dict.c - platform/external/libxml2 - Gitiles

 /*
  * dict.c: dictionary of reusable strings, just used to avoid allocation
  *         and freeing operations.
  *
  * Copyright (C) 2003 Daniel Veillard.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE AUTHORS AND
  * CONTRIBUTORS ACCEPT NO RESPONSIBILITY IN ANY CONCEIVABLE MANNER.
  *
  * Author: daniel@veillard.com
  */

 #define IN_LIBXML
 #include "libxml.h"

 #include <string.h>
 #include <libxml/tree.h>
 #include <libxml/dict.h>
 #include <libxml/xmlmemory.h>
 #include <libxml/xmlerror.h>
 #include <libxml/globals.h>

 #define MAX_HASH_LEN 4
 #define MIN_DICT_SIZE 128
 #define MAX_DICT_HASH 8 * 2048

 /* #define ALLOW_REMOVAL */
 /* #define DEBUG_GROW */

 /*
  * An entry in the dictionnary
  */
 typedef struct _xmlDictEntry xmlDictEntry;
 typedef xmlDictEntry *xmlDictEntryPtr;
 struct _xmlDictEntry {
     struct _xmlDictEntry *next;
     const xmlChar *name;
     int len;
     int valid;
 };

 typedef struct _xmlDictStrings xmlDictStrings;
 typedef xmlDictStrings *xmlDictStringsPtr;
 struct _xmlDictStrings {
     xmlDictStringsPtr next;
     xmlChar *free;
     xmlChar *end;
     int size;
     int nbStrings;
     xmlChar array[1];
 };
 /*
  * The entire dictionnary
  */
 struct _xmlDict {
     int ref_counter;

     struct _xmlDictEntry *dict;
     int size;
     int nbElems;
     xmlDictStringsPtr strings;

     struct _xmlDict *subdict;
 };

 /*
  * xmlDictAddString:
  * @dict: the dictionnary
  * @name: the name of the userdata
  * @len: the length of the name, if -1 it is recomputed
  *
  * Add the string to the array[s]
  *
  * Returns the pointer of the local string, or NULL in case of error.
  */
 static const xmlChar *
 xmlDictAddString(xmlDictPtr dict, const xmlChar *name, int namelen) {
     xmlDictStringsPtr pool;
     const xmlChar *ret;
     int size = 0; /* + sizeof(_xmlDictStrings) == 1024 */

     pool = dict->strings;
     while (pool != NULL) {
 	if (pool->end - pool->free > namelen)
 	    goto found_pool;
 	if (pool->size > size) size = pool->size;
 	pool = pool->next;
     }
     /*
      * Not found, need to allocate
      */
     if (pool == NULL) {
         if (size == 0) size = 1000;
 	else size *= 4; /* exponential growth */
         if (size < 4 * namelen)
 	    size = 4 * namelen; /* just in case ! */
 	pool = (xmlDictStringsPtr) xmlMalloc(sizeof(xmlDictStrings) + size);
 	if (pool == NULL)
 	    return(NULL);
 	pool->size = size;
 	pool->nbStrings = 0;
 	pool->free = &pool->array[0];
 	pool->end = &pool->array[size];
 	pool->next = dict->strings;
 	dict->strings = pool;
     }
 found_pool:
     ret = pool->free;
     memcpy(pool->free, name, namelen);
     pool->free += namelen;
     *(pool->free++) = 0;
     return(ret);
 }

 /*
  * xmlDictAddQString:
  * @dict: the dictionnary
  * @prefix: the prefix of the userdata
  * @name: the name of the userdata
  * @len: the length of the name, if -1 it is recomputed
  *
  * Add the QName to the array[s]
  *
  * Returns the pointer of the local string, or NULL in case of error.
  */
 static const xmlChar *
 xmlDictAddQString(xmlDictPtr dict, const xmlChar *prefix,
                  const xmlChar *name, int namelen)
 {
     xmlDictStringsPtr pool;
     const xmlChar *ret;
     int size = 0; /* + sizeof(_xmlDictStrings) == 1024 */
     int plen;

     if (prefix == NULL) return(xmlDictAddString(dict, name, namelen));
     plen = xmlStrlen(prefix);

     pool = dict->strings;
     while (pool != NULL) {
 	if (pool->end - pool->free > namelen)
 	    goto found_pool;
 	if (pool->size > size) size = pool->size;
 	pool = pool->next;
     }
     /*
      * Not found, need to allocate
      */
     if (pool == NULL) {
         if (size == 0) size = 1000;
 	else size *= 4; /* exponential growth */
         if (size < 4 * namelen)
 	    size = 4 * namelen; /* just in case ! */
 	pool = (xmlDictStringsPtr) xmlMalloc(sizeof(xmlDictStrings) + size);
 	if (pool == NULL)
 	    return(NULL);
 	pool->size = size;
 	pool->nbStrings = 0;
 	pool->free = &pool->array[0];
 	pool->end = &pool->array[size];
 	pool->next = dict->strings;
 	dict->strings = pool;
     }
 found_pool:
     ret = pool->free;
     memcpy(pool->free, prefix, plen);
     pool->free += plen;
     *(pool->free++) = ':';
     namelen -= plen + 1;
     memcpy(pool->free, name, namelen);
     pool->free += namelen;
     *(pool->free++) = 0;
     return(ret);
 }

 /*
  * xmlDictComputeKey:
  * Calculate the hash key
  */
 static unsigned long
 xmlDictComputeKey(const xmlChar *name, int namelen) {
     unsigned long value = 0L;

     if (name == NULL) return(0);
     value = *name;
     value <<= 5;
     if (namelen > 10) {
         value += name[namelen - 1];
         namelen = 10;
     }
     switch (namelen) {
         case 10: value += name[9];
         case 9: value += name[8];
         case 8: value += name[7];
         case 7: value += name[6];
         case 6: value += name[5];
         case 5: value += name[4];
         case 4: value += name[3];
         case 3: value += name[2];
         case 2: value += name[1];
         default: break;
     }
     return(value);
 }

