class.cpp

一个功能强大的内存数据库源代码,c++编写,有详细的注释

	    }
	    *(bool*)(dst + fd->dbsOffs) = b;
	    break;

	  case dbField::tpInt1:
	    switch (fd->oldDbsType) { 
	      case dbField::tpBool:
		i1 = *(bool*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt1:
		i1 = *(int1*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt2:
		i1 = (int1)*(int2*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt4:
		i1 = (int1)*(int4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt8:
		i1 = (int1)*(db_int8*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal4:
		i1 = (int1)*(real4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal8:
		i1 = (int1)*(real8*)(src + fd->oldDbsOffs);
		break;
	      default:
		i1 = 0;
	    }
	    *(int1*)(dst + fd->dbsOffs) = i1;
	    break;

	  case dbField::tpInt2:
	    switch (fd->oldDbsType) { 
	      case dbField::tpBool:
		i2 = *(bool*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt1:
		i2 = *(int1*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt2:
		i2 = *(int2*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt4:
		i2 = (int2)*(int4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt8:
		i2 = (int2)*(db_int8*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal4:
		i2 = (int2)*(real4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal8:
		i2 = (int2)*(real8*)(src + fd->oldDbsOffs);
		break;
	      default:
		i2 = 0;
	    }
	    *(int2*)(dst + fd->dbsOffs) = i2;
	    break;

	  case dbField::tpInt4:
	    switch (fd->oldDbsType) { 
	      case dbField::tpBool:
		i4 = *(bool*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt1:
		i4 = *(int1*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt2:
		i4 = *(int2*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt4:
		i4 = *(int4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt8:
		i4 = (int4)*(db_int8*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal4:
		i4 = (int4)*(real4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal8:
		i4 = (int4)*(real8*)(src + fd->oldDbsOffs);
		break;
	      default:
		i4 = 0;
	    }
	    *(int4*)(dst + fd->dbsOffs) = i4;
	    break;

	  case dbField::tpInt8:
	    switch (fd->oldDbsType) { 
	      case dbField::tpBool:
		i8 = *(bool*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt1:
		i8 = *(int1*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt2:
		i8 = *(int2*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt4:
		i8 = *(int4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt8:
		i8 = *(db_int8*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal4:
		i8 = (db_int8)*(real4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal8:
		i8 = (db_int8)*(real8*)(src + fd->oldDbsOffs);
		break;
	      default:
		i8 = 0;
	    }
	    *(db_int8*)(dst + fd->dbsOffs) = i8;
	    break;

	  case dbField::tpReal4:
	    switch (fd->oldDbsType) { 
	      case dbField::tpBool:
		f4 = (real4)*(bool*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt1:
		f4 = (real4)*(int1*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt2:
		f4 = (real4)*(int2*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt4:
		f4 = (real4)*(int4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt8:
		f4 = (real4)*(db_int8*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal4:
		f4 = *(real4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal8:
		f4 = (real4)*(real8*)(src + fd->oldDbsOffs);
		break;
	      default:
		f4 = 0;
	    }
	    *(real4*)(dst + fd->dbsOffs) = f4;
	    break;

	  case dbField::tpReal8:
	    switch (fd->oldDbsType) { 
	      case dbField::tpBool:
		f8 = (real8)*(bool*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt1:
		f8 = (real8)*(int1*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt2:
		f8 = (real8)*(int2*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt4:
		f8 = (real8)*(int4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpInt8:
		f8 = (real8)*(db_int8*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal4:
		f8 = *(real4*)(src + fd->oldDbsOffs);
		break;
	      case dbField::tpReal8:
		f8 = *(real8*)(src + fd->oldDbsOffs);
		break;
	      default:
		f8 = 0;
	    }
	    *(real8*)(dst + fd->dbsOffs) = f8;
	    break;

	  case dbField::tpRawBinary:
	    if (fd->oldDbsType == dbField::tpRawBinary) {
                memcpy(dst + fd->dbsOffs, src + fd->oldDbsOffs, 
		       size_t(fd->oldDbsSize) < fd->dbsSize 
		       ? size_t(fd->oldDbsSize) : fd->dbsSize);
            } 
            break;

