cxx_db.cpp 17.1 KB
Newer Older
ram@mysql.r18.ru's avatar
ram@mysql.r18.ru committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605
/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1997-2002
 *	Sleepycat Software.  All rights reserved.
 */

#include "db_config.h"

#ifndef lint
static const char revid[] = "$Id: cxx_db.cpp,v 11.71 2002/08/26 22:13:36 mjc Exp $";
#endif /* not lint */

#include <errno.h>
#include <string.h>

#include "db_cxx.h"
#include "dbinc/cxx_int.h"

#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc_auto/db_auto.h"
#include "dbinc_auto/crdel_auto.h"
#include "dbinc/db_dispatch.h"
#include "dbinc_auto/db_ext.h"
#include "dbinc_auto/common_ext.h"

// Helper macros for simple methods that pass through to the
// underlying C method. It may return an error or raise an exception.
// Note this macro expects that input _argspec is an argument
// list element (e.g., "char *arg") and that _arglist is the arguments
// that should be passed through to the C method (e.g., "(db, arg)")
//
#define	DB_METHOD(_name, _argspec, _arglist, _retok)			\
int Db::_name _argspec							\
{									\
	int ret;							\
	DB *db = unwrap(this);						\
									\
	ret = db->_name _arglist;					\
	if (!_retok(ret))						\
		DB_ERROR("Db::" # _name, ret, error_policy());		\
	return (ret);							\
}

#define	DB_METHOD_CHECKED(_name, _cleanup, _argspec, _arglist, _retok)	\
int Db::_name _argspec							\
{									\
	int ret;							\
	DB *db = unwrap(this);						\
									\
	if (!db) {							\
		DB_ERROR("Db::" # _name, EINVAL, error_policy());	\
		return (EINVAL);					\
	}								\
	if (_cleanup)							\
		cleanup();						\
	ret = db->_name _arglist;					\
	if (!_retok(ret))						\
		DB_ERROR("Db::" # _name, ret, error_policy());		\
	return (ret);							\
}

#define	DB_METHOD_QUIET(_name, _argspec, _arglist)			\
int Db::_name _argspec							\
{									\
	DB *db = unwrap(this);						\
									\
	return (db->_name _arglist);					\
}

#define	DB_METHOD_VOID(_name, _argspec, _arglist)			\
void Db::_name _argspec							\
{									\
	DB *db = unwrap(this);						\
									\
	db->_name _arglist;						\
}

// A truism for the Db object is that there is a valid
// DB handle from the constructor until close().
// After the close, the DB handle is invalid and
// no operations are permitted on the Db (other than
// destructor).  Leaving the Db handle open and not
// doing a close is generally considered an error.
//
// We used to allow Db objects to be closed and reopened.
// This implied always keeping a valid DB object, and
// coordinating the open objects between Db/DbEnv turned
// out to be overly complicated.  Now we do not allow this.

Db::Db(DbEnv *env, u_int32_t flags)
:	imp_(0)
,	env_(env)
,	construct_error_(0)
,	flags_(0)
,	construct_flags_(flags)
,	append_recno_callback_(0)
,	associate_callback_(0)
,	bt_compare_callback_(0)
,	bt_prefix_callback_(0)
,	dup_compare_callback_(0)
,	feedback_callback_(0)
,	h_hash_callback_(0)
{
	if (env_ == 0)
		flags_ |= DB_CXX_PRIVATE_ENV;

	if ((construct_error_ = initialize()) != 0)
		DB_ERROR("Db::Db", construct_error_, error_policy());
}

// If the DB handle is still open, we close it.  This is to make stack
// allocation of Db objects easier so that they are cleaned up in the error
// path.  If the environment was closed prior to this, it may cause a trap, but
// an error message is generated during the environment close.  Applications
// should call close explicitly in normal (non-exceptional) cases to check the
// return value.
//
Db::~Db()
{
	DB *db;

	db = unwrap(this);
	if (db != NULL) {
		cleanup();
		(void)db->close(db, 0);
	}
}

// private method to initialize during constructor.
// initialize must create a backing DB object,
// and if that creates a new DB_ENV, it must be tied to a new DbEnv.
//
int Db::initialize()
{
	DB *db;
	DB_ENV *cenv = unwrap(env_);
	int ret;
	u_int32_t cxx_flags;

	cxx_flags = construct_flags_ & DB_CXX_NO_EXCEPTIONS;

