hi_util_kmap.c

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/*
*
*  kmap.c  -  a generic map library - maps key + data pairs
*  
*  Uses Lexical Keyword Trie 
*    The tree uses linked lists to build the finite automata
*
*  MapKeyFind(): Performs a setwise strcmp() equivalant.
*
*  Notes:
*
*  Keys may be ascii or binary, both may be of random sizes.
*  Each key may be a different size, or all one size.
*  Fast dictionary lookup, proportional to the length of the key,
*  and independent of the number of keys in the table.
*  May use more memory than a hash table, depends.
*  Memory is allocated as needed, so none is wasted.
*   
*  Copyright (C) 2002 Marc Norton
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "hi_util_kmap.h"
#include "hi_util_xmalloc.h"

//#define MEMASSERT(p) if(!p){printf("KMAP-No Memory: File: %s Line:%d!\n",__FILE__,__LINE__);exit(0);}

#define MEMASSERT(p) 
#define LOWERCASE tolower

/*
*
*/
static void * s_malloc( int n )
{
    void * p;
    
    p = xmalloc( n );
    
    MEMASSERT(p);
    
    return p;
}

/*
*
*/
static void s_free( void * p )
{
    if( p ) xfree( p );
}
/*
*
*/
KMAP * KMapNew( void (*userfree)(void*p) )
{
    KMAP * km = (KMAP*) s_malloc( sizeof(KMAP) );
    
    if( !km ) return 0;
    
    memset(km, 0, sizeof(KMAP));  
    
    km->userfree = userfree;
    
    return km;
}
/*
*
*/
void KMapSetNoCase( KMAP * km, int flag )
{
    km->nocase = flag;
}

/*
*   Free the list of key+data pair nodes - used by findfirst/next
*/
static int KMapFreeNodeList(KMAP * km )
{
    KEYNODE * k, *kold;
    
    for( k=km->keylist; k; )
    {
        if( k->key )
        {
            s_free( k->key );
        }
        if( km->userfree && k->userdata )
        {
            km->userfree( k->userdata ); 
        }
        kold = k;
        k = k->next;
        s_free(kold);
    }
    
    return 0;
}
/*
*     Recursively walk and free nodes
*/
static void KMapFreeNode( KMAP * km, KMAPNODE * r)
{
    if( r->sibling )
    {
        KMapFreeNode( km, r->sibling );
    }
    
    if( r->child )
    {
        KMapFreeNode( km, r->child );
    }
    
    s_free( r );
} 
/*
*  Free the KMAP and all of it's memory and nodes
*/
void KMapDelete( KMAP * km )
{
    KMAPNODE * r;
    int        i;
    
    /* Free the tree - on root node at a time */
    for(i=0;i<256;i++)
    {
        r = km->root[i];
        if( r )
        { 
            KMapFreeNode(km,r); 
        }
    }
    
    /* Free the node list */
    KMapFreeNodeList( km );
    
    s_free(km);
}

/*
*  Add key + data pair to the linked list of nodes
*/
static KEYNODE *  KMapAddKeyNode(KMAP * km,void * key, int n, void * userdata )
{
    KEYNODE * knode = (KEYNODE*) s_malloc( sizeof(KEYNODE) );
    
    if( !knode || n < 0 ) 
        return 0;
    
    memset(knode, 0, sizeof(KEYNODE) );  
    
    knode->key = (unsigned char*)s_malloc(n); // Alloc the key space
    if( !knode->key ) 
    {
        free(knode);
        return 0;
    }
    
    memcpy(knode->key,key,n); // Copy the key
    knode->nkey     = n;
    knode->userdata = userdata;
    
    if( km->keylist ) // Insert at front of list 
    {
        knode->next = km->keylist;
        km->keylist = knode;
    }
    else
    {
        km->keylist = knode;
    }
    
    return knode;
}
/*
*  Create a character node
*/
static KMAPNODE * KMapCreateNode(KMAP * km)
{
    KMAPNODE * mn=(KMAPNODE*)s_malloc( sizeof(KMAPNODE) );
    
