Annotation of libwww/Library/src/HTProt.html, revision 2.24
2.1 frystyk 1: <HTML>
2: <HEAD>
2.16 eric 3: <!-- Changed by: Henrik Frystyk Nielsen, 26-Mar-1996 -->
4: <NEXTID N="z11">
2.22 frystyk 5: <TITLE>W3C Sample Code Library libwww Protocol Class</TITLE>
2.1 frystyk 6: </HEAD>
7: <BODY>
2.16 eric 8: <H1>
2.18 frystyk 9: The Protocol Class
2.16 eric 10: </H1>
2.1 frystyk 11: <PRE>
12: /*
13: ** (c) COPYRIGHT MIT 1995.
14: ** Please first read the full copyright statement in the file COPYRIGH.
15: */
16: </PRE>
2.16 eric 17: <P>
2.18 frystyk 18: The Protocol class defines an application level protocol (HTTP, FTP, Gopher,
19: etc.) to be used by libwww. Please note that access to the local file system
20: also is considered to be an appliaction level protocol treated identically
21: to for example the HTTP protocol. The Protocol class does only know about
22: the application layer protocol and it relies on the
23: <A HREF="HTTrans.html">Transport Class</A> to do the actualt communication
24: with the network, the local file system etc. The protocol class defines an
25: access method for botg a client and a server. A typical client application
26: would probably only want to use the client method and a server only the server
27: method. However, any application can use both which allows it to seemlessly
28: to change between server and client profile as needed.
29: <P>
30: <B>Note</B>: The library <B>core</B> does not define any default application
31: layer protocols - they are all considered part of the application. The library
32: comes with a default set of protocols including the ones mentioned above
2.20 frystyk 33: which can be initiated using the function <CODE>HTProtocolInit()</CODE> in
2.18 frystyk 34: <A HREF="HTInit.html">HTInit module</A>
2.16 eric 35: <P>
36: This module is implemented by <A HREF="HTProt.c">HTProt.c</A>, and it is
2.23 frystyk 37: a part of the <A HREF="http://www.w3.org/Library/"> W3C Sample Code
2.16 eric 38: Library</A>.
2.1 frystyk 39: <PRE>
40: #ifndef HTPROT_H
41: #define HTPROT_H
42:
2.21 frystyk 43: typedef struct _HTProtocol HTProtocol;
44: typedef u_short HTProtocolId;
45:
2.5 frystyk 46: #include "HTReq.h"
2.1 frystyk 47: #include "HTAnchor.h"
2.16 eric 48: #include "HTEvent.h"
2.15 frystyk 49: #include "HTTrans.h"
2.1 frystyk 50: </PRE>
2.16 eric 51: <P>
52: An access scheme module takes as a parameter a socket (which is an invalid
53: socket the first time the function is called), a
54: <A HREF="HTReqMan.html">request structure</A> containing details of the request,
55: and the action by which the (valid) socket was selected in the event loop.
56: When the protocol class routine is called, the anchor element in the request
57: is already valid (made valid by HTAccess).
2.18 frystyk 58: <H2>
59: Creation and Deletion Methods
60: </H2>
2.16 eric 61: <H3>
2.18 frystyk 62: Add an Protocol
2.16 eric 63: </H3>
64: <P>
65: This functions registers a protocol module and binds it to a specific access
2.18 frystyk 66: acheme (the part before the first colon in a URL). For example, the HTTP
67: client module is bound to http URLs. The callback function is the function
68: to be called for loading.
2.1 frystyk 69: <PRE>
2.21 frystyk 70: typedef int HTProtCallback (SOCKET, HTRequest *);
71:
2.13 frystyk 72: extern BOOL HTProtocol_add (const char * name,
2.15 frystyk 73: const char * transport,
2.21 frystyk 74: HTProtocolId port,
2.12 frystyk 75: BOOL preemptive,
2.21 frystyk 76: HTProtCallback * client,
77: HTProtCallback * server);
2.1 frystyk 78: </PRE>
2.16 eric 79: <H3>
2.18 frystyk 80: Delete a Protocol
2.16 eric 81: </H3>
82: <P>
83: This functions deletes a registered protocol module so that it can not be
84: used for accessing a resource anymore.
