mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2024-12-22 05:35:25 +00:00
oops, forgot hash.[ch], Daniel
This commit is contained in:
Daniel Veillard
parent
978d57bbe4
commit
f113c5978e
460
src/hash.c
Normal file
460
src/hash.c
Normal file
@ -0,0 +1,460 @@
|
||||
/*
|
||||
* hash.c: chained hash tables
|
||||
*
|
||||
* Reference: Your favorite introductory book on algorithms
|
||||
*
|
||||
* Copyright (C) 2000 Bjorn Reese and 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: breese@users.sourceforge.net
|
||||
*/
|
||||
|
||||
#define IN_LIBXML
|
||||
|
||||
#include <string.h>
|
||||
#include "hash.h"
|
||||
|
||||
#define MAX_HASH_LEN 8
|
||||
|
||||
/* #define DEBUG_GROW */
|
||||
|
||||
/*
|
||||
* A single entry in the hash table
|
||||
*/
|
||||
typedef struct _xenHashEntry xenHashEntry;
|
||||
typedef xenHashEntry *xenHashEntryPtr;
|
||||
struct _xenHashEntry {
|
||||
struct _xenHashEntry *next;
|
||||
char *name;
|
||||
void *payload;
|
||||
int valid;
|
||||
};
|
||||
|
||||
/*
|
||||
* The entire hash table
|
||||
*/
|
||||
struct _xenHashTable {
|
||||
struct _xenHashEntry *table;
|
||||
int size;
|
||||
int nbElems;
|
||||
};
|
||||
|
||||
/*
|
||||
* xenHashComputeKey:
|
||||
* Calculate the hash key
|
||||
*/
|
||||
static unsigned long
|
||||
xenHashComputeKey(xenHashTablePtr table, const char *name) {
|
||||
unsigned long value = 0L;
|
||||
char ch;
|
||||
|
||||
if (name != NULL) {
|
||||
value += 30 * (*name);
|
||||
while ((ch = *name++) != 0) {
|
||||
value = value ^ ((value << 5) + (value >> 3) + (unsigned long)ch);
|
||||
}
|
||||
}
|
||||
return (value % table->size);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashCreate:
|
||||
* @size: the size of the hash table
|
||||
*
|
||||
* Create a new xenHashTablePtr.
|
||||
*
|
||||
* Returns the newly created object, or NULL if an error occured.
|
||||
*/
|
||||
xenHashTablePtr
|
||||
xenHashCreate(int size) {
|
||||
xenHashTablePtr table;
|
||||
|
||||
if (size <= 0)
|
||||
size = 256;
|
||||
|
||||
table = malloc(sizeof(xenHashTable));
|
||||
if (table) {
|
||||
table->size = size;
|
||||
table->nbElems = 0;
|
||||
table->table = malloc(size * sizeof(xenHashEntry));
|
||||
if (table->table) {
|
||||
memset(table->table, 0, size * sizeof(xenHashEntry));
|
||||
return(table);
|
||||
}
|
||||
free(table);
|
||||
}
|
||||
return(NULL);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashGrow:
|
||||
* @table: the hash table
|
||||
* @size: the new size of the hash table
|
||||
*
|
||||
* resize the hash table
|
||||
*
|
||||
* Returns 0 in case of success, -1 in case of failure
|
||||
*/
|
||||
static int
|
||||
xenHashGrow(xenHashTablePtr table, int size) {
|
||||
unsigned long key;
|
||||
int oldsize, i;
|
||||
xenHashEntryPtr iter, next;
|
||||
struct _xenHashEntry *oldtable;
|
||||
#ifdef DEBUG_GROW
|
||||
unsigned long nbElem = 0;
|
||||
#endif
|
||||
|
||||
if (table == NULL)
|
||||
return(-1);
|
||||
if (size < 8)
|
||||
return(-1);
|
||||
if (size > 8 * 2048)
|
||||
return(-1);
|
||||
|
||||
oldsize = table->size;
|
||||
oldtable = table->table;
|
||||
if (oldtable == NULL)
|
||||
return(-1);
|
||||
|
||||
table->table = malloc(size * sizeof(xenHashEntry));
|
||||
if (table->table == NULL) {
|
