gecko-dev/db/include/db_cxx.h

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C++

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997, 1998
* Sleepycat Software. All rights reserved.
*
* @(#)db_cxx.h 10.17 (Sleepycat) 5/2/98
*/
#ifndef _DB_CXX_H_
#define _DB_CXX_H_
//
// C++ assumptions:
//
// To ensure portability to many platforms, both new and old, we make
// few assumptions about the C++ compiler and library. For example,
// we do not expect STL, templates or namespaces to be available. The
// "newest" C++ feature used is exceptions, which are used liberally
// to transmit error information. Even the use of exceptions can be
// disabled at runtime, see setErrorModel().
//
// C++ naming conventions:
//
// - All top level class names start with Db.
// - All class members start with lower case letter.
// - All private data members are suffixed with underscore.
// - Use underscores to divide names into multiple words.
// - Simple data accessors are named with get_ or set_ prefix.
// - All method names are taken from names of functions in the C
// layer of db (usually by dropping a prefix like "db_").
// These methods have the same argument types and order,
// other than dropping the explicit arg that acts as "this".
//
// As a rule, each DbFoo object has exactly one underlying DB_FOO struct
// (defined in db.h) associated with it. In many cases, we inherit directly
// from the DB_FOO structure to make this relationship explicit. Often,
// the underlying C layer allocates and deallocates these structures, so
// there is no easy way to add any data to the DbFoo class. When you see
// a comment about whether data is permitted to be added, this is what
// is going on. Of course, if we need to add data to such C++ classes
// in the future, we will arrange to have an indirect pointer to the
// DB_FOO struct (as some of the classes already have).
//
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Forward declarations
//
#include "db.h"
class Db; // forward
class Dbc; // forward
class DbEnv; // forward
class DbException; // forward
class DbInfo; // forward
class DbLock; // forward
class DbLockTab; // forward
class DbLog; // forward
class DbLsn; // forward
class DbMpool; // forward
class DbMpoolFile; // forward
class Dbt; // forward
class DbTxn; // forward
class DbTxnMgr; // forward
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Mechanisms for declaring classes
//
//
// Every class defined in this file has an _exported next to the class name.
// This is needed for WinTel machines so that the class methods can
// be exported or imported in a DLL as appropriate. Users of the DLL
// use the define DB_USE_DLL. When the DLL is built, DB_CREATE_DLL
// must be defined.
//
#if defined(_MSC_VER)
# if defined(DB_CREATE_DLL)
# define _exported __declspec(dllexport) // creator of dll
# elif defined(DB_USE_DLL)
# define _exported __declspec(dllimport) // user of dll
# else
# define _exported // static lib creator or user
# endif
#else
# define _exported
#endif
// DEFINE_DB_CLASS defines an imp_ data member and imp() accessor.
// The underlying type is a pointer to an opaque *Imp class, that
// gets converted to the correct implementation class by the implementation.
//
// Since these defines use "private/public" labels, and leave the access
// being "private", we always use these by convention before any data
// members in the private section of a class. Keeping them in the
// private section also emphasizes that they are off limits to user code.
//
#define DEFINE_DB_CLASS(name) \
public: class name##Imp* imp() { return imp_; } \
public: const class name##Imp* imp() const { return imp_; } \
private: class name##Imp* imp_
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Turn off inappropriate compiler warnings
//
#ifdef _MSC_VER
// These are level 4 warnings that are explicitly disabled.
// With Visual C++, by default you do not see above level 3 unless
// you use /W4. But we like to compile with the highest level
// warnings to catch other errors.
//
// 4201: nameless struct/union
// triggered by standard include file <winnt.h>
//
// 4514: unreferenced inline function has been removed
// certain include files in MSVC define methods that are not called
//
#pragma warning(disable: 4201 4514)
#endif
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Exception classes
//
// Almost any error in the DB library throws a DbException.
// Every exception should be considered an abnormality
// (e.g. bug, misuse of DB, file system error).
//
// NOTE: We would like to inherit from class exception and
// let it handle what(), but there are
// MSVC++ problems when <exception> is included.
