htndir.c

www工具包

/*							       	     HTNDir.c
**	GENERIC NEWS LISTINGS
**
**	(c) COPYRIGHT MIT 1995.
**	Please first read the full copyright statement in the file COPYRIGH.
**	@(#) $Id: HTNDir.c,v 2.12 1999/02/22 22:10:11 frystyk Exp $
**
**	Creates listings for all kind of News output.
**
** Authors:
**	HF	Henrik Frystyk, MIT, <[e-mail]>
**	MP	Maciej Puzio <[e-mail]>
** History:
**	   Oct 95  HFN	written
**	   Mar 96  MP	modified heavily     
*/

/* Library include files */
#include "wwwsys.h"
#include "WWWUtil.h"
#include "WWWCore.h"
#include "WWWHTML.h"
#include "HTNews.h"
#include "HTNewsLs.h"
#include "HTNDir.h"					 /* Implemented here */

/* Macros and other defines */
#define PUTC(c)		(*target->isa->put_character)(target, c)
#define PUTS(s)		(*target->isa->put_string)(target, s)
#define START(e)	(*target->isa->start_element)(target, e, 0, 0)
#define END(e)		(*target->isa->end_element)(target, e)
#define FREE_TARGET	(*target->isa->_free)(target)

#define DEFAULT_MAXW	80			       /* Default line width */

/* Type definitions and global variables etc. local to this module */
struct _HTStructured {
    const HTStructuredClass *	isa;
    /* ... */
};

struct _HTNewsNode {
    int		index;
    char *	name;
    char *	subject;
    char *	from;
    time_t	date;
    int		refs;			 /* Number of references */
    BOOL	is_tmplate;

    /* Added by MP: */
    HTList* refNames;        /*  referee names list */
    HTList* refObjects;      /*  referee objects list */
    HTNewsNode * refParent;  /* direct parent (referee) */
    HTNewsNode * lastChild;  /* last child (referer) */
    BOOL    show;            /* show this node on the list? */
    BOOL    fake;            /* create anchor with this node? */
    int     refChildren;     /* number of referers */
    int     refLevel;        /* reference level - to speed sorting */
    int     minRefIndex;     /* minimal index in reference subtree */
    int     maxRefIndex;     /* maximal index in reference subtree */
    time_t  minRefDate;      /* minimal date in reference subtree */
    time_t  maxRefDate;      /* maximal date in reference subtree */
};

struct _HTNewsDir {
    HTStructured *	target;
    HTRequest *		request;
    HTNewsDirKey	key;				  /* Key for sorting */
    char *   	        name;        /* Name of the newsgroup(s) Added by MP */
    char *		tmplate;
    HTNewsNode *	tmplate_node;
    int 	        lastLevel;    /* Last printed ref level Added by MP. */
    HTArray *		array;			/* Array for sorted listings */
    HTArray *		cache;			  /* Only created on request */
};

PRIVATE int MaxLineW = DEFAULT_MAXW;

/*  Forward references - added by MP. */
PRIVATE void HTNewsDir_addLevelTags (HTNewsDir* dir, int level);
PRIVATE HTNewsNode* HTNewsDir_addFakeElement (HTNewsDir* dir, char* subject,
    char* name);
PRIVATE HTNewsNode* HTNewsDir_findNodeNamed (HTNewsDir* dir, char* name);

#define FNWS_ANY       0x0000
/* Date */
#define FNWS_MIN       0x0001
#define FNWS_MAX       0x0002
/* Fake/not-fake */
#define FNWS_ONLYFAKE  0x0010
#define FNWS_NOTFAKE   0x0020
/* Fake or not-fake with references */
#define FNWS_NOTORPHAN 0x0040
PRIVATE HTNewsNode* HTNewsDir_findNodeWithSubject (HTNewsDir* dir, 
    char* subject, int which, HTNewsNode* avoidNode);


/* ------------------------------------------------------------------------- */
/*				NODE  MANAGEMENT 			     */
/* ------------------------------------------------------------------------- */

PRIVATE HTNewsNode * HTNewsNode_new (int index, char * subject, char * from,
				     time_t date, char * name,
				     int refs, HTList * refNames)
{
    HTNewsNode * node;
    if ((node = (HTNewsNode *) HT_CALLOC(1, sizeof(HTNewsNode))) == NULL)
        HT_OUTOFMEM("HTNewsNode_new");
    if (name) StrAllocCopy(node->name, name);
    if (subject) {
	StrAllocCopy(node->subject, subject);
	node->subject = HTStrip(node->subject);
    }
    if (from) StrAllocCopy(node->from, from);
    node->index = index;
    node->date = date;
    node->refs = refs;
    node->refNames = refNames;
    node->show = (name != NULL);
    node->fake = (name == NULL);
    node->minRefIndex = index;
    node->maxRefIndex = index;
    node->minRefDate = date;
    node->maxRefDate = date;
    return node;
}