	// Create a new underlying DB object.
	// We rely on the fact that if a NULL DB_ENV* is given,
	// one is allocated by DB.
	//
	if ((ret = db_create(&db, cenv,
			     construct_flags_ & ~cxx_flags)) != 0)
		return (ret);

	// Associate the DB with this object
	imp_ = wrap(db);
	db->api_internal = this;

	// Create a new DbEnv from a DB_ENV* if it was created locally.
	// It is deleted in Db::close().
	//
	if ((flags_ & DB_CXX_PRIVATE_ENV) != 0)
		env_ = new DbEnv(db->dbenv, cxx_flags);

	return (0);
}

// private method to cleanup after destructor or during close.
// If the environment was created by this Db object, we optionally
// delete it, or return it so the caller can delete it after
// last use.
//
void Db::cleanup()
{
	DB *db = unwrap(this);

	if (db != NULL) {
		// extra safety
		db->api_internal = 0;
		imp_ = 0;

		// we must dispose of the DbEnv object if
		// we created it.  This will be the case
		// if a NULL DbEnv was passed into the constructor.
		// The underlying DB_ENV object will be inaccessible
		// after the close, so we must clean it up now.
		//
		if ((flags_ & DB_CXX_PRIVATE_ENV) != 0) {
			env_->cleanup();
			delete env_;
			env_ = 0;
		}
	}
}

// Return a tristate value corresponding to whether we should
// throw exceptions on errors:
//   ON_ERROR_RETURN
//   ON_ERROR_THROW
//   ON_ERROR_UNKNOWN
//
int Db::error_policy()
{
	if (env_ != NULL)
		return (env_->error_policy());
	else {
		// If the env_ is null, that means that the user
		// did not attach an environment, so the correct error
		// policy can be deduced from constructor flags
		// for this Db.
		//
		if ((construct_flags_ & DB_CXX_NO_EXCEPTIONS) != 0) {
			return (ON_ERROR_RETURN);
		}
		else {
			return (ON_ERROR_THROW);
		}
	}
}

int Db::close(u_int32_t flags)
{
	DB *db = unwrap(this);
	int ret;

	// after a DB->close (no matter if success or failure),
	// the underlying DB object must not be accessed,
	// so we clean up in advance.
	//
	cleanup();

	// It's safe to throw an error after the close,
	// since our error mechanism does not peer into
	// the DB* structures.
	//
	if ((ret = db->close(db, flags)) != 0)
		DB_ERROR("Db::close", ret, error_policy());

	return (ret);
}

// The following cast implies that Dbc can be no larger than DBC
DB_METHOD(cursor, (DbTxn *txnid, Dbc **cursorp, u_int32_t flags),
    (db, unwrap(txnid), (DBC **)cursorp, flags),
    DB_RETOK_STD)

DB_METHOD(del, (DbTxn *txnid, Dbt *key, u_int32_t flags),
    (db, unwrap(txnid), key, flags),
    DB_RETOK_DBDEL)

void Db::err(int error, const char *format, ...)
{
	DB *db = unwrap(this);

	DB_REAL_ERR(db->dbenv, error, 1, 1, format);
}

void Db::errx(const char *format, ...)
{
	DB *db = unwrap(this);

	DB_REAL_ERR(db->dbenv, 0, 0, 1, format);
}

DB_METHOD(fd, (int *fdp),
    (db, fdp),
    DB_RETOK_STD)

int Db::get(DbTxn *txnid, Dbt *key, Dbt *value, u_int32_t flags)
{
	DB *db = unwrap(this);
	int ret;

	ret = db->get(db, unwrap(txnid), key, value, flags);

	if (!DB_RETOK_DBGET(ret)) {
		if (ret == ENOMEM && DB_OVERFLOWED_DBT(value))
			DB_ERROR_DBT("Db::get", value, error_policy());
		else
			DB_ERROR("Db::get", ret, error_policy());
	}

	return (ret);
}

int Db::get_byteswapped(int *isswapped)
{
	DB *db = (DB *)unwrapConst(this);
	return (db->get_byteswapped(db, isswapped));
}

int Db::get_type(DBTYPE *dbtype)
{
	DB *db = (DB *)unwrapConst(this);
	return (db->get_type(db, dbtype));
}