//
class _exported DbException
{
public:
virtual ~DbException();
DbException(int err);
DbException(const char *description);
DbException(const char *prefix, int err);
DbException(const char *prefix1, const char *prefix2, int err);
const int get_errno();
virtual const char *what() const;
DbException(const DbException &);
DbException &operator = (const DbException &);
private:
char *what_;
int err_; // errno
};
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Lock classes
//
class _exported DbLock
{
friend DbLockTab;
public:
DbLock(u_int);
DbLock();
u_int get_lock_id();
void set_lock_id(u_int);
int put(DbLockTab *locktab);
DbLock(const DbLock &);
DbLock &operator = (const DbLock &);
protected:
// We can add data to this class if needed
// since its contained class is not allocated by db.
// (see comment at top)
DB_LOCK lock_;
};
class _exported DbLockTab
{
friend DbEnv;
public:
int close();
int detect(u_int32_t flags, int atype);
int get(u_int32_t locker, u_int32_t flags, const Dbt *obj,
db_lockmode_t lock_mode, DbLock *lock);
int id(u_int32_t *idp);
int vec(u_int32_t locker, u_int32_t flags, DB_LOCKREQ list[],
int nlist, DB_LOCKREQ **elistp);
// Create or remove new locktab files
//
static int open(const char *dir, u_int32_t flags, int mode,
DbEnv* dbenv, DbLockTab **regionp);
static int unlink(const char *dir, int force, DbEnv* dbenv);
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// copying not allowed
//
DbLockTab(const DbLockTab &);
DbLockTab &operator = (const DbLockTab &);
// Note: use DbLockTab::open() or DbEnv::get_lk_info()
// to get pointers to a DbLockTab,
// and call DbLockTab::close() rather than delete to release them.
//
DbLockTab();
~DbLockTab();
DEFINE_DB_CLASS(DbLockTab);
};
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Log classes
//
class _exported DbLsn : protected DB_LSN
{
friend DbLog; // friendship needed to cast to base class
friend DbMpool;
};
class _exported DbLog
{
friend DbEnv;
public:
int archive(char **list[], u_int32_t flags, void *(*db_malloc)(size_t));
int close();
static int compare(const DbLsn *lsn0, const DbLsn *lsn1);
int file(DbLsn *lsn, char *namep, int len);
int flush(const DbLsn *lsn);
int get(DbLsn *lsn, Dbt *data, u_int32_t flags);
int put(DbLsn *lsn, const Dbt *data, u_int32_t flags);
// Normally these would be called register and unregister to
// parallel the C interface, but "register" is a reserved word.
//
int db_register(Db *dbp, const char *name, DBTYPE type, u_int32_t *fidp);
int db_unregister(u_int32_t fid);
// Create or remove new log files
//
static int open(const char *dir, u_int32_t flags, int mode,
DbEnv* dbenv, DbLog **regionp);
static int unlink(const char *dir, int force, DbEnv* dbenv);
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// Note: use DbLog::open() or DbEnv::get_lg_info()
// to get pointers to a DbLog,
// and call DbLog::close() rather than delete to release them.
//
DbLog();
~DbLog();
// no copying
DbLog(const DbLog &);
operator = (const DbLog &);
DEFINE_DB_CLASS(DbLog);
};
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Memory pool classes
//
class _exported DbMpoolFile
{
friend DbEnv;
public:
int close();
int get(db_pgno_t *pgnoaddr, u_int32_t flags, void *pagep);
int put(void *pgaddr, u_int32_t flags);
int set(void *pgaddr, u_int32_t flags);
int sync();
static int open(DbMpool *mp, const char *file,
u_int32_t flags, int mode, size_t pagesize,
DB_MPOOL_FINFO *finfop, DbMpoolFile **mpf);
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// Note: use DbMpoolFile::open()
// to get pointers to a DbMpoolFile,
// and call DbMpoolFile::close() rather than delete to release them.
//
DbMpoolFile();
// Shut g++ up.
protected:
~DbMpoolFile();
private:
// no copying
DbMpoolFile(const DbMpoolFile &);
operator = (const DbMpoolFile &);
DEFINE_DB_CLASS(DbMpoolFile);
};
class _exported DbMpool
{
friend DbEnv;
public:
int close();
// access to low level interface
// Normally this would be called register to parallel
// the C interface, but "register" is a reserved word.
