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remove unneeded data items from hashtable code

These items were used for statistics tracking, but no code at all
exists to consume them. By removing them we save

a) space
   because they counters required space, and did so in each and every
   json object

b) performance
   because calloc() needs to write less data and the counters are
   no longer maintained; cache performance can be better, load
   on OS main memory is lighter

We could conditionally enable/disable these counters, but I have not
done this they were really nowhere used and it looked more like a
left-over from the import of hashtable code.
tags/json-c-0.13-20171207
Rainer Gerhards 10 years ago
parent
commit
1ae4b50bde
3 changed files with 11 additions and 47 deletions
  1. +2
    -2
      json_object.c
  2. +6
    -11
      linkhash.c
  3. +3
    -34
      linkhash.h

+ 2
- 2
json_object.c View File

@@ -69,7 +69,7 @@ static struct lh_table *json_object_table;
static void json_object_init(void) __attribute__ ((constructor));
static void json_object_init(void) {
MC_DEBUG("json_object_init: creating object table\n");
json_object_table = lh_kptr_table_new(128, "json_object_table", NULL);
json_object_table = lh_kptr_table_new(128, NULL);
}

static void json_object_fini(void) __attribute__ ((destructor));
@@ -374,7 +374,7 @@ struct json_object* json_object_new_object(void)
jso->_delete = &json_object_object_delete;
jso->_to_json_string = &json_object_object_to_json_string;
jso->o.c_object = lh_kchar_table_new(JSON_OBJECT_DEF_HASH_ENTRIES,
NULL, &json_object_lh_entry_free);
&json_object_lh_entry_free);
if (!jso->o.c_object)
{
json_object_generic_delete(jso);


+ 6
- 11
linkhash.c View File

@@ -458,7 +458,7 @@ int lh_char_equal(const void *k1, const void *k2)
return (strcmp((const char*)k1, (const char*)k2) == 0);
}

struct lh_table* lh_table_new(int size, const char *name,
struct lh_table* lh_table_new(int size,
lh_entry_free_fn *free_fn,
lh_hash_fn *hash_fn,
lh_equal_fn *equal_fn)
@@ -470,7 +470,6 @@ struct lh_table* lh_table_new(int size, const char *name,
if(!t) lh_abort("lh_table_new: calloc failed\n");
t->count = 0;
t->size = size;
t->name = name;
t->table = (struct lh_entry*)calloc(size, sizeof(struct lh_entry));
if(!t->table) lh_abort("lh_table_new: calloc failed\n");
t->free_fn = free_fn;
@@ -480,16 +479,16 @@ struct lh_table* lh_table_new(int size, const char *name,
return t;
}

struct lh_table* lh_kchar_table_new(int size, const char *name,
struct lh_table* lh_kchar_table_new(int size,
lh_entry_free_fn *free_fn)
{
return lh_table_new(size, name, free_fn, char_hash_fn, lh_char_equal);
return lh_table_new(size, free_fn, char_hash_fn, lh_char_equal);
}

struct lh_table* lh_kptr_table_new(int size, const char *name,
struct lh_table* lh_kptr_table_new(int size,
lh_entry_free_fn *free_fn)
{
return lh_table_new(size, name, free_fn, lh_ptr_hash, lh_ptr_equal);
return lh_table_new(size, free_fn, lh_ptr_hash, lh_ptr_equal);
}

void lh_table_resize(struct lh_table *t, int new_size)
@@ -497,7 +496,7 @@ void lh_table_resize(struct lh_table *t, int new_size)
struct lh_table *new_t;
struct lh_entry *ent;

new_t = lh_table_new(new_size, t->name, NULL, t->hash_fn, t->equal_fn);
new_t = lh_table_new(new_size, NULL, t->hash_fn, t->equal_fn);
ent = t->head;
while(ent) {
lh_table_insert(new_t, ent->k, ent->v);
@@ -508,7 +507,6 @@ void lh_table_resize(struct lh_table *t, int new_size)
t->size = new_size;
t->head = new_t->head;
t->tail = new_t->tail;
t->resizes++;
free(new_t);
}

@@ -529,14 +527,12 @@ int lh_table_insert_w_hash(struct lh_table *t, void *k, const void *v, const uns
{
unsigned long n;

t->inserts++;
if(t->count >= t->size * LH_LOAD_FACTOR) lh_table_resize(t, t->size * 2);

n = h % t->size;

while( 1 ) {
if(t->table[n].k == LH_EMPTY || t->table[n].k == LH_FREED) break;
t->collisions++;
if ((int)++n == t->size) n = 0;
}

@@ -568,7 +564,6 @@ struct lh_entry* lh_table_lookup_entry_w_hash(struct lh_table *t, const void *k,
unsigned long n = h % t->size;
int count = 0;

t->lookups++;
while( count < t->size ) {
if(t->table[n].k == LH_EMPTY) return NULL;
if(t->table[n].k != LH_FREED &&


+ 3
- 34
linkhash.h View File

@@ -110,36 +110,6 @@ struct lh_table {
*/
int count;

/**
* Number of collisions.
*/
int collisions;

/**
* Number of resizes.
*/
int resizes;

/**
* Number of lookups.
*/
int lookups;

/**
* Number of inserts.
*/
int inserts;

/**
* Number of deletes.
*/
int deletes;

/**
* Name of the hash table.
*/
const char *name;

/**
* The first entry.
*/
@@ -179,7 +149,6 @@ for(entry = table->head; entry && ((tmp = entry->next) || 1); entry = tmp)
* Create a new linkhash table.
* @param size initial table size. The table is automatically resized
* although this incurs a performance penalty.
* @param name the table name.
* @param free_fn callback function used to free memory for entries
* when lh_table_free or lh_table_delete is called.
* If NULL is provided, then memory for keys and values
@@ -192,7 +161,7 @@ for(entry = table->head; entry && ((tmp = entry->next) || 1); entry = tmp)
* and C strings respectively.
* @return a pointer onto the linkhash table.
*/
extern struct lh_table* lh_table_new(int size, const char *name,
extern struct lh_table* lh_table_new(int size,
lh_entry_free_fn *free_fn,
lh_hash_fn *hash_fn,
lh_equal_fn *equal_fn);
@@ -205,7 +174,7 @@ extern struct lh_table* lh_table_new(int size, const char *name,
* @param free_fn callback function used to free memory for entries.
* @return a pointer onto the linkhash table.
*/
extern struct lh_table* lh_kchar_table_new(int size, const char *name,
extern struct lh_table* lh_kchar_table_new(int size,
lh_entry_free_fn *free_fn);


@@ -217,7 +186,7 @@ extern struct lh_table* lh_kchar_table_new(int size, const char *name,
* @param free_fn callback function used to free memory for entries.
* @return a pointer onto the linkhash table.
*/
extern struct lh_table* lh_kptr_table_new(int size, const char *name,
extern struct lh_table* lh_kptr_table_new(int size,
lh_entry_free_fn *free_fn);




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