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Diffstat (limited to 'innobase/ha/ha0ha.c')
-rw-r--r-- | innobase/ha/ha0ha.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/innobase/ha/ha0ha.c b/innobase/ha/ha0ha.c new file mode 100644 index 00000000000..3e4473126cf --- /dev/null +++ b/innobase/ha/ha0ha.c @@ -0,0 +1,317 @@ +/************************************************************************ +The hash table with external chains + +(c) 1994-1997 Innobase Oy + +Created 8/22/1994 Heikki Tuuri +*************************************************************************/ + +#include "ha0ha.h" +#ifdef UNIV_NONINL +#include "ha0ha.ic" +#endif + +#include "buf0buf.h" + +/***************************************************************** +Creates a hash table with >= n array cells. The actual number of cells is +chosen to be a prime number slightly bigger than n. */ + +hash_table_t* +ha_create( +/*======*/ + /* out, own: created table */ + ibool in_btr_search, /* in: TRUE if the hash table is used in + the btr_search module */ + ulint n, /* in: number of array cells */ + ulint n_mutexes, /* in: number of mutexes to protect the + hash table: must be a power of 2, or 0 */ + ulint mutex_level) /* in: level of the mutexes in the latching + order: this is used in the debug version */ +{ + hash_table_t* table; + ulint i; + + table = hash_create(n); + + if (n_mutexes == 0) { + if (in_btr_search) { + table->heap = mem_heap_create_in_btr_search(4096); + } else { + table->heap = mem_heap_create_in_buffer(4096); + } + + return(table); + } + + hash_create_mutexes(table, n_mutexes, mutex_level); + + table->heaps = mem_alloc(n_mutexes * sizeof(void*)); + + for (i = 0; i < n_mutexes; i++) { + if (in_btr_search) { + table->heaps[i] = mem_heap_create_in_btr_search(4096); + } else { + table->heaps[i] = mem_heap_create_in_buffer(4096); + } + } + + return(table); +} + +/***************************************************************** +Checks that a hash table node is in the chain. */ + +ibool +ha_node_in_chain( +/*=============*/ + /* out: TRUE if in chain */ + hash_cell_t* cell, /* in: hash table cell */ + ha_node_t* node) /* in: external chain node */ +{ + ha_node_t* node2; + + node2 = cell->node; + + while (node2 != NULL) { + + if (node2 == node) { + + return(TRUE); + } + + node2 = node2->next; + } + + return(FALSE); +} + +/***************************************************************** +Inserts an entry into a hash table. If an entry with the same fold number +is found, its node is updated to point to the new data, and no new node +is inserted. */ + +ibool +ha_insert_for_fold( +/*===============*/ + /* out: TRUE if succeed, FALSE if no more + memory could be allocated */ + hash_table_t* table, /* in: hash table */ + ulint fold, /* in: folded value of data; if a node with + the same fold value already exists, it is + updated to point to the same data, and no new + node is created! */ + void* data) /* in: data, must not be NULL */ +{ + hash_cell_t* cell; + ha_node_t* node; + ha_node_t* prev_node; + ulint hash; + + ut_ad(table && data); + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); + + hash = hash_calc_hash(fold, table); + + cell = hash_get_nth_cell(table, hash); + + prev_node = cell->node; + + while (prev_node != NULL) { + if (prev_node->fold == fold) { + + prev_node->data = data; + + return(TRUE); + } + + prev_node = prev_node->next; + } + + /* We have to allocate a new chain node */ + + node = mem_heap_alloc(hash_get_heap(table, fold), sizeof(ha_node_t)); + + if (node == NULL) { + /* It was a btr search type memory heap and at the moment + no more memory could be allocated: return */ + + ut_ad(hash_get_heap(table, fold)->type & MEM_HEAP_BTR_SEARCH); + + return(FALSE); + } + + ha_node_set_data(node, data); + node->fold = fold; + + node->next = NULL; + + prev_node = cell->node; + + if (prev_node == NULL) { + + cell->node = node; + + return(TRUE); + } + + while (prev_node->next != NULL) { + + prev_node = prev_node->next; + } + + prev_node->next = node; + + return(TRUE); +} + +/*************************************************************** +Deletes a hash node. */ + +void +ha_delete_hash_node( +/*================*/ + hash_table_t* table, /* in: hash table */ + ha_node_t* del_node) /* in: node to be deleted */ +{ + HASH_DELETE_AND_COMPACT(ha_node_t, next, table, del_node); +} + +/***************************************************************** +Deletes an entry from a hash table. */ + +void +ha_delete( +/*======*/ + hash_table_t* table, /* in: hash table */ + ulint fold, /* in: folded value of data */ + void* data) /* in: data, must not be NULL and must exist + in the hash table */ +{ + ha_node_t* node; + + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); + + node = ha_search_with_data(table, fold, data); + + ut_ad(node); + + ha_delete_hash_node(table, node); +} + +/********************************************************************* +Removes from the chain determined by fold all nodes whose data pointer +points to the page given. */ + +void +ha_remove_all_nodes_to_page( +/*========================*/ + hash_table_t* table, /* in: hash table */ + ulint fold, /* in: fold value */ + page_t* page) /* in: buffer page */ +{ + ha_node_t* node; + + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); + + node = ha_chain_get_first(table, fold); + + while (node) { + if (buf_frame_align(ha_node_get_data(node)) == page) { + + /* Remove the hash node */ + + ha_delete_hash_node(table, node); + + /* Start again from the first node in the chain + because the deletion may compact the heap of + nodes and move other nodes! */ + + node = ha_chain_get_first(table, fold); + } else { + node = ha_chain_get_next(table, node); + } + } +} + +/***************************************************************** +Validates a hash table. */ + +ibool +ha_validate( +/*========*/ + /* out: TRUE if ok */ + hash_table_t* table) /* in: hash table */ +{ + hash_cell_t* cell; + ha_node_t* node; + ulint i; + + for (i = 0; i < hash_get_n_cells(table); i++) { + + cell = hash_get_nth_cell(table, i); + + node = cell->node; + + while (node) { + ut_a(hash_calc_hash(node->fold, table) == i); + + node = node->next; + } + } + + return(TRUE); +} + +/***************************************************************** +Prints info of a hash table. */ + +void +ha_print_info( +/*==========*/ + hash_table_t* table) /* in: hash table */ +{ + hash_cell_t* cell; + ha_node_t* node; + ulint nodes = 0; + ulint cells = 0; + ulint len = 0; + ulint max_len = 0; + ulint i; + + for (i = 0; i < hash_get_n_cells(table); i++) { + + cell = hash_get_nth_cell(table, i); + + if (cell->node) { + + cells++; + + len = 0; + + node = cell->node; + + for (;;) { + len++; + nodes++; + + if (ha_chain_get_next(table, node) == NULL) { + + break; + } + + node = node->next; + } + + if (len > max_len) { + max_len = len; + } + } + } + + printf("Hash table size %lu, used cells %lu, nodes %lu\n", + hash_get_n_cells(table), cells, nodes); + printf("max chain length %lu\n", max_len); + + ut_a(ha_validate(table)); +} |