Annotation of libwww/Library/src/HTNet.html, revision 2.52
2.1 frystyk 1: <HTML>
2: <HEAD>
2.50 frystyk 3: <TITLE>W3C Sample Code Library libwww HTNet Class</TITLE>
2.1 frystyk 4: </HEAD>
5: <BODY>
2.43 frystyk 6: <H1>
7: The Net Class
2.36 eric 8: </H1>
2.5 frystyk 9: <PRE>
10: /*
2.8 frystyk 11: ** (c) COPYRIGHT MIT 1995.
2.5 frystyk 12: ** Please first read the full copyright statement in the file COPYRIGH.
13: */
14: </PRE>
2.36 eric 15: <P>
2.38 frystyk 16: The Net class manages information related to a "thread" in libwww. As libwww
17: threads are not really threads but a notion of using interleaved, non-blocking
18: I/O for accessing data objects from the network (or local file system), they
19: can be used on any platform with or without support for native threads. In
20: the case where you have an application using real threads the Net class is
21: simply a object maintaining links to all other objects involved in serving
22: the request. If you are using the libwww pseudo threads then the Net object
23: contains enough information to stop and start a request based on which BSD
24: sockets are ready. In practise this is of course transparent to the application
25: - this is just to explain the difference.
26: <P>
27: When a <A HREF="HTReq.html">Request object</A> is passed to the Library ,
28: the core creates a new HTNet object pr <A HREF="HTChannl.html">channel</A>
29: used by the request. In many cases a request only uses a single
30: <A HREF="HTChannl.html">channel object </A>but for example FTP requests use
31: at least two - one for the control connection and one for the data connection.
32: <P>
33: You can find more information about the libwww pseudo thread model in the
34: <A HREF="../User/Architecture/"> Multithread Specifications</A>.
2.36 eric 35: <P>
36: This module is implemented by <A HREF="HTNet.c">HTNet.c</A>, and it is a
2.52 ! frystyk 37: part of the <A HREF="http://www.w3.org/Library/">W3C Sample Code
2.36 eric 38: Library</A>.
2.1 frystyk 39: <PRE>
2.17 frystyk 40: #ifndef HTNET_H
41: #define HTNET_H
2.1 frystyk 42: </PRE>
2.36 eric 43: <P>
44: The <CODE>HTNet</CODE> object is the core of the request queue management.
45: This object contains information about the socket descriptor, the input read
46: buffer etc. required to identify and service a request.
2.1 frystyk 47: <PRE>
2.18 frystyk 48: typedef struct _HTNet HTNet;
2.34 frystyk 49:
2.36 eric 50: #include "HTEvent.h"
2.34 frystyk 51: #include "HTReq.h"
2.44 frystyk 52: #include "HTResponse.h"
2.34 frystyk 53: #include "HTTrans.h"
54: #include "HTHost.h"
2.46 frystyk 55: #include "HTProt.h"
2.34 frystyk 56: #include "HTChannl.h"
57: #include "HTDNS.h"
2.1 frystyk 58: </PRE>
2.36 eric 59: <H2>
2.44 frystyk 60: <A NAME="callout">Generic BEFORE and AFTER Filter Management</A>
2.36 eric 61: </H2>
62: <P>
2.43 frystyk 63: Filter functions can be registered to be called <EM>before</EM> and
2.44 frystyk 64: <EM>after</EM> a request has either been started or has terminated. The
65: conditions for <I>BEFORE</I> and <I>AFTER</I> filters are not the same so
66: we maintain them independently. Filters can be registered globally or locally.
67: The global filters are registered directly by the Net Object (this module)
68: and the local filters are registered by the
69: <A HREF="HTReq.html">HTRequest</A> Object. However, both local and
70: global filters use the same regisration mechanism which we provide here.
71: <H3>
72: Filter Ordering
73: </H3>
74: <P>
75: Filters can be registered by anyone and as they are an often used mechanism
76: for introducing extensions in libwww, they are videly used to handle
77: authentication, redirection, etc. Many filters can be registered at once
78: and not all of the filters may know about the other filters. Therefore, it
79: is difficult to specify an absolute ordering by which the filters should
80: be called. Instead you can decide a relative order by which the filters should
81: be called. The order works pretty much like the Unix priority mechanism running
82: from <CODE>HT_FILTER_FIRST</CODE> to <CODE>HT_FILTER_LAST</CODE> having
83: <CODE>HT_FILTER_MIDDLE</CODE> being the "normal" case.
