自学教程：C++ GetDB函数代码示例

// Create CDDB filebool Dbase::Write(const Cddb::Album& album){    CachePut(album);    const QString genre = !album.discGenre.isEmpty() ?        album.discGenre.toLower().toUtf8() : "misc";    LOG(VB_MEDIA, LOG_INFO, "WriteDB " + genre +        QString(" %1 ").arg(album.discID,0,16) +        album.artist + " / " + album.title);    if (QDir(GetDB()).mkpath(genre))    {        QFile file(GetDB() + '/' + genre + '/' +             QString::number(album.discID,16));        if (file.open(QIODevice::WriteOnly | QIODevice::Text))        {            QTextStream(&file) << album;            return true;        }        else            LOG(VB_GENERAL, LOG_ERR, "Cddb can't write " + file.fileName());    }    else        LOG(VB_GENERAL, LOG_ERR, "Cddb can't mkpath " + GetDB() + '/' + genre);    return false;}

Boolean  Pfml2::InnerGetAlmStatus(TBlkAttr *pAboObj,UINT nID){	CPFMDatabase  *pDB = GetDB();	if (NULL !=pDB)		return pDB->GetAlmStatus(pAboObj,nID);	return SDB_RET_FAILED ;};

BOOL KGatewayDataProcess::CheckConnectAddress(){	S3PDBConVBC* pConn = GetDB(0);	if (pConn)		return S3PAccount::CheckAddress(pConn, m_Address, m_Port) == ACTION_SUCCESS;	return FALSE;}

static VALUEbdb_sary_slice_bang(int argc, VALUE *argv, VALUE obj){    VALUE arg1, arg2;    long pos, len;    bdb_DB *dbst;    GetDB(obj, dbst);    if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {	pos = NUM2LONG(arg1);	len = NUM2LONG(arg2);      delete_pos_len:	if (pos < 0) {	    pos = dbst->len + pos;	}	arg2 = bdb_sary_subseq(obj, pos, len);	bdb_sary_replace(obj, pos, len, Qnil);	return arg2;    }    if (!FIXNUM_P(arg1) && rb_range_beg_len(arg1, &pos, &len, dbst->len, 1)) {	goto delete_pos_len;    }    pos = NUM2LONG(arg1);    if (pos >= dbst->len) return Qnil;    if (pos < 0) pos += dbst->len;    if (pos < 0) return Qnil;    arg1 = INT2NUM(pos);    arg2 = bdb_sary_at(obj, arg1);    if (bdb_del(obj, arg1) != Qnil) dbst->len--;    return arg2;}

/* * call-seq: *     db[nth] *     db[start..end] *     db[start, length] * * Element reference - with the following syntax: * * * db[nth] * *     Retrieves the +nth+ item from an array.  Index starts from *     zero.  If index is the negative, counts backward from the end *     of the array.  The index of the last element is -1. Returns *     +nil+, if the +nth+ element does not exist in the array. * * * db[start..end] * *     Returns an array containing the objects from +start+ to +end+, *     including both ends. if end is larger than the length of the *     array, it will be rounded to the length.  If +start+ is out of *     an array range , returns +nil+.  And if +start+ is larger than *     end with in array range, returns empty array ([]). * * * db[start, length] * *     Returns an array containing +length+ items from +start+. *     Returns +nil+ if +length+ is negative. */static VALUEbdb_sary_aref(int argc, VALUE *argv, VALUE obj){    VALUE arg1, arg2;    long beg, len;    bdb_DB *dbst;    GetDB(obj, dbst);    if (rb_scan_args(argc, argv, "11", &arg1, &arg2) == 2) {	beg = NUM2LONG(arg1);	len = NUM2LONG(arg2);	if (beg < 0) {	    beg = dbst->len + beg;	}	return bdb_sary_subseq(obj, beg, len);    }    if (FIXNUM_P(arg1)) {	return bdb_sary_entry(obj, arg1);    }    else if (TYPE(arg1) == T_BIGNUM) {	rb_raise(rb_eIndexError, "index too big");    }    else {	switch (rb_range_beg_len(arg1, &beg, &len, dbst->len, 0)) {	  case Qfalse:	    break;	  case Qnil:	    return Qnil;	  default:	    return bdb_sary_subseq(obj, beg, len);	}    }    return bdb_sary_entry(obj, arg1);}

