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_util.h | 96 ++++++++++++++++++++++++++++++++-------- 1 file changed, 78 insertions(+), 18 deletions(-) (limited to 'erts/emulator/beam/erl_db_util.h') diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h index 0f333e8b34..10ba755e80 100644 --- a/erts/emulator/beam/erl_db_util.h +++ b/erts/emulator/beam/erl_db_util.h @@ -52,22 +52,27 @@ is broken.*/ #define DB_ERROR_UNSPEC -10 /* Unspecified error */ +/*#define DEBUG_CLONE*/ /* * A datatype for a database entry stored out of a process heap */ typedef struct db_term { struct erl_off_heap_header* first_oh; /* Off heap data for term. */ - Uint size; /* Size of term in "words" */ - Eterm tpl[1]; /* Untagged "constant pointer" to top tuple */ - /* (assumed to be first in buffer) */ + Uint size; /* Heap size of term in "words" */ +#ifdef DEBUG_CLONE + Eterm* debug_clone; /* An uncompressed copy */ +#endif + Eterm tpl[1]; /* Term data. Top tuple always first */ + + /* Compression: is_immed and key element are uncompressed. + Compressed elements are stored in external format after each other + last in dbterm. The top tuple elements contains byte offsets, to + the start of the data, tagged as headers. + The allocated size of the dbterm in bytes is stored at tpl[arity+1]. + */ } DbTerm; -/* "Assign" a value to DbTerm.tpl */ -#define DBTERM_SET_TPL(dbtermPtr,tplPtr) ASSERT((tplPtr)==(dbtermPtr->tpl)) -/* Get start of term buffer */ -#define DBTERM_BUF(dbtermPtr) ((dbtermPtr)->tpl) - union db_table; typedef union db_table DbTable; @@ -186,6 +191,12 @@ typedef struct db_table_method } DbTableMethod; +typedef struct db_fixation { + Eterm pid; + Uint counter; + struct db_fixation *next; +} DbFixation; + /* * This structure contains data for all different types of database * tables. Note that these fields must match the same fields @@ -194,13 +205,6 @@ typedef struct db_table_method * operations may be the same on different types of tables. */ -typedef struct db_fixation { - Eterm pid; - Uint counter; - struct db_fixation *next; -} DbFixation; - - typedef struct db_table_common { erts_refc_t ref; erts_refc_t fixref; /* fixation counter */ @@ -226,6 +230,7 @@ typedef struct db_table_common { Uint32 status; /* bit masks defined below */ int slot; /* slot index in meta_main_tab */ int keypos; /* defaults to 1 */ + int compress; } DbTableCommon; /* These are status bit patterns */ @@ -252,6 +257,54 @@ typedef struct db_table_common { #define IS_FIXED(T) (NFIXED(T) != 0) Eterm erts_ets_copy_object(Eterm, Process*); +Eterm db_copy_from_comp(DbTableCommon* tb, DbTerm* bp, Eterm** hpp, + ErlOffHeap* off_heap); +int db_eq_comp(DbTableCommon* tb, Eterm a, DbTerm* b); +DbTerm* db_alloc_tmp_uncompressed(DbTableCommon* tb, DbTerm* org); + +ERTS_GLB_INLINE Eterm db_copy_object_from_ets(DbTableCommon* tb, DbTerm* bp, + Eterm** hpp, ErlOffHeap* off_heap); +ERTS_GLB_INLINE int db_eq(DbTableCommon* tb, Eterm a, DbTerm* b); +ERTS_GLB_INLINE Eterm db_do_read_element(DbUpdateHandle* handle, Sint position); + +#if ERTS_GLB_INLINE_INCL_FUNC_DEF +ERTS_GLB_INLINE Eterm db_copy_object_from_ets(DbTableCommon* tb, DbTerm* bp, + Eterm** hpp, ErlOffHeap* off_heap) +{ + if (tb->compress) { + return db_copy_from_comp(tb, bp, hpp, off_heap); + } + else { + return copy_shallow(bp->tpl, bp->size, hpp, off_heap); + } +} + +ERTS_GLB_INLINE int db_eq(DbTableCommon* tb, Eterm a, DbTerm* b) +{ + if (!tb->compress) { + return eq(a, make_tuple(b->tpl)); + } + else { + return db_eq_comp(tb, a, b); + } +} + +/* Must be called to read elements after db_lookup_dbterm. +** Will decompress if needed. */ +ERTS_GLB_INLINE Eterm db_do_read_element(DbUpdateHandle* handle, Sint position) +{ + Eterm elem = handle->dbterm->tpl[position]; + if (!is_header(elem)) { + return elem; + } + ASSERT(((DbTableCommon*)handle->tb)->compress); + ASSERT(!handle->mustResize); + handle->dbterm = db_alloc_tmp_uncompressed((DbTableCommon*)handle->tb, handle->dbterm); + handle->mustResize = 1; + return handle->dbterm->tpl[position]; +} + +#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */ /* optimised version of copy_object (normal case? atomic object) */ #define COPY_OBJECT(obj, p, objp) \ @@ -277,14 +330,19 @@ Eterm db_set_trace_control_word_1(Process *p, Eterm val); void db_initialize_util(void); Eterm db_getkey(int keypos, Eterm obj); -void db_free_term_data(DbTerm* p); -void* db_get_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj); +void db_cleanup_offheap_comp(DbTerm* p); +void db_free_term(DbTable *tb, void* basep, Uint offset); +void* db_store_term(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj); +void* db_store_term_comp(DbTableCommon *tb, DbTerm* old, Uint offset, Eterm obj); +Eterm db_copy_element_from_ets(DbTableCommon* tb, Process* p, DbTerm* obj, + Uint pos, Eterm** hpp, Uint extra); int db_has_variable(Eterm obj); int db_is_variable(Eterm obj); +Eterm db_do_read_element(DbUpdateHandle* handle, Sint position); void db_do_update_element(DbUpdateHandle* handle, Sint position, Eterm newval); -void db_finalize_update_element(DbUpdateHandle* handle); +void db_finalize_resize(DbUpdateHandle* handle, Uint offset); Eterm db_add_counter(Eterm** hpp, Eterm counter, Eterm incr); Eterm db_match_set_lint(Process *p, Eterm matchexpr, Uint flags); Binary *db_match_set_compile(Process *p, Eterm matchexpr, @@ -366,6 +424,8 @@ Binary *db_match_compile(Eterm *matchexpr, Eterm *guards, Eterm *body, int num_matches, Uint flags, DMCErrInfo *err_info); +Eterm db_prog_match_and_copy(DbTableCommon* tb, Process* c_p, Binary* bprog, + int all, DbTerm* obj, Eterm** hpp, Uint extra); /* Returns newly allocated MatchProg binary with refc == 0*/ Eterm db_prog_match(Process *p, Binary *prog, Eterm term, Eterm *termp, int arity, Uint32 *return_flags /* Zeroed on enter */); -- cgit v1.2.3