	  case dbField::tpString:
	    if (fd->oldDbsType == dbField::tpUnknown) { 
		((dbVarying*)(dst + fd->dbsOffs))->size = 1;
		((dbVarying*)(dst + fd->dbsOffs))->offs = offs;
		*(char*)(dst + offs++) = '\0';
	    } else { 
		size_t len = 
		    ((dbVarying*)(src + fd->oldDbsOffs))->size;
		((dbVarying*)(dst + fd->dbsOffs))->size = len;
		((dbVarying*)(dst + fd->dbsOffs))->offs = offs;
		memcpy(dst + offs, 
		       src + ((dbVarying*)(src+fd->oldDbsOffs))->offs, len);
		offs += len;
	    }
	    break;

	  case dbField::tpArray:
	    if (fd->oldDbsType == dbField::tpUnknown) { 
		((dbVarying*)(dst + fd->dbsOffs))->size = 0;
		((dbVarying*)(dst + fd->dbsOffs))->offs = 0;
	    } else { 
		int len = ((dbVarying*)(src+fd->oldDbsOffs))->size;
		byte* srcElem = src + ((dbVarying*)(src+fd->oldDbsOffs))->offs;
		((dbVarying*)(dst + fd->dbsOffs))->size = len;
	        byte* dstElem = 
		    (byte*)DOALIGN(long(dst)+offs, fd->components->alignment);
		offs = dstElem - dst;
		((dbVarying*)(dst+fd->dbsOffs))->offs = offs;
		size_t offsElem = len*fd->components->dbsSize; 
		offs += offsElem;
		while (--len >= 0) { 
		    offsElem = fd->components->convertRecord(dstElem, srcElem,
							     offsElem);
		    offsElem -= fd->components->dbsSize;
		    dstElem += fd->components->dbsSize;
		    srcElem += fd->components->oldDbsSize;
		}
		offs += offsElem;
	    }
	    break;

	  case dbField::tpStructure:
	    offs = fd->components->convertRecord(dst, src, offs);
	    break;

	  case dbField::tpReference:
	    if (fd->oldDbsType == dbField::tpUnknown) { 
		*(oid_t*)(dst + fd->dbsOffs) = 0;
	    } else { 
		*(oid_t*)(dst + fd->dbsOffs) = *(oid_t*)(src + fd->oldDbsOffs);
	    }
	    break;
	  default:
	    return offs;
	}
    } while ((fd = fd->next) != this);

    return offs;
}


int dbTableDescriptor::initialAutoincrementCount;


dbTableDescriptor::dbTableDescriptor(char*              tableName, 
				     dbDatabase*        database,
				     size_t             objSize, 
				     describeFunc       func,
				     dbTableDescriptor* original)
{
    cloneOf = original;
    isStatic = true;
    if (original == NULL) {
	next = chain;
	chain = this;
    }
    name = tableName;
    dbSymbolTable::add(name, tkn_ident, FASTDB_CLONE_ANY_IDENTIFIER);
    describeComponentsFunc = func;
    columns = (*func)();
    nextFieldLink = &firstField;
    hashedFields = NULL;
    indexedFields = NULL;
    inverseFields = NULL;
    tableId = 0;
    nFields = 0;
    nColumns = 0;
    db = database;
    fixedDatabase = database != NULL;
    fixedSize = sizeof(dbRecord);
    int attr = dbFieldDescriptor::OneToOneMapping;
    appSize = 0;
    autoincrementCount = initialAutoincrementCount;
    size_t maxAlignment = calculateFieldsAttributes(columns, "", 
						    sizeof(dbRecord), 
						    HASHED|INDEXED, attr);
#if CHECK_RECORD_SIZE
    appSize = DOALIGN(appSize, maxAlignment);
    if (appSize < objSize) { 
	fprintf(stderr, "Warning: may be not all fields of the class '%s' "
		"were described\n", name);
    }
#endif
    *nextFieldLink = NULL;
}