2.5 frystyk 85: <PRE>
2.13 frystyk 86: extern BOOL HTProtocol_delete (const char * name);
2.5 frystyk 87: </PRE>
2.16 eric 88: <H3>
2.18 frystyk 89: Remove ALL Registered Protocols
2.16 eric 90: </H3>
91: <P>
92: This is the garbage collection function. It is called by
2.19 frystyk 93: <A HREF="HTLib.html">HTLibTerminate()</A>
2.5 frystyk 94: <PRE>
95: extern BOOL HTProtocol_deleteAll (void);
96: </PRE>
2.18 frystyk 97: <H2>
98: Protocol Class Methods
99: </H2>
2.16 eric 100: <H3>
101: Find a Protocol Object
102: </H3>
103: <P>
104: You can search the list of registered protocol objects as a function of the
105: access acheme. If an access scheme is found then the protocol object is returned.
2.1 frystyk 106: <PRE>
2.13 frystyk 107: extern HTProtocol * HTProtocol_find (HTRequest * request, const char * access);
2.1 frystyk 108: </PRE>
2.16 eric 109: <H3>
110: Get the callback functions
111: </H3>
112: <P>
113: You can get the callback functions registered together with a protocol object
114: using the following methods.
2.1 frystyk 115: <PRE>
2.21 frystyk 116: extern HTProtCallback * HTProtocol_client (HTProtocol * protocol);
117: extern HTProtCallback * HTProtocol_server (HTProtocol * protocol);
118: </PRE>
119: <H3>
120: Get the default Protocol ID
121: </H3>
122: <P>
123: Each protocol is registered with a default protocol ID which is the default port number that this protocol is using. In the case of FTP it is 21, for HTTP, it is 80 and for NNTP it is 119.
124: <PRE>
125: extern HTProtocolId HTProtocol_id (HTProtocol * protocol);
2.1 frystyk 126: </PRE>
2.16 eric 127: <H3>
2.24 ! frystyk 128: Get the Protocol Name
! 129: </H3>
! 130: <P>
! 131: Get the protocol name that was registered when the protocol object was created
! 132: <PRE>
! 133: extern const char * HTProtocol_name (HTProtocol * protocol);
! 134: </PRE>
! 135: <H3>
2.16 eric 136: Is Access Scheme Preemptive
137: </H3>
138: <P>
139: Returns YES if the implementation of the access scheme supports preemptive
140: access only.
2.1 frystyk 141: <PRE>
2.12 frystyk 142: extern BOOL HTProtocol_preemptive (HTProtocol * protocol);
2.1 frystyk 143: </PRE>
2.16 eric 144: <H3>
2.18 frystyk 145: Binding to the Transport Class
2.16 eric 146: </H3>
2.18 frystyk 147: <P>
148: An application protocol is registered together with a
149: <A HREF="HTTrans.html">transport protocol </A>in order to communicate with
150: the thansport layer.
2.1 frystyk 151: <PRE>
2.15 frystyk 152: extern BOOL HTProtocol_setTransport (HTProtocol * protoccol,
153: const char * transport);
154: extern const char * HTProtocol_transport (HTProtocol * protocol);
155: </PRE>
156: <PRE>
2.1 frystyk 157: #endif /* HTPROT_H */
158: </PRE>
2.16 eric 159: <P>
160: <HR>
2.15 frystyk 161: <ADDRESS>
2.24 ! frystyk 162: @(#) $Id: HTProt.html,v 2.23 1998/05/14 02:10:56 frystyk Exp $
2.15 frystyk 163: </ADDRESS>
2.16 eric 164: </BODY></HTML>
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