84: <PRE>
2.45 frystyk 85: typedef enum _HTFilterOrder {
86: HT_FILTER_FIRST = 0x0, /* 0 */
87: HT_FILTER_EARLY = 0x3FFF, /* 16383 */
88: HT_FILTER_MIDDLE = 0x7FFF, /* 32767 */
89: HT_FILTER_LATE = 0xBFFE, /* 49150 */
90: HT_FILTER_LAST = 0xFFFF /* 65535 */
91: } HTFilterOrder;
2.44 frystyk 92: </PRE>
93: <P>
94: In case multiple filters are registered with the same order then they are
95: called in the <I>inverse</I> order they were registered.
96: <H3>
97: Filter URL Templates
98: </H3>
99: <P>
100: Both <I>BEFORE</I> and <I>AFTER</I> filters can be registered with a <I>URL
101: template</I> in which case they are only called when the <I>Request URL</I>
102: matches the template. A template is simply a string which is matched against
103: the <I>Request URL</I>. The string can be terminated by a single
104: "<CODE>*</CODE>" in which case all strings matching the template up til the
105: "*" is considered a match. A template can be as short as the access scheme
106: which enmables a filter for a specific access method only, for example
107: "<CODE>http//<star></CODE>".
108: <H3>
109: BEFORE Filters
110: </H3>
111: <P>
112: A <I>BEFORE</I> filter is called whenever we issue a request and they have
113: been selected by the execution procedure. <I>BEFORE</I> filters are registered
114: with a <I>context</I> and a <I>filter order</I> by which they are to be called
115: and a <I>URL template</I> which may be NULL. In this case, the filter is
116: called on every request. The mode can be used by anybody to pass an extra
2.45 frystyk 117: parameter to a filter. This is not really OO thinking - but hey - this is
118: C ;-)
2.44 frystyk 119: <PRE>typedef int HTNetBefore (HTRequest * request, void * param, int mode);
120: </PRE>
121: <P>
122: You can add a <I>BEFORE</I> filter in the list provided by the caller. Several
123: filters can be registered in which case they are called with the filter ordering
124: in mind.
125: <PRE>
126: extern BOOL HTNetCall_addBefore (HTList * list, HTNetBefore * before,
127: const char * tmplate, void * param,
2.45 frystyk 128: HTFilterOrder order);
2.44 frystyk 129: </PRE>
130: <P>
131: You can also unregister all instances of a BEFORE filter from a list using
132: the following function
133: <PRE>
134: extern BOOL HTNetCall_deleteBefore (HTList * list, HTNetBefore * before);
135: </PRE>
136: <P>
137: You get rid of all BEFORE filters usign this function
138: <PRE>
139: extern BOOL HTNetCall_deleteBeforeAll (HTList * list);
140: </PRE>
141: <P>
142: The BEFORE filters are expected and called if appropriate every time we issue
143: a new request. Libwww calls the BEFORE filters in the order specified at
144: registration time. If a filter returns other than HT_OK then stop and return
145: immediately. Otherwise return what the last filter returns.
146: <PRE>
147: extern int HTNetCall_executeBefore (HTList * list, HTRequest * request);
148: </PRE>
149: <H3>
150: AFTER Filters
151: </H3>
152: <P>
153: An <I>AFTER</I> filter is called whenever we have terminated a request. That
154: is, on the way out from the <A HREF="HTProt.html">protocol module</A> and
155: back to the application. <I>AFTER</I> filters are registered with a
156: <I>context</I>, a <I>status</I>, a <I>filter order</I> by which they are
157: to be called and a <I>URL template</I> which may be NULL. The status of the
158: request may determine which filter to call. The set of possible values are
159: given below. An <I>AFTER</I> filter can be registered to handle one or more
160: of the codes.