    if(!mn)
        return NULL;
    
    memset(mn,0,sizeof(KMAPNODE));
    
    km->nchars++;
    
    return mn;
}

/*
*    key : ptr to bytes of data used to identify this item
*          may be text string, or binary character sequence.
*    n   : > 0 number of bytes in the key
*          <=0 key is a null terminated  ascii string
*    userdata - ptr to data to associate with this key
*
*   returns:
*            -1 - no memory
*             1 - key already in table
*             0 - key added successfully
*/
int KMapAdd( KMAP *km, void * key, int n, void * userdata )
{
    int            i,ksize;
    int            type;
    unsigned char *P = (unsigned char *)key;
    KMAPNODE      *root;
    unsigned char  xkey[256];
    
    if( n <= 0 )
    {
        n = strlen( (char*) key );
        if( n > sizeof(xkey) )
            return -99;
    }
    
    if( km->nocase )
    {
        for(i=0;i<n;i++)
            xkey[i] = LOWERCASE( P[i] );
        P = xkey;
    }
    
    /* Save key size */
    ksize = n;
    
    //printf("adding key='%.*s'\n",n,P);
    
    /* Make sure we at least have a root character for the tree */
    if( !km->root[ *P ] )
    {
        root = KMapCreateNode(km);
        if( !root )
            return -1;
        km->root[ *P ] = root;
        root->nodechar = *P;
        
    }else{
        
        root = km->root[ *P ];
    }
    
    /* Walk exisitng Patterns */   
    while( n )
    {
        if( root->nodechar == *P )
        {
            //printf("matched char = %c, nleft = %d\n",*P,n-1);
            P++;
            n--;
            if( n && root->child )
            {
                root=root->child;   
            }
            else /* cannot continue */
            {
                type = 0; /* Expand the tree via the child */
                break; 
            }
        }
        else
        {
            if( root->sibling )
            {
                root=root->sibling;
            }
            else /* cannot continue */
            {
                type = 1; /* Expand the tree via the sibling */
                break; 
            }
        }
    }
    
    
    /* 
    * Add the next char of the Keyword, if any
    */
    if( n )
    {
        if( type == 0 )
        {
        /*
        *  Start with a new child to finish this Keyword 
            */
            //printf("added child branch nodechar = %c \n",*P);
            root->child= KMapCreateNode( km );
            if( !root->child )
                return -1;
            root=root->child;
            root->nodechar  = *P;
            P++;
            n--;
        }
        else
        { 
        /*
        *  Start a new sibling bracnch to finish this Keyword 
            */
            //printf("added sibling branch nodechar = %c \n",*P);
            root->sibling= KMapCreateNode( km );
            if( !root->sibling )
                return -1;
            root=root->sibling;
            root->nodechar  = *P;
            P++;
            n--;
        }
    }
    
    /*
    *    Finish the keyword as child nodes
    */
    while( n )
    {
        //printf("added child nodechar = %c \n",*P);
        root->child = KMapCreateNode(km);
        if( !root->child )
            return -1;
        root=root->child;
        root->nodechar  = *P;
        P++;
        n--;
    }
    
    /* 
    * Iteration support - Add this key/data to the linked list 
    * This allows us to do a findfirst/findnext search of 
    * all map nodes.
    */
    if( root->knode ) /* Already present */
        return 1;
    
    root->knode = KMapAddKeyNode( km, key, ksize, userdata );
    if( !root->knode )
        return -1;
    
    return 0;
}

/*
*  Exact Keyword Match - unique keys, with just one piece of 
*  'userdata' , for multiple entries, we could use a list
*  of 'userdata' nodes.
*/
void *  KMapFind( KMAP * ks, void * key, int n )
{
    unsigned char * T = (unsigned char *)key;
    KMAPNODE      * root;
    unsigned char   xkey[256];
    int             i;
    
    if( n <= 0 )
    {
        n = strlen( (char*)key );
        if( n > sizeof(xkey) )
            return 0;
        
