StreamingDataset

java.lang.Object
- com.inductiveautomation.ignition.common.StreamingDataset

All Implemented Interfaces:

Dataset, StreamingDatasetWriter, java.io.Serializable
```
public class StreamingDataset
extends java.lang.Object
implements Dataset, StreamingDatasetWriter
```
This is an implementation of Dataset that received data in a streaming manner. All of the functions will block until the information requested is available, dictated by an overall timeout that can be set.
The dataset can operate as a normal dataset, or if "transientDataMode" is true, will discard data after it is read, freeing up memory when using a large dataset for data processing purposes.
Since the streaming dataset won't normally know how many rows to expect (unless it was told the number in the initialize), the interaction with it is a little different than normal. Instead of calling getRowCount(), which will return -1 if the number of rows isn't known, it's better to call hasRow(x) (with x being the next row you hope to get) until it returns False.
If you need to treat this dataset as a normal dataset, you can call readFully() to block and retrieve all data. After that, it will behave like a normal dataset, with getRowCount() returning the correct value.

See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`protected static class`	`StreamingDataset.Column`
`static class`	`StreamingDataset.Row`
`static class`	`StreamingDataset.StreamingException`

Constructor Summary

Constructors
Constructor and Description
`StreamingDataset()`
`StreamingDataset(long waitTimeout, boolean transientDataMode)` Constructs the dataset with the given timeout and mode.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`binarySearch(int column, java.lang.Object key)` Performs a binary search on the specified column, looking for the specified key.
`protected void`	`checkError()`
`void`	`finish()` Notifies the writer to close- all data has been written.
`void`	`finishWithError(java.lang.Exception e)` Finishes the stream while indicating an error occurred.
`int`	`getColumnCount()` Returns the number of columns.
`int`	`getColumnIndex(java.lang.String name)` Returns the index of the given column, case insensitive
`java.lang.String`	`getColumnName(int col)` Returns the name of the given column.
`java.util.List<java.lang.String>`	`getColumnNames()` Returns an unmodifiable list of this dataset's column names, in order.
`java.lang.Class<?>`	`getColumnType(int col)` Returns the type of the given column.
`java.util.List<java.lang.Class<?>>`	`getColumnTypes()` Returns an unmodifiable list of this dataset's column types, in order.
`int`	`getInternalRowCount()` Mostly for unit testing
`double`	`getPrimitiveValueAt(int row, int col)` If the given column is a numeric type or a Date, then the value will be returned as a double.
`QualityCode`	`getQualityAt(int row, int col)` Returns the quality of the value at the given location.
`StreamingDataset.Row`	`getRow(int row)`
`int`	`getRowCount()` Return the number of rows in this dataset
`java.lang.Object`	`getValueAt(int row, int col)` Returns the value in the dataset at the given location.
`java.lang.Object`	`getValueAt(int row, java.lang.String colName)` Returns the value at the given row and at a column named colName.
`boolean`	`hasRow(int row)` This is somewhat similar to isClosed, but will potentially wait for more data to come in, or for the dataset to close.
`void`	`initialize(java.lang.String[] columnNames, java.lang.Class<?>[] columnTypes, boolean supportsQuality, int expectedRows)` Initializes the streaming dataset with important information, primarily the column names and types.
`boolean`	`isClosed()` Returns whether this dataset has been closed to further writing.
`static StreamingDataset`	`newWriter()` Returns a new streaming dataset that is only intended to write, and not read.
`void`	`readFully()` Blocks until all of the data has been read.
`void`	`setBlockingWrites(boolean value)` If true, the dataset will block on writes until the previously written row is read (standard producer/consumer).
`void`	`setTransientMode(boolean transientMode)`
`protected StreamingDataset.Row`	`waitFor(int row)`
`protected void`	`waitForColumns()`
`void`	`write(java.lang.Object[] data, QualityCode[] quality)` Writes a row with the given data.
`void`	`write(StreamingDataset.Row row)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.inductiveautomation.ignition.common.Dataset
getColumnAsList