2.17 frystyk 161: <DL>
2.36 eric 162: <DT>
163: HT_ERROR
164: <DD>
165: An error occured
166: <DT>
167: HT_LOADED
168: <DD>
169: The document was loaded
170: <DT>
171: HT_NO_DATA
172: <DD>
173: OK, but no data
174: <DT>
2.43 frystyk 175: HT_NO_ACCESS
176: <DD>
177: The request could not be succeeded due to lack of credentials
178: <DT>
179: HT_NO_PROXY_ACCESS
180: <DD>
181: The request could not be succeeded due to lack of credentials for accessing
182: an intermediate proxy
183: <DT>
2.36 eric 184: HT_RETRY
185: <DD>
186: Retry request after at a later time
187: <DT>
2.40 frystyk 188: HT_PERM_REDIRECT
2.36 eric 189: <DD>
2.40 frystyk 190: The request has been permanently redirected and we send back the new URL
191: <DT>
192: HT_TEMP_REDIRECT
193: <DD>
194: The request has been temporaryly redirected and we send back the new URL
2.36 eric 195: <DT>
196: HT_ALL
197: <DD>
198: All of above
2.17 frystyk 199: </DL>
2.36 eric 200: <P>
2.44 frystyk 201: A Protocol module can also in certain cases return a <CODE>HT_IGNORE </CODE>in
202: which case no filters are called
203: <PRE>
204: typedef int HTNetAfter (HTRequest * request, HTResponse * response,
205: void * param, int status);
206: </PRE>
207: <P>
208: You can register a AFTER filter in the list provided by the caller. Several
209: filters can be registered in which case they are called with the filter ordering
210: in mind.
2.1 frystyk 211: <PRE>
2.44 frystyk 212: extern BOOL HTNetCall_addAfter (HTList * list, HTNetAfter * after,
213: const char * tmplate, void * param,
2.45 frystyk 214: int status, HTFilterOrder order);
2.9 frystyk 215: </PRE>
2.36 eric 216: <P>
2.45 frystyk 217: You can either unregister all filters registered for a given status using
218: this function or the filter for all status codes.
2.9 frystyk 219: <PRE>
2.44 frystyk 220: extern BOOL HTNetCall_deleteAfter (HTList * list, HTNetAfter * after);
221: extern BOOL HTNetCall_deleteAfterStatus (HTList * list, int status);
2.1 frystyk 222: </PRE>
2.36 eric 223: <P>
2.44 frystyk 224: You can also delete all AFTER filters in list
2.24 frystyk 225: <PRE>
2.44 frystyk 226: extern BOOL HTNetCall_deleteAfterAll (HTList * list);
2.24 frystyk 227: </PRE>
2.36 eric 228: <P>
2.44 frystyk 229: This function calls all the AFTER filters in the order specified at registration
230: time and if it has the right status code and it's not <CODE>HT_IGNORE</CODE>.
231: We also check for any template and whether it matches or not. If a filter
232: returns other than HT_OK then stop and return immediately. Otherwise return
233: what the last filter returns.
2.24 frystyk 234: <PRE>
2.44 frystyk 235: extern int HTNetCall_executeAfter (HTList * list, HTRequest * request,
236: int status);
2.24 frystyk 237: </PRE>
2.44 frystyk 238: <H2>
2.45 frystyk 239: <A NAME="Global">Global BEFORE and AFTER Filter Management</A>
2.44 frystyk 240: </H2>
241: <P>
242: Global filters are inspected on every request (they do not have to be called
243: - only if the conditions match). You can also register filters locally in
244: the Request object.
245: <H4>
246: Global BEFORE Filters
247: </H4>
2.36 eric 248: <P>
2.44 frystyk 249: These are the methods to handle global <I>BEFORE</I> Filters.
2.24 frystyk 250: <PRE>
2.44 frystyk 251: extern BOOL HTNet_setBefore (HTList * list);
252:
253: extern HTList * HTNet_before (void);
2.42 frystyk 254:
2.44 frystyk 255: extern BOOL HTNet_addBefore (HTNetBefore * before, const char * tmplate,
2.45 frystyk 256: void * param, HTFilterOrder order);
2.42 frystyk 257:
2.44 frystyk 258: extern BOOL HTNet_deleteBefore (HTNetBefore * before);
2.24 frystyk 259: </PRE>
2.36 eric 260: <P>
2.44 frystyk 261: You can call both the local and the global BEFORE filters (if any)
262: <PRE>
263: extern int HTNet_executeBeforeAll (HTRequest * request);
264: </PRE>
265: <H4>
266: Global AFTER Filters
267: </H4>
268: <P>
269: These are the methods to handle global <I>AFTER</I> Filters.
