cxx_db.cpp

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/*-
 * 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),