//
int db_register(int ftype,
int (*pgin)(db_pgno_t pgno, void *pgaddr, DBT *pgcookie),
int (*pgout)(db_pgno_t pgno, void *pgaddr, DBT *pgcookie));
int stat(DB_MPOOL_STAT **gsp, DB_MPOOL_FSTAT ***fsp,
void *(*db_malloc)(size_t));
int sync(DbLsn *lsn);
int trickle(int pct, int *nwrotep);
// Create or remove new mpool files
//
static int open(const char *dir, u_int32_t flags, int mode,
DbEnv* dbenv, DbMpool **regionp);
static int unlink(const char *dir, int force, DbEnv* dbenv);
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// Note: use DbMpool::open() or DbEnv::get_mp_info()
// to get pointers to a DbMpool,
// and call DbMpool::close() rather than delete to release them.
//
DbMpool();
~DbMpool();
// no copying
DbMpool(const DbMpool &);
DbMpool &operator = (const DbMpool &);
DEFINE_DB_CLASS(DbMpool);
};
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Transaction classes
//
class _exported DbTxnMgr
{
friend DbEnv;
public:
int begin(DbTxn *pid, DbTxn **tid);
int checkpoint(u_int32_t kbyte, u_int32_t min) const;
int close();
int stat(DB_TXN_STAT **statp, void *(*db_malloc)(size_t));
// Create or remove new txnmgr files
//
static int open(const char *dir, u_int32_t flags, int mode,
DbEnv* dbenv, DbTxnMgr **regionp);
static int unlink(const char *dir, int force, DbEnv* dbenv);
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// Note: use DbTxnMgr::open() or DbEnv::get_tx_info()
// to get pointers to a DbTxnMgr,
// and call DbTxnMgr::close() rather than delete to release them.
//
DbTxnMgr();
~DbTxnMgr();
// no copying
DbTxnMgr(const DbTxnMgr &);
operator = (const DbTxnMgr &);
DEFINE_DB_CLASS(DbTxnMgr);
};
class _exported DbTxn
{
friend DbTxnMgr;
public:
int abort();
int commit();
u_int32_t id();
int prepare();
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// Note: use DbTxnMgr::begin() to get pointers to a DbTxn,
// and call DbTxn::abort() or DbTxn::commit rather than
// delete to release them.
//
DbTxn();
~DbTxn();
// no copying
DbTxn(const DbTxn &);
operator = (const DbTxn &);
DEFINE_DB_CLASS(DbTxn);
};
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Application classes
//
//
// A set of application options - define how this application uses
// the db library.
//
class _exported DbInfo : protected DB_INFO
{
friend DbEnv;
friend Db;
public:
DbInfo();
~DbInfo();
// Byte order.
int get_lorder() const;
void set_lorder(int);
// Underlying cache size.
size_t get_cachesize() const;
void set_cachesize(size_t);
// Underlying page size.
size_t get_pagesize() const;
void set_pagesize(size_t);
// Local heap allocation.
typedef void *(*db_malloc_fcn)(size_t);
db_malloc_fcn get_malloc() const;
void set_malloc(db_malloc_fcn);
////////////////////////////////////////////////////////////////
// Btree access method.
// Maximum keys per page.
int get_bt_maxkey() const;
void set_bt_maxkey(int);
// Minimum keys per page.
int get_bt_minkey() const;
void set_bt_minkey(int);
// Comparison function.
typedef int (*bt_compare_fcn)(const DBT *, const DBT *);
bt_compare_fcn get_bt_compare() const;
void set_bt_compare(bt_compare_fcn);
// Prefix function.
typedef size_t (*bt_prefix_fcn)(const DBT *, const DBT *);
bt_prefix_fcn get_bt_prefix() const;
void set_bt_prefix(bt_prefix_fcn);
////////////////////////////////////////////////////////////////
// Hash access method.
// Fill factor.
u_int32_t get_h_ffactor() const;
void set_h_ffactor(u_int32_t);
// Number of elements.
u_int32_t get_h_nelem() const;
void set_h_nelem(u_int32_t);
// Hash function.
typedef u_int32_t (*h_hash_fcn)(const void *, u_int32_t);
h_hash_fcn get_h_hash() const;
void set_h_hash(h_hash_fcn);
////////////////////////////////////////////////////////////////
// Recno access method.
