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Diffstat (limited to 'libnetdata/simple_hashtable.h')
| -rw-r--r-- | libnetdata/simple_hashtable.h | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/libnetdata/simple_hashtable.h b/libnetdata/simple_hashtable.h new file mode 100644 index 000000000..f6b6db906 --- /dev/null +++ b/libnetdata/simple_hashtable.h @@ -0,0 +1,396 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#ifndef NETDATA_SIMPLE_HASHTABLE_H +#define NETDATA_SIMPLE_HASHTABLE_H + +#ifndef XXH_INLINE_ALL +#define XXH_INLINE_ALL +#endif +#include "xxhash.h" + +typedef uint64_t SIMPLE_HASHTABLE_HASH; +#define SIMPLE_HASHTABLE_HASH_SECOND_HASH_SHIFTS 32 + +#ifndef SIMPLE_HASHTABLE_NAME +#define SIMPLE_HASHTABLE_NAME +#endif + +#ifndef SIMPLE_HASHTABLE_VALUE_TYPE +#define SIMPLE_HASHTABLE_VALUE_TYPE void +#endif + +// First layer of macro for token concatenation +#define CONCAT_INTERNAL(a, b) a ## b +// Second layer of macro, which ensures proper expansion +#define CONCAT(a, b) CONCAT_INTERNAL(a, b) + +// define names for all structures and structures +#define simple_hashtable_init_named CONCAT(simple_hashtable_init, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_destroy_named CONCAT(simple_hashtable_destroy, SIMPLE_HASHTABLE_NAME) + +#define simple_hashtable_slot_named CONCAT(simple_hashtable_slot, SIMPLE_HASHTABLE_NAME) +#define SIMPLE_HASHTABLE_SLOT_NAMED CONCAT(SIMPLE_HASHTABLE_SLOT, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_named CONCAT(simple_hashtable, SIMPLE_HASHTABLE_NAME) +#define SIMPLE_HASHTABLE_NAMED CONCAT(SIMPLE_HASHTABLE, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_resize_named CONCAT(simple_hashtable_resize, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_get_slot_named CONCAT(simple_hashtable_get_slot, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_del_slot_named CONCAT(simple_hashtable_del_slot, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_set_slot_named CONCAT(simple_hashtable_set_slot, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_first_read_only_named CONCAT(simple_hashtable_first_read_only, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_next_read_only_named CONCAT(simple_hashtable_next_read_only, SIMPLE_HASHTABLE_NAME) + +#define simple_hashtable_sorted_binary_search_named CONCAT(simple_hashtable_sorted_binary_search, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_add_value_sorted_named CONCAT(simple_hashtable_add_value_sorted, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_del_value_sorted_named CONCAT(simple_hashtable_del_value_sorted, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_replace_value_sorted_named CONCAT(simple_hashtable_replace_value_sorted, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_sorted_array_first_read_only_named CONCAT(simple_hashtable_sorted_array_first_read_only, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_sorted_array_next_read_only_named CONCAT(simple_hashtable_sorted_array_next_read_only, SIMPLE_HASHTABLE_NAME) + +typedef struct simple_hashtable_slot_named { + SIMPLE_HASHTABLE_HASH hash; + SIMPLE_HASHTABLE_VALUE_TYPE *data; +} SIMPLE_HASHTABLE_SLOT_NAMED; + +typedef struct simple_hashtable_named { + size_t