Annotation of libwww/Library/src/HTProt.html, revision 2.13
2.1 frystyk 1: <HTML>
2: <HEAD>
3: <TITLE>Access Scheme Manager</TITLE>
2.11 frystyk 4: <!-- Changed by: Henrik Frystyk Nielsen, 24-Nov-1995 -->
2.1 frystyk 5: <NEXTID N="z11">
6: </HEAD>
7: <BODY>
8:
9: <H1>Access Scheme Manager</H1>
10:
11: <PRE>
12: /*
13: ** (c) COPYRIGHT MIT 1995.
14: ** Please first read the full copyright statement in the file COPYRIGH.
15: */
16: </PRE>
17:
18: This module keeps a list of valid protocol (naming scheme) specifiers
19: with associated access code. New access protocols may be registered at
20: any time.<P>
21:
22: This module is implemented by <A HREF="HTProt.c">HTProt.c</A>, and it
2.7 frystyk 23: is a part of the <A HREF="http://www.w3.org/pub/WWW/Library/"> W3C
24: Reference Library</A>. <P>
2.1 frystyk 25:
26: <PRE>
27: #ifndef HTPROT_H
28: #define HTPROT_H
29:
2.5 frystyk 30: #include "HTReq.h"
2.1 frystyk 31: #include "HTAnchor.h"
2.5 frystyk 32: #include "HTEvntrg.h"
2.1 frystyk 33: </PRE>
34:
2.5 frystyk 35: After the new architecture based on call back functions managed by an
36: eventloop and protocol state machines, the protocol structure has been
37: modified to reflect this call back structure. The
2.9 frystyk 38: <CODE>HTEventCallback</CODE> is defined in <A
2.5 frystyk 39: HREF="HTEvntrg.html">HTEvntrg module</A>. <P>
40:
2.8 frystyk 41: All the access schemes supported in the Library can be initiated using
42: the function <CODE>HTAccessInit()</CODE> in <A
43: HREF="HTInit.html">HTInit module</A><P>
2.5 frystyk 44:
45: An access scheme module takes as a parameter a socket (which is an
46: invalid socket the first time the function is called), a <A
2.6 frystyk 47: HREF="HTReqMan.html">request structure</A> containing details of the
2.5 frystyk 48: request, and the action by which the (valid) socket was selected in
49: the event loop. When the protocol class routine is called, the anchor
2.1 frystyk 50: element in the request is already valid (made valid by HTAccess).
51:
52: <PRE>
2.5 frystyk 53: typedef struct _HTProtocol HTProtocol;
2.1 frystyk 54: </PRE>
55:
56: <H3>Add an Access Scheme</H3>
57:
58: This functions registers a protocol module and binds it to a specific
2.5 frystyk 59: access acheme. For example HTTP.c is bound to http URLs. The call back
60: function is the function to be called for loading. The reason why it
61: is of type HTEventCallback is that it then can be used directly in the
2.12 frystyk 62: event loop when used in non-preemptive mode.
2.1 frystyk 63:
64: <PRE>
2.13 ! frystyk 65: extern BOOL HTProtocol_add (const char * name,
2.12 frystyk 66: BOOL preemptive,
2.11 frystyk 67: HTEventCallback * client,
68: HTEventCallback * server);
2.1 frystyk 69: </PRE>
70:
2.5 frystyk 71: <H3>Delete an Access Scheme</H3>
72:
73: This functions deletes a registered protocol module so that it can not
74: be used for accessing a resource anymore.
75:
76: <PRE>
2.13 ! frystyk 77: extern BOOL HTProtocol_delete (const char * name);
2.5 frystyk 78: </PRE>
79:
80: <H3>Remove ALL Registered Schemes</H3>
81:
82: This is the garbage collection function. It is called by <A
2.7 frystyk 83: HREF="HTAccess.html#Library">HTLibTerminate()</A>
2.5 frystyk 84:
85: <PRE>
86: extern BOOL HTProtocol_deleteAll (void);
87: </PRE>
88:
2.11 frystyk 89: <H3>Find a Protocol Object</H3>
2.1 frystyk 90:
2.11 frystyk 91: You can search the list of registered protocol objects as a function
92: of the access acheme. If an access scheme is found then the protocol
93: object is returned.
2.1 frystyk 94:
95: <PRE>
2.13 ! frystyk 96: extern HTProtocol * HTProtocol_find (HTRequest * request, const char * access);
2.1 frystyk 97: </PRE>
98:
2.11 frystyk 99: <H3>Get the callback functions</H3>
2.1 frystyk 100:
2.11 frystyk 101: You can get the callback functions registered together with a protocol
102: object using the following methods.
2.1 frystyk 103:
104: <PRE>
2.11 frystyk 105: extern HTEventCallback * HTProtocol_client (HTProtocol * protocol);
106: extern HTEventCallback * HTProtocol_server (HTProtocol * protocol);
2.1 frystyk 107: </PRE>
108:
2.12 frystyk 109: <H3>Is Access Scheme Preemptive</H3>
2.1 frystyk 110:
2.5 frystyk 111: Returns YES if the implementation of the access scheme supports
2.12 frystyk 112: preemptive access only.
2.1 frystyk 113:
114: <PRE>
2.12 frystyk 115: extern BOOL HTProtocol_preemptive (HTProtocol * protocol);
2.1 frystyk 116: </PRE>
117:
118: <PRE>
119: #endif /* HTPROT_H */
120: </PRE>
121:
122: End of Declaration
123:
124: </BODY>
125: </HTML>
Webmaster