moonbridge
view reference.txt @ 140:9ca22af4d4b1
Added methods "read_call" and "read_yield"
| author | jbe |
|---|---|
| date | Fri May 01 01:46:07 2015 +0200 (2015-05-01) |
| parents | 118e320a7812 |
| children | 41da87a681d6 |
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. If no bytes could be read but EOF was encountered,
74 then true is returned.
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_nb(maxlen, terminator)
82 Same as socket:read_nb(maxlen, terminator), but discards the input and returns
83 the number of discarded bytes. If no bytes could be read but EOF was
84 encountered, then true is returned.
86 In case of an I/O error, nil (as first return value) plus an error message (as
87 second return value) are returned.
90 ### socket:finish()
92 Sends a TCP FIN packet to indicate EOF on write stream. Subsequent reads are
93 still possible. When there is no more input data to be read, the connection
94 should finally be closed with socket:close().
96 In case of local sockets (Unix Domain Sockets), socket:finish() simply closes
97 the underlying socket and emulates EOF on subsequent reads. Also in this case,
98 the connection should be finally closed with socket:close().
101 ### socket:flush(...)
103 Same as socket:write(...) but additionally flushes the socket (i.e. all pending
104 data is passed to the operating system).
106 In case of an I/O error, nil (as first return value) plus an error message (as
107 second return value) are returned. On success, the socket userdata object is
108 returned.
111 ### socket:flush_nb(...)
113 Same as socket:write_nb(...) but additionally flushes the socket (i.e. all
114 pending data is passed to the operating system). The total number of bytes that
115 could not be passed yet to the operating system is returned. Zero is returned
116 if all data could be flushed out.
118 In case of an I/O error, nil (as first return value) plus an error message (as
119 second return value) are returned.
122 ### socket.interval
124 Set to the name of an interval timer if the "connect" handler was called due to
125 an elapsed interval timer. Otherwise nil.
128 ### socket.local_ip4
130 Local IPv4 address used for the connection. Encoded as 4 raw bytes in form of a
131 string.
134 ### socket.local_ip6
136 Local IPv6 address used for the connection. Encoded as 16 raw bytes in form of
137 a string.
140 ### socket.local_tcpport
142 Local TCP port used for the connection.
145 ### socket:read(maxlen, terminator)
147 Read up to maxlen bytes or until an optional termination character is
148 encountered (which is included in the result). The maxlen value may be nil, in
149 which case there is no limit on the number of bytes read.
151 If EOF is encountered before any data could be read, then false (as first
152 return value) plus a notice string (as second return value) are returned.
154 In case of an I/O error, nil (as first return value) plus an error message (as
155 second return value) are returned.
158 ### socket:read_call(waitfunc, maxlen, terminator)
160 Same as socket:read(maxlen, terminator), but calls waitfunc(socket, "r") (in an
161 infinite loop) as long as the reading is blocked.
164 ### socket:read_nb(maxlen, terminator)
166 Read up to maxlen bytes, until an optional termination character is encountered
167 (which is included in the result), or until no more data is available for
168 reading. The maxlen value may be nil, in which case there is no limit on the
169 number of bytes read.
171 If EOF is encountered before any data could be read, then false (as first
172 return value) plus a notice string (as second return value) are returned.
174 If no data was available for reading, but no EOF was encountered, then an empty
175 string is returned.
177 In case of an I/O error, nil (as first return value) plus an error message (as
178 second return value) are returned.
181 ### socket:read_yield(maxlen, terminator)
183 Alias for socket:read_call(coroutine.yield, maxlen, terminator)
186 ### socket.remote_ip4
188 Remote IPv4 address used for the connection. Encoded as 4 raw bytes in form of
189 a string.
192 ### socket.remote_ip6
194 Remote IPv6 address used for the connection. Encoded as 16 raw bytes in form of
195 a string.
198 ### socket.remote_tcpport
200 Remote TCP port used for the connection.
203 ### socket:reset()
205 Alias for socket:close(0). Closes the socket connection by sending a TCP RST
206 packet if possible to indicate error condition.
208 Returns true on success, or nil (as first return value) plus error message (as
209 second return value) in case of an I/O error. Using this method on sockets that
210 have already been closed (or reset) will throw an error.
212 Warning: Previously sent (and flushed) data may be lost during transmission.
215 ### socket:write(...)
217 Takes a variable number of strings and sends them to the peer. The operation is
218 buffered, so to actually send out the data, it is necessary to eventually call
219 socket:flush(), socket:finish(), or socket:close().
221 In case of an I/O error, nil (as first return value) plus an error message (as
222 second return value) are returned. On success, the socket userdata object is
223 returned.