static VALUEbdb_sary_delete(VALUE obj, VALUE item){    bdb_DB *dbst;    long i1, i2;    VALUE tmp, a;    GetDB(obj, dbst);    i2 = dbst->len;    for (i1 = 0; i1 < dbst->len;) {	tmp = INT2NUM(i1);	a = bdb_get(1, &tmp, obj);	if (rb_equal(a, item)) {	    bdb_del(obj, INT2NUM(i1));	    dbst->len--;	}	else {	    i1++;	}    }    if (dbst->len == i2) {	if (rb_block_given_p()) {	    return rb_yield(item);	}	return Qnil;    }    return item;}

static VALUEbdb_sary_reverse_bang(VALUE obj){    long i, j;    bdb_DB *dbst;    VALUE tmp[2], interm;    GetDB(obj, dbst);    if (dbst->len <= 1) return obj;    i = 0;    j = dbst->len - 1;    while (i < j) {	tmp[0] = INT2NUM(i);	interm = bdb_get(1, tmp, obj);	tmp[0] = INT2NUM(j);	tmp[1] = bdb_get(1, tmp, obj);	tmp[0] = INT2NUM(i);	bdb_put(2, tmp, obj);	tmp[0] = INT2NUM(j);	tmp[1] = interm;	bdb_put(2, tmp, obj);	i++; j--;    }    return obj;}

static VALUEbdb_sary_unshift_m(int argc, VALUE *argv, VALUE obj){    bdb_DB *dbst;    VALUE tmp[2];    long i;    if (argc == 0) {	rb_raise(rb_eArgError, "wrong # of arguments(at least 1)");    }    if (argc > 0) {/* ++ */	GetDB(obj, dbst);	for (i = dbst->len - 1; i >= 0; i++) {	    tmp[0] = INT2NUM(i);	    tmp[1] = bdb_get(1, tmp, obj);	    tmp[0] = INT2NUM(i + argc);	    bdb_put(2, tmp, obj);	}	for (i = 0; i < argc; i++) {	    tmp[0] = INT2NUM(i);	    tmp[1] = argv[i];	    bdb_put(2, tmp, obj);	    dbst->len++;	}    }    return obj;}

void ContrastDialog::OnGetForegroundDB( wxCommandEvent &event ){   SetStartTime(mForegroundStartT->GetTimeValue());   SetEndTime(mForegroundEndT->GetTimeValue());   foregrounddB = GetDB();   m_pButton_UseCurrentF->SetFocus();   results();}

		Configure::~Configure()		{			Database::Typed<Entry> &db = GetDB();			if (mPrev)				db.Put(mTagId, mPrev);			else				db.Delete(mTagId);		}

int  Pfml2::AlmGetAll(list<SAlmDataItem> &listAlm){	CModAutoLocker locker(this);	CPFMDatabase  *pDB = GetDB();	if (NULL !=pDB)		return pDB->AlmGetAll(listAlm);	return SDB_RET_FAILED ;}

bool BaseIndex::WriteBestBlock(const CBlockIndex* block_index){    LOCK(cs_main);    if (!GetDB().WriteBestBlock(chainActive.GetLocator(block_index))) {        return error("%s: Failed to write locator to disk", __func__);    }    return true;}

void ContrastDialog::OnGetBackgroundDB( wxCommandEvent & WXUNUSED(event)){   SetStartTime(mBackgroundStartT->GetTimeValue());   SetEndTime(mBackgroundEndT->GetTimeValue());   backgrounddB = GetDB();   m_pButton_UseCurrentB->SetFocus();   results();}