int dbTableDescriptor::calculateFieldsAttributes(dbFieldDescriptor* first,
						 char const*        prefix, 
						 int                offs,
						 int                indexMask, 
						 int&               attr)
{
    dbFieldDescriptor *field = first;
    size_t alignment = 1;
    do { 
	if (field->method) { 
	    assert(((void)"Not empty record", field != first));
	    do { 
		assert(((void)"Methods should be specified after variables", 
			field->method != NULL));
		field->dbsOffs = first->dbsOffs;
		field->components = first;
		if (attr & dbFieldDescriptor::OneToOneMapping) { 
		    field->method = field->method->optimize();
		}
	    } while ((field = field->next) != first);
	    break;
	}
	if (*prefix != '\0') { 
	    char* p = new char[strlen(prefix)+strlen(field->name)+1];
	    sprintf(p, "%s%s", prefix, field->name);
	    field->longName = p;
	} else { 
	    nColumns += 1;
	    field->longName = new char[strlen(field->name)+1];
	    strcpy(field->longName, field->name);
	}
	field->defTable = this;
	field->indexType &= indexMask|DB_FIELD_INHERITED_MASK;
	field->attr = (attr & dbFieldDescriptor::ComponentOfArray) 
	            | dbFieldDescriptor::OneToOneMapping;
	if (field->inverseRefName) { 
	    assert(!(attr & dbFieldDescriptor::ComponentOfArray)
		   && (field->type == dbField::tpReference 
		       || (field->type == dbField::tpArray 
			   && field->components->type==dbField::tpReference)));
	    field->nextInverseField = inverseFields;
	    inverseFields = field; 
	}
	*nextFieldLink = field;
	nextFieldLink = &field->nextField;
	field->fieldNo = nFields++;
		   
	switch (field->type) { 
	  case dbField::tpArray:
	    { 
		size_t saveOffs = fixedSize;
		size_t saveAppSize = appSize;
		fixedSize = 0;
		attr = (attr | dbFieldDescriptor::HasArrayComponents)
		     & ~dbFieldDescriptor::OneToOneMapping;
		field->attr |= dbFieldDescriptor::ComponentOfArray;
		calculateFieldsAttributes(field->components, field->longName,
					  0, 0, field->attr);
		if (field->components->dbsSize != field->components->appSize) {
		    field->attr &= ~dbFieldDescriptor::OneToOneMapping;
		}
		fixedSize = saveOffs;
		appSize = DOALIGN(saveAppSize, sizeof(void*)) 
		    + sizeof(void*)*3;
		break;
	    }
	  case dbField::tpStructure:
	    { 
		char* aggregateName = new char[strlen(field->longName) + 2];
		sprintf(aggregateName, "%s.", field->longName);
		size_t saveOffs = fixedSize;	    
		size_t saveAppSize = appSize;	    
		appSize = 0;
		size_t struct_alignment = 
		    calculateFieldsAttributes(field->components, 
					      aggregateName,
					      offs + field->appOffs, 
					      field->indexType,
					      field->attr);
		field->alignment = struct_alignment;
		field->dbsOffs = field->components->dbsOffs;
		attr |= field->attr & dbFieldDescriptor::HasArrayComponents;
		attr &= field->attr | ~dbFieldDescriptor::OneToOneMapping;
		field->dbsSize = DOALIGN(fixedSize-saveOffs, struct_alignment);
		if ((field->attr & dbFieldDescriptor::HasArrayComponents)
		    && struct_alignment < sizeof(void*))
		{
		    struct_alignment = sizeof(void*);
		}
		appSize = DOALIGN(appSize, struct_alignment) 
		        + DOALIGN(saveAppSize, struct_alignment);
		delete[] aggregateName;
		break;
	    } 
	  case dbField::tpString:
	    attr = (attr | dbFieldDescriptor::HasArrayComponents)
		& ~dbFieldDescriptor::OneToOneMapping;
	    // no break
	  default:
	    appSize = DOALIGN(appSize, field->appSize) + field->appSize;
	}
	if (alignment < field->alignment) { 
	    alignment = field->alignment;
	}
	if (field->type != dbField::tpStructure) { 
	    field->dbsOffs = fixedSize = DOALIGN(fixedSize, field->alignment);
	    fixedSize += field->dbsSize;
	    if (field->dbsOffs != offs + field->appOffs) { 
		attr &= ~dbFieldDescriptor::OneToOneMapping;
	    }

