output_chunk_size
382 - request_header_size_limit: maximum size of HTTP request headers
383 - maximum_input_chunk_size: maximum chunk size when streaming a request body or
384 certain POST fields (bigger chunks will be fragmented automatically)
385 - minimum_output_chunk_size: minimum size for a chunk when sending a response
386 body (smaller chunks will be buffered and concatenated with future data;
387 ignored when request:flush() is called)
388 - static_headers: a set of headers to be included in every HTTP response
389 (may be a string, a table or strings, or a table of key-value pairs)
391 The callback function receives a single request object as argument, which is
392 described below.
395 ### request.body
397 The request body (without headers) as a string. Accessing this value makes
398 further access to request.post_params and request.post_params_list, or
399 invocation of request:stream_request_body(...) impossible.
402 ### request:close_after_finish()
404 Closes the connection after answering the request.
406 This method can only be called before the HTTP response header section has been
407 finished (i.e. before request:finish_headers(), request:send_data(...), or
408 request:finish() were called), but it may be called before a status code has
409 been sent using request:send_status(...).
411 A corresponding "Connection: close" header is automatically sent.
414 ### request.cookies
416 A table with all cookies sent by the client.
419 ### request.defer_reading()
421 Disables automatic request body processing on write. Can be called before
422 sending a HTTP status code to send a response before the request has been fully
423 received.
425 CAUTION: Responding to a request before the request body has been processed may
426 lead to a deadlock if the browser does not process the response while trying to
427 send the request. Therefore, this function should only be used if:
429 - the TCP stack has enough buffer space for the response (i.e. if the response
430 is small enough), and if
431 - a timer is used to cancel the response in case of a deadlock.
433 It is recommended to not use this function unless certain performance tweaks
434 are desired.
437 ### request.faulty
439 Normally set to false. In case of a read or write error on the client
440 connection, this value is set to true before a Lua error is raised.
442 A faulty request handle must not be used, or another Lua error will be raised.
445 ### request:finish()
447 Finishes and flushes a HTTP response. May be called multiple times. An
448 HTTP status, all headers, and the response body (if applicable) must have been
449 previously sent. After calling this method, no further data may be written.
452 ### request:finish_headers()
454 Finishes and flushes the HTTP response header section. May be called multiple
455 times, as long as the request is not finished completely. This method is
456 automatically invoked if the application is beginning to send a response body.
457 After calling this method, no further headers may be sent.
460 ### request:flush()
462 Flushes any pending output data. Note: In order to mark the end of a response
463 body, it is required to call request:finish().
466 ### request.get_params
468 A table that maps field names to their corresponding GET value. If there are
469 several GET values with the given field name, then the first value is used.
471 Note: May be implemented through metamethods, but does support iteration
472 through pairs(...).
475 ### request.get_params_list
477 A table that maps field names to a sequence of their corresponding GET values.
479 Note: May be implemented through metamethods, but does support iteration
480 through pairs(...).
483 ### request.headers
485 A table that maps (case-insensitively) a HTTP header field name to a sequence
486 of values. One entry is created for every occurrence of a header line with the
487 given field name).
490 ### request.headers_csv_string
492 A table that maps (case-insensitively) a HTTP header field name to a comma
493 separated string. Multiple occurrences of the header with the given field name
494 are automatically merged into the comma separated string.
497 ### request.headers_csv_table
499 A table that maps (case-insensitively) a HTTP header field name to a sequence
500 of values. One entry is created for every comma separated value of each header
501 with the given field name.
504 ### request.headers_flags
506 A table that maps (case-insensitively) a HTTP header field name to another
507 table which (again case-insensitively) maps a string to a boolean, depending on
508 whether this string occurred in the list of comma separated values of one
509 header line with the given field name that was the key in the first table.
512 ### request.headers_value
514 A table that maps (case-insensitively) a HTTP header field name to a value. If
515 multiple header lines with the given field name have been received, false is
516 used as value.
519 ### request.method
521 The HTTP request method, e.g. "HEAD", "GET", or "POST".
524 ### request.path
526 The requested path without a leading slash and without the query part (e.g.
527 "index.html" if "/index.html?a=b&c=d" has been requested). For the query part,
528 see request.query.
530 This value will be nil if (and only if) the request method is "OPTIONS" with a
531 request target equal to "*" (see also asterisk-form of request-target in
532 section 5.3.4 in RFC 7230).