 /*
  * xmlDictComputeQKey:
  * Calculate the hash key
  */
 static unsigned long
 xmlDictComputeQKey(const xmlChar *prefix, const xmlChar *name, int len)
 {
     unsigned long value = 0L;
     int plen;

     if (prefix == NULL)
         return(xmlDictComputeKey(name, len));

     plen = xmlStrlen(prefix);
     if (plen == 0)
 	value += 30 * (unsigned long) ':';
     else
 	value += 30 * (*prefix);

     if (len > 10) {
         value += name[len - (plen + 1 + 1)];
         len = 10;
 	if (plen > 10)
 	    plen = 10;
     }
     switch (plen) {
         case 10: value += prefix[9];
         case 9: value += prefix[8];
         case 8: value += prefix[7];
         case 7: value += prefix[6];
         case 6: value += prefix[5];
         case 5: value += prefix[4];
         case 4: value += prefix[3];
         case 3: value += prefix[2];
         case 2: value += prefix[1];
         case 1: value += prefix[0];
         default: break;
     }
     len -= plen;
     if (len > 0) {
         value += (unsigned long) ':';
 	len--;
     }
     switch (len) {
         case 10: value += name[9];
         case 9: value += name[8];
         case 8: value += name[7];
         case 7: value += name[6];
         case 6: value += name[5];
         case 5: value += name[4];
         case 4: value += name[3];
         case 3: value += name[2];
         case 2: value += name[1];
         case 1: value += name[0];
         default: break;
     }
     return(value);
 }

 /**
  * xmlDictCreate:
  *
  * Create a new dictionary
  *
  * Returns the newly created dictionnary, or NULL if an error occured.
  */
 xmlDictPtr
 xmlDictCreate(void) {
     xmlDictPtr dict;

     dict = xmlMalloc(sizeof(xmlDict));
     if (dict) {
         dict->ref_counter = 1;

         dict->size = MIN_DICT_SIZE;
 	dict->nbElems = 0;
         dict->dict = xmlMalloc(MIN_DICT_SIZE * sizeof(xmlDictEntry));
 	dict->strings = NULL;
 	dict->subdict = NULL;
         if (dict->dict) {
   	    memset(dict->dict, 0, MIN_DICT_SIZE * sizeof(xmlDictEntry));
   	    return(dict);
         }
         xmlFree(dict);
     }
     return(NULL);
 }

 /**
  * xmlDictCreateSub:
  * @sub: an existing dictionnary
  *
  * Create a new dictionary, inheriting strings from the read-only
  * dictionnary @sub. On lookup, strings are first searched in the
  * new dictionnary, then in @sub, and if not found are created in the
  * new dictionnary.
  *
  * Returns the newly created dictionnary, or NULL if an error occured.
  */
 xmlDictPtr
 xmlDictCreateSub(xmlDictPtr sub) {
     xmlDictPtr dict = xmlDictCreate();

     if ((dict != NULL) && (sub != NULL)) {
         dict->subdict = sub;
 	xmlDictReference(dict->subdict);
     }
     return(dict);
 }

 /**
  * xmlDictReference:
  * @dict: the dictionnary
  *
  * Increment the reference counter of a dictionary
  *
  * Returns 0 in case of success and -1 in case of error
  */
 int
 xmlDictReference(xmlDictPtr dict) {
     if (dict == NULL) return -1;
     dict->ref_counter++;
     return(0);
 }

 /**
  * xmlDictGrow:
  * @dict: the dictionnary
  * @size: the new size of the dictionnary
  *
  * resize the dictionnary
  *
  * Returns 0 in case of success, -1 in case of failure
  */
 static int
 xmlDictGrow(xmlDictPtr dict, int size) {
     unsigned long key;
     int oldsize, i;
     xmlDictEntryPtr iter, next;
     struct _xmlDictEntry *olddict;
 #ifdef DEBUG_GROW
     unsigned long nbElem = 0;
 #endif

     if (dict == NULL)
 	return(-1);
     if (size < 8)
         return(-1);
     if (size > 8 * 2048)
 	return(-1);

     oldsize = dict->size;
     olddict = dict->dict;
     if (olddict == NULL)
         return(-1);

     dict->dict = xmlMalloc(size * sizeof(xmlDictEntry));
     if (dict->dict == NULL) {
 	dict->dict = olddict;
 	return(-1);
     }
     memset(dict->dict, 0, size * sizeof(xmlDictEntry));
     dict->size = size;

     /*	If the two loops are merged, there would be situations where
 	a new entry needs to allocated and data copied into it from
 	the main dict. So instead, we run through the array twice, first
 	copying all the elements in the main array (where we can't get
 	conflicts) and then the rest, so we only free (and don't allocate)
     */
     for (i = 0; i < oldsize; i++) {
 	if (olddict[i].valid == 0)
 	    continue;
 	key = xmlDictComputeKey(olddict[i].name, olddict[i].len) % dict->size;
 	memcpy(&(dict->dict[key]), &(olddict[i]), sizeof(xmlDictEntry));
 	dict->dict[key].next = NULL;
 #ifdef DEBUG_GROW
 	nbElem++;
 #endif
     }

     for (i = 0; i < oldsize; i++) {
 	iter = olddict[i].next;
 	while (iter) {
 	    next = iter->next;

 	    /*
 	     * put back the entry in the new dict
 	     */

 	    key = xmlDictComputeKey(iter->name, iter->len) % dict->size;
 	    if (dict->dict[key].valid == 0) {
 		memcpy(&(dict->dict[key]), iter, sizeof(xmlDictEntry));
 		dict->dict[key].next = NULL;
 		dict->dict[key].valid = 1;
 		xmlFree(iter);
 	    } else {
 	    	iter->next = dict->dict[key].next;
 	    	dict->dict[key].next = iter;
 	    }

