moonbridge

view reference.txt @ 179:77d8fdd124e6

Throw error if key is not a string when accessing headers table
author jbe
date Thu Jun 18 22:38:53 2015 +0200 (2015-06-18)
parents 2a5bd37034c6
children 97d3ca77c86a
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_call(waitfunc, ...)
124 Same as socket:flush(...), but calls waitfunc() (in an infinite loop) as long
125 as the writing is blocked.
128 ### socket:flush_nb(...)
130 Same as socket:write_nb(...) but additionally flushes the socket (i.e. all
131 pending data is passed to the operating system). The total number of bytes that
132 could not be passed yet to the operating system is returned. Zero is returned
133 if all data could be flushed out.
135 In case of an I/O error, nil (as first return value) plus an error message (as
136 second return value) are returned.
139 ### socket:flush_yield(...)
141 Alias for socket:flush_call(coroutine.yield, ...)
144 ### socket.interval
146 Set to the name of an interval timer if the "connect" handler was called due to
147 an elapsed interval timer. Otherwise nil.
150 ### socket.local_ip4
152 Local IPv4 address used for the connection. Encoded as 4 raw bytes in form of a
153 string.
156 ### socket.local_ip6
158 Local IPv6 address used for the connection. Encoded as 16 raw bytes in form of
159 a string.
162 ### socket.local_tcpport
164 Local TCP port used for the connection.
167 ### socket:read(maxlen, terminator)
169 Reads up to maxlen bytes or until an optional termination character is
170 encountered (which is included in the result). The maxlen value may be nil, in
171 which case there is no limit on the number of bytes read.
173 In case of an I/O error, nil (as first return value) plus an error message (as
174 second return value) are returned.
176 In all other cases (including EOF), the following two values are returned:
178 - a string containing the bytes read (first return value, may be empty string)
179 - a status code equal to "term", "maxlen", or "eof" (second return value)
181 If an EOF is encountered before all data could be read, then "eof" is returned
182 as second return value. If maxlen bytes have been read and no termination
183 character has been read, then "maxlen" is returned as second return value. If
184 the termination character is the last character of the read string, the second
185 return value will be "term".
188 ### socket:read_call(waitfunc, maxlen, terminator)
190 Same as socket:read(maxlen, terminator), but calls waitfunc() (in an infinite
191 loop) as long as the reading is blocked.
194 ### socket:read_nb(maxlen, terminator)
196 Same as socket:read(maxlen, terminator), but does not block.
198 In case of an I/O error, nil (as first return value) plus an error message (as
199 second return value) are returned.
201 In all other cases (including EOF), the following two values are returned:
203 - a string containing the bytes read (first return value, may be empty string)
204 - a status code equal to "term", "maxlen", "eof", "block" (second return value)
206 The status code "block" as second return value is used if the function returned
207 prematurely because it would block otherwise. In this case, the first return
208 value is a string that contains the bytes that could be read without blocking.
211 ### socket:read_yield(maxlen, terminator)
213 Alias for socket:read_call(coroutine.yield, maxlen, terminator)
216 ### socket.remote_ip4
218 Remote IPv4 address used for the connection. Encoded as 4 raw bytes in form of
219 a string.
222 ### socket.remote_ip6
224 Remote IPv6 address used for the connection. Encoded as 16 raw bytes in form of
225 a string.
228 ### socket.remote_tcpport
230 Remote TCP port used for the connection.
233 ### socket:reset()
235 Alias for socket:close(0). Closes the socket connection by sending a TCP RST
236 packet if possible to indicate error condition.
238 Returns true on success, or nil (as first return value) plus error message (as
239 second return value) in case of an I/O error. Using this method on sockets that
240 have already been closed (or reset) will throw an error.
242 Warning: Previously sent (and flushed) data may be lost during transmission.
245 ### socket:write(...)
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(), socket:finish(), or socket:close().
251 In case of an I/O error, nil (as first return value) plus an error message (as
252 second return value) are returned. On success, the socket userdata object is
253 returned.
256 ### socket:write_call(waitfunc, ...)
258 Same as socket:write(...), but calls waitfunc() (in an infinite loop) as long
259 as the writing is blocked.
262 ### socket:write_nb(...)
264 Takes a variable number of strings and sends them to the peer. The operation is
265 buffered, so to actually send out the data, it is necessary to eventually call
266 socket:flush_nb(), socket:flush(), socket:finish(), or socket:close().
268 This function always returns immediately (i.e. it does not block). If all data
269 (but a small buffered portion) could be sent out, then zero is returned.