// Dbc is a "compatible" subclass of DBC - that is, no virtual functions
// or even extra data members, so these casts, although technically
// non-portable, "should" always be okay.
DB_METHOD(join, (Dbc **curslist, Dbc **cursorp, u_int32_t flags),
    (db, (DBC **)curslist, (DBC **)cursorp, flags),
    DB_RETOK_STD)

DB_METHOD(key_range,
    (DbTxn *txnid, Dbt *key, DB_KEY_RANGE *results, u_int32_t flags),
    (db, unwrap(txnid), key, results, flags),
    DB_RETOK_STD)

// If an error occurred during the constructor, report it now.
// Otherwise, call the underlying DB->open method.
//
int Db::open(DbTxn *txnid, const char *file, const char *database,
	     DBTYPE type, u_int32_t flags, int mode)
{
	int ret;
	DB *db = unwrap(this);

	if (construct_error_ != 0)
		ret = construct_error_;
	else
		ret = db->open(db, unwrap(txnid), file, database, type, flags,
		    mode);

	if (!DB_RETOK_STD(ret))
		DB_ERROR("Db::open", ret, error_policy());

	return (ret);
}

int Db::pget(DbTxn *txnid, Dbt *key, Dbt *pkey, Dbt *value, u_int32_t flags)
{
	DB *db = unwrap(this);
	int ret;

	ret = db->pget(db, unwrap(txnid), key, pkey, value, flags);

	/* The logic here is identical to Db::get - reuse the macro. */
	if (!DB_RETOK_DBGET(ret)) {
		if (ret == ENOMEM && DB_OVERFLOWED_DBT(value))
			DB_ERROR_DBT("Db::pget", value, error_policy());
		else
			DB_ERROR("Db::pget", ret, error_policy());
	}

	return (ret);
}

DB_METHOD(put,
    (DbTxn *txnid, Dbt *key, Dbt *value, u_int32_t flags),
    (db, unwrap(txnid), key, value, flags),
    DB_RETOK_DBPUT)

DB_METHOD_CHECKED(rename, 1,
    (const char *file, const char *database, const char *newname,
    u_int32_t flags),
    (db, file, database, newname, flags), DB_RETOK_STD)

DB_METHOD_CHECKED(remove, 1,
    (const char *file, const char *database, u_int32_t flags),
    (db, file, database, flags), DB_RETOK_STD)

DB_METHOD_CHECKED(truncate, 0,
    (DbTxn *txnid, u_int32_t *countp, u_int32_t flags),
    (db, unwrap(txnid), countp, flags), DB_RETOK_STD)

DB_METHOD_CHECKED(stat, 0,
    (void *sp, u_int32_t flags), (db, sp, flags), DB_RETOK_STD)

DB_METHOD_CHECKED(sync, 0,
    (u_int32_t flags), (db, flags), DB_RETOK_STD)

DB_METHOD_CHECKED(upgrade, 0,
    (const char *name, u_int32_t flags), (db, name, flags), DB_RETOK_STD)

////////////////////////////////////////////////////////////////////////
//
// callbacks
//
// *_intercept_c are 'glue' functions that must be declared
// as extern "C" so to be typesafe.  Using a C++ method, even
// a static class method with 'correct' arguments, will not pass
// the test; some picky compilers do not allow mixing of function
// pointers to 'C' functions with function pointers to C++ functions.
//
// One wart with this scheme is that the *_callback_ method pointer
// must be declared public to be accessible by the C intercept.
// It's possible to accomplish the goal without this, and with
// another public transfer method, but it's just too much overhead.
// These callbacks are supposed to be *fast*.
//
// The DBTs we receive in these callbacks from the C layer may be
// manufactured there, but we want to treat them as a Dbts.
// Technically speaking, these DBTs were not constructed as a Dbts,
// but it should be safe to cast them as such given that Dbt is a
// *very* thin extension of the DBT.  That is, Dbt has no additional
// data elements, does not use virtual functions, virtual inheritance,
// multiple inheritance, RTI, or any other language feature that
// causes the structure to grow or be displaced.  Although this may
// sound risky, a design goal of C++ is complete structure
// compatibility with C, and has the philosophy 'if you don't use it,
// you shouldn't incur the overhead'.  If the C/C++ compilers you're
// using on a given machine do not have matching struct layouts, then
// a lot more things will be broken than just this.
//
// The alternative, creating a Dbt here in the callback, and populating
// it from the DBT, is just too slow and cumbersome to be very useful.