resizes; + size_t searches; + size_t collisions; + size_t deletions; + size_t deleted; + size_t used; + size_t size; + SIMPLE_HASHTABLE_SLOT_NAMED *hashtable; + +#ifdef SIMPLE_HASHTABLE_SORT_FUNCTION + struct { + size_t used; + size_t size; + SIMPLE_HASHTABLE_VALUE_TYPE **array; + } sorted; +#endif +} SIMPLE_HASHTABLE_NAMED; + +#ifdef SIMPLE_HASHTABLE_SORT_FUNCTION +static inline size_t simple_hashtable_sorted_binary_search_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_VALUE_TYPE *value) { + size_t left = 0, right = ht->sorted.used; + + while (left < right) { + size_t mid = left + (right - left) / 2; + if (SIMPLE_HASHTABLE_SORT_FUNCTION(ht->sorted.array[mid], value) < 0) + left = mid + 1; + else + right = mid; + } + + return left; +} + +static inline void simple_hashtable_add_value_sorted_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_VALUE_TYPE *value) { + size_t index = simple_hashtable_sorted_binary_search_named(ht, value); + + // Ensure there's enough space in the sorted array + if (ht->sorted.used >= ht->sorted.size) { + size_t size = ht->sorted.size ? ht->sorted.size * 2 : 64; + SIMPLE_HASHTABLE_VALUE_TYPE **array = mallocz(size * sizeof(SIMPLE_HASHTABLE_VALUE_TYPE *)); + if(ht->sorted.array) { + memcpy(array, ht->sorted.array, ht->sorted.size * sizeof(SIMPLE_HASHTABLE_VALUE_TYPE *)); + freez(ht->sorted.array); + } + ht->sorted.array = array; + ht->sorted.size = size; + } + + // Use memmove to shift elements and create space for the new element + memmove(&ht->sorted.array[index + 1], &ht->sorted.array[index], (ht->sorted.used - index) * sizeof(SIMPLE_HASHTABLE_VALUE_TYPE *)); + + ht->sorted.array[index] = value; + ht->sorted.used++; +} + +static inline void simple_hashtable_del_value_sorted_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_VALUE_TYPE *value) { + size_t index = simple_hashtable_sorted_binary_search_named(ht, value); + + // Check if the value exists at the found index + assert(index < ht->sorted.used && ht->sorted.array[index] == value); + + // Use memmove to shift elements and close the gap + memmove(&ht->sorted.array[index], &ht->sorted.array[index + 1], (ht->sorted.used - index - 1) * sizeof(SIMPLE_HASHTABLE_VALUE_TYPE *)); + ht->sorted.used--; +} + +static inline void simple_hashtable_replace_value_sorted_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_VALUE_TYPE *old_value, SIMPLE_HASHTABLE_VALUE_TYPE *new_value) { + if(new_value == old_value) + return; + + size_t old_value_index = simple_hashtable_sorted_binary_search_named(ht, old_value); + assert(old_value_index < ht->sorted.used && ht->sorted.array[old_value_index] == old_value); + + int r = SIMPLE_HASHTABLE_SORT_FUNCTION(old_value, new_value); + if(r == 0) { + // Same value, so use the same index + ht->sorted.array[old_value_index] = new_value; + return; + } + + size_t new_value_index = simple_hashtable_sorted_binary_search_named(ht, new_value); + if(old_value_index == new_value_index) { + // Not the same value, but still at the same index + ht->sorted.array[old_value_index] = new_value; + return; + } + else if (old_value_index < new_value_index) { + // The old value is before the new value + size_t shift_start = old_value_index + 1; + size_t shift_end = new_value_index - 1; + size_t shift_size = shift_end - old_value_index; + + memmove(&ht->sorted.array[old_value_index], &ht->sorted.array[shift_start], shift_size * sizeof(SIMPLE_HASHTABLE_VALUE_TYPE *)); + ht->sorted.array[shift_end] = new_value; + } + else { + // The old value is after the new value + size_t shift_start = new_value_index; + size_t shift_end = old_value_index; + size_t shift_size = shift_end - new_value_index; + + memmove(&ht->sorted.array[new_value_index + 1], &ht->sorted.array[shift_start], shift_size * sizeof(SIMPLE_HASHTABLE_VALUE_TYPE *)); + ht->sorted.array[new_value_index] = new_value; + } +} + +static inline SIMPLE_HASHTABLE_VALUE_TYPE **simple_hashtable_sorted_array_first_read_only_named(SIMPLE_HASHTABLE_NAMED *ht) { + if (ht->sorted.used > 0) { + return &ht->sorted.array[0]; + } + return NULL; +} + +static inline SIMPLE_HASHTABLE_VALUE_TYPE **simple_hashtable_sorted_array_next_read_only_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_VALUE_TYPE **last) { + if (!last) return NULL; + + // Calculate the current position in the sorted array + size_t currentIndex = last - ht->sorted.array; + + // Proceed to the next element if it exists + if (currentIndex + 1 < ht->sorted.used) { + return &ht->sorted.array[currentIndex + 1]; + } + + // If no more elements, return NULL + return NULL; +} + +#define SIMPLE_HASHTABLE_SORTED_FOREACH_READ_ONLY(ht, var, type, name) \ + for (type **(var) = simple_hashtable_sorted_array_first_read_only ## name(ht); \ + var; \ + (var) = simple_hashtable_sorted_array_next_read_only ## name(ht, var)) + +#define SIMPLE_HASHTABLE_SORTED_FOREACH_READ_ONLY_VALUE(var) (*(var)) + +#else +static inline void simple_hashtable_add_value_sorted_named(SIMPLE_HASHTABLE_NAMED *ht __maybe_unused, SIMPLE_HASHTABLE_VALUE_TYPE *value __maybe_unused) { ; } +static inline void simple_hashtable_del_value_sorted_named(SIMPLE_HASHTABLE_NAMED *ht __maybe_unused, SIMPLE_HASHTABLE_VALUE_TYPE *value __maybe_unused) { ; } +static inline void simple_hashtable_replace_value_sorted_named(SIMPLE_HASHTABLE_NAMED *ht __maybe_unused, SIMPLE_HASHTABLE_VALUE_TYPE *old_value __maybe_unused, SIMPLE_HASHTABLE_VALUE_TYPE *new_value __maybe_unused) { ; } +#endif + +static void simple_hashtable_init_named(SIMPLE_HASHTABLE_NAMED *ht, size_t size) { + memset(ht, 0, sizeof(*ht)); + ht->size = size; + ht->hashtable = callocz(ht->size, sizeof(*ht->hashtable)); +} + +static void simple_hashtable_destroy_named(SIMPLE_HASHTABLE_NAMED *ht) { +#ifdef SIMPLE_HASHTABLE_SORT_FUNCTION + freez(ht->sorted.array); +#endif + + freez(ht->hashtable); + memset(ht, 0, sizeof(*ht)); +} + +static inline void simple_hashtable_resize_named(SIMPLE_HASHTABLE_NAMED *ht); + +#define SHTS_DATA_UNSET ((void *)NULL) +#define SHTS_DATA_DELETED ((void *)0x01) +#define SHTS_DATA_USERNULL ((void *)0x02) +#define SHTS_IS_UNSET(sl) ((sl)->data == SHTS_DATA_UNSET) +#define SHTS_IS_DELETED(sl) ((sl)->data == SHTS_DATA_DELETED) +#define SHTS_IS_USERNULL(sl) ((sl)->data == SHTS_DATA_USERNULL) +#define SIMPLE_HASHTABLE_SLOT_DATA(sl) ((SHTS_IS_UNSET(sl) || SHTS_IS_DELETED(sl) || SHTS_IS_USERNULL(sl)) ? NULL : (sl)->data) +#define SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(sl) ((SHTS_IS_UNSET(sl) || SHTS_IS_DELETED(sl)) ? NULL : (sl)->data) + +// IMPORTANT +// The pointer returned by this call is valid up to the next call of this function (or the resize one) +// If you need to cache something, cache the hash, not the slot pointer. +static inline SIMPLE_HASHTABLE_SLOT_NAMED *simple_hashtable_get_slot_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_HASH hash, bool resize) { + ht->searches++; + + size_t slot; + SIMPLE_HASHTABLE_SLOT_NAMED *sl; + SIMPLE_HASHTABLE_SLOT_NAMED *deleted; + + slot = hash % ht->size; + sl = &ht->hashtable[slot]; + deleted = SHTS_IS_DELETED(sl) ? sl : NULL; + if(likely(!SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(sl) || sl->hash == hash)) + return (SHTS_IS_UNSET(sl) && deleted) ? deleted : sl; + + ht->collisions++; + + if(unlikely(resize && (ht->size <= (ht->used << 1) || ht->used >= ht->size))) { + simple_hashtable_resize_named(ht); + + slot = hash % ht->size; + sl = &ht->hashtable[slot]; + deleted = (!deleted && SHTS_IS_DELETED(sl)) ? sl : deleted; + if(likely(!SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(sl) || sl->hash == hash)) + return (SHTS_IS_UNSET(sl) && deleted) ? deleted : sl; + + ht->collisions++; + } + + slot = ((hash >> SIMPLE_HASHTABLE_HASH_SECOND_HASH_SHIFTS) + 1) % ht->size; + sl = &ht->hashtable[slot]; + deleted = (!deleted && SHTS_IS_DELETED(sl)) ? sl : deleted; + + // Linear probing until we find it + while (SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(sl) && sl->hash != hash) { + slot = (slot + 1) % ht->size; // Wrap around if necessary + sl = &ht->hashtable[slot]; + deleted = (!deleted && SHTS_IS_DELETED(sl)) ? sl : deleted; + ht->collisions++; + } + + return (SHTS_IS_UNSET(sl) && deleted) ? deleted : sl; +} + +static inline bool simple_hashtable_del_slot_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_SLOT_NAMED *sl) { + if(SHTS_IS_UNSET(sl) || SHTS_IS_DELETED(sl)) + return false; + + ht->deletions++; + ht->deleted++; + + simple_hashtable_del_value_sorted_named(ht, SIMPLE_HASHTABLE_SLOT_DATA(sl)); + + sl->data = SHTS_DATA_DELETED; + return true; +} + +static inline void simple_hashtable_set_slot_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_SLOT_NAMED *sl, SIMPLE_HASHTABLE_HASH hash, SIMPLE_HASHTABLE_VALUE_TYPE *data) { + if(data == NULL) + data = SHTS_DATA_USERNULL; + + if(unlikely(data == SHTS_DATA_UNSET || data == SHTS_DATA_DELETED)) { + simple_hashtable_del_slot_named(ht, sl); + return; + } + + if(likely(SHTS_IS_UNSET(sl))) { + simple_hashtable_add_value_sorted_named(ht, data); + ht->used++; + } + + else if(unlikely(SHTS_IS_DELETED(sl))) { + ht->deleted--; + } + + else + simple_hashtable_replace_value_sorted_named(ht, SIMPLE_HASHTABLE_SLOT_DATA(sl), data); + + sl->hash = hash; + sl->data = data; +} + +// IMPORTANT +// this call invalidates all SIMPLE_HASHTABLE_SLOT_NAMED pointers +static inline void simple_hashtable_resize_named(SIMPLE_HASHTABLE_NAMED *ht) { + SIMPLE_HASHTABLE_SLOT_NAMED *old = ht->hashtable; + size_t old_size = ht->size; + + ht->resizes++; + ht->size = (ht->size << 1) - ((ht->size > 16) ? 