 #ifdef DEBUG_GROW
 	    nbElem++;
 #endif

 	    iter = next;
 	}
     }

     xmlFree(olddict);

 #ifdef DEBUG_GROW
     xmlGenericError(xmlGenericErrorContext,
 	    "xmlDictGrow : from %d to %d, %d elems\n", oldsize, size, nbElem);
 #endif

     return(0);
 }

 /**
  * xmlDictFree:
  * @dict: the dictionnary
  *
  * Free the hash @dict and its contents. The userdata is
  * deallocated with @f if provided.
  */
 void
 xmlDictFree(xmlDictPtr dict) {
     int i;
     xmlDictEntryPtr iter;
     xmlDictEntryPtr next;
     int inside_dict = 0;
     xmlDictStringsPtr pool, nextp;

     if (dict == NULL)
 	return;

     /* decrement the counter, it may be shared by a parser and docs */
     dict->ref_counter--;
     if (dict->ref_counter > 0) return;

     if (dict->subdict != NULL) {
         xmlDictFree(dict->subdict);
     }

     if (dict->dict) {
 	for(i = 0; ((i < dict->size) && (dict->nbElems > 0)); i++) {
 	    iter = &(dict->dict[i]);
 	    if (iter->valid == 0)
 		continue;
 	    inside_dict = 1;
 	    while (iter) {
 		next = iter->next;
 		if (!inside_dict)
 		    xmlFree(iter);
 		dict->nbElems--;
 		inside_dict = 0;
 		iter = next;
 	    }
 	    inside_dict = 0;
 	}
 	xmlFree(dict->dict);
     }
     pool = dict->strings;
     while (pool != NULL) {
         nextp = pool->next;
 	xmlFree(pool);
 	pool = nextp;
     }
     xmlFree(dict);
 }

 /**
  * xmlDictLookup:
  * @dict: the dictionnary
  * @name: the name of the userdata
  * @len: the length of the name, if -1 it is recomputed
  *
  * Add the @name to the dictionnary @dict if not present.
  *
  * Returns the internal copy of the name or NULL in case of internal error
  */
 const xmlChar *
 xmlDictLookup(xmlDictPtr dict, const xmlChar *name, int len) {
     unsigned long key, okey, nbi = 0;
     xmlDictEntryPtr entry;
     xmlDictEntryPtr insert;
     const xmlChar *ret;

     if ((dict == NULL) || (name == NULL))
 	return(NULL);

     if (len < 0)
         len = xmlStrlen(name);

     /*
      * Check for duplicate and insertion location.
      */
     okey = xmlDictComputeKey(name, len);
     key = okey % dict->size;
     if (dict->dict[key].valid == 0) {
 	insert = NULL;
     } else {
 	for (insert = &(dict->dict[key]); insert->next != NULL;
 	     insert = insert->next) {
 #ifdef __GNUC__
 	    if (insert->len == len) {
 		if (!memcmp(insert->name, name, len))
 		    return(insert->name);
 	    }
 #else
 	    if ((insert->len == len) &&
 	        (!xmlStrncmp(insert->name, name, len)))
 		return(insert->name);
 #endif
 	    nbi++;
 	}
 #ifdef __GNUC__
 	if (insert->len == len) {
 	    if (!memcmp(insert->name, name, len))
 		return(insert->name);
 	}
 #else
 	if ((insert->len == len) &&
 	    (!xmlStrncmp(insert->name, name, len)))
 	    return(insert->name);
 #endif
     }

     if (dict->subdict) {
 	key = okey % dict->subdict->size;
 	if (dict->subdict->dict[key].valid != 0) {
 	    xmlDictEntryPtr tmp;

 	    for (tmp = &(dict->subdict->dict[key]); tmp->next != NULL;
 		 tmp = tmp->next) {
 #ifdef __GNUC__
 		if (tmp->len == len) {
 		    if (!memcmp(tmp->name, name, len))
 			return(tmp->name);
 		}
 #else
 		if ((tmp->len == len) &&
 		    (!xmlStrncmp(tmp->name, name, len)))
 		    return(tmp->name);
 #endif
 		nbi++;
 	    }
 #ifdef __GNUC__
 	    if (tmp->len == len) {
 		if (!memcmp(tmp->name, name, len))
 		    return(tmp->name);
 	    }
 #else
 	    if ((tmp->len == len) &&
 		(!xmlStrncmp(tmp->name, name, len)))
 		return(tmp->name);
 #endif
 	}
 	key = okey % dict->size;
     }

     ret = xmlDictAddString(dict, name, len);
     if (ret == NULL)
         return(NULL);
     if (insert == NULL) {
 	entry = &(dict->dict[key]);
     } else {
 	entry = xmlMalloc(sizeof(xmlDictEntry));
 	if (entry == NULL)
 	     return(NULL);
     }
     entry->name = ret;
     entry->len = len;
     entry->next = NULL;
     entry->valid = 1;


     if (insert != NULL)
 	insert->next = entry;

     dict->nbElems++;

     if ((nbi > MAX_HASH_LEN) &&
         (dict->size <= ((MAX_DICT_HASH / 2) / MAX_HASH_LEN)))
 	xmlDictGrow(dict, MAX_HASH_LEN * 2 * dict->size);
     /* Note that entry may have been freed at this point by xmlDictGrow */

     return(ret);
 }

 /**
  * xmlDictExists:
  * @dict: the dictionnary
  * @name: the name of the userdata
  * @len: the length of the name, if -1 it is recomputed
  *
  * Check if the @name exists in the dictionnary @dict.
  *
  * Returns the internal copy of the name or NULL if not found.
  */
 const xmlChar *
 xmlDictExists(xmlDictPtr dict, const xmlChar *name, int len) {
     unsigned long key, okey, nbi = 0;
     xmlDictEntryPtr insert;

     if ((dict == NULL) || (name == NULL))
 	return(NULL);

     if (len < 0)
         len = xmlStrlen(name);

