Changeset bc216a0 in mainline for uspace/lib/nic/src/nic_addr_db.c

Timestamp:

2012-08-07T22:13:44Z (12 years ago)

Author:

Adam Hraska <adam.hraska+hos@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

da68871a

Parents:

b17518e

Message:

Refactored any users of hash_table to use opaque void* keys instead of the cumbersome unsigned long[] keys. Switched from the ad hoc computations of hashes of multiple values to hash_combine().

File:

• uspace/lib/nic/src/nic_addr_db.c (modified) (12 diffs)

uspace/lib/nic/src/nic_addr_db.c

@@ -36 +36 @@
  */
 #include "nic_addr_db.h"
+#include "libarch/common.h"
 #include <assert.h>
 #include <stdlib.h>
@@ -43 +44 @@
 #include <adt/hash_table.h>
 #include <macros.h>
-
-/* The key count hash table field is not used. Use this dummy value. */
-#define KEY_CNT 1
-
-/**
- * Maximal length of addresses in the DB (in bytes).
- */
-#define NIC_ADDR_MAX_LENGTH             16
+#include <stdint.h>
+
 
 /**
@@ -56 +51 @@
  */
 typedef struct nic_addr_entry {
-        link_t link;
-        uint8_t addr[NIC_ADDR_MAX_LENGTH];
+        ht_link_t link;
+        uint8_t len;
+        uint8_t addr[1];
 } nic_addr_entry_t;
 
@@ -64 +60 @@
  * Hash table helper functions 
  */
-
-static bool nic_addr_match(unsigned long *key, size_t key_cnt, 
-        const link_t *item)
-{
-        uint8_t *addr = (uint8_t*)key;
-        nic_addr_entry_t *entry = member_to_inst(item, nic_addr_entry_t, link);
-
-        return 0 == bcmp(entry->addr, addr, NIC_ADDR_MAX_LENGTH);
-}
-
-static size_t nic_addr_key_hash(unsigned long *key)
-{
-        uint8_t *addr = (uint8_t*)key;
+typedef struct {
+        size_t len;
+        const uint8_t *addr;
+} addr_key_t;
+
+static bool nic_addr_key_equal(void *key_arg, const ht_link_t *item)
+{
+        addr_key_t *key = (addr_key_t*)key_arg;
+        nic_addr_entry_t *entry = member_to_inst(item, nic_addr_entry_t, link);
+        
+        return 0 == bcmp(entry->addr, key->addr, entry->len);
+}
+
+static size_t addr_hash(size_t len, const uint8_t *addr)
+{
         size_t hash = 0;
-
-        for (int i = NIC_ADDR_MAX_LENGTH - 1; i >= 0; --i) {
-                hash = (hash << 8) ^ (hash >> 24) ^ addr[i];
+        
+        for (size_t i = 0; i < len; ++i) {
+                hash = (hash << 5) ^ addr[i];
         }
         
@@ -86 +84 @@
 }
 
-static size_t nic_addr_hash(const link_t *item)
-{
-        nic_addr_entry_t *entry = member_to_inst(item, nic_addr_entry_t, link);
-        
-        unsigned long *key = (unsigned long*)entry->addr;
-        return nic_addr_key_hash(key);
-}
-
-static void nic_addr_removed(link_t *item)
+static size_t nic_addr_key_hash(void *k)
+{
+        addr_key_t *key = (addr_key_t*)k;
+        return addr_hash(key->len, key->addr);
+}
+
+static size_t nic_addr_hash(const ht_link_t *item)
+{
+        nic_addr_entry_t *entry = member_to_inst(item, nic_addr_entry_t, link);
+        return addr_hash(entry->len, entry->addr);
+}
+
+static void nic_addr_removed(ht_link_t *item)
 {
         nic_addr_entry_t *entry = member_to_inst(item, nic_addr_entry_t, link);
@@ -104 +106 @@
         .hash = nic_addr_hash,
         .key_hash = nic_addr_key_hash,
-        .match = nic_addr_match,
+        .key_equal = nic_addr_key_equal,
         .equal = 0,
         .remove_callback = nic_addr_removed
@@ -122 +124 @@
 {
         assert(db);
-        if (addr_len > NIC_ADDR_MAX_LENGTH) {
+        
+        if (addr_len > UCHAR_MAX)
                 return EINVAL;
-        }
-        
-        if (!hash_table_create(&db->set, 0, KEY_CNT, &set_ops))
+        
+        if (!hash_table_create(&db->set, 0, 0, &set_ops))
                 return ENOMEM;
         
@@ -152 +154 @@
 {
         assert(db);
-        nic_addr_db_clear(db);
         hash_table_destroy(&db->set);
 }
@@ -171 +172 @@
 {
         assert(db && addr);
-        /* Ugly type-punning hack. */
-        unsigned long *key = (unsigned long*)addr;
-        
-        if (hash_table_find(&db->set, key))
+
+        addr_key_t key = {
+                .len = db->addr_len,
+                .addr = addr
+        };
+        
+        if (hash_table_find(&db->set, &key))
                 return EEXIST;
         
-        nic_addr_entry_t *entry = malloc(sizeof(nic_addr_entry_t));
+        nic_addr_entry_t *entry = malloc(sizeof(nic_addr_entry_t) + db->addr_len - 1);
         if (entry == NULL) 
                 return ENOMEM;
-        
-        link_initialize(&entry->link);
-        
-        bzero(entry->addr, NIC_ADDR_MAX_LENGTH);
+
+        entry->len = (uint8_t) db->addr_len;
         memcpy(entry->addr, addr, db->addr_len);
         
@@ -202 +204 @@
 {
         assert(db && addr);
-        unsigned long *key = (unsigned long*)addr;
-        
-        link_t *item = hash_table_find(&db->set, key);
-        
-        if (item) {
-                hash_table_remove_item(&db->set, item);
+        
+        addr_key_t key = {
+                .len = db->addr_len,
+                .addr = addr
+        };
+        
+        if (hash_table_remove(&db->set, &key))
                 return EOK;
-        } else {
+        else
                 return ENOENT;
-        }
 }
 
@@ -225 +227 @@
 {
         assert(db && addr);
-        unsigned long *key = (unsigned long*)addr;
-        
-        return 0 != hash_table_find(&db->set, key);
+        
+        addr_key_t key = {
+                .len = db->addr_len,
+                .addr = addr
+        };
+        
+        return 0 != hash_table_find(&db->set, &key);
 }
 
@@ -241 +247 @@
  * Helper function for nic_addr_db_foreach
  */
-static bool nic_addr_db_fe_helper(link_t *item, void *arg) 
+static bool nic_addr_db_fe_helper(ht_link_t *item, void *arg) 
 {
         nic_addr_db_fe_arg_t *hs = (nic_addr_db_fe_arg_t *) arg;