IDfsFileIO Interface

Interface containing the raw read and write functions of the dynamic items in a dfs file.

The functionality is based on a file pointer pointing into the file on the disk.

Whenever calling one of the read or write methods, the file pointer will move to the next static item or dynamic item-timestep in the file.

The methods reading the next static or dynamic item will depend on previous calls to any of the read and write methods.

The ReadItemTimeStepNext is the most efficient way of iterating through the data in the file. If iterating in another way, for example over all the time steps of one item, and then the next item, this will imply a performance hit, since the file pointer needs to be repositioned at each read.

Namespace: DHI.Generic.MikeZero.DFS
Assembly: DHI.Generic.MIKEZero.DFS (in DHI.Generic.MIKEZero.DFS.dll) Version: 19.0.0.0 (11.1.1.1111)

Syntax

C++

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public interface IDfsFileIO

Public Interface IDfsFileIO

public interface class IDfsFileIO

type IDfsFileIO =  interface end

The IDfsFileIO type exposes the following members.

Methods

	Name	Description
	Close	Close the file and release all ressources associated with it. The header information is still valid (for reading) even though the file has been closed.
	FindItem	Positions the file pointer at the location in the file where the specified dynamic item at the specified time step starts.
	FindTimeStep	Positions the file pointer at the location in the file where the specified time step starts.
	Flush	Flush cached data to the file. This will especially update the header information, such that if another process is reading the file while it is being read, the new header information can be retrieved.
	FlushTimeStep	Flush cached data to the file. This will update the time part of the header information, but not other parts of the header. Compared to the Flush method; the Flush will update statistics of all items (if enabled) and all modifications to the header data. This method will only update the time part. The Flush method can be an expensive operations especially for files with many dynamic items. This method is independent of the file at hand.
	ReadItemTimeStep(Int32, Int32)	Reads the dynamic item-timestep as specified from the file. It throws an exception if itemNumber or timestepIndex is out of range.
	ReadItemTimeStep(IDfsItemData, Int32)	Read the specified item and time step. With this you can reuse the data buffer in IDfsItemData, Data. The data is updated in place. If the data from one timestep is to be saved for later, the user is responsible to copy the data before using this method again.
	ReadItemTimeStepNext	Reads the next dynamic item-timestep. First time called it returns the first timestep of the first item. It cycles through each timestep, and each item in the timestep. For a file with 3 items, it returns (itemnumber, timestepIndex) in the following order: (1,0), (2,0), (3,0), (1,1), (2,1), (3,1), (1,2), etc. If one of the ReadItemTimeStep is called with for example (1,4) the next call to this method will continue from there and return (2,4). If one of the methods reading/writing static item data is called, the iterator is reset, and the next call to this method again returns the first item-timestep. This is the most efficient way to iterate through all the items and timesteps in a file, since it iterates exactly as the data is stored on the disk.
	Reset	Resets the file pointer to point on the first dynamic item time step in the file. Can also be used if it is required to restart reading the static items.
	WriteItemTimeStep	Writes data to the specified item and timestep in the file. If the item-timestep exists already, data is updated. If it does not exist, the item number and timestep index must match exactly the next item-timestep after the last one in the file. The size of the data must match the data size of the item that is to be written. The time value is only relevant for files with non-equidistant time axis. For files with an equidistant time axis, the time value is ignored, and a zero can be used.
	WriteItemTimeStepNext	Writes the next dynamic item-timestep. If the file pointer points to the end of the file, this will append a new item-timestep to the file. If the file pointer points to an existing item-timestep, the data of that item-timestep is updated. Remember that the file pointer position depends on the mode that the file was opened: In edit mode the file pointer points at the first item-timestep. In append mode the file pointer points initially at the end of file. It iterates over the item-timesteps as the ReadItemTimeStepNext, see there for more details. This is the most efficient way to iterate through and update/append the items and timesteps in a file, since it iterates exactly as the data is stored on the disk. The size of the data must match the data size of the item that is to be written. The time value is only relevant for files with non-equidistant time axis. For files with an equidistant time axis, the time value is ignored, and a zero can be used.

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Reference

DHI.Generic.MikeZero.DFS Namespace