2.10 frystyk 270: <PRE>
2.44 frystyk 271: extern BOOL HTNet_setAfter (HTList * list);
272:
273: extern HTList * HTNet_after (void);
274:
275: extern BOOL HTNet_addAfter (HTNetAfter * after, const char * tmplate,
2.45 frystyk 276: void * param, int status,
277: HTFilterOrder order);
2.42 frystyk 278:
2.44 frystyk 279: extern BOOL HTNet_deleteAfter (HTNetAfter * after);
2.42 frystyk 280:
2.44 frystyk 281: extern BOOL HTNet_deleteAfterStatus (int status);
282: </PRE>
283: <P>
284: You can call both the local and the global AFTER filters (if any)
285: <PRE>
286: extern int HTNet_executeAfterAll (HTRequest * request, int status);
2.10 frystyk 287: </PRE>
2.36 eric 288: <H2>
2.43 frystyk 289: Socket Resource Management
2.36 eric 290: </H2>
291: <P>
292: The request queue ensures that no more than a fixed number of TCP connections
293: are open at the same time. If more requests are handed to the Library, they
294: are put into the pending queue and initiated when sockets become free.
295: <H3>
296: Number of Simultanous open TCP connections
297: </H3>
298: <P>
299: Set the max number of simultanous sockets. The default value is HT_MAX_SOCKETS
300: which is 6. The number of persistent connections depend on this value as
301: a deadlock can occur if all available sockets a persistent (see the
302: <A HREF="HTDNS.html">DNS Manager</A> for more information on setting the
303: number of persistent connections). The number of persistent connections can
304: never be more than the max number of sockets-2, so letting newmax=2 prevents
305: persistent sockets.
2.1 frystyk 306: <PRE>
2.17 frystyk 307: extern BOOL HTNet_setMaxSocket (int newmax);
308: extern int HTNet_maxSocket (void);
2.1 frystyk 309: </PRE>
2.36 eric 310: <H3>
2.43 frystyk 311: Socket Counters
312: </H3>
313: <PRE>
314: extern void HTNet_increaseSocket (void);
315: extern void HTNet_decreaseSocket (void);
316:
317: extern int HTNet_availableSockets (void);
318: </PRE>
319: <H3>
320: Persistent Socket Counters
321: </H3>
322: <PRE>
323: extern void HTNet_increasePersistentSocket (void);
324: extern void HTNet_decreasePersistentSocket (void);
325:
326: extern int HTNet_availablePersistentSockets (void);
327: </PRE>
328: <H3>
329: Any Ongoing Connections?
330: </H3>
331: <P>
332: Returns whether there are active requests. Idle persistent sockets do not
333: count as active.
334: <PRE>
335: extern BOOL HTNet_isIdle (void);
336: </PRE>
337: <H3>
2.36 eric 338: List Active Queue
339: </H3>
340: <P>
341: Returns the list of active requests that are currently having an open connection.
342: Returns list of HTNet objects or NULL if error.
2.1 frystyk 343: <PRE>
2.17 frystyk 344: extern HTList *HTNet_activeQueue (void);
2.22 frystyk 345: extern BOOL HTNet_idle (void);
2.29 frystyk 346: </PRE>
2.36 eric 347: <H3>
348: Are we Active?
349: </H3>
350: <P>
351: We have some small functions that tell whether there are registered requests
352: in the Net manager. There are tree queues: The <EM>active</EM>, the
353: <EM>pending</EM>, and the <EM>persistent</EM>. The <EM>active</EM> queue
354: is the set of requests that are actively sending or receiving data. The
355: <EM>pending</EM> is the requests that we have registered but which are waiting
356: for a free socket. The <EM>Persistent</EM> queue are requets that are waiting
357: to use the same socket in order to save network resoures (if the server
358: understands persistent connections).
359: <H4>
2.46 frystyk 360: Active Requests?
2.36 eric 361: </H4>
362: <P>
2.29 frystyk 363: Returns whether there are requests in the <EM>active</EM> queue or not
364: <PRE>
365: extern BOOL HTNet_idle (void);
366: </PRE>
2.36 eric 367: <H4>
368: Registered Requests?
