Annotation of libwww/Library/src/HTHost.html, revision 2.2
2.1 frystyk 1: <HTML>
2: <HEAD>
3: <TITLE>W3C Reference Library libwww Remote host information</TITLE>
4: <!-- Changed by: Henrik Frystyk Nielsen, 5-Apr-1996 -->
5: </HEAD>
6: <BODY>
7:
8: <H1>Remote Host Information</H1>
9:
10: <PRE>
11: /*
12: ** (c) COPYRIGHT MIT 1995.
13: ** Please first read the full copyright statement in the file COPYRIGH.
14: */
15: </PRE>
16:
17: This object manages the information that we know about a remote host.
18: This can for example be what type of host it is, and what version it
19: is using. Notive that a host can be both a server or a client. All
20: information in this module can be shared regardless of whether it is
21: to be used in a server application or a client application.<P>
22:
23: This module is implemented by <A HREF="HTHost.c">HTHost.c</A>, and it
24: is a part of the <A HREF="http://www.w3.org/pub/WWW/Library/"> W3C
25: Reference Library</A>.
26:
27: <PRE>
28: #ifndef HTHOST_H
29: #define HTHOST_H
30:
31: typedef struct _HTHost HTHost;
32:
33: #include "HTChannl.h"
34: #include "HTReq.h"
2.2 ! frystyk 35: #include "HTEvent.h"
2.1 frystyk 36: </PRE>
37:
38: <H2>The Host Object</H2>
39:
40: The Host object contains information about the remote host, for
41: example the type (HTTP/1.0, HTTP/1.1, FTP etc.) along with information
42: on how the connections can be used (if it supports persistent
43: connections, interleaved access etc.)
44:
45: <H2>Create a Host Object</H2>
46:
47: We keep a cache of information that we know about a remote host. This
48: allows us to be much more detailed in geneating requests. Search the
49: host info cache for a host object or create a new one and add
50: it. Examples of host names are
51:
52: <UL>
53: <LI>www.w3.org
54: <LI>www.foo.com:8000
55: </UL>
56:
57: <PRE>
58: extern HTHost * HTHost_new (char * host);
59: </PRE>
60:
61: <H2>Remote Host Information</H2>
62:
63: This is what we know about the remote host
64:
65: <H3>Set the Host Class and Version</H3>
66:
67: Define the <EM>host class</EM> of the host at the other end. A
68: class is a generic description of the protocol which is exactly like
69: the access method in a URL, for example "http" etc. The <EM>host
70: version</EM> is a finer distinction (sub-class) between various
71: versions of the host class, for example HTTP/0.9, HTTP/1.1 etc. The
72: host version is a bit flag that the protocol module can define on
73: its own. That way we don't have to change this module when registering
74: a new protocol module. The <EM>host type</EM> is a description of
75: whether we can keep the connection persistent or not.
76:
77: <PRE>
78: extern char * HTHost_class (HTHost * host);
79: extern void HTHost_setClass (HTHost * host, char * s_class);
80:
81: extern int HTHost_version (HTHost * host);
82: extern void HTHost_setVersion (HTHost * host, int version);
83: </PRE>
84:
85: <H2>Persistent Channels</H2>
86:
87: The HTHost object is also responsible for handline persistent connections
88:
89: <H3>Register a Persistent Channel</H3>
90:
91: We don't want more than MaxSockets-2 connections to be persistent in order to avoid deadlock.
92:
93: <PRE>
94: extern BOOL HTHost_setChannel (HTHost * host, HTChannel * channel);
95: extern BOOL HTHost_clearChannel (HTHost * host);
96:
97: extern HTChannel * HTHost_channel (HTHost * host);
98: </PRE>
99:
100: <H3>Is this host Persistent?</H3>
101:
102: Check whether we have a persistent channel or not
103:
104: <PRE>
105: extern BOOL HTHost_isPersistent (HTHost * host);
106: </PRE>
107:
108: <H3>Catching a Close Event</H3>
109:
110: This function is registered when the socket is idle so that we get a
111: notification if the socket closes at the other end. At this point we
112: can't use the request object as it might have been freed a long time
113: ago.
114:
115: <PRE>
116: extern int HTHost_catchClose (SOCKET soc, HTRequest * request, SockOps ops);
117: </PRE>
118:
119: <H3>Timing Persistent Channels</H3>
120:
121: Normally we wait for the peer process to close persistent connections
122: but in order not to use up our own resources, we have a timeout on our
123: own. The default value is 1 hour, but you can modify the value using
124: the following methods:
125:
126: <PRE>
127: extern time_t HTHost_persistTimeout (time_t timeout);
128: extern void HTHost_setPersistTimeout (time_t timeout);
129: </PRE>
130:
131: Each persistent connection has an absolute value of when this
132: connection most likely will expire. If the peer process does not
133: inform us, we use our own timeout.
134:
135: <PRE>
136: extern void HTHost_setPersistExpires (HTHost * host, time_t expires);
137: extern time_t HTHost_persistExpires (HTHost * host);
138: </PRE>
139:
140: <PRE>
141: #endif /* HTHOST_H */
142: </PRE>
143:
144: <HR>
145: <ADDRESS>
2.2 ! frystyk 146: @(#) $Id: HTHost.html,v 2.1 1996/04/12 17:47:19 frystyk Exp $
2.1 frystyk 147: </ADDRESS>
148: </BODY>
149: </HTML>
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