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Diffstat (limited to 'storage/innobase/ha/ha0ha.c')
-rw-r--r-- | storage/innobase/ha/ha0ha.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/storage/innobase/ha/ha0ha.c b/storage/innobase/ha/ha0ha.c new file mode 100644 index 00000000000..ad1391ff83e --- /dev/null +++ b/storage/innobase/ha/ha0ha.c @@ -0,0 +1,357 @@ +/************************************************************************ +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 (in_btr_search) { + table->adaptive = TRUE; + } else { + table->adaptive = FALSE; + } + + 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); +} + +/***************************************************************** +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; + buf_block_t* prev_block; + ulint hash; + + ut_ad(table && data); +#ifdef UNIV_SYNC_DEBUG + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); +#endif /* UNIV_SYNC_DEBUG */ + 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) { + if (table->adaptive) { + prev_block = buf_block_align(prev_node->data); + ut_a(prev_block->n_pointers > 0); + prev_block->n_pointers--; + buf_block_align(data)->n_pointers++; + } + + 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); + + if (table->adaptive) { + buf_block_align(data)->n_pointers++; + } + + 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 */ +{ + if (table->adaptive) { + ut_a(buf_block_align(del_node->data)->n_pointers > 0); + buf_block_align(del_node->data)->n_pointers--; + } + + 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; + +#ifdef UNIV_SYNC_DEBUG + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); +#endif /* UNIV_SYNC_DEBUG */ + node = ha_search_with_data(table, fold, data); + + ut_a(node); + + ha_delete_hash_node(table, node); +} + +/************************************************************* +Looks for an element when we know the pointer to the data, and updates +the pointer to data, if found. */ + +void +ha_search_and_update_if_found( +/*==========================*/ + hash_table_t* table, /* in: hash table */ + ulint fold, /* in: folded value of the searched data */ + void* data, /* in: pointer to the data */ + void* new_data)/* in: new pointer to the data */ +{ + ha_node_t* node; + +#ifdef UNIV_SYNC_DEBUG + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); +#endif /* UNIV_SYNC_DEBUG */ + + node = ha_search_with_data(table, fold, data); + + if (node) { + if (table->adaptive) { + ut_a(buf_block_align(node->data)->n_pointers > 0); + buf_block_align(node->data)->n_pointers--; + buf_block_align(new_data)->n_pointers++; + } + + node->data = new_data; + } +} + +/********************************************************************* +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; + +#ifdef UNIV_SYNC_DEBUG + ut_ad(!table->mutexes || mutex_own(hash_get_mutex(table, fold))); +#endif /* UNIV_SYNC_DEBUG */ + 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(node); + } + } +#ifdef UNIV_DEBUG + /* Check that all nodes really got deleted */ + + node = ha_chain_get_first(table, fold); + + while (node) { + ut_a(buf_frame_align(ha_node_get_data(node)) != page); + + node = ha_chain_get_next(node); + } +#endif +} + +/***************************************************************** +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; + ibool ok = TRUE; + ulint i; + + for (i = 0; i < hash_get_n_cells(table); i++) { + + cell = hash_get_nth_cell(table, i); + + node = cell->node; + + while (node) { + if (hash_calc_hash(node->fold, table) != i) { + ut_print_timestamp(stderr); + fprintf(stderr, +"InnoDB: Error: hash table node fold value %lu does not\n" +"InnoDB: match with the cell number %lu.\n", + (ulong) node->fold, (ulong) i); + + ok = FALSE; + } + + node = node->next; + } + } + + return(ok); +} + +/***************************************************************** +Prints info of a hash table. */ + +void +ha_print_info( +/*==========*/ + FILE* file, /* in: file where to print */ + hash_table_t* table) /* in: hash table */ +{ + hash_cell_t* cell; + ulint cells = 0; + ulint n_bufs; + ulint i; + + for (i = 0; i < hash_get_n_cells(table); i++) { + + cell = hash_get_nth_cell(table, i); + + if (cell->node) { + + cells++; + } + } + + fprintf(file, + "Hash table size %lu, used cells %lu", + (ulong) hash_get_n_cells(table), (ulong) cells); + + if (table->heaps == NULL && table->heap != NULL) { + + /* This calculation is intended for the adaptive hash + index: how many buffer frames we have reserved? */ + + n_bufs = UT_LIST_GET_LEN(table->heap->base) - 1; + + if (table->heap->free_block) { + n_bufs++; + } + + fprintf(file, ", node heap has %lu buffer(s)\n", (ulong) n_bufs); + } +} |