369: </H4>
370: <P>
371: Returns whether there are requests registered in any of the lists or not
2.29 frystyk 372: <PRE>
373: extern BOOL HTNet_isEmpty (void);
2.46 frystyk 374: extern int HTNet_count (void);
2.1 frystyk 375: </PRE>
2.36 eric 376: <H3>
377: List Pending Queue
378: </H3>
379: <P>
380: Returns the list of pending requests that are waiting to become active. Returns
381: list of HTNet objects or NULL if error
2.1 frystyk 382: <PRE>
2.17 frystyk 383: extern HTList *HTNet_pendingQueue (void);
2.1 frystyk 384: </PRE>
2.36 eric 385: <H2>
2.37 frystyk 386: Creation and Deletion Methods
2.36 eric 387: </H2>
388: <P>
2.37 frystyk 389: The Net object is intended to live as long as the request is still active.
390: In that regard it is very similar to the <A HREF="HTReq.html">Request Object
391: </A>. However, the main difference is that a Net object represents a "thread"
392: in the Library and a request may have multiple "threads" - an example is
393: a FTP request which has a thread to handle the control connection and one
394: to handle the data connections.
395: <H3>
396: Create a new Object
397: </H3>
398: <P>
399: If we have more than HTMaxActive connections already then put this into the
400: pending queue, else start the request by calling the call back function
401: registered with this access method. Returns YES if OK, else NO
2.27 frystyk 402: <PRE>
2.28 frystyk 403: extern BOOL HTNet_newClient (HTRequest * request);
2.27 frystyk 404: </PRE>
2.36 eric 405: <P>
406: You can create a new HTNet object as a new request to be handled. If we have
407: more than HTMaxActive connections already then return NO. Returns YES if
408: OK, else NO
2.17 frystyk 409: <PRE>
2.39 frystyk 410: extern BOOL HTNet_newServer (HTRequest * request, HTNet * net, char *access);
2.26 frystyk 411: </PRE>
2.36 eric 412: <P>
2.27 frystyk 413: And you can create a plain new HTNet object using the following method:
2.26 frystyk 414: <PRE>
2.46 frystyk 415: extern HTNet * HTNet_new (HTRequest * request);
2.20 frystyk 416: </PRE>
2.36 eric 417: <H3>
2.37 frystyk 418: Duplicate an existing Object
2.36 eric 419: </H3>
420: <P>
421: Creates a new HTNet object as a duplicate of the same request. Returns YES
422: if OK, else NO.
2.20 frystyk 423: <PRE>
2.30 frystyk 424: extern HTNet * HTNet_dup (HTNet * src);
2.17 frystyk 425: </PRE>
2.37 frystyk 426: <H3>
2.43 frystyk 427: Launch a Net Object
428: </H3>
429: <P>
430: Start a Net obejct by calling the protocol module.
431: <PRE>extern BOOL HTNet_start (HTNet * net);
432: </PRE>
2.46 frystyk 433: <H3>
2.51 frystyk 434: Call a Net Event Handler
2.46 frystyk 435: </H3>
2.51 frystyk 436: <P>
437: This functions lets the caller play event manager as it can calls any event
438: handler with the event type and context passed to the function
2.46 frystyk 439: <PRE>
440: extern BOOL HTNet_execute (HTNet * net, HTEventType type);
2.49 frystyk 441:
442: extern HTEvent * HTNet_event (HTNet * net);
443: extern BOOL HTNet_setEventParam (HTNet * net, void * eventParam);
444: extern void * HTNet_eventParam (HTNet * net);
445: extern BOOL HTNet_setEventCallback(HTNet * net, HTEventCallback * cbf);
446: extern HTEventCallback * HTNet_eventCallback(HTNet * net);
2.46 frystyk 447: </PRE>
2.43 frystyk 448: <H3>
2.37 frystyk 449: Delete an Object
450: </H3>
451: <P>
452: Deletes the HTNet object from the list of active requests and calls any
453: registered call back functions IF not the status is HT_IGNORE. This is used
454: if we have internal requests that the app doesn't know about. We also see
455: if we have pending requests that can be started up now when we have a socket
2.43 frystyk 456: free. The filters are called in the reverse order of which they were registered
457: (last one first);
2.37 frystyk 458: <PRE>
459: extern BOOL HTNet_delete (HTNet * me, int status);
460: </PRE>
461: <H3>
462: Delete ALL HTNet Objects
463: </H3>
464: <P>
465: Deletes all HTNet object that might either be active or pending We DO NOT
466: call the call back functions - A crude way of saying goodbye!