PRIVATE BOOL HTNewsNode_delete (HTNewsNode * node, BOOL cache)
{
    if (node) {
    	if (!cache || node->is_tmplate) HT_FREE(node->name);
	HT_FREE(node->subject);
	HT_FREE(node->from);
        if (node->refNames) {
	    HTList * cur = node->refNames;
	    char * pres;	    
            while ((pres = (char *) HTList_nextObject(cur))) HT_FREE(pres);
            HTList_delete(node->refNames);
        }
        if (node->refObjects) HTList_delete(node->refObjects);
	HT_FREE(node);
	return YES;
    }
    return NO;
}

/* Added by MP. */
PRIVATE BOOL HTNewsNode_isAncestor (HTNewsNode* node, HTNewsNode* refered)
{
    HTNewsNode* p;
    for (p = refered; p; p = p->refParent)
        if (p == node) return YES;
    return NO;
}

/* Added by MP. */
PRIVATE BOOL HTNewsNode_linkRef (HTNewsNode* node, HTNewsNode* referer)
{
    if (node && referer) {
	node->refChildren++;
	node->lastChild = referer;
	node->minRefIndex = (node->minRefIndex != 0 ? 
			     HTMIN(node->minRefIndex, referer->index) :
			     referer->index);
	node->maxRefIndex = (node->maxRefIndex != 0 ? 
			     HTMAX(node->maxRefIndex, referer->index) :
			     referer->index);
	node->minRefDate = (node->minRefDate != 0 ? 
			    HTMIN(node->minRefDate, referer->date) :
			    referer->date);
	node->maxRefDate = (node->maxRefDate != 0 ? 
			    HTMAX(node->maxRefDate, referer->date) :
			    referer->date);
	referer->refParent = node;
	return YES;
    }
    return NO;
}

/* Added by MP. */
PRIVATE int HTNewsNode_refLevel (HTNewsNode* node)
{
    int cnt = 0;
    HTNewsNode* p;
    for (p = node->refParent; p && p->show; p = p->refParent)
        cnt++;
    return cnt;
}

/* Added by MP. */
/* Returns index field for non-fake nodes, minimal or maximal subtreee */
/* index for fake nodes. */
PRIVATE time_t HTNewsNode_getIndex (HTNewsNode* node, BOOL minimal)
{
    if (node->index != 0)
        return node->index;
    else if (minimal)
        return node->minRefIndex;
    else
        return node->maxRefIndex;
}

/* Added by MP. */
/* Returns date field for non-fake nodes, minimal or maximal subtreee */
/* date for fake nodes. */
PRIVATE time_t HTNewsNode_getDate (HTNewsNode* node, BOOL minimal)
{
    if (node->date != 0)
        return node->date;
    else if (minimal)
        return node->minRefDate;
    else
        return node->maxRefDate;
}

/* Helper function - added by MP. */
PRIVATE char* UnReSubject (char* subject)
{
    if (strlen(subject) >= 3 && strncasecomp(subject, "re:", 3) == 0)
    {
        char* p = subject + 3;  /* "Re:XXX" */
        if (*p == ' ')  p ++;   /* "Re: XXX" */
        return p;
    }
    return subject;
}

/* Added by MP. */
PRIVATE void HTNewsNode_setRefInfo_pass1 (HTNewsDir* dir, HTNewsNode* node)
{
    HTList* ptr = node->refNames;
    char* name = NULL;
    if (node->fake)
        return;
    if (ptr != NULL)
        name = (char*) HTList_nextObject(ptr);
    while (ptr != NULL)
    {
        HTNewsNode* parent;
        parent = HTNewsDir_findNodeNamed(dir, name);
        if (parent)
        {
            if (!node->refObjects)  node->refObjects = HTList_new();
            HTList_addObject (node->refObjects, parent);
        }
        name = (char*) HTList_nextObject(ptr);
    }
}

/* Added by MP. */
PRIVATE void HTNewsNode_setRefInfo_pass2 (HTNewsDir* dir, HTNewsNode* node)
{
    HTNewsNode* maxParent = NULL;
    HTList* ptr = node->refObjects;
    HTNewsNode* parent = NULL;
    if (node->fake)
        return;
    if (ptr != NULL)
        parent = (HTNewsNode*) HTList_nextObject(ptr);
    while (ptr != NULL)
    {
        if (!maxParent || maxParent->date < parent->date)
            maxParent = parent;
        parent = (HTNewsNode*) HTList_nextObject(ptr);
    }
    if (maxParent)
    {
        if (!HTNewsNode_isAncestor(node, maxParent))  /* better be careful */
            HTNewsNode_linkRef (maxParent, node);
    }
    else
    {
        char* refSubject;
        BOOL re;

