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Annotation of libwww/Library/src/HTProt.html, revision 2.7

2.1       frystyk     1: <HTML>
                      2: <HEAD>
                      3: <TITLE>Access Scheme Manager</TITLE>
2.7     ! frystyk     4: <!-- Changed by: Henrik Frystyk Nielsen, 24-Oct-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
                     38: <CODE>HTEventCallBack</CODE> is defined in <A
                     39: HREF="HTEvntrg.html">HTEvntrg module</A>. <P>
                     40: 
                     41: By default, all the access schemes supported in the Library are
                     42: initiated automaticly using the function <CODE>HTAccessInit()</CODE>
                     43: in <A HREF="HTInit.html">HTInit module</A>. However, this can be
                     44: changed if defined <CODE>HT_NO_INIT</CODE> <P>
                     45: 
                     46: An access scheme module takes as a parameter a socket (which is an
                     47: invalid socket the first time the function is called), a <A
2.6       frystyk    48: HREF="HTReqMan.html">request structure</A> containing details of the
2.5       frystyk    49: request, and the action by which the (valid) socket was selected in
                     50: the event loop.  When the protocol class routine is called, the anchor
2.1       frystyk    51: element in the request is already valid (made valid by HTAccess).
                     52: 
                     53: <PRE>
2.5       frystyk    54: typedef struct _HTProtocol HTProtocol;
2.1       frystyk    55: </PRE>
                     56: 
                     57: <H3>Add an Access Scheme</H3>
                     58: 
                     59: This functions registers a protocol module and binds it to a specific
2.5       frystyk    60: access acheme. For example HTTP.c is bound to http URLs. The call back
                     61: function is the function to be called for loading. The reason why it
                     62: is of type HTEventCallback is that it then can be used directly in the
                     63: event loop when used in non-preemtive mode.
2.1       frystyk    64: 
                     65: <PRE>
2.5       frystyk    66: extern BOOL HTProtocol_add (CONST char *               name,
                     67:                            BOOL                preemtive,
                     68:                            HTEventCallBack *   callback);
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>
                     77: extern BOOL HTProtocol_delete (CONST char * name);
                     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: 
                     89: <H3>Bind an Access Scheme to an Anchor</H3>
2.1       frystyk    90: 
                     91: This function finds the access scheme that is bound to the anchor's
                     92: type of URL. Returns YES if found, else NO
                     93: 
                     94: <PRE>
2.5       frystyk    95: extern BOOL HTProtocol_bind            PARAMS((HTParentAnchor * anchor));
2.1       frystyk    96: </PRE>
                     97: 
2.5       frystyk    98: <H3Finds the Callback Function</H3>
2.1       frystyk    99: 
2.5       frystyk   100: Returns the callback function registered with this access scheme if any.
2.1       frystyk   101: 
                    102: <PRE>
2.5       frystyk   103: extern HTEventCallBack *HTProtocol_callback (HTProtocol * protocol);
2.1       frystyk   104: </PRE>
                    105: 
2.5       frystyk   106: <H3>Is Access Scheme Preemtive</H3>
2.1       frystyk   107: 
2.5       frystyk   108: Returns YES if the implementation of the access scheme supports
                    109: preemtive access only.
2.1       frystyk   110: 
                    111: <PRE>
2.5       frystyk   112: extern BOOL HTProtocol_preemtive (HTProtocol * protocol);
2.1       frystyk   113: </PRE>
                    114: 
                    115: <PRE>
                    116: #endif /* HTPROT_H */
                    117: </PRE>
                    118: 
                    119: End of Declaration
                    120: 
                    121: </BODY>
                    122: </HTML>
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