467: <PRE>
468: extern BOOL HTNet_deleteAll (void);
469: </PRE>
2.36 eric 470: <H2>
2.38 frystyk 471: Net Class Methods
2.36 eric 472: </H2>
473: <H3>
474: Make an Object Wait
475: </H3>
476: <P>
477: Let a net object wait for a persistent socket. It will be launched from the
478: HTNet_delete() function when the socket gets free.
2.19 frystyk 479: <PRE>
480: extern BOOL HTNet_wait (HTNet *net);
481: </PRE>
2.36 eric 482: <H3>
483: Priority Management
484: </H3>
485: <P>
486: Each HTNet object is created with a priority which it inherits from the
487: <A HREF="HTReq.html">Request manager</A>. However, in some stuations it is
488: useful to be to change the current priority after the request has been started.
489: These two functions allow you to do this. The effect will show up the first
490: time (which might be imidiately) the socket blocks and control returns to
491: the event loop. Also have a look at how you can do this before the request
492: is issued in the <A HREF="HTReq.html">request manager</A>.
2.23 frystyk 493: <PRE>
494: extern HTPriority HTNet_priority (HTNet * net);
495: extern BOOL HTNet_setPriority (HTNet * net, HTPriority priority);
496: </PRE>
2.36 eric 497: <H3>
498: Persistent Connections
499: </H3>
500: <P>
501: You can set a Net object to handle persistent connections for example using
502: HTTP, NNTP, or FTP. You can control whether a Net object supports persistent
503: connections or not using this function.
2.33 frystyk 504: <PRE>
505: extern BOOL HTNet_persistent (HTNet * net);
506: </PRE>
2.36 eric 507: <P>
508: You can set or disable a Net object supporting persistent connections using
509: this function:
2.33 frystyk 510: <PRE>
2.43 frystyk 511: extern BOOL HTNet_setPersistent (HTNet * net,
512: BOOL persistent,
513: HTTransportMode mode);
2.33 frystyk 514: </PRE>
2.36 eric 515: <H3>
516: Kill a Request
517: </H3>
518: <P>
519: Kill the request by calling the call back function with a request for closing
520: the connection. Does not remove the object. This is done by HTNet_delete()
521: function which is called by the load routine. Returns OK if success, NO on
522: error
2.1 frystyk 523: <PRE>
2.17 frystyk 524: extern BOOL HTNet_kill (HTNet * me);
2.1 frystyk 525: </PRE>
2.36 eric 526: <H3>
527: Kill ALL requests
528: </H3>
529: <P>
530: Kills all registered (active+pending) requests by calling the call back function
531: with a request for closing the connection. We do not remove the HTNet object
532: as it is done by HTNet_delete(). Returns OK if success, NO on error
2.1 frystyk 533: <PRE>
2.17 frystyk 534: extern BOOL HTNet_killAll (void);
2.28 frystyk 535: </PRE>
2.36 eric 536: <H3>
537: Create Input and Output Streams
538: </H3>
539: <P>
540: You create the input stream and bind it to the channel using the following
541: methods. Please read the description in the
542: <A HREF="HTIOStream.html">HTIOStream module</A> on the parameters
543: <EM>target</EM>, <EM>param</EM>, and <EM>mode</EM>. Both methods return YES
544: if OK, else NO.
2.34 frystyk 545: <PRE>
2.46 frystyk 546: #if 0
2.34 frystyk 547: extern HTInputStream * HTNet_getInput (HTNet * net, HTStream * target,
548: void * param, int mode);
2.46 frystyk 549: #endif
550: extern HTOutputStream * HTNet_getOutput (HTNet * me, void * param, int mode);
2.34 frystyk 551: </PRE>
2.37 frystyk 552: <H3>
553: Net Context Descriptor
554: </H3>
2.36 eric 555: <P>
2.37 frystyk 556: Just like the <A HREF="../../../../WWW/Library/src/HTReq.html#context">request
557: object</A>, a net object can be assigned a context which keeps track of context
558: dependent information. The Library does not use this information nor does
559: it depend on it but it allows the application to customize a net object to
560: specific uses.