     /*
      * Check for duplicate and insertion location.
      */
     okey = xmlDictComputeKey(name, len);
     key = okey % dict->size;
     if (dict->dict[key].valid == 0) {
 	insert = NULL;
     } else {
 	for (insert = &(dict->dict[key]); insert->next != NULL;
 	     insert = insert->next) {
 #ifdef __GNUC__
 	    if (insert->len == len) {
 		if (!memcmp(insert->name, name, len))
 		    return(insert->name);
 	    }
 #else
 	    if ((insert->len == len) &&
 	        (!xmlStrncmp(insert->name, name, len)))
 		return(insert->name);
 #endif
 	    nbi++;
 	}
 #ifdef __GNUC__
 	if (insert->len == len) {
 	    if (!memcmp(insert->name, name, len))
 		return(insert->name);
 	}
 #else
 	if ((insert->len == len) &&
 	    (!xmlStrncmp(insert->name, name, len)))
 	    return(insert->name);
 #endif
     }

     if (dict->subdict) {
 	key = okey % dict->subdict->size;
 	if (dict->subdict->dict[key].valid != 0) {
 	    xmlDictEntryPtr tmp;

 	    for (tmp = &(dict->subdict->dict[key]); tmp->next != NULL;
 		 tmp = tmp->next) {
 #ifdef __GNUC__
 		if (tmp->len == len) {
 		    if (!memcmp(tmp->name, name, len))
 			return(tmp->name);
 		}
 #else
 		if ((tmp->len == len) &&
 		    (!xmlStrncmp(tmp->name, name, len)))
 		    return(tmp->name);
 #endif
 		nbi++;
 	    }
 #ifdef __GNUC__
 	    if (tmp->len == len) {
 		if (!memcmp(tmp->name, name, len))
 		    return(tmp->name);
 	    }
 #else
 	    if ((tmp->len == len) &&
 		(!xmlStrncmp(tmp->name, name, len)))
 		return(tmp->name);
 #endif
 	}
 	key = okey % dict->size;
     }

     /* not found */
     return(NULL);
 }

 /**
  * xmlDictQLookup:
  * @dict: the dictionnary
  * @prefix: the prefix
  * @name: the name
  *
  * Add the QName @prefix:@name to the hash @dict if not present.
  *
  * Returns the internal copy of the QName or NULL in case of internal error
  */
 const xmlChar *
 xmlDictQLookup(xmlDictPtr dict, const xmlChar *prefix, const xmlChar *name) {
     unsigned long okey, key, nbi = 0;
     xmlDictEntryPtr entry;
     xmlDictEntryPtr insert;
     const xmlChar *ret;
     int len;

     if ((dict == NULL) || (name == NULL))
 	return(NULL);

     len = xmlStrlen(name);
     if (prefix != NULL)
         len += 1 + xmlStrlen(prefix);

     /*
      * Check for duplicate and insertion location.
      */
     okey = xmlDictComputeQKey(prefix, name, len);
     key = okey % dict->size;
     if (dict->dict[key].valid == 0) {
 	insert = NULL;
     } else {
 	for (insert = &(dict->dict[key]); insert->next != NULL;
 	     insert = insert->next) {
 	    if ((insert->len == len) &&
 	        (xmlStrQEqual(prefix, name, insert->name)))
 		return(insert->name);
 	    nbi++;
 	}
 	if ((insert->len == len) &&
 	    (xmlStrQEqual(prefix, name, insert->name)))
 	    return(insert->name);
     }

     if (dict->subdict) {
 	key = okey % dict->subdict->size;
 	if (dict->subdict->dict[key].valid != 0) {
 	    xmlDictEntryPtr tmp;
 	    for (tmp = &(dict->subdict->dict[key]); tmp->next != NULL;
 		 tmp = tmp->next) {
 		if ((tmp->len == len) &&
 		    (xmlStrQEqual(prefix, name, tmp->name)))
 		    return(tmp->name);
 		nbi++;
 	    }
 	    if ((tmp->len == len) &&
 		(xmlStrQEqual(prefix, name, tmp->name)))
 		return(tmp->name);
 	}
 	key = okey % dict->size;
     }

     ret = xmlDictAddQString(dict, prefix, name, len);
     if (ret == NULL)
         return(NULL);
     if (insert == NULL) {
 	entry = &(dict->dict[key]);
     } else {
 	entry = xmlMalloc(sizeof(xmlDictEntry));
 	if (entry == NULL)
 	     return(NULL);
     }
     entry->name = ret;
     entry->len = len;
     entry->next = NULL;
     entry->valid = 1;

     if (insert != NULL)
 	insert->next = entry;

     dict->nbElems++;

     if ((nbi > MAX_HASH_LEN) &&
         (dict->size <= ((MAX_DICT_HASH / 2) / MAX_HASH_LEN)))
 	xmlDictGrow(dict, MAX_HASH_LEN * 2 * dict->size);
     /* Note that entry may have been freed at this point by xmlDictGrow */

     return(ret);
 }

 /**
  * xmlDictOwns:
  * @dict: the dictionnary
  * @str: the string
  *
  * check if a string is owned by the disctionary
  *
  * Returns 1 if true, 0 if false and -1 in case of error
  * -1 in case of error
  */
 int
 xmlDictOwns(xmlDictPtr dict, const xmlChar *str) {
     xmlDictStringsPtr pool;

     if ((dict == NULL) || (str == NULL))
 	return(-1);
     pool = dict->strings;
     while (pool != NULL) {
         if ((str >= &pool->array[0]) && (str <= pool->free))
 	    return(1);
 	pool = pool->next;
     }
     if (dict->subdict)
         return(xmlDictOwns(dict->subdict, str));
     return(0);
 }

