Mayank Grover | f3b7818 | 2017-12-19 13:31:30 +0530 | [diff] [blame] | 1 | |
| 2 | #include "libufdt.h" |
| 3 | #include "ufdt_util.h" |
| 4 | |
| 5 | /* |
| 6 | * BEGIN of Hash table internal implementations. |
| 7 | */ |
| 8 | |
| 9 | #define DICT_LIMIT_NUM 2 |
| 10 | #define DICT_LIMIT_DEN 3 |
| 11 | |
| 12 | static bool _ufdt_node_dict_is_too_full(struct ufdt_node_dict *dict) { |
| 13 | /* |
| 14 | * We say a dict is too full if it's DICT_LIMIT_NUM / DICT_LIMIT_DEN full. |
| 15 | */ |
| 16 | if (dict->num_used * DICT_LIMIT_DEN > dict->mem_size * DICT_LIMIT_NUM) |
| 17 | return true; |
| 18 | return false; |
| 19 | } |
| 20 | |
| 21 | /* |
| 22 | * If collision happened, use linear probing to find idx in the hash table. |
| 23 | */ |
| 24 | static int _ufdt_node_dict_find_index_by_name_len(struct ufdt_node **hash_table, |
| 25 | int size, const char *name, |
| 26 | int len) { |
| 27 | if (!name || !size) return -1; |
| 28 | /* |
| 29 | * All size should be 2^k for some k |
| 30 | */ |
| 31 | int hsh = get_hash_len(name, len); |
| 32 | int idx = hsh & (size - 1); |
| 33 | for (int cnt = 0; cnt < size; ++cnt) { |
| 34 | if (hash_table[idx] == NULL) return idx; |
| 35 | if (node_name_eq(hash_table[idx], name, len) == 1) return idx; |
| 36 | ++idx; |
| 37 | idx &= (size - 1); |
| 38 | } |
| 39 | return -1; |
| 40 | } |
| 41 | |
| 42 | static int _ufdt_node_dict_find_index_by_name(struct ufdt_node **hash_table, |
| 43 | int size, const char *name) { |
| 44 | return _ufdt_node_dict_find_index_by_name_len(hash_table, size, name, |
| 45 | dto_strlen(name)); |
| 46 | } |
| 47 | |
| 48 | static int _ufdt_node_dict_find_index_in_ht(struct ufdt_node **hash_table, |
| 49 | int size, struct ufdt_node *x) { |
| 50 | if (x == NULL) return -1; |
| 51 | return _ufdt_node_dict_find_index_by_name(hash_table, size, name_of(x)); |
| 52 | } |
| 53 | |
| 54 | /* |
| 55 | * END of Hash table internal implementations. |
| 56 | */ |
| 57 | |
| 58 | /* |
| 59 | * ufdt_node_dict methods. |
| 60 | */ |
| 61 | |
| 62 | struct ufdt_node_dict ufdt_node_dict_construct() { |
| 63 | struct ufdt_node_dict res; |
| 64 | res.mem_size = DTNL_INIT_SZ; |
| 65 | res.num_used = 0; |
| 66 | res.nodes = dto_malloc(DTNL_INIT_SZ * sizeof(struct ufdt_node *)); |
| 67 | if (res.nodes == NULL) { |
| 68 | res.mem_size = 0; |
| 69 | return res; |
| 70 | } |
| 71 | dto_memset(res.nodes, 0, DTNL_INIT_SZ * sizeof(struct ufdt_node *)); |
| 72 | return res; |
| 73 | } |
| 74 | |
| 75 | void ufdt_node_dict_destruct(struct ufdt_node_dict *dict) { |
| 76 | if (dict == NULL) return; |
| 77 | dto_free(dict->nodes); |
| 78 | dict->mem_size = dict->num_used = 0; |
| 79 | } |
| 80 | |
| 81 | static int ufdt_node_dict_resize(struct ufdt_node_dict *dict) { |
| 82 | if (dict == NULL) return -1; |
| 83 | |
| 84 | int new_size = dict->mem_size << 1; |
| 85 | |
| 86 | struct ufdt_node **new_nodes = |
| 87 | dto_malloc(new_size * sizeof(struct ufdt_node *)); |
| 88 | |
| 89 | dto_memset(new_nodes, 0, new_size * sizeof(struct ufdt_node *)); |
| 90 | |
