/// <summary>
/// Updates an object.
/// </summary>
/// <remarks>
/// Updates an object. <pre>Try to update in place. Only change what has changed. This is restricted to particular types (fixed size types). If in place update is
/// not possible, then deletes the current object and creates a new at the end of the database file and updates
/// OID object position.
/// @param object The object to be updated
/// @param forceUpdate when true, no verification is done to check if update must be done.
/// @return The oid of the object, as a negative number
/// @</pre>
/// </remarks>
public OID UpdateNonNativeObjectInfo(NonNativeObjectInfo nnoi, bool forceUpdate)
{
var hasObject = true;
var @object = nnoi.GetObject();
var oid = nnoi.GetOid();
if (@object == null)
hasObject = false;
// When there is index,we must *always* load the old meta representation
// to compute index keys
var withIndex = !nnoi.GetClassInfo().GetIndexes().IsEmpty();
NonNativeObjectInfo oldMetaRepresentation = null;
// Used to check consistency, at the end, the number of
// nbConnectedObjects must and nbUnconnected must remain unchanged
//TODO: why we are not using / checking that? (below is continuity)
nnoi.GetClassInfo().CommitedZoneInfo.GetNumberbOfObjects();
nnoi.GetClassInfo().UncommittedZoneInfo.GetNumberbOfObjects();
var objectHasChanged = false;
try
{
var lsession = _session;
var positionBeforeWrite = _objectWriter.FileSystemProcessor.FileSystemInterface.GetPosition();
var tmpCache = lsession.GetTmpCache();
var cache = lsession.GetCache();
// Get header of the object (position, previous object position,
// next
// object position and class info position)
// The header must be in the cache.
var lastHeader = cache.GetObjectInfoHeaderByOid(oid, true);
if (lastHeader == null)
throw new OdbRuntimeException(
NDatabaseError.UnexpectedSituation.AddParameter("Header is null in update"));
if (lastHeader.GetOid() == null)
throw new OdbRuntimeException(
NDatabaseError.InternalError.AddParameter("Header oid is null for oid " + oid));
var objectIsInConnectedZone = cache.IsInCommitedZone(oid);
var currentPosition = lastHeader.GetPosition();
if (currentPosition == -1)
{
throw new OdbRuntimeException(
NDatabaseError.InstancePositionIsNegative.AddParameter(currentPosition).AddParameter(oid).
AddParameter("In Object Info Header"));
}
// triggers,FIXME passing null to old object representation
_storageEngine.GetTriggerManager().ManageUpdateTriggerBefore(nnoi.GetClassInfo().UnderlyingType,
null, hasObject ? @object : nnoi, oid);
// Use to control if the in place update is ok. The
// ObjectInstrospector stores the number of changes
// that were detected and here we try to apply them using in place
// update.If at the end
// of the in place update the number of applied changes is smaller
// then the number
// of detected changes, then in place update was not successfully,
// we
// must do a real update,
// creating an object elsewhere :-(
if (!forceUpdate)
{
var cachedOid = cache.IdOfInsertingObject(@object);
if (cachedOid != null)
{
// The object is being inserted (must be a cyclic
// reference), simply returns id id
return cachedOid;
}
// the nnoi (NonNativeObjectInfo is the meta representation of
// the object to update
// To know what must be upated we must get the meta
// representation of this object before
// The modification. Taking this 'old' meta representation from
// the
// cache does not resolve
// : because cache is a reference to the real object and object
// has been changed,
// so the cache is pointing to the reference, that has changed!
// This old meta representation must be re-read from the last
// committed database
// false, = returnInstance (java object) = false
try
{
var useCache = !objectIsInConnectedZone;
oldMetaRepresentation = _objectReader.ReadNonNativeObjectInfoFromPosition(null, oid,
currentPosition,
useCache, false);
tmpCache.ClearObjectInfos();
}
catch (OdbRuntimeException e)
{
var position = currentPosition.ToString();
throw new OdbRuntimeException(
NDatabaseError.InternalError.AddParameter("Error while reading old Object Info of oid " +
oid + " at pos " + position), e);
}
// Make sure we work with the last version of the object
var onDiskVersion = oldMetaRepresentation.GetHeader().GetObjectVersion();
var onDiskUpdateDate = oldMetaRepresentation.GetHeader().GetUpdateDate();
var inCacheVersion = lastHeader.GetObjectVersion();
var inCacheUpdateDate = lastHeader.GetUpdateDate();
if (onDiskUpdateDate > inCacheUpdateDate || onDiskVersion > inCacheVersion)
lastHeader = oldMetaRepresentation.GetHeader();
nnoi.SetHeader(lastHeader);
// increase the object version number from the old meta
// representation
nnoi.GetHeader().IncrementVersionAndUpdateDate();
// Keep the creation date
nnoi.GetHeader().SetCreationDate(oldMetaRepresentation.GetHeader().GetCreationDate());
// Set the object of the old meta to make the object comparator
// understand, they are 2
// meta representation of the same object
// TODO , check if if is the best way to do
oldMetaRepresentation.SetObject(nnoi.GetObject());
// Reset the comparator
_comparator.Clear();
objectHasChanged = _comparator.HasChanged(oldMetaRepresentation, nnoi);
if (!objectHasChanged)
{
_objectWriter.FileSystemProcessor.FileSystemInterface.SetWritePosition(positionBeforeWrite, true);
return oid;
}
}
// If we reach this update, In Place Update was not possible. Do a
// normal update. Deletes the
// current object and creates a new one
if (oldMetaRepresentation == null && withIndex)
{
// We must load old meta representation to be able to compute
// old index key to update index
oldMetaRepresentation = _objectReader.ReadNonNativeObjectInfoFromPosition(null, oid, currentPosition,
false, false);
}
var previousObjectOID = lastHeader.GetPreviousObjectOID();
var nextObjectOid = lastHeader.GetNextObjectOID();
nnoi.SetPreviousInstanceOID(previousObjectOID);
nnoi.SetNextObjectOID(nextObjectOid);
// Mark the block of current object as deleted
_objectWriter.MarkAsDeleted(currentPosition, objectIsInConnectedZone);
// Creates the new object
oid = InsertNonNativeObject(oid, nnoi, false);
// This position after write must be call just after the insert!!
var positionAfterWrite = _objectWriter.FileSystemProcessor.FileSystemInterface.GetPosition();
if (hasObject)
{
// update cache
cache.AddObject(oid, @object, nnoi.GetHeader());
}
_objectWriter.FileSystemProcessor.FileSystemInterface.SetWritePosition(positionAfterWrite, true);
//TODO: why we are not using / checking that? (below is continuity)
nnoi.GetClassInfo().CommitedZoneInfo.GetNumberbOfObjects();
nnoi.GetClassInfo().UncommittedZoneInfo.GetNumberbOfObjects();
return oid;
}
catch (Exception e)
{
var message = string.Format("Error updating object {0} : {1}", nnoi, e);
throw new OdbRuntimeException(e, message);
}
finally
{
if (objectHasChanged)
{
if (withIndex)
ManageIndexesForUpdate(oid, nnoi, oldMetaRepresentation);
// triggers,FIXME passing null to old object representation
// (oldMetaRepresentation may be null)
_storageEngine.GetTriggerManager().ManageUpdateTriggerAfter(
nnoi.GetClassInfo().UnderlyingType, oldMetaRepresentation, hasObject ? @object : nnoi, oid);
}
}
}