| IDfsFile Interface |
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 two ReadStaticItemNext and ReadItemTimeStepNext are 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. Especially fro dfs0 files this is noticable; not very much data is being read for one item timestep, and it is faster reading data sequentially than moving the file pointer.
Namespace: DHI.Generic.MikeZero.DFS
Assembly: DHI.Generic.MikeZero.DFS (in DHI.Generic.MikeZero.DFS.dll) Version: 16.0.0.0 (11.1.1.1111)
SyntaxThe IDfsFile type exposes the following members.
Properties| Name | Description | |
|---|---|---|
 | FileInfo |
Information in the header.
|
| FileMode |
Mode of the current file
This is set to Closed when the file has been closed. |
| ItemInfo |
List of dynamic item info's.
|
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.
(Inherited from IDfsFileIO.) |
| DfsCurrentVersion |
Returns the current version of the Dfs file library
|
| Dispose | Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. (Inherited from IDisposable.) |
| FindItem |
Positions the file pointer at the location in the file where the
specified dynamic item at the specified time step starts.
(Inherited from IDfsFileIO.) |
| FindTimeStep |
Positions the file pointer at the location in the file where the
specified time step starts.
(Inherited from IDfsFileIO.) |
| 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.
(Inherited from IDfsFileIO.) |
| FlushTimeStep |
Flush cached data to the file. This will update the time part of the header information,
but not other parts of the header.
(Inherited from IDfsFileIO.)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.
(Inherited from IDfsFileIO.) |
| 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.
(Inherited from IDfsFileIO.)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. |
| ReadStaticItem |
Read the number staticItemNo static item from the file.
(Inherited from IDfsFileStaticIO.) |
| ReadStaticItemNext |
Reads the next static item. First time called it returns the first
static item.
If ReadStaticItem(Int32) is called for example with argument
staticItemNo 3, the next call to this method will return static item number 4.
If one of the methods reading/writing dynamic item data is called, see
IDfsFileIO, the static item number is reset, and
the next call to this method again returns the first item number.
(Inherited from IDfsFileStaticIO.) |
| Reset |
Resets the file pointer to point on the first dynamic item time step in the file.
(Inherited from IDfsFileIO.)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.
(Inherited from IDfsFileIO.)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. |
| WriteStaticItemData |
Write the static item back to the file. the staticItem must
originate from this file. This will update and overwrite the static item information and
the data of the static item.
(Inherited from IDfsFileStaticIO.) |
Extension Methods| Name | Description | |
|---|---|---|
 | CreateEmptyItemData(Int32) | Overloaded.
Create an IDfsItemDataT of the correct type for the
item with the given itemNumber.
(Defined by DfsExtensions.)The result can be used by ReadItemTimeStep(IDfsItemData, Int32) |
| CreateEmptyItemDataT(Int32) | Overloaded.
Create an IDfsItemDataT of the correct type for the
item with the given itemNumber.
(Defined by DfsExtensions.)The result can be used by ReadItemTimeStep(IDfsItemData, Int32) If not the item is of type {T}, an exception will be thrown. |
| CreateEmptyItemDatas | Overloaded.
Create an IDfsItemDataT of the correct type for each of the
dynamic items in the file.
(Defined by DfsExtensions.)The result can be used by ReadItemTimeStep(IDfsItemData, Int32) |
| CreateEmptyItemDatasT | Overloaded.
Create an IDfsItemDataT of the provided type for each of the
dynamic items in the file.
(Defined by DfsExtensions.)The result can be used by ReadItemTimeStep(IDfsItemData, Int32) If not all items are of type {T}, an exception will be thrown. |
| Search(DateTime) | Overloaded.
Searches the dfs file for the time step index of a time,
and returns the zero-based time step index. The time axis of the file
must be a calendar type time axis
(Defined by DfsExtensions.)NOTE: For the non-equidistant time axes, the metod will read the first item in the file for a number of timesteps in random order, performing a binary search in the file data on disc. This will be slow if used many times on the same file. For the equidistant time axis, the method will calculate the time step index directly without reading data from the file. |
| Search(Double) | Overloaded.
Searches the dfs file for the time step index of a time,
and returns the zero-based time step index.
(Defined by DfsExtensions.)NOTE: For the non-equidistant time axes, the metod will read the first item in the file for a number of timesteps in random order, performing a binary search in the file data on disc. This will be slow if used many times on the same file. For the equidistant time axis, the method will calculate the time step index directly without reading data from the file. |
See Also