From 454335cd043561cc9fe874bc325c152a0727328b Mon Sep 17 00:00:00 2001 From: Sverker Eriksson Date: Tue, 2 Nov 2010 18:08:04 +0100 Subject: ETS 'compressed' option. The compressed format is using a slighty modified variant of the extern format (term_to_binary). To not worsen key lookup's too much, the top tuple itself and the key element are not compressed. Table objects with only immediate non-key elements will therefor not gain anything (but actually consume one extra word for "alloc_size"). --- erts/emulator/beam/erl_db.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) (limited to 'erts/emulator/beam/erl_db.c') diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c index 1c2c0fe4cb..8577354d27 100644 --- a/erts/emulator/beam/erl_db.c +++ b/erts/emulator/beam/erl_db.c @@ -179,6 +179,7 @@ extern DbTableMethod db_tree; int user_requested_db_max_tabs; int erts_ets_realloc_always_moves; +int erts_ets_always_compress; static int db_max_tabs; static DbTable *meta_pid_to_tab; /* Pid mapped to owned tables */ static DbTable *meta_pid_to_fixed_tab; /* Pid mapped to fixed tables */ @@ -931,7 +932,7 @@ BIF_RETTYPE ets_update_counter_3(BIF_ALIST_3) position > arityval(handle.dbterm->tpl[0])) { goto finalize; } - oldcnt = handle.dbterm->tpl[position]; + oldcnt = db_do_read_element(&handle, position); if (is_big(oldcnt)) { halloc_size += BIG_NEED_SIZE(big_arity(oldcnt)); } @@ -1276,7 +1277,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2) UWord heir_data; Uint32 status; Sint keypos; - int is_named, is_fine_locked, frequent_read; + int is_named, is_fine_locked, frequent_read, is_compressed; int cret; DeclareTmpHeap(meta_tuple,3,BIF_P); DbTableMethod* meth; @@ -1296,6 +1297,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2) frequent_read = 0; heir = am_none; heir_data = (UWord) am_undefined; + is_compressed = erts_ets_always_compress; list = BIF_ARG_2; while(is_list(list)) { @@ -1358,6 +1360,9 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2) else if (val == am_named_table) { is_named = 1; } + else if (val == am_compressed) { + is_compressed = 1; + } else if (val == am_set || val == am_protected) ; else break; @@ -1418,6 +1423,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2) erts_smp_atomic_init(&tb->common.nitems, 0); tb->common.fixations = NULL; + tb->common.compress = is_compressed; cret = meth->db_create(BIF_P, tb); ASSERT(cret == DB_ERROR_NONE); @@ -2572,7 +2578,7 @@ BIF_RETTYPE ets_match_object_3(BIF_ALIST_3) BIF_RETTYPE ets_info_1(BIF_ALIST_1) { static Eterm fields[] = {am_protection, am_keypos, am_type, am_named_table, - am_node, am_size, am_name, am_heir, am_owner, am_memory}; + am_node, am_size, am_name, am_heir, am_owner, am_memory, am_compressed}; Eterm results[sizeof(fields)/sizeof(Eterm)]; DbTable* tb; Eterm res; @@ -2837,6 +2843,7 @@ void init_db(void) erts_smp_atomic_init(&meta_pid_to_tab->common.nitems, 0); meta_pid_to_tab->common.slot = -1; meta_pid_to_tab->common.meth = &db_hash; + meta_pid_to_tab->common.compress = 0; erts_refc_init(&meta_pid_to_tab->common.ref, 1); erts_refc_init(&meta_pid_to_tab->common.fixref, 0); @@ -2869,6 +2876,7 @@ void init_db(void) erts_smp_atomic_init(&meta_pid_to_fixed_tab->common.nitems, 0); meta_pid_to_fixed_tab->common.slot = -1; meta_pid_to_fixed_tab->common.meth = &db_hash; + meta_pid_to_fixed_tab->common.compress = 0; erts_refc_init(&meta_pid_to_fixed_tab->common.ref, 1); erts_refc_init(&meta_pid_to_fixed_tab->common.fixref, 0); @@ -3077,7 +3085,7 @@ retry: db_unlock(tb,LCK_WRITE); heir_data = tb->common.heir_data; if (!is_immed(heir_data)) { - Eterm* tpv = DBTERM_BUF((DbTerm*)heir_data); /* tuple_val */ + Eterm* tpv = ((DbTerm*)heir_data)->tpl; /* tuple_val */ ASSERT(arityval(*tpv) == 1); heir_data = tpv[1]; } @@ -3251,7 +3259,8 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks) pp = &(*pp)->next) { if ((*pp)->pid == pid) { DbFixation* fix = *pp; - erts_refc_add(&tb->common.fixref,-fix->counter,0); + long diff = -(long)fix->counter; + erts_refc_add(&tb->common.fixref,diff,0); *pp = fix->next; erts_db_free(ERTS_ALC_T_DB_FIXATION, tb, fix, sizeof(DbFixation)); @@ -3469,8 +3478,8 @@ static void set_heir(Process* me, DbTable* tb, Eterm heir, UWord heir_data) UseTmpHeap(2,me); /* Make a dummy 1-tuple around data to use db_get_term() */ - heir_data = (UWord) db_get_term(&tb->common, NULL, 0, - TUPLE1(tmp,heir_data)); + heir_data = (UWord) db_store_term(&tb->common, NULL, 0, + TUPLE1(tmp,heir_data)); UnUseTmpHeap(2,me); ASSERT(!is_immed(heir_data)); } @@ -3481,7 +3490,7 @@ static void free_heir_data(DbTable* tb) { if (tb->common.heir != am_none && !is_immed(tb->common.heir_data)) { DbTerm* p = (DbTerm*) tb->common.heir_data; - db_free_term_data(p); + db_cleanup_offheap_comp(p); erts_db_free(ERTS_ALC_T_DB_TERM, tb, (void *)p, sizeof(DbTerm) + (p->size-1)*sizeof(Eterm)); } @@ -3618,10 +3627,13 @@ static Eterm table_info(Process* p, DbTable* tb, Eterm What) ret = erts_this_dist_entry->sysname; } else if (What == am_named_table) { ret = is_atom(tb->common.id) ? am_true : am_false; + } else if (What == am_compressed) { + ret = tb->common.compress ? am_true : am_false; + } /* * For debugging purposes */ - } else if (What == am_data) { + else if (What == am_data) { print_table(ERTS_PRINT_STDOUT, NULL, 1, tb); ret = am_true; } else if (What == am_atom_put("fixed",5)) { -- cgit v1.2.3