||||
table->table = oldtable;
|
||||
return(-1);
|
||||
}
|
||||
memset(table->table, 0, size * sizeof(xenHashEntry));
|
||||
table->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 table. 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 (oldtable[i].valid == 0)
|
||||
continue;
|
||||
key = xenHashComputeKey(table, oldtable[i].name);
|
||||
memcpy(&(table->table[key]), &(oldtable[i]), sizeof(xenHashEntry));
|
||||
table->table[key].next = NULL;
|
||||
}
|
||||
|
||||
for (i = 0; i < oldsize; i++) {
|
||||
iter = oldtable[i].next;
|
||||
while (iter) {
|
||||
next = iter->next;
|
||||
|
||||
/*
|
||||
* put back the entry in the new table
|
||||
*/
|
||||
|
||||
key = xenHashComputeKey(table, iter->name);
|
||||
if (table->table[key].valid == 0) {
|
||||
memcpy(&(table->table[key]), iter, sizeof(xenHashEntry));
|
||||
table->table[key].next = NULL;
|
||||
free(iter);
|
||||
} else {
|
||||
iter->next = table->table[key].next;
|
||||
table->table[key].next = iter;
|
||||
}
|
||||
|
||||
#ifdef DEBUG_GROW
|
||||
nbElem++;
|
||||
#endif
|
||||
|
||||
iter = next;
|
||||
}
|
||||
}
|
||||
|
||||
free(oldtable);
|
||||
|
||||
#ifdef DEBUG_GROW
|
||||
xmlGenericError(xmlGenericErrorContext,
|
||||
"xenHashGrow : from %d to %d, %d elems\n", oldsize, size, nbElem);
|
||||
#endif
|
||||
|
||||
return(0);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashFree:
|
||||
* @table: the hash table
|
||||
* @f: the deallocator function for items in the hash
|
||||
*
|
||||
* Free the hash @table and its contents. The userdata is
|
||||
* deallocated with @f if provided.
|
||||
*/
|
||||
void
|
||||
xenHashFree(xenHashTablePtr table, xenHashDeallocator f) {
|
||||
int i;
|
||||
xenHashEntryPtr iter;
|
||||
xenHashEntryPtr next;
|
||||
int inside_table = 0;
|
||||
int nbElems;
|
||||
|
||||
if (table == NULL)
|
||||
return;
|
||||
if (table->table) {
|
||||
nbElems = table->nbElems;
|
||||
for(i = 0; (i < table->size) && (nbElems > 0); i++) {
|
||||
iter = &(table->table[i]);
|
||||
if (iter->valid == 0)
|
||||
continue;
|
||||
inside_table = 1;
|
||||
while (iter) {
|
||||
next = iter->next;
|
||||
if ((f != NULL) && (iter->payload != NULL))
|
||||
f(iter->payload, iter->name);
|
||||
if (iter->name)
|
||||
free(iter->name);
|
||||
iter->payload = NULL;
|
||||
if (!inside_table)
|
||||
free(iter);
|
||||
nbElems--;
|
||||
inside_table = 0;
|
||||
iter = next;
|
||||
}
|
||||
inside_table = 0;
|
||||
}
|
||||
free(table->table);
|
||||
}
|
||||
free(table);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashAddEntry3:
|
||||
* @table: the hash table
|
||||
* @name: the name of the userdata
|
||||
* @userdata: a pointer to the userdata
|
||||
*
|
||||
* Add the @userdata to the hash @table. This can later be retrieved
|
||||
* by using @name. Duplicate entries generate errors.
|
||||
*
|
||||
* Returns 0 the addition succeeded and -1 in case of error.
|
||||
*/
|
||||
int
|
||||
xenHashAddEntry(xenHashTablePtr table, const char *name,
|
||||
void *userdata) {
|
||||
unsigned long key, len = 0;
|
||||
xenHashEntryPtr entry;
|
||||
xenHashEntryPtr insert;
|
||||
|
||||
if ((table == NULL) || (name == NULL))
|
||||
return(-1);
|
||||
|
||||
/*
|
||||
* Check for duplicate and insertion location.