1 : 0); + ht->hashtable = callocz(ht->size, sizeof(*ht->hashtable)); + ht->used = ht->deleted = 0; + for(size_t i = 0 ; i < old_size ; i++) { + if(!SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(&old[i])) + continue; + + SIMPLE_HASHTABLE_SLOT_NAMED *slot = simple_hashtable_get_slot_named(ht, old[i].hash, false); + *slot = old[i]; + ht->used++; + } + + freez(old); +} + +// ---------------------------------------------------------------------------- +// hashtable traversal, in read-only mode +// the hashtable should not be modified while the traversal is taking place + +static inline SIMPLE_HASHTABLE_SLOT_NAMED *simple_hashtable_first_read_only_named(SIMPLE_HASHTABLE_NAMED *ht) { + for(size_t i = 0; i < ht->used ;i++) { + SIMPLE_HASHTABLE_SLOT_NAMED *sl = &ht->hashtable[i]; + if(!SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(sl)) + return sl; + } + + return NULL; +} + +static inline SIMPLE_HASHTABLE_SLOT_NAMED *simple_hashtable_next_read_only_named(SIMPLE_HASHTABLE_NAMED *ht, SIMPLE_HASHTABLE_SLOT_NAMED *last) { + if (!last) return NULL; + + // Calculate the current position in the array + size_t currentIndex = last - ht->hashtable; + + // Iterate over the hashtable starting from the next element + for (size_t i = currentIndex + 1; i < ht->size; i++) { + SIMPLE_HASHTABLE_SLOT_NAMED *sl = &ht->hashtable[i]; + if (!SIMPLE_HASHTABLE_SLOT_UNSET_OR_DELETED(sl)) { + return sl; + } + } + + // If no more data slots are found, return NULL + return NULL; +} + +#define SIMPLE_HASHTABLE_FOREACH_READ_ONLY(ht, var, name) \ + for(struct simple_hashtable_slot ## name *(var) = simple_hashtable_first_read_only ## name(ht); \ + var; \ + (var) = simple_hashtable_next_read_only ## name(ht, var)) + +#define SIMPLE_HASHTABLE_FOREACH_READ_ONLY_VALUE(var) SIMPLE_HASHTABLE_SLOT_DATA(var) + +// ---------------------------------------------------------------------------- +// high level implementation + +#ifdef SIMPLE_HASHTABLE_SAMPLE_IMPLEMENTATION + +#define simple_hashtable_set_named CONCAT(simple_hashtable_set, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_get_named CONCAT(simple_hashtable_get, SIMPLE_HASHTABLE_NAME) +#define simple_hashtable_del_named CONCAT(simple_hashtable_del, SIMPLE_HASHTABLE_NAME) + +static inline SIMPLE_HASHTABLE_VALUE_TYPE *simple_hashtable_set_named(SIMPLE_HASHTABLE_NAMED *ht, void *key, size_t key_len, SIMPLE_HASHTABLE_VALUE_TYPE *data) { + XXH64_hash_t hash = XXH3_64bits(key, key_len); + SIMPLE_HASHTABLE_SLOT_NAMED *sl = simple_hashtable_get_slot_named(ht, hash, true); + simple_hashtable_set_slot_named(ht, sl, hash, data); + return SIMPLE_HASHTABLE_SLOT_DATA(sl); +} + +static inline SIMPLE_HASHTABLE_VALUE_TYPE *simple_hashtable_get_named(SIMPLE_HASHTABLE_NAMED *ht, void *key, size_t key_len, SIMPLE_HASHTABLE_VALUE_TYPE *data) { + XXH64_hash_t hash = XXH3_64bits(key, key_len); + SIMPLE_HASHTABLE_SLOT_NAMED *sl = simple_hashtable_get_slot_named(ht, hash, true); + return SIMPLE_HASHTABLE_SLOT_DATA(sl); +} + +static inline bool simple_hashtable_del_named(SIMPLE_HASHTABLE_NAMED *ht, void *key, size_t key_len, SIMPLE_HASHTABLE_VALUE_TYPE *data) { + XXH64_hash_t hash = XXH3_64bits(key, key_len); + SIMPLE_HASHTABLE_SLOT_NAMED *sl = simple_hashtable_get_slot_named(ht, hash, true); + return simple_hashtable_del_slot_named(ht, sl); +} + +#endif // SIMPLE_HASHTABLE_SAMPLE_IMPLEMENTATION + +#endif //NETDATA_SIMPLE_HASHTABLE_H |