535 ### request.post_metadata
537 Only set for multipart/form-data POST requests. A table that maps field names
538 to their corresponding POST metadata table which contains two entries:
539 "file_name" and "content_type". If there are several POST values with the given
540 field name, then the first value/file is used.
543 ### request.post_metadata_list
545 Only set for multipart/form-data POST requests. A table that maps field names
546 to a sequence with their corresponding POST metadata tables. Needed if multiple
547 files are uploaded with the same field name.
550 ### request.post_params
552 A table that maps field names to their corresponding POST value. If there are
553 several POST values with the given field name, then the first value is used.
555 Note: May be implemented through metamethods, but does support iteration
556 through pairs(...).
559 ### request.post_params_list
561 A table that maps field names to a sequence of their corresponding POST values.
563 Note: May be implemented through metamethods, but does support iteration
564 through pairs(...).
567 ### request.query
569 Query part of the request target including the leading question mark, e.g.
570 "?a=b&c=d" if the requested target is "/index.html?a=b&c=d". The data is
571 automatically parsed and made available through request.get_params and
572 request.get_params_list.
574 If there is no query part given in the request target, then this string is
575 the empty string. This value will be nil if (and only if) the request method
576 is "OPTIONS" with a request target equal to "*" (see also asterisk-form of
577 request-target in section 5.3.4 in RFC 7230).
580 ### request:process_request_body()
582 Starts processing the request body (if existent) to set the values
583 request.post_params, request.post_params_list, request.post_metadata, and
584 and request.post_metadata_list and/or to call POST field stream handlers that
585 have been previously registered with request:stream_post_param(...) or
586 request:stream_post_params(...).
588 This method gets invoked automatically when the POST param tables
589 (request.post_params, etc.) are accessed, or if a response is sent (to avoid
590 deadlocks with the webbrowser). (Note: Automatic request body processing on
591 write may be disabled by calling request:defer_reading().)
593 After this method returned, all registered POST field stream handlers have
594 received all data. Registration of other POST field stream handlers is not
595 possible after this method has been called (or after request.post_params_list
596 or request.post_params have been accessed).
599 ### request:send_data(...)
601 Sends data as response body. All arguments are converted via tostring(...) and
602 concatenated. May be called multiple times until the request has been finished
603 by calling request:finish().
605 If the request method (see request.method) is "HEAD", then calls to
606 request:send_data(...) are automatically ignored.
609 ### request:send_header(key, value)
611 Sends a HTTP response header that consists of the given key and the given
612 value. Note: Key and value must be provided as separate arguments. Before any
613 headers can be sent, a HTTP status must have been set with
614 request:send_status(status_string).
617 ### request:send_status(status_string)
619 Sends a HTTP response status that is given as a string consisting of a 3-digit
620 number and an explanatory string, e.g. "200 OK" or "404 Not Found". This
621 function must be called once before any headers or response body data may be
622 sent.
625 ### request.socket
627 The underlaying socket. Can be used to force a TCP RST, etc.
630 ### request:stream_post_param(field_name, callback)
632 Registers a stream handler for the given POST parameter. The callback function
633 will be called in the following manner:
635 - For the initial chunk, the first chunk gets passed as first argument while a
636 table with metadata ("field_name" and "content_type") gets passed as second
637 argument. In case of an immediate EOF (i.e. an empty file), the passed
638 chunk is the empty string. In all other cases the chunk has a length greater
639 than zero.
640 - For any remaining chunks, the respective chunk gets passed as first and only
641 argument (no metadata). Here, the chunk has always a length greater than
642 zero.
643 - To indicate the end of the stream, the callback function is called without
644 arguments. This also happens in case of an immediate EOF (see above).
646 In case of an immediate EOF (i.e. an empty file), the callback function is thus
647 called as follows:
649 - The first time with an empty string as first argument, and with the metadata
650 as second argument.
651 - The second time without any arguments.
654 ### request:stream_post_params(pattern, callback)
656 Same as request:stream_post_param(...) but providing a string pattern to match
657 multiple field names (e.g. "^file_[0-9]+$").
660 ### request:stream_request_body(callback)
662 Start streaming of request body. For each chunk of the request body, the
663 callback function is called with the corresponding chunk. End of data is
664 indicated through return of request:stream_request_body(...) (not by calling
665 the callback without arguments).
667 The function may be called with nil instead of a callback function. In this
668 case, the request body is read and discarded. Only if nil is passed instead of
669 a callback, then the function may also be invoked when the request body has
670 already been read and/or processed. In the latter case, the function performs
671 no operation.