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Annotation of libwww/Library/src/HTProt.html, revision 2.2

2.1       frystyk     1: <HTML>
                      2: <HEAD>
                      3: <TITLE>Access Scheme Manager</TITLE>
                      4: <!-- Changed by: Henrik Frystyk Nielsen,  7-Jul-1995 -->
                      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
                     23: is a part of the <A NAME="z10"
2.2     ! frystyk    24: HREF="http://www.w3.org/hypertext/WWW/Library/">
        !            25: W3C Reference Library</A>. <P>
2.1       frystyk    26: 
                     27: <PRE>
                     28: #ifndef HTPROT_H
                     29: #define HTPROT_H
                     30: 
                     31: #include "HTAccess.h"
                     32: #include "HTAnchor.h"
                     33: </PRE>
                     34: 
                     35: An access scheme is defined by an HTProtocol structure which point to
                     36: the routines for performing the various logical operations on an
                     37: object: in HTTP terms, GET, PUT, and POST. The access schemes
                     38: supported in the Library are initiated automaticly using the function
                     39: <CODE>HTAccessInit()</CODE> <B>if not</B> defined
                     40: <CODE>HT_NO_INIT</CODE> <P>
                     41: 
                     42: Each of these routine takes as a parameter a <A NAME="z2"
                     43: HREF="HTAccess.html#z1">request structure</A> containing details of
                     44: the request.  When the protocol class routine is called, the anchor
                     45: element in the request is already valid (made valid by HTAccess).
                     46: 
                     47: <PRE>
                     48: typedef enum _HTSocBlock {
                     49:     SOC_BLOCK,
                     50:     SOC_NON_BLOCK
                     51: } HTSocBlock;
                     52: 
                     53: typedef struct _HTProtocol {
                     54:     char *     name;
                     55:     HTSocBlock block;  
                     56:     int                (*load)         PARAMS((HTRequest *     request));
                     57:     HTStream*  (*saveStream)   PARAMS((HTRequest *     request));
                     58:     HTStream*  (*postStream)   PARAMS((HTRequest *     request,
                     59:                                        HTParentAnchor* postTo));
                     60: } HTProtocol;
                     61: </PRE>
                     62: 
                     63: <H3>Add an Access Scheme</H3>
                     64: 
                     65: This functions registers a protocol module and binds it to a specific
                     66: access acheme. For example HTTP.c is bound to http URLs.
                     67: 
                     68: <PRE>
                     69: extern BOOL HTProtocol_add             PARAMS((HTProtocol * protocol));
                     70: </PRE>
                     71: 
                     72: <H3>Get an Access Scheme</H3>
                     73: 
                     74: This function finds the access scheme that is bound to the anchor's
                     75: type of URL. Returns YES if found, else NO
                     76: 
                     77: <PRE>
                     78: extern BOOL HTProtocol_getScheme       PARAMS((HTParentAnchor * anchor));
                     79: </PRE>
                     80: 
                     81: <H3>Remove ALL Registered Schemes</H3>
                     82: 
                     83: This is the garbage collection function. It is called by <A
                     84: HREF="HTAccess.html#Library">HTLibTerminate</A>
                     85: 
                     86: <PRE>
                     87: extern void HTProtocol_deleteAll       NOPARAMS;
                     88: </PRE>
                     89: 
                     90: <H3>Is the Scheme using Blocking I/O?</H3>
                     91: 
                     92: A small function to make life easier. Returns <CODE>YES</CODE> or
                     93: <CODE>NO</CODE>. If the Library is run in non-interactive mode then
                     94: the function always returns YES;
                     95: 
                     96: <PRE>
                     97: #define HTProtocol_isBlocking(me) \
                     98:        ((me) &amp;&amp; ((me)->BlockingIO || \
                     99:                ((me)->anchor &amp;&amp; (me)->anchor->protocol &amp;&amp; \
                    100:                        ((HTProtocol*)((me)->anchor->protocol))->block==SOC_BLOCK)))
                    101: </PRE>
                    102: 
                    103: <PRE>
                    104: #endif /* HTPROT_H */
                    105: </PRE>
                    106: 
                    107: End of Declaration
                    108: 
                    109: </BODY>
                    110: </HTML>
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