        /* Here is the only place we REALLY have to check for circular */
        /* references. It is normally possible that a node refers to */
        /* orphan node and both have the same subject. In this situation */
        /* we can't make the orphan to refer to it's child. Without checking */
        /* for circular references this is likely to happen here. */

        refSubject = UnReSubject(node->subject);
        re = (strcasecomp(refSubject, node->subject) != 0);
        if (re)
            parent = HTNewsDir_findNodeWithSubject(dir, refSubject, 
                FNWS_MIN | FNWS_NOTFAKE, node);
        if (!parent || HTNewsNode_isAncestor(node, parent))
            parent = HTNewsDir_findNodeWithSubject(dir, refSubject,
                FNWS_MIN | FNWS_ONLYFAKE, node);
        if (!parent && re)
        {
            parent = HTNewsDir_findNodeWithSubject(dir, node->subject, 
                FNWS_MIN | FNWS_ONLYFAKE, node);
        }
    
        if (!parent) parent = HTNewsDir_addFakeElement (dir, refSubject, NULL);
	if (parent) {
	    HTNewsNode_linkRef (parent, node);
	    if (parent->refChildren > 1) /* Multi-children fake node visible */
		parent->show = YES;
	}
    }
}

/*
** Added by MP.
*/
#if 0
PRIVATE void HTNewsNode_setRefInfo_pass3 (HTNewsDir* dir, HTNewsNode* node)
{
    HTNewsNode* parent = NULL;
    char* refSubject;
    BOOL re;

    if (node->fake || node->refParent)
        return;  /* This is only for nodes not handled in pass 2 */
    
    /* Here is the only place we REALLY have to check for circular */
    /* references. It is normally possible that a node refers to */
    /* orphan node and both have the same subject. In this situation */
    /* we can't make the orphan to refer to it's child. Without checking */
    /* for circular references this is likely to happen here. */

    refSubject = UnReSubject(node->subject);
    re = (strcasecomp(refSubject, node->subject) != 0);
    if (re)
        parent = HTNewsDir_findNodeWithSubject(dir, refSubject, 
            FNWS_MIN | FNWS_NOTFAKE, node);
    if (!parent || HTNewsNode_isAncestor(node, parent))
        parent = HTNewsDir_findNodeWithSubject(dir, refSubject,
            FNWS_MIN | FNWS_ONLYFAKE, node);
    if (!parent && re)
    {
        parent = HTNewsDir_findNodeWithSubject(dir, node->subject, 
            FNWS_MIN | FNWS_ONLYFAKE, node);
    }
    
    if (!parent) parent = HTNewsDir_addFakeElement (dir, refSubject, NULL);
    if (parent) {
	HTNewsNode_linkRef (parent, node);
	if (parent->refChildren > 1)  	 /* multi-children fake node visible */
	    parent->show = YES;
    }
}
#else
PRIVATE void HTNewsNode_setRefInfo_pass3 (HTNewsDir* dir, HTNewsNode* node)
{
    if (!node->fake)
        node->refLevel = HTNewsNode_refLevel(node);
}
#endif

/* Added by MP. */
PRIVATE int HTNewsNode_compareRefThread (HTNewsNode* node1, HTNewsNode* node2)
{
    int level1 = node1->refLevel;
    int level2 = node2->refLevel;
    int level = HTMAX(level1, level2);
    int i;
    HTNewsNode* parent1;
    HTNewsNode* parent2;
    int diff = 0;
    for (i = level; i >= 0; i--)
    {
        parent1 = (i < level1 ? parent1->refParent : node1);
        parent2 = (i < level2 ? parent2->refParent : node2);
        if (parent1 == parent2)
            return diff;  /* related messages (in same subtree) */
        else
        {
            time_t date1 = (i > level1 ? 0 : HTNewsNode_getDate(parent1, YES));
            time_t date2 = (i > level2 ? 0 : HTNewsNode_getDate(parent2, YES));
            diff = date1 - date2;
            if (diff == 0)
            {
                int idx1 = (i > level1 ? 0 : HTNewsNode_getIndex(parent1, YES));
                int idx2 = (i > level2 ? 0 : HTNewsNode_getIndex(parent2, YES));
                diff = idx1 - idx2;
            }
        }
    }
    return diff;  /* completely unrelated messages */
}

/*
**	Output an element in HTML
**	Returns YES if OK, else NO
*/
PRIVATE BOOL HTNewsNode_print (HTNewsDir * dir, HTNewsNode * node)
{
    if (node && node->show) {
	HTStructured *target = dir->target;
	char  * escaped;
    
	HTNewsDir_addLevelTags (dir, node->refLevel);  /* Added by MP. */
	START(HTML_LI);

	/* Start the anchor and put the subject as anchor text */
	/*  Changed by MP to allow nodes without names */
	if (!node->fake && node->name && node->subject)  {
	    escaped = HTEscape(node->name, URL_XPALPHAS);
	    HTStartAnchor(target, NULL, escaped);
	}
	if (node->subject) PUTS(node->subject);
	if (!node->fake && node->name && node->subject) {
	    END(HTML_A);
	    HT_FREE(escaped);
	}

	/* From field */
	if (node->from)  {
	    PUTS (" by ");  /* Changed by MP. */
	    PUTS(node->from);
	}

	/*  In group listing, put number of groups in the set; added by MP. */
	if (node->name && strrchr(node->name, '*')) {
	    char buf[16];
	    sprintf (buf, " (%d groups)", node->refChildren);
	    PUTS (buf);
	}
    }
    return YES;
}

/* ------------------------------------------------------------------------- */
/*				DIRECTORY MANAGEMENT 			     */
/* ------------------------------------------------------------------------- */