	    if (field->indexType & (HASHED|INDEXED)) {
		assert(!(field->attr & dbFieldDescriptor::ComponentOfArray));
		if (field->indexType & HASHED) { 
		    field->nextHashedField = hashedFields;
		    hashedFields = field;
		}
		if (field->indexType & INDEXED) { 
		    field->nextIndexedField = indexedFields;
		    indexedFields = field;
		}
	    }
	}
    } while ((field = field->next) != first);

    return alignment;
}


int dbFieldDescriptor::sizeWithoutOneField(dbFieldDescriptor* field, 
					   byte* base, size_t& size)
{
    dbFieldDescriptor* fd = this;
    int offs, last = 0;
    do { 
	if (fd != field) { 
	    if (fd->type == dbField::tpArray || fd->type == dbField::tpString){
		dbVarying* arr = (dbVarying*)(base + fd->dbsOffs);
		if (arr->offs > last) { 
		    last = arr->offs;
		}
		int n = arr->size;
		size = DOALIGN(size, fd->components->alignment)
		     + fd->components->dbsSize * n;
		if (fd->attr & HasArrayComponents) { 
		    byte* elem = base + arr->offs;
		    while (--n >= 0) {
			offs = fd->components->sizeWithoutOneField(field, 
								   elem, size);
			if (arr->offs + offs > last) { 
			    last = arr->offs + offs;
			}
			elem += fd->components->dbsSize;
		    }
		}
	    } else if (fd->attr & HasArrayComponents) { 
		offs = fd->components->sizeWithoutOneField(field, base, size);
		if (offs > last) { 
		    last = offs;
		}
	    }
	}
    } while ((fd = fd->next) != this);

    return last;
}


size_t dbFieldDescriptor::copyRecordExceptOneField(dbFieldDescriptor* field, 
						   byte* dst, byte* src, 
						   size_t offs)
{
    dbFieldDescriptor* fd = this;
    do { 
	if (fd != field) { 
	    if (fd->type == dbField::tpArray || fd->type == dbField::tpString){
		dbVarying* srcArr = (dbVarying*)(src + fd->dbsOffs);
		dbVarying* dstArr = (dbVarying*)(dst + fd->dbsOffs);
		int n = srcArr->size;
		byte* srcElem = src + srcArr->offs;
		byte* dstElem = (byte*)DOALIGN(long(dst) + offs, 
					       fd->components->alignment);
		dstArr->offs = offs = dstElem - dst;
		dstArr->size = n;
		size_t sizeElem = fd->components->dbsSize;
		size_t offsElem = sizeElem * n;
		offs += offsElem;
		if (fd->attr & HasArrayComponents) { 
		    while (--n >= 0) {
			offsElem = fd->components->
			    copyRecordExceptOneField(field, dstElem, srcElem,
						     offsElem);
			offsElem -= sizeElem;
			dstElem += sizeElem;
			srcElem += sizeElem;
		    }
		    offs += offsElem;
		} else { 
		    memcpy(dstElem, srcElem, offsElem);
		} 
	    } else if (fd->attr & HasArrayComponents) { 
		offs = fd->components->copyRecordExceptOneField(field, dst, 
								src, offs);
	    } else if (fd->method == NULL) {
		memcpy(dst+fd->dbsOffs, src+fd->dbsOffs, fd->dbsSize);
	    }
	}
    } while ((fd = fd->next) != this);