    }
    if( ks->nocase )
    {
        for(i=0;i<n;i++)
            xkey[i] = LOWERCASE( T[i] );
        
        T = xkey;
    }
    //printf("finding key='%.*s'\n",n,T);
    
    /* Check if any keywords start with this character */
    root = ks->root[ *T ];
    if( !root ) return NULL;
    
    while( n )
    {
        if( root->nodechar == *T )
        {
            T++;
            n--;
            if( n && root->child )
            {
                root = root->child;   
            }
            else /* cannot continue -- match is over */
            {
                break; 
            }
        }
        else
        {
            if( root->sibling )
            {
                root = root->sibling;
            }
            else /* cannot continue */
            {
                break; 
            }
        }
    }
    
    if( !n )
    {
        if (root && root->knode)
            return root->knode->userdata; /* success */
    }
    
    return NULL;
}
/*
*
*/
KEYNODE * KMapFindFirstKey( KMAP * km )
{
    km->keynext = km->keylist;
    
    if(!km->keynext)
    {
        return NULL;
    }
    
    return km->keynext;
}
/*
*
*/
void * KMapFindFirst( KMAP * km )
{
    km->keynext = km->keylist;
    
    if(!km->keynext)
    {
        return NULL;
    }
    
    return km->keynext->userdata;
}
/*
*
*/
KEYNODE * KMapFindNextKey( KMAP * km )
{
    if( !km->keynext )
        return 0;
    
    km->keynext = km->keynext->next; 
    
    if( !km->keynext )
        return 0;
    
    return km->keynext;
}
/*
*
*/
void * KMapFindNext( KMAP * km )
{
    if( !km->keynext )
        return 0;
    
    km->keynext = km->keynext->next; 
    
    if( !km->keynext )
        return 0;
    
    return km->keynext->userdata;
}

#ifdef KMAP_MAIN
/*
*
*/
int main( int argc, char ** argv )
{
    int    i,n=10;
    KMAP * km;
    char * p;
    char   str[80];
    
    printf("usage: kmap nkeys (default=10)\n\n");
    
    km = KMapNew( free );  /* use 'free' to free 'userdata' */
    
    KMapSetNoCase(km,1);  //need to add xlat....
    
    if( argc > 1 )
    {
        n = atoi(argv[1]);
    }
    
    for(i=1;i<=n;i++)
    {
        sprintf(str,"KeyWord%d",i);
        KMapAdd( km, str, 0 /* strlen(str) */, strupr(strdup(str)) );
        printf("Adding Key=%s\n",str);
    }
    printf("xmem: %u bytes, %d chars\n",xmalloc_bytes(),km->nchars);
    
    printf("\nKey Find test...\n");
    for(i=1;i<=n;i++)
    {
        sprintf(str,"KeyWord%d",i);
        p = (char*) KMapFind( km, str,  0 /*strlen(str) */ );
        if(p)printf("key=%s, data=%*s\n",str,strlen(str),p);
        else printf("'%s' NOT found.\n",str);
    }
    
    KMapSetNoCase(km,0);  // this should fail all key searches
    printf("\nKey Find test2...\n");
    for(i=1;i<=n;i++)
    {
        sprintf(str,"KeyWord%d",i);
        p = (char*) KMapFind( km, str,  0 /*strlen(str) */ );
        if(p)printf("key=%s, data=%*s\n",str,strlen(str),p);
        else printf("'%s' NOT found.\n",str);
    }
    
    printf("\nKey FindFirst/Next test...\n");
    for(p = (char*) KMapFindFirst(km); p; p=(char*)KMapFindNext(km) )
        printf("data=%s\n",p);
    
    printf("\nKey FindFirst/Next test done.\n");
    
    KMapDelete( km );
    
    printf("xmem: %u bytes\n",xmalloc_bytes());
    
    printf("normal pgm finish.\n");
    
    return 0;
}

#endif