// Fixed-length padding byte.
int get_re_pad() const;
void set_re_pad(int);
// Variable-length delimiting byte.
int get_re_delim() const;
void set_re_delim(int);
// Length for fixed-length records.
u_int32_t get_re_len() const;
void set_re_len(u_int32_t);
// Source file name.
char *get_re_source() const;
void set_re_source(char *);
// Note: some flags are set as side effects of calling
// above "set" methods.
//
u_int32_t get_flags() const;
void set_flags(u_int32_t);
// (deep) copying of this object is allowed.
//
DbInfo(const DbInfo &);
DbInfo &operator = (const DbInfo &);
private:
// We can add data to this class if needed
// since parent class is not allocated by db.
// (see comment at top)
};
//
// Base application class. Provides functions for opening a database.
// User of this library can use this class as a starting point for
// developing a DB application - derive their application class from
// this one, add application control logic.
//
// Note that if you use the default constructor, you must explicitly
// call appinit() before any other db activity (e.g. opening files)
//
class _exported DbEnv : protected DB_ENV
{
friend DbTxnMgr;
friend DbLog;
friend DbLockTab;
friend DbMpool;
friend Db;
public:
~DbEnv();
// This constructor can be used to immediately initialize the
// application with these arguments. Do not use it if you
// need to set other parameters via the access methods.
//
DbEnv(const char *homeDir, char *const *db_config, u_int32_t flags);
// Use this constructor if you wish to *delay* the initialization
// of the db library. This is useful if you need to set
// any particular parameters via the access methods below.
// Then call appinit() to complete the initialization.
//
DbEnv();
// Used in conjunction with the default constructor to
// complete the initialization of the db library.
//
int appinit(const char *homeDir, char *const *db_config, u_int32_t flags);
// Called automatically when DbEnv is destroyed, or can be
// called at any time to shut down Db.
//
int appexit();
////////////////////////////////////////////////////////////////
// simple get/set access methods
//
// If you are calling set_ methods, you need to
// use the default constructor along with appinit().
// Byte order.
int get_lorder() const;
void set_lorder(int);
// Error message callback.
typedef void (*db_errcall_fcn)(const char *, char *);
db_errcall_fcn get_errcall() const;
void set_errcall(db_errcall_fcn);
// Error message file stream.
FILE *get_errfile() const;
void set_errfile(FILE *);
// Error message prefix.
const char *get_errpfx() const;
void set_errpfx(const char *);
// Generate debugging messages.
int get_verbose() const;
void set_verbose(int);
////////////////////////////////////////////////////////////////
// User paths.
// Database home.
char *get_home() const;
void set_home(char *);
// Database log file directory.
char *get_log_dir() const;
void set_log_dir(char *);
// Database tmp file directory.
char *get_tmp_dir() const;
void set_tmp_dir(char *);
// Database data file directories.
char **get_data_dir() const;
void set_data_dir(char **);
// Database data file slots.
int get_data_cnt() const;
void set_data_cnt(int);
// Next Database data file slot.
int get_data_next() const;
void set_data_next(int);
////////////////////////////////////////////////////////////////
// Locking.
// Return from lock_open().
DbLockTab *get_lk_info() const;
// Two dimensional conflict matrix.
u_int8_t *get_lk_conflicts() const;
void set_lk_conflicts(u_int8_t *);
// Number of lock modes in table.
int get_lk_modes() const;
void set_lk_modes(int);
// Maximum number of locks.
u_int32_t get_lk_max() const;
void set_lk_max(u_int32_t);
// Deadlock detect on every conflict.
u_int32_t get_lk_detect() const;
void set_lk_detect(u_int32_t);
////////////////////////////////////////////////////////////////
// Logging.
// Return from log_open().
DbLog *get_lg_info() const;
// Maximum file size.
u_int32_t get_lg_max() const;
void set_lg_max(u_int32_t);
////////////////////////////////////////////////////////////////
// Memory pool.
// Return from memp_open().
DbMpool *get_mp_info() const;
// Maximum file size for mmap.
size_t get_mp_mmapsize() const;
void set_mp_mmapsize(size_t);
// Bytes in the mpool cache.
size_t get_mp_size() const;
void set_mp_size(size_t);
////////////////////////////////////////////////////////////////
// Transactions.
// Return from txn_open().