270 Otherwise, all arguments that could not be sent are stored in a buffer of
271 unlimited size (up to memory capabilities) and an integer is returned that
272 indicates the number of bytes currently in the buffer.
274 In case of an I/O error, nil (as first return value) plus an error message (as
275 second return value) are returned.
278 ### socket:write_yield(...)
280 Alias for socket:write_call(coroutine.yield, ...)
284 I/O library
285 -----------
287 The Moonbridge Network Server for Lua Applications comes with its own I/O
288 library to support blocking as well as nonblocking I/O operations.
290 All methods on an I/O handle (e.g. socket) are described in the previous
291 section regarding the "socket" object. All other functions of the library are
292 listed below.
295 ### moonbridge_io.localconnect(path)
297 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
298 a socket object on success, or nil (as first return value) plus an error
299 message (as second return value) in case of error.
302 ### moonbridge_io.localconnect_nb(path)
304 Tries to connect to a local socket (also known as Unix Domain Socket). Returns
305 a socket object on success, or nil (as first return value) plus an error
306 message (as second return value) in case of error.
308 Same as moonbridge_io.localconnect(path), except that this function does not
309 block and immediately returns a socket object.
311 In case of an I/O error, nil (as first return value) plus an error message (as
312 second return value) may be returned. However, connection errors may also be
313 reported on first read or write on the socket.
316 ### moonbridge_io.locallisten(path)
318 Attempts to create a local socket (also known as Unix Domain Socket) to accept
319 incoming connections. If the file does already exist and is a socket, then it
320 is deleted automatically before being re-created.
322 In case of an I/O error, nil (as first return value) plus an error message (as
323 second return value) may be returned.On success, a listener object is returned
324 which supports the methods :accept(), :accept_nb(), and :close().
326 The method :accept() blocks until a new incoming connection is available in
327 which case a socket object is returned.
329 The method :accept_nb() works like :accept(), except that the call is
330 nonblocking and returns false (plus a notice as second return value) in case no
331 incoming connection is available. It is possible to wait for an incoming
332 connection by including the listener object in the input_set of the
333 moonbridge_io.poll(...) call.
335 The method :close() will close the listening socket. In case of local sockets
336 (Unix Domain Sockets), the socket will not be unlinked in the file system.
338 I/O errors by the methods of the listener object are also reported by returning
339 nil (as first return value) plus an error message (as second return value).
342 ### moonbridge_io.poll(input_set, output_set, timeout)
344 This function waits for at least one of the given file descriptors and/or
345 I/O handles to be ready for input or output. The two sets of file descriptors
346 and/or handles must contain the file descriptor or handle as a key, and a value
347 which does evaluate to true. If a set is nil, it is treated as being empty.
349 Returns true when at least one file descriptor or handle is ready for reading
350 or writing respectively. Returns false (as first return value) plus a status
351 message (as second return value) in case of timeout or when a signal was
352 received.
355 ### moonbridge_io.tcpconnect(hostname, port)
357 Tries to open a TCP connection with the given host and TCP port number. Returns
358 a socket object on success, or nil (as first return value) plus an error
359 message (as second return value) in case of error.
362 ### moonbridge_io.tcpconnect_nb(hostname, port)
364 Same as moonbridge_io.tcpconnect(hostname, port), except that this function
365 does not block and immediately returns a socket object.
367 Note: The current implementation still blocks during the DNS lookup. Use a
368 numeric IP address as hostname to be truly nonblocking.
370 In case of an I/O error, nil (as first return value) plus an error message (as
371 second return value) may be returned. However, connection errors may also be
372 reported on first read or write on the socket.
375 ### moonbridge_io.tcplisten(hostname, port)
377 Attempts to open a TCP port for listening. To listen on the loopback interface,
378 use "::1" as hostname if IPv6 shall be used, or use "127.0.0.1" as hostname if
379 IPv4 shall be used. To listen on all available interfaces, use "::" (IPv6) or
380 "0.0.0.0" (IPv4) respectively.
382 In case of an I/O error, nil (as first return value) plus an error message (as
383 second return value) may be returned. On success, a listener object is returned
384 which supports the methods :accept(), :accept_nb(), and :close(). See reference
385 for moonbridge.io_locallisten(...).
389 HTTP module
390 -----------
392 The http module exports the function http.generate_handler(callback) that
393 converts an HTTP handler to a "connect" handler. See file "example.lua" for an
394 example of invocation. A table with options may be passed either as a second
395 argument, or as a first argument preceeding the callback function (whichever is
396 more convenient).