// These macros avoid a lot of boilerplate code for callbacks

#define	DB_CALLBACK_C_INTERCEPT(_name, _rettype, _cargspec,		\
    _return, _cxxargs)							\
extern "C" _rettype _db_##_name##_intercept_c _cargspec			\
{									\
	Db *cxxthis;							\
									\
	DB_ASSERT(cthis != NULL);					\
	cxxthis = (Db *)cthis->api_internal;				\
	DB_ASSERT(cxxthis != NULL);					\
	DB_ASSERT(cxxthis->_name##_callback_ != 0);			\
									\
	_return (*cxxthis->_name##_callback_) _cxxargs;			\
}

#define	DB_SET_CALLBACK(_cxxname, _name, _cxxargspec, _cb)		\
int Db::_cxxname _cxxargspec						\
{									\
	DB *cthis = unwrap(this);					\
									\
	_name##_callback_ = _cb;					\
	return ((*(cthis->_cxxname))(cthis,				\
	    (_cb) ? _db_##_name##_intercept_c : NULL));			\
}

/* associate callback - doesn't quite fit the pattern because of the flags */
DB_CALLBACK_C_INTERCEPT(associate,
    int, (DB *cthis, const DBT *key, const DBT *data, DBT *retval),
    return, (cxxthis, Dbt::get_const_Dbt(key), Dbt::get_const_Dbt(data),
    Dbt::get_Dbt(retval)))

int Db::associate(DbTxn *txn, Db *secondary, int (*callback)(Db *, const Dbt *,
	const Dbt *, Dbt *), u_int32_t flags)
{
	DB *cthis = unwrap(this);

	/* Since the secondary Db is used as the first argument
	 * to the callback, we store the C++ callback on it
	 * rather than on 'this'.
	 */
	secondary->associate_callback_ = callback;
	return ((*(cthis->associate))(cthis, unwrap(txn), unwrap(secondary),
	    (callback) ? _db_associate_intercept_c : NULL, flags));
}

DB_CALLBACK_C_INTERCEPT(feedback,
    void, (DB *cthis, int opcode, int pct),
    /* no return */ (void), (cxxthis, opcode, pct))

DB_SET_CALLBACK(set_feedback, feedback,
    (void (*arg)(Db *cxxthis, int opcode, int pct)), arg)

DB_CALLBACK_C_INTERCEPT(append_recno,
    int, (DB *cthis, DBT *data, db_recno_t recno),
    return, (cxxthis, Dbt::get_Dbt(data), recno))

DB_SET_CALLBACK(set_append_recno, append_recno,
    (int (*arg)(Db *cxxthis, Dbt *data, db_recno_t recno)), arg)

DB_CALLBACK_C_INTERCEPT(bt_compare,
    int, (DB *cthis, const DBT *data1, const DBT *data2),
    return,
    (cxxthis, Dbt::get_const_Dbt(data1), Dbt::get_const_Dbt(data2)))

DB_SET_CALLBACK(set_bt_compare, bt_compare,
    (int (*arg)(Db *cxxthis, const Dbt *data1, const Dbt *data2)), arg)

DB_CALLBACK_C_INTERCEPT(bt_prefix,
    size_t, (DB *cthis, const DBT *data1, const DBT *data2),
    return,
    (cxxthis, Dbt::get_const_Dbt(data1), Dbt::get_const_Dbt(data2)))

DB_SET_CALLBACK(set_bt_prefix, bt_prefix,
    (size_t (*arg)(Db *cxxthis, const Dbt *data1, const Dbt *data2)), arg)

DB_CALLBACK_C_INTERCEPT(dup_compare,
    int, (DB *cthis, const DBT *data1, const DBT *data2),
    return,
    (cxxthis, Dbt::get_const_Dbt(data1), Dbt::get_const_Dbt(data2)))

DB_SET_CALLBACK(set_dup_compare, dup_compare,
    (int (*arg)(Db *cxxthis, const Dbt *data1, const Dbt *data2)), arg)

DB_CALLBACK_C_INTERCEPT(h_hash,
    u_int32_t, (DB *cthis, const void *data, u_int32_t len),
    return, (cxxthis, data, len))

DB_SET_CALLBACK(set_h_hash, h_hash,
    (u_int32_t (*arg)(Db *cxxthis, const void *data, u_int32_t len)), arg)