561: <PRE>extern BOOL HTNet_setContext (HTNet * net, void * context);
562: extern void * HTNet_context (HTNet * net);
563: </PRE>
2.36 eric 564: <H3>
565: Socket Descriptor
566: </H3>
2.28 frystyk 567: <PRE>
568: extern BOOL HTNet_setSocket (HTNet * net, SOCKET sockfd);
569: extern SOCKET HTNet_socket (HTNet * net);
2.17 frystyk 570: </PRE>
2.36 eric 571: <H3>
2.48 frystyk 572: Preemptive or Non-preemptive Access
573: </H3>
574: <P>
575: A access scheme is defined with a default for using either preemptive (blocking
576: I/O) or non-premitve (non-blocking I/O). This is basically a result of the
577: implementation of the protocol module itself. However, if non-blocking I/O
578: is the default then some times it is nice to be able to set the mode to blocking
579: instead. For example when loading the first document (the home page) then
580: blocking can be used instead of non-blocking.
581: <PRE>
582: extern BOOL HTNet_preemptive (HTNet * net);
583: </PRE>
584: <H3>
2.39 frystyk 585: The Request Object
586: </H3>
587: <P>
2.43 frystyk 588: The <A HREF="HTReq.html">Request object</A> is normally set up automatically
589: but can be changed at a later time.
2.39 frystyk 590: <PRE>
591: extern BOOL HTNet_setRequest (HTNet * net, HTRequest * request);
592: extern HTRequest * HTNet_request (HTNet * net);
593: </PRE>
2.46 frystyk 594: <H3>
2.51 frystyk 595: The Protocol Object
2.46 frystyk 596: </H3>
597: <PRE>
598: extern BOOL HTNet_setProtocol (HTNet * net, HTProtocol * protocol);
599: extern HTProtocol * HTNet_protocol (HTNet * net);
600: </PRE>
2.39 frystyk 601: <H3>
2.36 eric 602: The Transport Object
603: </H3>
604: <P>
2.51 frystyk 605: The <A HREF="HTTrans.html">transport object</A> is normally set up automatically
606: but can be changed at a later time.
2.17 frystyk 607: <PRE>
2.34 frystyk 608: extern BOOL HTNet_setTransport (HTNet * net, HTTransport * tp);
609: extern HTTransport * HTNet_transport (HTNet * net);
610: </PRE>
2.36 eric 611: <H3>
612: The Channel Object
613: </H3>
2.34 frystyk 614: <PRE>
615: extern BOOL HTNet_setChannel (HTNet * net, HTChannel * channel);
616: extern HTChannel * HTNet_channel (HTNet * net);
617: </PRE>
2.36 eric 618: <H3>
619: The Host Object
620: </H3>
2.34 frystyk 621: <PRE>
622: extern BOOL HTNet_setHost (HTNet * net, HTHost * host);
623: extern HTHost * HTNet_host (HTNet * net);
624: </PRE>
2.36 eric 625: <H3>
626: The DNS Object
627: </H3>
2.43 frystyk 628: <P>
629: The DNS object keeps track of the DNS entries that we have already checked
630: out.
2.34 frystyk 631: <PRE>
632: extern BOOL HTNet_setDns (HTNet * net, HTdns * dns);
633: extern HTdns * HTNet_dns (HTNet * net);
634: </PRE>
2.43 frystyk 635: <P>
2.46 frystyk 636: <H3>
2.51 frystyk 637: Target for Input Read Stream
2.46 frystyk 638: </H3>
639: <PRE>
640: extern HTStream * HTNet_readStream(HTNet * net);
641: extern BOOL HTNet_setReadStream (HTNet * net, HTStream * stream);
642: </PRE>
2.34 frystyk 643: <PRE>
2.17 frystyk 644: #endif /* HTNET_H */
2.1 frystyk 645: </PRE>
2.36 eric 646: <P>
647: <HR>
2.34 frystyk 648: <ADDRESS>
2.52 ! frystyk 649: @(#) $Id: HTNet.html,v 2.51 1998/05/04 19:37:06 frystyk Exp $
2.34 frystyk 650: </ADDRESS>
2.36 eric 651: </BODY></HTML>
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