 /**
  * xmlDictSize:
  * @dict: the dictionnary
  *
  * Query the number of elements installed in the hash @dict.
  *
  * Returns the number of elements in the dictionnary or
  * -1 in case of error
  */
 int
 xmlDictSize(xmlDictPtr dict) {
     if (dict == NULL)
 	return(-1);
     if (dict->subdict)
         return(dict->nbElems + dict->subdict->nbElems);
     return(dict->nbElems);
 }
	/*
	* dict.c: dictionary of reusable strings, just used to avoid allocation
	* and freeing operations.
	*
	* Copyright (C) 2003 Daniel Veillard.
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
	* MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE AUTHORS AND
	* CONTRIBUTORS ACCEPT NO RESPONSIBILITY IN ANY CONCEIVABLE MANNER.
	*
	* Author: daniel@veillard.com
	*/

	#define IN_LIBXML
	#include "libxml.h"

	#include <string.h>
	#include <libxml/tree.h>
	#include <libxml/dict.h>
	#include <libxml/xmlmemory.h>
	#include <libxml/xmlerror.h>
	#include <libxml/globals.h>

	#define MAX_HASH_LEN 4
	#define MIN_DICT_SIZE 128
	#define MAX_DICT_HASH 8 * 2048

	/* #define ALLOW_REMOVAL */
	/* #define DEBUG_GROW */

	/*
	* An entry in the dictionnary
	*/
	typedef struct _xmlDictEntry xmlDictEntry;
	typedef xmlDictEntry *xmlDictEntryPtr;
	struct _xmlDictEntry {
	struct _xmlDictEntry *next;
	const xmlChar *name;
	int len;
	int valid;
	};

	typedef struct _xmlDictStrings xmlDictStrings;
	typedef xmlDictStrings *xmlDictStringsPtr;
	struct _xmlDictStrings {
	xmlDictStringsPtr next;
	xmlChar *free;
	xmlChar *end;
	int size;
	int nbStrings;
	xmlChar array[1];
	};
	/*
	* The entire dictionnary
	*/
	struct _xmlDict {
	int ref_counter;

	struct _xmlDictEntry *dict;
	int size;
	int nbElems;
	xmlDictStringsPtr strings;

	struct _xmlDict *subdict;
	};

	/*
	* xmlDictAddString:
	* @dict: the dictionnary
	* @name: the name of the userdata
	* @len: the length of the name, if -1 it is recomputed
	*
	* Add the string to the array[s]
	*
	* Returns the pointer of the local string, or NULL in case of error.
	*/
	static const xmlChar *
	xmlDictAddString(xmlDictPtr dict, const xmlChar *name, int namelen) {
	xmlDictStringsPtr pool;
	const xmlChar *ret;
	int size = 0; /* + sizeof(_xmlDictStrings) == 1024 */

	pool = dict->strings;
	while (pool != NULL) {
	if (pool->end - pool->free > namelen)
	goto found_pool;
	if (pool->size > size) size = pool->size;
	pool = pool->next;
	}
	/*
	* Not found, need to allocate
	*/
	if (pool == NULL) {
	if (size == 0) size = 1000;
	else size = 4; / exponential growth */
	if (size < 4 * namelen)
	size = 4 * namelen; /* just in case ! */
	pool = (xmlDictStringsPtr) xmlMalloc(sizeof(xmlDictStrings) + size);
	if (pool == NULL)
	return(NULL);
	pool->size = size;
	pool->nbStrings = 0;
	pool->free = &pool->array[0];
	pool->end = &pool->array[size];
	pool->next = dict->strings;
	dict->strings = pool;
	}
	found_pool:
	ret = pool->free;
	memcpy(pool->free, name, namelen);
	pool->free += namelen;
	*(pool->free++) = 0;
	return(ret);
	}

	/*
	* xmlDictAddQString:
	* @dict: the dictionnary
	* @prefix: the prefix of the userdata
	* @name: the name of the userdata
	* @len: the length of the name, if -1 it is recomputed
	*
	* Add the QName to the array[s]
	*
	* Returns the pointer of the local string, or NULL in case of error.
	*/
	static const xmlChar *
	xmlDictAddQString(xmlDictPtr dict, const xmlChar *prefix,
	const xmlChar *name, int namelen)
	{
	xmlDictStringsPtr pool;
	const xmlChar *ret;
	int size = 0; /* + sizeof(_xmlDictStrings) == 1024 */
	int plen;

	if (prefix == NULL) return(xmlDictAddString(dict, name, namelen));
	plen = xmlStrlen(prefix);

	pool = dict->strings;
	while (pool != NULL) {
	if (pool->end - pool->free > namelen)
	goto found_pool;
	if (pool->size > size) size = pool->size;
	pool = pool->next;
	}
	/*
	* Not found, need to allocate
	*/
	if (pool == NULL) {
	if (size == 0) size = 1000;
	else size = 4; / exponential growth */
	if (size < 4 * namelen)
	size = 4 * namelen; /* just in case ! */
	pool = (xmlDictStringsPtr) xmlMalloc(sizeof(xmlDictStrings) + size);
	if (pool == NULL)
	return(NULL);
	pool->size = size;
	pool->nbStrings = 0;
	pool->free = &pool->array[0];
	pool->end = &pool->array[size];
	pool->next = dict->strings;
	dict->strings = pool;
	}
	found_pool:
	ret = pool->free;
	memcpy(pool->free, prefix, plen);
	pool->free += plen;
	*(pool->free++) = ':';
	namelen -= plen + 1;
	memcpy(pool->free, name, namelen);
	pool->free += namelen;
	*(pool->free++) = 0;
	return(ret);
	}