226 ### socket:write_nb(...)
228 Takes a variable number of strings and sends them to the peer. The operation is
229 buffered, so to actually send out the data, it is necessary to eventually call
230 socket:flush_nb(), socket:flush(), socket:finish(), or socket:close().
232 This function always returns immediately (i.e. it does not block). If all data
233 (but a small buffered portion) could be sent out, then zero is returned.
234 Otherwise, all arguments that could not be sent are stored in a buffer of
235 unlimited size (up to memory capabilities) and an integer is returned that
236 indicates the number of bytes currently in the buffer.
238 In case of an I/O error, nil (as first return value) plus an error message (as
239 second return value) are returned.
243 I/O library
244 -----------
246 The Moonbridge Network Server for Lua Applications comes with its own I/O
247 library to support blocking as well as nonblocking I/O operations.
249 All methods on an I/O handle (e.g. socket) are described in the previous
250 section regarding the "socket" object. All other functions of the library are
251 listed below.
254 ### moonbridge_io.localconnect(path)
256 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
257 a socket object on success, or nil (as first return value) plus an error
258 message (as second return value) in case of error.
261 ### moonbridge_io.localconnect_nb(path)
263 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
264 a socket object on success, or nil (as first return value) plus an error
265 message (as second return value) in case of error.
267 Same as moonbridge_io.localconnect(path), except that this function does not
268 block and immediately returns a socket object.
270 In case of an I/O error, nil (as first return value) plus an error message (as
271 second return value) may be returned. However, connection errors may also be
272 reported on first read or write on the socket.
275 ### moonbridge_io.locallisten(path)
277 Attempts to create a local socket (also known as Unix Domain Socket) to accept
278 incoming connections. If the file does already exist and is a socket, then it
279 is deleted automatically before being re-created.
281 In case of an I/O error, nil (as first return value) plus an error message (as
282 second return value) may be returned.On success, a listener object is returned
283 which supports the methods :accept(), :accept_nb(), and :close().
285 The method :accept() blocks until a new incoming connection is available in
286 which case a socket object is returned.
288 The method :accept_nb() works like :accept(), except that the call is
289 nonblocking and returns false (plus a notice as second return value) in case no
290 incoming connection is available. It is possible to wait for an incoming
291 connection by including the listener object in the input_set of the
292 moonbridge_io.poll(...) call.
294 The method :close() will close the listening socket. In case of local sockets
295 (Unix Domain Sockets), the socket will not be unlinked in the file system.
297 I/O errors by the methods of the listener object are also reported by returning
298 nil (as first return value) plus an error message (as second return value).
301 ### moonbridge_io.poll(input_set, output_set, timeout)
303 This function waits for at least one of the given file descriptors and/or
304 I/O handles to be ready for input or output. The two sets of file descriptors
305 and/or handles must contain the file descriptor or handle as a key, and a value
306 which does evaluate to true. If a set is nil, it is treated as being empty.
308 Returns true when at least one file descriptor or handle is ready for reading
309 or writing respectively. Returns false (as first return value) plus a status
310 message (as second return value) in case of timeout or when a signal was
311 received.
314 ### moonbridge_io.tcpconnect(hostname, port)
316 Tries to open a TCP connection with the given host and TCP port number. Returns
317 a socket object on success, or nil (as first return value) plus an error
318 message (as second return value) in case of error.
321 ### moonbridge_io.tcpconnect_nb(hostname, port)
323 Same as moonbridge_io.tcpconnect(hostname, port), except that this function
324 does not block and immediately returns a socket object.
326 Note: The current implementation still blocks during the DNS lookup. Use a
327 numeric IP address as hostname to be truly nonblocking.
329 In case of an I/O error, nil (as first return value) plus an error message (as
330 second return value) may be returned. However, connection errors may also be
331 reported on first read or write on the socket.
334 ### moonbridge_io.tcplisten(hostname, port)
336 Attempts to open a TCP port for listening. To listen on the loopback interface,
337 use "::1" as hostname if IPv6 shall be used, or use "127.0.0.1" as hostname if
338 IPv4 shall be used. To listen on all available interfaces, use "::" (IPv6) or
339 "0.0.0.0" (IPv4) respectively.
341 In case of an I/O error, nil (as first return value) plus an error message (as
342 second return value) may be returned. On success, a listener object is returned
343 which supports the methods :accept(), :accept_nb(), and :close(). See reference
344 for moonbridge.io_locallisten(...).
348 HTTP module
349 -----------
351 The http module exports the function http.generate_handler(callback) that
352 converts an HTTP handler to a "connect" handler. See file "example.lua" for an
353 example of invocation. A table with options may be passed either as a second
354 argument, or as a first argument preceeding the callback function (whichever is
355 more convenient).