398 The following options are supported:
400 - request_body_size_limit: maximum size of payload of HTTP request body
401 (transfer encoding is allowed to add a limited amount of extra data)
402 - chunk_size: optional default value for maximum_input_chunk_size and
403 minimum_output_chunk_size
404 - request_header_size_limit: maximum size of HTTP request headers
405 - maximum_input_chunk_size: maximum chunk size when streaming a request body or
406 certain POST fields (bigger chunks will be fragmented automatically)
407 - minimum_output_chunk_size: minimum size for a chunk when sending a response
408 body (smaller chunks will be buffered and concatenated with future data;
409 ignored when request:flush() is called)
410 - static_headers: a set of headers to be included in every HTTP response
411 (may be a string, a table or strings, or a table of key-value pairs)
413 The callback function receives a single request object as argument, which is
414 described below.
417 ### request.body
419 The request body (without headers) as a string. Accessing this value makes
420 further access to request.post_params and request.post_params_list, or
421 invocation of request:stream_request_body(...) impossible.
424 ### request:close_after_finish()
426 Closes the connection after answering the request.
428 This method can only be called before the HTTP response header section has been
429 finished (i.e. before request:finish_headers(), request:send_data(...), or
430 request:finish() were called), but it may be called before a status code has
431 been sent using request:send_status(...).
433 A corresponding "Connection: close" header is automatically sent.
436 ### request.cookies
438 A table with all cookies sent by the client.
441 ### request.defer_reading()
443 Disables automatic request body processing on write. Can be called before
444 sending a HTTP status code to send a response before the request has been fully
445 received.
447 CAUTION: Responding to a request before the request body has been processed may
448 lead to a deadlock if the browser does not process the response while trying to
449 send the request. Therefore, this function should only be used if:
451 - the TCP stack has enough buffer space for the response (i.e. if the response
452 is small enough), and if
453 - a timer is used to cancel the response in case of a deadlock.
455 It is recommended to not use this function unless certain performance tweaks
456 are desired.
459 ### request.faulty
461 Normally set to false. In case of a read or write error on the client
462 connection, this value is set to true before a Lua error is raised.
464 A faulty request handle must not be used, or another Lua error will be raised.
467 ### request:finish()
469 Finishes and flushes a HTTP response. May be called multiple times. An
470 HTTP status, all headers, and the response body (if applicable) must have been
471 previously sent. After calling this method, no further data may be written.
474 ### request:finish_headers()
476 Finishes and flushes the HTTP response header section. May be called multiple
477 times, as long as the request is not finished completely. This method is
478 automatically invoked if the application is beginning to send a response body.
479 After calling this method, no further headers may be sent.
482 ### request:flush()
484 Flushes any pending output data. Note: In order to mark the end of a response
485 body, it is required to call request:finish().
488 ### request.get_params
490 A table that maps field names to their corresponding GET value. If there are
491 several GET values with the given field name, then the first value is used.
493 Note: May be implemented through metamethods, but does support iteration
494 through pairs(...).
497 ### request.get_params_list
499 A table that maps field names to a sequence of their corresponding GET values.
501 Note: May be implemented through metamethods, but does support iteration
502 through pairs(...).
505 ### request.headers
507 A table that maps (case-insensitively) a HTTP header field name to a sequence
508 of values. One entry is created for every occurrence of a header line with the
509 given field name).
512 ### request.headers_csv_string
514 A table that maps (case-insensitively) a HTTP header field name to a comma
515 separated string. Multiple occurrences of the header with the given field name
516 are automatically merged into the comma separated string.
519 ### request.headers_csv_table
521 A table that maps (case-insensitively) a HTTP header field name to a sequence
522 of values. One entry is created for every comma separated value of each header
523 with the given field name.
526 ### request.headers_flags
528 A table that maps (case-insensitively) a HTTP header field name to another
529 table which (again case-insensitively) maps a string to a boolean, depending on
530 whether this string occurred in the list of comma separated values of one
531 header line with the given field name that was the key in the first table.
534 ### request.headers_value
536 A table that maps (case-insensitively) a HTTP header field name to a value. If
537 multiple header lines with the given field name have been received, false is
538 used as value.
541 ### request.method
543 The HTTP request method, e.g. "HEAD", "GET", or "POST".
546 ### request.path
548 The requested path without a leading slash and without the query part (e.g.
549 "index.html" if "/index.html?a=b&c=d" has been requested). For the query part,
550 see request.query.