	/*
	* xmlDictComputeKey:
	* Calculate the hash key
	*/
	static unsigned long
	xmlDictComputeKey(const xmlChar *name, int namelen) {
	unsigned long value = 0L;

	if (name == NULL) return(0);
	value = *name;
	value <<= 5;
	if (namelen > 10) {
	value += name[namelen - 1];
	namelen = 10;
	}
	switch (namelen) {
	case 10: value += name[9];
	case 9: value += name[8];
	case 8: value += name[7];
	case 7: value += name[6];
	case 6: value += name[5];
	case 5: value += name[4];
	case 4: value += name[3];
	case 3: value += name[2];
	case 2: value += name[1];
	default: break;
	}
	return(value);
	}

	/*
	* xmlDictComputeQKey:
	* Calculate the hash key
	*/
	static unsigned long
	xmlDictComputeQKey(const xmlChar prefix, const xmlChar name, int len)
	{
	unsigned long value = 0L;
	int plen;

	if (prefix == NULL)
	return(xmlDictComputeKey(name, len));

	plen = xmlStrlen(prefix);
	if (plen == 0)
	value += 30 * (unsigned long) ':';
	else
	value += 30 * (*prefix);

	if (len > 10) {
	value += name[len - (plen + 1 + 1)];
	len = 10;
	if (plen > 10)
	plen = 10;
	}
	switch (plen) {
	case 10: value += prefix[9];
	case 9: value += prefix[8];
	case 8: value += prefix[7];
	case 7: value += prefix[6];
	case 6: value += prefix[5];
	case 5: value += prefix[4];
	case 4: value += prefix[3];
	case 3: value += prefix[2];
	case 2: value += prefix[1];
	case 1: value += prefix[0];
	default: break;
	}
	len -= plen;
	if (len > 0) {
	value += (unsigned long) ':';
	len--;
	}
	switch (len) {
	case 10: value += name[9];
	case 9: value += name[8];
	case 8: value += name[7];
	case 7: value += name[6];
	case 6: value += name[5];
	case 5: value += name[4];
	case 4: value += name[3];
	case 3: value += name[2];
	case 2: value += name[1];
	case 1: value += name[0];
	default: break;
	}
	return(value);
	}

	/**
	* xmlDictCreate:
	*
	* Create a new dictionary
	*
	* Returns the newly created dictionnary, or NULL if an error occured.
	*/
	xmlDictPtr
	xmlDictCreate(void) {
	xmlDictPtr dict;

	dict = xmlMalloc(sizeof(xmlDict));
	if (dict) {
	dict->ref_counter = 1;

	dict->size = MIN_DICT_SIZE;
	dict->nbElems = 0;
	dict->dict = xmlMalloc(MIN_DICT_SIZE * sizeof(xmlDictEntry));
	dict->strings = NULL;
	dict->subdict = NULL;
	if (dict->dict) {
	memset(dict->dict, 0, MIN_DICT_SIZE * sizeof(xmlDictEntry));
	return(dict);
	}
	xmlFree(dict);
	}
	return(NULL);
	}

	/**
	* xmlDictCreateSub:
	* @sub: an existing dictionnary
	*
	* Create a new dictionary, inheriting strings from the read-only
	* dictionnary @sub. On lookup, strings are first searched in the
	* new dictionnary, then in @sub, and if not found are created in the
	* new dictionnary.
	*
	* Returns the newly created dictionnary, or NULL if an error occured.
	*/
	xmlDictPtr
	xmlDictCreateSub(xmlDictPtr sub) {
	xmlDictPtr dict = xmlDictCreate();

	if ((dict != NULL) && (sub != NULL)) {
	dict->subdict = sub;
	xmlDictReference(dict->subdict);
	}
	return(dict);
	}

	/**
	* xmlDictReference:
	* @dict: the dictionnary
	*
	* Increment the reference counter of a dictionary
	*
	* Returns 0 in case of success and -1 in case of error
	*/
	int
	xmlDictReference(xmlDictPtr dict) {
	if (dict == NULL) return -1;
	dict->ref_counter++;
	return(0);
	}

	/**
	* xmlDictGrow:
	* @dict: the dictionnary
	* @size: the new size of the dictionnary
	*
	* resize the dictionnary
	*
	* Returns 0 in case of success, -1 in case of failure
	*/
	static int
	xmlDictGrow(xmlDictPtr dict, int size) {
	unsigned long key;
	int oldsize, i;
	xmlDictEntryPtr iter, next;
	struct _xmlDictEntry *olddict;
	#ifdef DEBUG_GROW
	unsigned long nbElem = 0;
	#endif

	if (dict == NULL)
	return(-1);
	if (size < 8)
	return(-1);
	if (size > 8 * 2048)
	return(-1);

	oldsize = dict->size;
	olddict = dict->dict;
	if (olddict == NULL)
	return(-1);

	dict->dict = xmlMalloc(size * sizeof(xmlDictEntry));
	if (dict->dict == NULL) {
	dict->dict = olddict;
	return(-1);
	}
	memset(dict->dict, 0, size * sizeof(xmlDictEntry));
	dict->size = size;

	/* If the two loops are merged, there would be situations where
	a new entry needs to allocated and data copied into it from
	the main dict. So instead, we run through the array twice, first
	copying all the elements in the main array (where we can't get
	conflicts) and then the rest, so we only free (and don't allocate)
	*/
	for (i = 0; i < oldsize; i++) {
	if (olddict[i].valid == 0)
	continue;
	key = xmlDictComputeKey(olddict[i].name, olddict[i].len) % dict->size;
	memcpy(&(dict->dict[key]), &(olddict[i]), sizeof(xmlDictEntry));
	dict->dict[key].next = NULL;
	#ifdef DEBUG_GROW
	nbElem++;
	#endif
	}

	for (i = 0; i < oldsize; i++) {
	iter = olddict[i].next;
	while (iter) {
	next = iter->next;

	/*
	* put back the entry in the new dict
	*/

	key = xmlDictComputeKey(iter->name, iter->len) % dict->size;
	if (dict->dict[key].valid == 0) {
	memcpy(&(dict->dict[key]), iter, sizeof(xmlDictEntry));
	dict->dict[key].next = NULL;
	dict->dict[key].valid = 1;
	xmlFree(iter);
	} else {
	iter->next = dict->dict[key].next;
	dict->dict[key].next = iter;
	}