| 91 | for (int i = 0; i < dict->mem_size; i++) { |
| 92 | struct ufdt_node *node = dict->nodes[i]; |
| 93 | if (node == NULL) continue; |
| 94 | int idx = _ufdt_node_dict_find_index_in_ht(new_nodes, new_size, node); |
| 95 | if (idx < 0) { |
| 96 | dto_error( |
| 97 | "failed to find new index in ufdt_node_dict resize for entry :%s:\n", |
| 98 | name_of(node)); |
| 99 | dto_free(new_nodes); |
| 100 | return -1; |
| 101 | } |
| 102 | new_nodes[idx] = node; |
| 103 | } |
| 104 | |
| 105 | dto_free(dict->nodes); |
| 106 | |
| 107 | dict->mem_size = new_size; |
| 108 | dict->nodes = new_nodes; |
| 109 | return 0; |
| 110 | } |
| 111 | |
| 112 | int ufdt_node_dict_add(struct ufdt_node_dict *dict, struct ufdt_node *node) { |
| 113 | if (node == NULL) return -1; |
| 114 | if (dict == NULL) return -1; |
| 115 | |
| 116 | int idx = _ufdt_node_dict_find_index_in_ht(dict->nodes, dict->mem_size, node); |
| 117 | if (idx < 0) { |
| 118 | dto_error("failed to find new index in ufdt_node_dict add for entry :%s:\n", |
| 119 | name_of(node)); |
| 120 | return -1; |
| 121 | } |
| 122 | |
| 123 | if (dict->nodes[idx] == NULL) ++dict->num_used; |
| 124 | dict->nodes[idx] = node; |
| 125 | |
| 126 | /* |
| 127 | * When the hash table is too full, double the size and rehashing. |
| 128 | */ |
| 129 | int err = 0; |
| 130 | if (_ufdt_node_dict_is_too_full(dict)) { |
| 131 | err = ufdt_node_dict_resize(dict); |
| 132 | } |
| 133 | |
| 134 | return err; |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * BEGIN of ufdt_dict searching related methods. |
| 139 | */ |
| 140 | |
| 141 | /* |
| 142 | * return a pointer to the hash table entry |
| 143 | */ |
| 144 | struct ufdt_node **ufdt_node_dict_find_len(struct ufdt_node_dict *dict, |
| 145 | const char *name, int len) { |
| 146 | if (dict == NULL) return NULL; |
| 147 | int idx = _ufdt_node_dict_find_index_by_name_len(dict->nodes, dict->mem_size, |
| 148 | name, len); |
| 149 | if (idx < 0) return NULL; |
| 150 | if (dict->nodes[idx] == NULL) return NULL; |
| 151 | return dict->nodes + idx; |
| 152 | } |
| 153 | |
| 154 | struct ufdt_node **ufdt_node_dict_find(struct ufdt_node_dict *dict, |
| 155 | const char *name) { |
| 156 | return ufdt_node_dict_find_len(dict, name, dto_strlen(name)); |
| 157 | } |
| 158 | |
| 159 | struct ufdt_node *ufdt_node_dict_find_node_len(struct ufdt_node_dict *dict, |
| 160 | const char *name, int len) { |
| 161 | struct ufdt_node **res = ufdt_node_dict_find_len(dict, name, len); |
| 162 | if (res == NULL) return NULL; |
| 163 | return *res; |
| 164 | } |
| 165 | |
| 166 | struct ufdt_node *ufdt_node_dict_find_node(struct ufdt_node_dict *dict, |
| 167 | const char *name) { |
| 168 | return ufdt_node_dict_find_node_len(dict, name, dto_strlen(name)); |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * END of ufdt_dict searching related methods. |
| 173 | */ |
| 174 | |
| 175 | void ufdt_node_dict_print(struct ufdt_node_dict *dict) { |
| 176 | struct ufdt_node **it; |
| 177 | for_each(it, dict) dto_print("%ld -> %s\n", it - dict->nodes, name_of(*it)); |
| 178 | } |