552 This value will be nil if (and only if) the request method is "OPTIONS" with a
553 request target equal to "*" (see also asterisk-form of request-target in
554 section 5.3.4 in RFC 7230).
557 ### request.post_metadata
559 Only set for multipart/form-data POST requests. A table that maps field names
560 to their corresponding POST metadata table which contains two entries:
561 "file_name" and "content_type". If there are several POST values with the given
562 field name, then the first value/file is used.
565 ### request.post_metadata_list
567 Only set for multipart/form-data POST requests. A table that maps field names
568 to a sequence with their corresponding POST metadata tables. Needed if multiple
569 files are uploaded with the same field name.
572 ### request.post_params
574 A table that maps field names to their corresponding POST value. If there are
575 several POST 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.post_params_list
583 A table that maps field names to a sequence of their corresponding POST values.
585 Note: May be implemented through metamethods, but does support iteration
586 through pairs(...).
589 ### request.query
591 Query part of the request target including the leading question mark, e.g.
592 "?a=b&c=d" if the requested target is "/index.html?a=b&c=d". The data is
593 automatically parsed and made available through request.get_params and
594 request.get_params_list.
596 If there is no query part given in the request target, then this string is
597 the empty string. This value will be nil if (and only if) the request method
598 is "OPTIONS" with a request target equal to "*" (see also asterisk-form of
599 request-target in section 5.3.4 in RFC 7230).
602 ### request:process_request_body()
604 Starts processing the request body (if existent) to set the values
605 request.post_params, request.post_params_list, request.post_metadata, and
606 and request.post_metadata_list and/or to call POST field stream handlers that
607 have been previously registered with request:stream_post_param(...) or
608 request:stream_post_params(...).
610 This method gets invoked automatically when the POST param tables
611 (request.post_params, etc.) are accessed, or if a response is sent (to avoid
612 deadlocks with the webbrowser). (Note: Automatic request body processing on
613 write may be disabled by calling request:defer_reading().)
615 After this method returned, all registered POST field stream handlers have
616 received all data. Registration of other POST field stream handlers is not
617 possible after this method has been called (or after request.post_params_list
618 or request.post_params have been accessed).
621 ### request:send_data(...)
623 Sends data as response body. All arguments are converted via tostring(...) and
624 concatenated. May be called multiple times until the request has been finished
625 by calling request:finish().
627 If the request method (see request.method) is "HEAD", then calls to
628 request:send_data(...) are automatically ignored.
631 ### request:send_header(key, value)
633 Sends a HTTP response header that consists of the given key and the given
634 value. Note: Key and value must be provided as separate arguments. Before any
635 headers can be sent, a HTTP status must have been set with
636 request:send_status(status_string).
639 ### request:send_status(status_string)
641 Sends a HTTP response status that is given as a string consisting of a 3-digit
642 number and an explanatory string, e.g. "200 OK" or "404 Not Found". This
643 function must be called once before any headers or response body data may be
644 sent.
647 ### request.socket
649 The underlaying socket. Can be used to force a TCP RST, etc.
652 ### request:stream_post_param(field_name, callback)
654 Registers a stream handler for the given POST parameter. The callback function
655 will be called in the following manner:
657 - For the initial chunk, the first chunk gets passed as first argument while a
658 table with metadata ("field_name" and "content_type") gets passed as second
659 argument. In case of an immediate EOF (i.e. an empty file), the passed
660 chunk is the empty string. In all other cases the chunk has a length greater
661 than zero.
662 - For any remaining chunks, the respective chunk gets passed as first and only
663 argument (no metadata). Here, the chunk has always a length greater than
664 zero.
665 - To indicate the end of the stream, the callback function is called without
666 arguments. This also happens in case of an immediate EOF (see above).
668 In case of an immediate EOF (i.e. an empty file), the callback function is thus
669 called as follows:
671 - The first time with an empty string as first argument, and with the metadata
672 as second argument.
673 - The second time without any arguments.
676 ### request:stream_post_params(pattern, callback)
678 Same as request:stream_post_param(...) but providing a string pattern to match
679 multiple field names (e.g. "^file_[0-9]+$").
682 ### request:stream_request_body(callback)
684 Start streaming of request body. For each chunk of the request body, the
685 callback function is called with the corresponding chunk. End of data is
686 indicated through return of request:stream_request_body(...) (not by calling
687 the callback without arguments).
689 The function may be called with nil instead of a callback function. In this
690 case, the request body is read and discarded. Only if nil is passed instead of
691 a callback, then the function may also be invoked when the request body has
692 already been read and/or processed. In the latter case, the function performs
693 no operation.

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