	#ifdef DEBUG_GROW
	nbElem++;
	#endif

	iter = next;
	}
	}

	xmlFree(olddict);

	#ifdef DEBUG_GROW
	xmlGenericError(xmlGenericErrorContext,
	"xmlDictGrow : from %d to %d, %d elems\n", oldsize, size, nbElem);
	#endif

	return(0);
	}

	/**
	* xmlDictFree:
	* @dict: the dictionnary
	*
	* Free the hash @dict and its contents. The userdata is
	* deallocated with @f if provided.
	*/
	void
	xmlDictFree(xmlDictPtr dict) {
	int i;
	xmlDictEntryPtr iter;
	xmlDictEntryPtr next;
	int inside_dict = 0;
	xmlDictStringsPtr pool, nextp;

	if (dict == NULL)
	return;

	/* decrement the counter, it may be shared by a parser and docs */
	dict->ref_counter--;
	if (dict->ref_counter > 0) return;

	if (dict->subdict != NULL) {
	xmlDictFree(dict->subdict);
	}

	if (dict->dict) {
	for(i = 0; ((i < dict->size) && (dict->nbElems > 0)); i++) {
	iter = &(dict->dict[i]);
	if (iter->valid == 0)
	continue;
	inside_dict = 1;
	while (iter) {
	next = iter->next;
	if (!inside_dict)
	xmlFree(iter);
	dict->nbElems--;
	inside_dict = 0;
	iter = next;
	}
	inside_dict = 0;
	}
	xmlFree(dict->dict);
	}
	pool = dict->strings;
	while (pool != NULL) {
	nextp = pool->next;
	xmlFree(pool);
	pool = nextp;
	}
	xmlFree(dict);
	}

	/**
	* xmlDictLookup:
	* @dict: the dictionnary
	* @name: the name of the userdata
	* @len: the length of the name, if -1 it is recomputed
	*
	* Add the @name to the dictionnary @dict if not present.
	*
	* Returns the internal copy of the name or NULL in case of internal error
	*/
	const xmlChar *
	xmlDictLookup(xmlDictPtr dict, const xmlChar *name, int len) {
	unsigned long key, okey, nbi = 0;
	xmlDictEntryPtr entry;
	xmlDictEntryPtr insert;
	const xmlChar *ret;

	if ((dict == NULL) \|\| (name == NULL))
	return(NULL);

	if (len < 0)
	len = xmlStrlen(name);

	/*
	* Check for duplicate and insertion location.
	*/
	okey = xmlDictComputeKey(name, len);
	key = okey % dict->size;
	if (dict->dict[key].valid == 0) {
	insert = NULL;
	} else {
	for (insert = &(dict->dict[key]); insert->next != NULL;
	insert = insert->next) {
	#ifdef __GNUC__
	if (insert->len == len) {
	if (!memcmp(insert->name, name, len))
	return(insert->name);
	}
	#else
	if ((insert->len == len) &&
	(!xmlStrncmp(insert->name, name, len)))
	return(insert->name);
	#endif
	nbi++;
	}
	#ifdef __GNUC__
	if (insert->len == len) {
	if (!memcmp(insert->name, name, len))
	return(insert->name);
	}
	#else
	if ((insert->len == len) &&
	(!xmlStrncmp(insert->name, name, len)))
	return(insert->name);
	#endif
	}

	if (dict->subdict) {
	key = okey % dict->subdict->size;
	if (dict->subdict->dict[key].valid != 0) {
	xmlDictEntryPtr tmp;

	for (tmp = &(dict->subdict->dict[key]); tmp->next != NULL;
	tmp = tmp->next) {
	#ifdef __GNUC__
	if (tmp->len == len) {
	if (!memcmp(tmp->name, name, len))
	return(tmp->name);
	}
	#else
	if ((tmp->len == len) &&
	(!xmlStrncmp(tmp->name, name, len)))
	return(tmp->name);
	#endif
	nbi++;
	}
	#ifdef __GNUC__
	if (tmp->len == len) {
	if (!memcmp(tmp->name, name, len))
	return(tmp->name);
	}
	#else
	if ((tmp->len == len) &&
	(!xmlStrncmp(tmp->name, name, len)))
	return(tmp->name);
	#endif
	}
	key = okey % dict->size;
	}

	ret = xmlDictAddString(dict, name, len);
	if (ret == NULL)
	return(NULL);
	if (insert == NULL) {
	entry = &(dict->dict[key]);
	} else {
	entry = xmlMalloc(sizeof(xmlDictEntry));
	if (entry == NULL)
	return(NULL);
	}
	entry->name = ret;
	entry->len = len;
	entry->next = NULL;
	entry->valid = 1;


	if (insert != NULL)
	insert->next = entry;

	dict->nbElems++;

	if ((nbi > MAX_HASH_LEN) &&
	(dict->size <= ((MAX_DICT_HASH / 2) / MAX_HASH_LEN)))
	xmlDictGrow(dict, MAX_HASH_LEN * 2 * dict->size);
	/* Note that entry may have been freed at this point by xmlDictGrow */

	return(ret);
	}

	/**
	* xmlDictExists:
	* @dict: the dictionnary
	* @name: the name of the userdata
	* @len: the length of the name, if -1 it is recomputed
	*
	* Check if the @name exists in the dictionnary @dict.
	*
	* Returns the internal copy of the name or NULL if not found.
	*/
	const xmlChar *
	xmlDictExists(xmlDictPtr dict, const xmlChar *name, int len) {
	unsigned long key, okey, nbi = 0;
	xmlDictEntryPtr insert;

	if ((dict == NULL) \|\| (name == NULL))
	return(NULL);

	if (len < 0)
	len = xmlStrlen(name);