357 The following options are supported:
359 - request_body_size_limit: maximum size of payload of HTTP request body
360 (transfer encoding is allowed to add a limited amount of extra data)
361 - chunk_size: optional default value for maximum_input_chunk_size and
362 minimum_output_chunk_size
363 - request_header_size_limit: maximum size of HTTP request headers
364 - maximum_input_chunk_size: maximum chunk size when streaming a request body or
365 certain POST fields (bigger chunks will be fragmented automatically)
366 - minimum_output_chunk_size: minimum size for a chunk when sending a response
367 body (smaller chunks will be buffered and concatenated with future data;
368 ignored when request:flush() is called)
369 - static_headers: a set of headers to be included in every HTTP response
370 (may be a string, a table or strings, or a table of key-value pairs)
372 The callback function receives a single request object as argument, which is
373 described below.
376 ### request.body
378 The request body (without headers) as a string. Accessing this value makes
379 further access to request.post_params and request.post_params_list, or
380 invocation of request:stream_request_body(...) impossible.
383 ### request:close_after_finish()
385 Closes the connection after answering the request.
387 This method can only be called before the HTTP response header section has been
388 finished (i.e. before request:finish_headers(), request:send_data(...), or
389 request:finish() were called), but it may be called before a status code has
390 been sent using request:send_status(...).
392 A corresponding "Connection: close" header is automatically sent.
395 ### request.cookies
397 A table with all cookies sent by the client.
400 ### request.defer_reading()
402 Disables automatic request body processing on write. Can be called before
403 sending a HTTP status code to send a response before the request has been fully
404 received.
406 CAUTION: Responding to a request before the request body has been processed may
407 lead to a deadlock if the browser does not process the response while trying to
408 send the request. Therefore, this function should only be used if:
410 - the TCP stack has enough buffer space for the response (i.e. if the response
411 is small enough), and if
412 - a timer is used to cancel the response in case of a deadlock.
414 It is recommended to not use this function unless certain performance tweaks
415 are desired.
418 ### request.faulty
420 Normally set to false. In case of a read or write error on the client
421 connection, this value is set to true before a Lua error is raised.
423 A faulty request handle must not be used, or another Lua error will be raised.
426 ### request:finish()
428 Finishes and flushes a HTTP response. May be called multiple times. An
429 HTTP status, all headers, and the response body (if applicable) must have been
430 previously sent. After calling this method, no further data may be written.
433 ### request:finish_headers()
435 Finishes and flushes the HTTP response header section. May be called multiple
436 times, as long as the request is not finished completely. This method is
437 automatically invoked if the application is beginning to send a response body.
438 After calling this method, no further headers may be sent.
441 ### request:flush()
443 Flushes any pending output data. Note: In order to mark the end of a response
444 body, it is required to call request:finish().
447 ### request.get_params
449 A table that maps field names to their corresponding GET value. If there are
450 several GET values with the given field name, then the first value is used.
452 Note: May be implemented through metamethods, but does support iteration
453 through pairs(...).
456 ### request.get_params_list
458 A table that maps field names to a sequence of their corresponding GET values.
460 Note: May be implemented through metamethods, but does support iteration
461 through pairs(...).
464 ### request.headers
466 A table that maps (case-insensitively) a HTTP header field name to a sequence
467 of values. One entry is created for every occurrence of a header line with the
468 given field name).
471 ### request.headers_csv_string
473 A table that maps (case-insensitively) a HTTP header field name to a comma
474 separated string. Multiple occurrences of the header with the given field name
475 are automatically merged into the comma separated string.
478 ### request.headers_csv_table
480 A table that maps (case-insensitively) a HTTP header field name to a sequence
481 of values. One entry is created for every comma separated value of each header
482 with the given field name.
485 ### request.headers_flags
487 A table that maps (case-insensitively) a HTTP header field name to another
488 table which (again case-insensitively) maps a string to a boolean, depending on
489 whether this string occurred in the list of comma separated values of one
490 header line with the given field name that was the key in the first table.
493 ### request.headers_value
495 A table that maps (case-insensitively) a HTTP header field name to a value. If
496 multiple header lines with the given field name have been received, false is
497 used as value.
500 ### request.method
502 The HTTP request method, e.g. "HEAD", "GET", or "POST".
505 ### request.path
507 The requested path without a leading slash and without the query part (e.g.
508 "index.html" if "/index.html?a=b&c=d" has been requested). For the query part,
509 see request.query.
511 This value will be nil if (and only if) the request method is "OPTIONS" with a
512 request target equal to "*" (see also asterisk-form of request-target in
513 section 5.3.4 in RFC 7230).