|
||||
*/
|
||||
key = xenHashComputeKey(table, name);
|
||||
if (table->table[key].valid == 0) {
|
||||
insert = NULL;
|
||||
} else {
|
||||
for (insert = &(table->table[key]); insert->next != NULL;
|
||||
insert = insert->next) {
|
||||
if (!strcmp(insert->name, name))
|
||||
return(-1);
|
||||
len++;
|
||||
}
|
||||
if (!strcmp(insert->name, name))
|
||||
return(-1);
|
||||
}
|
||||
|
||||
if (insert == NULL) {
|
||||
entry = &(table->table[key]);
|
||||
} else {
|
||||
entry = malloc(sizeof(xenHashEntry));
|
||||
if (entry == NULL)
|
||||
return(-1);
|
||||
}
|
||||
|
||||
entry->name = strdup(name);
|
||||
entry->payload = userdata;
|
||||
entry->next = NULL;
|
||||
entry->valid = 1;
|
||||
|
||||
|
||||
if (insert != NULL)
|
||||
insert->next = entry;
|
||||
|
||||
table->nbElems++;
|
||||
|
||||
if (len > MAX_HASH_LEN)
|
||||
xenHashGrow(table, MAX_HASH_LEN * table->size);
|
||||
|
||||
return(0);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashUpdateEntry:
|
||||
* @table: the hash table
|
||||
* @name: the name of the userdata
|
||||
* @userdata: a pointer to the userdata
|
||||
* @f: the deallocator function for replaced item (if any)
|
||||
*
|
||||
* Add the @userdata to the hash @table. This can later be retrieved
|
||||
* by using @name. Existing entry for this tuple
|
||||
* will be removed and freed with @f if found.
|
||||
*
|
||||
* Returns 0 the addition succeeded and -1 in case of error.
|
||||
*/
|
||||
int
|
||||
xenHashUpdateEntry(xenHashTablePtr table, const char *name,
|
||||
void *userdata, xenHashDeallocator f) {
|
||||
unsigned long key;
|
||||
xenHashEntryPtr entry;
|
||||
xenHashEntryPtr insert;
|
||||
|
||||
if ((table == NULL) || name == NULL)
|
||||
return(-1);
|
||||
|
||||
/*
|
||||
* Check for duplicate and insertion location.
|
||||
*/
|
||||
key = xenHashComputeKey(table, name);
|
||||
if (table->table[key].valid == 0) {
|
||||
insert = NULL;
|
||||
} else {
|
||||
for (insert = &(table->table[key]); insert->next != NULL;
|
||||
insert = insert->next) {
|
||||
if (!strcmp(insert->name, name)) {
|
||||
if (f)
|
||||
f(insert->payload, insert->name);
|
||||
insert->payload = userdata;
|
||||
return(0);
|
||||
}
|
||||
}
|
||||
if (!strcmp(insert->name, name)) {
|
||||
if (f)
|
||||
f(insert->payload, insert->name);
|
||||
insert->payload = userdata;
|
||||
return(0);
|
||||
}
|
||||
}
|
||||
|
||||
if (insert == NULL) {
|
||||
entry = &(table->table[key]);
|
||||
} else {
|
||||
entry = malloc(sizeof(xenHashEntry));
|
||||
if (entry == NULL)
|
||||
return(-1);
|
||||
}
|
||||
|
||||
entry->name = strdup(name);
|
||||
entry->payload = userdata;
|
||||
entry->next = NULL;
|
||||
entry->valid = 1;
|
||||
table->nbElems++;
|
||||
|
||||
|
||||
if (insert != NULL) {
|
||||
insert->next = entry;
|
||||
}
|
||||
return(0);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashLookup:
|
||||
* @table: the hash table
|
||||
* @name: the name of the userdata
|
||||
*
|
||||
* Find the userdata specified by the (@name, @name2, @name3) tuple.
|
||||
*
|
||||
* Returns the a pointer to the userdata
|
||||
*/
|
||||
void *
|
||||
xenHashLookup(xenHashTablePtr table, const char *name) {
|
||||
unsigned long key;
|
||||
xenHashEntryPtr entry;
|
||||
|
||||
if (table == NULL)
|
||||
return(NULL);
|
||||
if (name == NULL)
|
||||
return(NULL);
|
||||
key = xenHashComputeKey(table, name);
|
||||
if (table->table[key].valid == 0)
|
||||
return(NULL);
|
||||
for (entry = &(table->table[key]); entry != NULL; entry = entry->next) {
|
||||
if (!strcmp(entry->name, name))
|
||||
return(entry->payload);
|
||||
}
|
||||
return(NULL);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashSize:
|
||||
* @table: the hash table
|
||||
*
|
||||
* Query the number of elements installed in the hash @table.
|
||||
*
|
||||
* Returns the number of elements in the hash table or
|
||||
* -1 in case of error
|
||||
*/
|
||||
int
|
||||
xenHashSize(xenHashTablePtr table) {
|
||||
if (table == NULL)
|
||||
return(-1);
|
||||
return(table->nbElems);
|
||||
}
|
||||
|
||||
/**
|
||||
* xenHashRemoveEntry:
|
||||
* @table: the hash table
|
||||
* @name: the name of the userdata
|
||||
* @f: the deallocator function for removed item (if any)
|
||||
*
|
||||
* Find the userdata specified by the @name and remove
|
||||
* it from the hash @table. Existing userdata for this tuple will be removed
|
||||
* and freed with @f.