// This is a 'glue' function declared as extern "C" so it will
// be compatible with picky compilers that do not allow mixing
// of function pointers to 'C' functions with function pointers
// to C++ functions.
//
extern "C"
int _verify_callback_c(void *handle, const void *str_arg)
{
	char *str;
	__DB_OSTREAMCLASS *out;

	str = (char *)str_arg;
	out = (__DB_OSTREAMCLASS *)handle;

	(*out) << str;
	if (out->fail())
		return (EIO);

	return (0);
}

int Db::verify(const char *name, const char *subdb,
	       __DB_OSTREAMCLASS *ostr, u_int32_t flags)
{
	DB *db = unwrap(this);
	int ret;

	if (!db)
		ret = EINVAL;
	else
		ret = __db_verify_internal(db, name, subdb, ostr,
		    _verify_callback_c, flags);

	if (!DB_RETOK_STD(ret))
		DB_ERROR("Db::verify", ret, error_policy());

	return (ret);
}

DB_METHOD(set_bt_compare, (bt_compare_fcn_type func),
    (db, func), DB_RETOK_STD)
DB_METHOD(set_bt_maxkey, (u_int32_t bt_maxkey),
    (db, bt_maxkey), DB_RETOK_STD)
DB_METHOD(set_bt_minkey, (u_int32_t bt_minkey),
    (db, bt_minkey), DB_RETOK_STD)
DB_METHOD(set_bt_prefix, (bt_prefix_fcn_type func),
    (db, func), DB_RETOK_STD)
DB_METHOD(set_dup_compare, (dup_compare_fcn_type func),
    (db, func), DB_RETOK_STD)
DB_METHOD(set_encrypt, (const char *passwd, int flags),
    (db, passwd, flags), DB_RETOK_STD)
DB_METHOD_VOID(set_errfile, (FILE *errfile), (db, errfile))
DB_METHOD_VOID(set_errpfx, (const char *errpfx), (db, errpfx))
DB_METHOD(set_flags, (u_int32_t flags), (db, flags),
    DB_RETOK_STD)
DB_METHOD(set_h_ffactor, (u_int32_t h_ffactor),
    (db, h_ffactor), DB_RETOK_STD)
DB_METHOD(set_h_hash, (h_hash_fcn_type func),
    (db, func), DB_RETOK_STD)
DB_METHOD(set_h_nelem, (u_int32_t h_nelem),
    (db, h_nelem), DB_RETOK_STD)
DB_METHOD(set_lorder, (int db_lorder), (db, db_lorder),
    DB_RETOK_STD)
DB_METHOD(set_pagesize, (u_int32_t db_pagesize),
    (db, db_pagesize), DB_RETOK_STD)
DB_METHOD(set_re_delim, (int re_delim),
    (db, re_delim), DB_RETOK_STD)
DB_METHOD(set_re_len, (u_int32_t re_len),
    (db, re_len), DB_RETOK_STD)
DB_METHOD(set_re_pad, (int re_pad),
    (db, re_pad), DB_RETOK_STD)
DB_METHOD(set_re_source, (char *re_source),
    (db, re_source), DB_RETOK_STD)
DB_METHOD(set_q_extentsize, (u_int32_t extentsize),
    (db, extentsize), DB_RETOK_STD)

DB_METHOD_QUIET(set_alloc, (db_malloc_fcn_type malloc_fcn,
    db_realloc_fcn_type realloc_fcn, db_free_fcn_type free_fcn),
    (db, malloc_fcn, realloc_fcn, free_fcn))

void Db::set_errcall(void (*arg)(const char *, char *))
{
	env_->set_errcall(arg);
}

void *Db::get_app_private() const
{
	return unwrapConst(this)->app_private;
}

void Db::set_app_private(void *value)
{
	unwrap(this)->app_private = value;
}

DB_METHOD(set_cachesize, (u_int32_t gbytes, u_int32_t bytes, int ncache),
    (db, gbytes, bytes, ncache), DB_RETOK_STD)
DB_METHOD(set_cache_priority, (DB_CACHE_PRIORITY priority),
    (db, priority), DB_RETOK_STD)

int Db::set_paniccall(void (*callback)(DbEnv *, int))
{
	return (env_->set_paniccall(callback));
}

void Db::set_error_stream(__DB_OSTREAMCLASS *error_stream)
{
	env_->set_error_stream(error_stream);
}