516 ### request.post_metadata
518 Only set for multipart/form-data POST requests. A table that maps field names
519 to their corresponding POST metadata table which contains two entries:
520 "file_name" and "content_type". If there are several POST values with the given
521 field name, then the first value/file is used.
524 ### request.post_metadata_list
526 Only set for multipart/form-data POST requests. A table that maps field names
527 to a sequence with their corresponding POST metadata tables. Needed if multiple
528 files are uploaded with the same field name.
531 ### request.post_params
533 A table that maps field names to their corresponding POST value. If there are
534 several POST values with the given field name, then the first value is used.
536 Note: May be implemented through metamethods, but does support iteration
537 through pairs(...).
540 ### request.post_params_list
542 A table that maps field names to a sequence of their corresponding POST values.
544 Note: May be implemented through metamethods, but does support iteration
545 through pairs(...).
548 ### request.query
550 Query part of the request target including the leading question mark, e.g.
551 "?a=b&c=d" if the requested target is "/index.html?a=b&c=d". The data is
552 automatically parsed and made available through request.get_params and
553 request.get_params_list.
555 If there is no query part given in the request target, then this string is
556 the empty string. This value will be nil if (and only if) the request method
557 is "OPTIONS" with a request target equal to "*" (see also asterisk-form of
558 request-target in section 5.3.4 in RFC 7230).
561 ### request:process_request_body()
563 Starts processing the request body (if existent) to set the values
564 request.post_params, request.post_params_list, request.post_metadata, and
565 and request.post_metadata_list and/or to call POST field stream handlers that
566 have been previously registered with request:stream_post_param(...) or
567 request:stream_post_params(...).
569 This method gets invoked automatically when the POST param tables
570 (request.post_params, etc.) are accessed, or if a response is sent (to avoid
571 deadlocks with the webbrowser). (Note: Automatic request body processing on
572 write may be disabled by calling request:defer_reading().)
574 After this method returned, all registered POST field stream handlers have
575 received all data. Registration of other POST field stream handlers is not
576 possible after this method has been called (or after request.post_params_list
577 or request.post_params have been accessed).
580 ### request:send_data(...)
582 Sends data as response body. All arguments are converted via tostring(...) and
583 concatenated. May be called multiple times until the request has been finished
584 by calling request:finish().
586 If the request method (see request.method) is "HEAD", then calls to
587 request:send_data(...) are automatically ignored.
590 ### request:send_header(key, value)
592 Sends a HTTP response header that consists of the given key and the given
593 value. Note: Key and value must be provided as separate arguments. Before any
594 headers can be sent, a HTTP status must have been set with
595 request:send_status(status_string).
598 ### request:send_status(status_string)
600 Sends a HTTP response status that is given as a string consisting of a 3-digit
601 number and an explanatory string, e.g. "200 OK" or "404 Not Found". This
602 function must be called once before any headers or response body data may be
603 sent.
606 ### request.socket
608 The underlaying socket. Can be used to force a TCP RST, etc.
611 ### request:stream_post_param(field_name, callback)
613 Registers a stream handler for the given POST parameter. The callback function
614 will be called in the following manner:
616 - For the initial chunk, the first chunk gets passed as first argument while a
617 table with metadata ("field_name" and "content_type") gets passed as second
618 argument. In case of an immediate EOF (i.e. an empty file), the passed
619 chunk is the empty string. In all other cases the chunk has a length greater
620 than zero.
621 - For any remaining chunks, the respective chunk gets passed as first and only
622 argument (no metadata). Here, the chunk has always a length greater than
623 zero.
624 - To indicate the end of the stream, the callback function is called without
625 arguments. This also happens in case of an immediate EOF (see above).
627 In case of an immediate EOF (i.e. an empty file), the callback function is thus
628 called as follows:
630 - The first time with an empty string as first argument, and with the metadata
631 as second argument.
632 - The second time without any arguments.
635 ### request:stream_post_params(pattern, callback)
637 Same as request:stream_post_param(...) but providing a string pattern to match
638 multiple field names (e.g. "^file_[0-9]+$").
641 ### request:stream_request_body(callback)
643 Start streaming of request body. For each chunk of the request body, the
644 callback function is called with the corresponding chunk. End of data is
645 indicated through return of request:stream_request_body(...) (not by calling
646 the callback without arguments).
648 The function may be called with nil instead of a callback function. In this
649 case, the request body is read and discarded. Only if nil is passed instead of
650 a callback, then the function may also be invoked when the request body has
651 already been read and/or processed. In the latter case, the function performs
652 no operation.