From 4a2cd966f5ef267545ec57f2490e3ec14f47d70f Mon Sep 17 00:00:00 2001 From: Keith Derrick Date: Thu, 12 Apr 2012 11:43:34 -0700 Subject: [PATCH] Add NULL-safe lookup function New lh_table_lookup_ex() method protects itself against null pointers and invalid objects being passed in. --- linkhash.c | 17 ++++++++++++++--- linkhash.h | 12 ++++++++++++ 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/linkhash.c b/linkhash.c index 88c0a7c..ddedc12 100644 --- a/linkhash.c +++ b/linkhash.c @@ -3,6 +3,7 @@ * * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd. * Michael Clark + * Copyright (c) 2009 Hewlett-Packard Development Company, L.P. * * This library is free software; you can redistribute it and/or modify * it under the terms of the MIT license. See COPYING for details. @@ -174,11 +175,21 @@ struct lh_entry* lh_table_lookup_entry(struct lh_table *t, const void *k) const void* lh_table_lookup(struct lh_table *t, const void *k) { - struct lh_entry *e = lh_table_lookup_entry(t, k); - if(e) return e->v; - return NULL; + void *result; + lh_table_lookup_ex(t, k, &result); + return result; } +json_bool lh_table_lookup_ex(struct lh_table* t, const void* k, void **v) +{ + struct lh_entry *e = lh_table_lookup_entry(t, k); + if (e != NULL) { + if (v != NULL) *v = (void *)e->v; + return TRUE; /* key found */ + } + if (v != NULL) *v = NULL; + return FALSE; /* key not found */ +} int lh_table_delete_entry(struct lh_table *t, struct lh_entry *e) { diff --git a/linkhash.h b/linkhash.h index 9d89460..bbb5488 100644 --- a/linkhash.h +++ b/linkhash.h @@ -3,6 +3,7 @@ * * Copyright (c) 2004, 2005 Metaparadigm Pte. Ltd. * Michael Clark + * Copyright (c) 2009 Hewlett-Packard Development Company, L.P. * * This library is free software; you can redistribute it and/or modify * it under the terms of the MIT license. See COPYING for details. @@ -12,6 +13,8 @@ #ifndef _linkhash_h_ #define _linkhash_h_ +#include "json_object.h" + #ifdef __cplusplus extern "C" { #endif @@ -241,9 +244,18 @@ extern struct lh_entry* lh_table_lookup_entry(struct lh_table *t, const void *k) * @param t the table to lookup * @param k a pointer to the key to lookup * @return a pointer to the found value or NULL if it does not exist. + * @deprecated Use lh_table_lookup_ex instead. */ extern const void* lh_table_lookup(struct lh_table *t, const void *k); +/** + * Lookup a record in the table + * @param t the table to lookup + * @param k a pointer to the key to lookup + * @param v a pointer to a where to store the found value (set to NULL if it doesn't exist). + * @return whether or not the key was found + */ +extern json_bool lh_table_lookup_ex(struct lh_table *t, const void *k, void **v); /** * Delete a record from the table. -- 2.7.4