cxx_db.cpp
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上传日期:2022-05-23
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文件大小:17k
- /*-
- * 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);
- }