DbTxnMgr *get_tx_info() const;
// Maximum number of transactions.
u_int32_t get_tx_max() const;
void set_tx_max(u_int32_t);
// Dispatch function for recovery.
typedef int (*tx_recover_fcn)(DB_LOG *, DBT *, DB_LSN *, int, void *);
tx_recover_fcn get_tx_recover() const;
void set_tx_recover(tx_recover_fcn);
// Flags.
u_int32_t get_flags() const;
void set_flags(u_int32_t);
////////////////////////////////////////////////////////////////
// The default error model is to throw an exception whenever
// an error occurs. This generally allows for cleaner logic
// for transaction processing, as a try block can surround a
// single transaction. Alternatively, since almost every method
// returns an error code (errno), the error model can be set to
// not throw exceptions, and instead return the appropriate code.
//
enum ErrorModel { Exception, ErrorReturn };
void set_error_model(ErrorModel);
ErrorModel get_error_model() const;
// If an error is detected and the error call function
// or stream is set, a message is dispatched or printed.
// If a prefix is set, each message is prefixed.
//
// You can use set_errcall() or set_errfile() above to control
// error functionality using a C model. Alternatively, you can
// call set_error_stream() to force all errors to a C++ stream.
// It is unwise to mix these approaches.
//
class ostream* get_error_stream() const;
void set_error_stream(class ostream*);
// used internally
static int runtime_error(const char *caller, int err, int in_destructor = 0);
private:
// We can add data to this class if needed
// since parent class is not allocated by db.
// (see comment at top)
// no copying
DbEnv(const DbEnv &);
operator = (const DbEnv &);
ErrorModel error_model_;
static void stream_error_function(const char *, char *);
static ostream *error_stream_;
};
////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////
//
// Table access classes
//
//
// Represents a database table = a set of keys with associated values.
//
class _exported Db
{
friend DbEnv;
public:
int close(u_int32_t flags);
int cursor(DbTxn *txnid, Dbc **cursorp);
int del(DbTxn *txnid, Dbt *key, u_int32_t flags);
int fd(int *fdp);
int get(DbTxn *txnid, Dbt *key, Dbt *data, u_int32_t flags);
int put(DbTxn *txnid, Dbt *key, Dbt *data, u_int32_t flags);
int stat(void *sp, void *(*db_malloc)(size_t), u_int32_t flags);
int sync(u_int32_t flags);
DBTYPE get_type() const;
static int open(const char *fname, DBTYPE type, u_int32_t flags,
int mode, DbEnv *dbenv, DbInfo *info, Db **dbpp);
private:
// We can add data to this class if needed
// since it is implemented via a pointer.
// (see comment at top)
// Note: use Db::open() to get initialize pointers to a Db,
// and call Db::close() rather than delete to release them.
Db();
~Db();
// no copying
Db(const Db &);
Db &operator = (const Db &);
DEFINE_DB_CLASS(Db);
};
//
// A chunk of data, maybe a key or value.
//
class _exported Dbt : private DBT
{
friend Dbc;
friend Db;
friend DbLog;
friend DbMpoolFile;
friend DbLockTab;
public:
// key/data
void *get_data() const;
void set_data(void *);
// key/data length
u_int32_t get_size() const;
void set_size(u_int32_t);
// RO: length of user buffer.
u_int32_t get_ulen() const;
void set_ulen(u_int32_t);
// RO: get/put record length.
u_int32_t get_dlen() const;
void set_dlen(u_int32_t);
// RO: get/put record offset.
u_int32_t get_doff() const;
void set_doff(u_int32_t);
// flags
u_int32_t get_flags() const;
void set_flags(u_int32_t);
Dbt(void *data, size_t size);
Dbt();
~Dbt();
Dbt(const Dbt &);
Dbt &operator = (const Dbt &);
private:
// We can add data to this class if needed
// since parent class is not allocated by db.
// (see comment at top)
};
class _exported Dbc : protected DBC
{
friend Db;
public:
int close();
int del(u_int32_t flags);
int get(Dbt* key, Dbt *data, u_int32_t flags);
int put(Dbt* key, Dbt *data, u_int32_t flags);
private:
// No data is permitted in this class (see comment at top)
// Note: use Db::cursor() to get pointers to a Dbc,
// and call Dbc::close() rather than delete to release them.
//
Dbc();
~Dbc();
// no copying
Dbc(const Dbc &);
Dbc &operator = (const Dbc &);
};
#endif /* !_DB_CXX_H_ */