|
||||
*
|
||||
* Returns 0 if the removal succeeded and -1 in case of error or not found.
|
||||
*/
|
||||
int
|
||||
xenHashRemoveEntry(xenHashTablePtr table, const char *name,
|
||||
xenHashDeallocator f) {
|
||||
unsigned long key;
|
||||
xenHashEntryPtr entry;
|
||||
xenHashEntryPtr prev = NULL;
|
||||
|
||||
if (table == NULL || name == NULL)
|
||||
return(-1);
|
||||
|
||||
key = xenHashComputeKey(table, name);
|
||||
if (table->table[key].valid == 0) {
|
||||
return(-1);
|
||||
} else {
|
||||
for (entry = &(table->table[key]); entry != NULL; entry = entry->next) {
|
||||
if (!strcmp(entry->name, name)) {
|
||||
if ((f != NULL) && (entry->payload != NULL))
|
||||
f(entry->payload, entry->name);
|
||||
entry->payload = NULL;
|
||||
if(entry->name)
|
||||
free(entry->name);
|
||||
if(prev) {
|
||||
prev->next = entry->next;
|
||||
free(entry);
|
||||
} else {
|
||||
if (entry->next == NULL) {
|
||||
entry->valid = 0;
|
||||
} else {
|
||||
entry = entry->next;
|
||||
memcpy(&(table->table[key]), entry, sizeof(xenHashEntry));
|
||||
free(entry);
|
||||
}
|
||||
}
|
||||
table->nbElems--;
|
||||
return(0);
|
||||
}
|
||||
prev = entry;
|
||||
}
|
||||
return(-1);
|
||||
}
|
||||
}
|
||||
|
||||
71
src/hash.h
Normal file
71
src/hash.h
Normal file
@ -0,0 +1,71 @@
|
||||
/*
|
||||
* Summary: Chained hash tables
|
||||
* Description: This module implements the hash table support used in
|
||||
* various places in the library.
|
||||
*
|
||||
* Copy: See Copyright for the status of this software.
|
||||
*
|
||||
* Author: Bjorn Reese <bjorn.reese@systematic.dk>
|
||||
*/
|
||||
|
||||
#ifndef __XEN_HASH_H__
|
||||
#define __XEN_HASH_H__
|
||||
|
||||
#ifdef __cplusplus
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
/*
|
||||
* The hash table.
|
||||
*/
|
||||
typedef struct _xenHashTable xenHashTable;
|
||||
typedef xenHashTable *xenHashTablePtr;
|
||||
|
||||
/*
|
||||
* function types:
|
||||
*/
|
||||
/**
|
||||
* xenHashDeallocator:
|
||||
* @payload: the data in the hash
|
||||
* @name: the name associated
|
||||
*
|
||||
* Callback to free data from a hash.
|
||||
*/
|
||||
typedef void (*xenHashDeallocator)(void *payload, char *name);
|
||||
|
||||
/*
|
||||
* Constructor and destructor.
|
||||
*/
|
||||
xenHashTablePtr xenHashCreate (int size);
|
||||
void
|
||||
xenHashFree (xenHashTablePtr table,
|
||||
xenHashDeallocator f);
|
||||
int xenHashSize (xenHashTablePtr table);
|
||||
|
||||
/*
|
||||
* Add a new entry to the hash table.
|
||||
*/
|
||||
int xenHashAddEntry (xenHashTablePtr table,
|
||||
const char *name,
|
||||
void *userdata);
|
||||
int xenHashUpdateEntry(xenHashTablePtr table,
|
||||
const char *name,
|
||||
void *userdata,
|
||||
xenHashDeallocator f);
|
||||
|
||||
/*
|
||||
* Remove an entry from the hash table.
|
||||
*/
|
||||
int xenHashRemoveEntry(xenHashTablePtr table,
|
||||
const char *name,
|
||||
xenHashDeallocator f);
|
||||
/*
|
||||
* Retrieve the userdata.
|
||||
*/
|
||||
void * xenHashLookup (xenHashTablePtr table,
|
||||
const char *name);
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
#endif
|
||||
#endif /* ! __XEN_HASH_H__ */
|
||||
Loading…
Reference in New Issue
Block a user