	/*
	* Check for duplicate and insertion location.
	*/
	okey = xmlDictComputeKey(name, len);
	key = okey % dict->size;
	if (dict->dict[key].valid == 0) {
	insert = NULL;
	} else {
	for (insert = &(dict->dict[key]); insert->next != NULL;
	insert = insert->next) {
	#ifdef __GNUC__
	if (insert->len == len) {
	if (!memcmp(insert->name, name, len))
	return(insert->name);
	}
	#else
	if ((insert->len == len) &&
	(!xmlStrncmp(insert->name, name, len)))
	return(insert->name);
	#endif
	nbi++;
	}
	#ifdef __GNUC__
	if (insert->len == len) {
	if (!memcmp(insert->name, name, len))
	return(insert->name);
	}
	#else
	if ((insert->len == len) &&
	(!xmlStrncmp(insert->name, name, len)))
	return(insert->name);
	#endif
	}

	if (dict->subdict) {
	key = okey % dict->subdict->size;
	if (dict->subdict->dict[key].valid != 0) {
	xmlDictEntryPtr tmp;

	for (tmp = &(dict->subdict->dict[key]); tmp->next != NULL;
	tmp = tmp->next) {
	#ifdef __GNUC__
	if (tmp->len == len) {
	if (!memcmp(tmp->name, name, len))
	return(tmp->name);
	}
	#else
	if ((tmp->len == len) &&
	(!xmlStrncmp(tmp->name, name, len)))
	return(tmp->name);
	#endif
	nbi++;
	}
	#ifdef __GNUC__
	if (tmp->len == len) {
	if (!memcmp(tmp->name, name, len))
	return(tmp->name);
	}
	#else
	if ((tmp->len == len) &&
	(!xmlStrncmp(tmp->name, name, len)))
	return(tmp->name);
	#endif
	}
	key = okey % dict->size;
	}

	/* not found */
	return(NULL);
	}

	/**
	* xmlDictQLookup:
	* @dict: the dictionnary
	* @prefix: the prefix
	* @name: the name
	*
	* Add the QName @prefix:@name to the hash @dict if not present.
	*
	* Returns the internal copy of the QName or NULL in case of internal error
	*/
	const xmlChar *
	xmlDictQLookup(xmlDictPtr dict, const xmlChar prefix, const xmlChar name) {
	unsigned long okey, key, nbi = 0;
	xmlDictEntryPtr entry;
	xmlDictEntryPtr insert;
	const xmlChar *ret;
	int len;

	if ((dict == NULL) \|\| (name == NULL))
	return(NULL);

	len = xmlStrlen(name);
	if (prefix != NULL)
	len += 1 + xmlStrlen(prefix);

	/*
	* Check for duplicate and insertion location.
	*/
	okey = xmlDictComputeQKey(prefix, name, len);
	key = okey % dict->size;
	if (dict->dict[key].valid == 0) {
	insert = NULL;
	} else {
	for (insert = &(dict->dict[key]); insert->next != NULL;
	insert = insert->next) {
	if ((insert->len == len) &&
	(xmlStrQEqual(prefix, name, insert->name)))
	return(insert->name);
	nbi++;
	}
	if ((insert->len == len) &&
	(xmlStrQEqual(prefix, name, insert->name)))
	return(insert->name);
	}

	if (dict->subdict) {
	key = okey % dict->subdict->size;
	if (dict->subdict->dict[key].valid != 0) {
	xmlDictEntryPtr tmp;
	for (tmp = &(dict->subdict->dict[key]); tmp->next != NULL;
	tmp = tmp->next) {
	if ((tmp->len == len) &&
	(xmlStrQEqual(prefix, name, tmp->name)))
	return(tmp->name);
	nbi++;
	}
	if ((tmp->len == len) &&
	(xmlStrQEqual(prefix, name, tmp->name)))
	return(tmp->name);
	}
	key = okey % dict->size;
	}

	ret = xmlDictAddQString(dict, prefix, name, len);
	if (ret == NULL)
	return(NULL);
	if (insert == NULL) {
	entry = &(dict->dict[key]);
	} else {
	entry = xmlMalloc(sizeof(xmlDictEntry));
	if (entry == NULL)
	return(NULL);
	}
	entry->name = ret;
	entry->len = len;
	entry->next = NULL;
	entry->valid = 1;

	if (insert != NULL)
	insert->next = entry;

	dict->nbElems++;

	if ((nbi > MAX_HASH_LEN) &&
	(dict->size <= ((MAX_DICT_HASH / 2) / MAX_HASH_LEN)))
	xmlDictGrow(dict, MAX_HASH_LEN * 2 * dict->size);
	/* Note that entry may have been freed at this point by xmlDictGrow */

	return(ret);
	}

	/**
	* xmlDictOwns:
	* @dict: the dictionnary
	* @str: the string
	*
	* check if a string is owned by the disctionary
	*
	* Returns 1 if true, 0 if false and -1 in case of error
	* -1 in case of error
	*/
	int
	xmlDictOwns(xmlDictPtr dict, const xmlChar *str) {
	xmlDictStringsPtr pool;

	if ((dict == NULL) \|\| (str == NULL))
	return(-1);
	pool = dict->strings;
	while (pool != NULL) {
	if ((str >= &pool->array[0]) && (str <= pool->free))
	return(1);
	pool = pool->next;
	}
	if (dict->subdict)
	return(xmlDictOwns(dict->subdict, str));
	return(0);
	}

	/**
	* xmlDictSize:
	* @dict: the dictionnary
	*
	* Query the number of elements installed in the hash @dict.
	*
	* Returns the number of elements in the dictionnary or
	* -1 in case of error
	*/
	int
	xmlDictSize(xmlDictPtr dict) {
	if (dict == NULL)
	return(-1);
	if (dict->subdict)
	return(dict->nbElems + dict->subdict->nbElems);
	return(dict->nbElems);
	}