- Constructor Detail
  - StreamingDataset
```
public StreamingDataset()
```
  - StreamingDataset
```
public StreamingDataset(long waitTimeout,
                        boolean transientDataMode)
```
    Constructs the dataset with the given timeout and mode. "Transient Data Mode" means that data will be discarded after it is read, so all requests to getData() should only move forward in row index. This is useful for minimizing memory usage with very large datasets when this object is only being used for data processing.
- Method Detail
  - setTransientMode
```
public void setTransientMode(boolean transientMode)
```
  - newWriter
```
public static StreamingDataset newWriter()
```
    Returns a new streaming dataset that is only intended to write, and not read. Essentially is a plain streaming dataset, with blocking writes enabled.
  - setBlockingWrites
```
public void setBlockingWrites(boolean value)
```
    If true, the dataset will block on writes until the previously written row is read (standard producer/consumer). This prevents a build up in memory of unread rows.
  - readFully
```
public void readFully()
```
    Blocks until all of the data has been read. Will throw a StreamingException if the overall timeout is exceeded.
  - isClosed
```
public boolean isClosed()
```
    Returns whether this dataset has been closed to further writing.
  - hasRow
```
public boolean hasRow(int row)
```
    This is somewhat similar to isClosed, but will potentially wait for more data to come in, or for the dataset to close. Will return immediately if we know there is a row greater than the requested row available. In general, this function should be called to wait for new data before each call to getValueAt.
  - checkError
```
protected void checkError()
```
  - waitForColumns
```
protected void waitForColumns()
```
  - getColumnNames
```
public java.util.List<java.lang.String> getColumnNames()
```
    Description copied from interface: Dataset
    
    Returns an unmodifiable list of this dataset's column names, in order.
    
    Specified by:
    
    getColumnNames in interface Dataset
  - getColumnTypes
```
public java.util.List<java.lang.Class<?>> getColumnTypes()
```
    Description copied from interface: Dataset
    
    Returns an unmodifiable list of this dataset's column types, in order.
    
    Specified by:
    
    getColumnTypes in interface Dataset
  - getColumnCount
```
public int getColumnCount()
```
    Description copied from interface: Dataset
    
    Returns the number of columns.
    
    Specified by:
    
    getColumnCount in interface Dataset
  - getRowCount
```
public int getRowCount()
```
    Description copied from interface: Dataset
    
    Return the number of rows in this dataset
    
    Specified by:
    
    getRowCount in interface Dataset
  - getColumnIndex
```
public int getColumnIndex(java.lang.String name)
```
    Description copied from interface: Dataset
    
    Returns the index of the given column, case insensitive
    
    Specified by:
    
    getColumnIndex in interface Dataset
    
    Parameters:
    
    name - the name of the column to look upw
    
    Returns:
    
    the index of the column
  - getColumnName
```
public java.lang.String getColumnName(int col)
```
    Description copied from interface: Dataset
    
    Returns the name of the given column.
    
    Specified by:
    
    getColumnName in interface Dataset
  - getColumnType
```
public java.lang.Class<?> getColumnType(int col)
```
    Description copied from interface: Dataset
    
    Returns the type of the given column.
    
    Specified by:
    
    getColumnType in interface Dataset
  - waitFor
```
protected StreamingDataset.Row waitFor(int row)
```
  - getValueAt
```
public java.lang.Object getValueAt(int row,
                                   int col)
```
    Description copied from interface: Dataset
    
    Returns the value in the dataset at the given location.
    
    Specified by:
    
    getValueAt in interface Dataset
  - getQualityAt
```
public QualityCode getQualityAt(int row,
                                int col)
```
    Description copied from interface: Dataset
    
    Returns the quality of the value at the given location.
    
    Specified by:
    
    getQualityAt in interface Dataset
  - getValueAt
```
public java.lang.Object getValueAt(int row,
                                   java.lang.String colName)
```
    Description copied from interface: Dataset
    
    Returns the value at the given row and at a column named colName. Column name matching is case insensitive.
    
    Specified by:
    
    getValueAt in interface Dataset
  - getPrimitiveValueAt
```
public double getPrimitiveValueAt(int row,
                                  int col)
```
    Description copied from interface: Dataset
    
    If the given column is a numeric type or a Date, then the value will be returned as a double. (Charts uses this functionality to provide a seamless interface with certain optimized dataset implementations.
    
    Specified by:
    
    getPrimitiveValueAt in interface Dataset
  - getRow
```
public StreamingDataset.Row getRow(int row)
```
  - binarySearch
```
public int binarySearch(int column,
                        java.lang.Object key)
```
    Description copied from interface: Dataset
    
    Performs a binary search on the specified column, looking for the specified key. Column MUST be sorted in ascending order. Dataset provides an inefficient default implementation of binary search that allocates a new array list for the entire column.
    
    Specified by:
    
    binarySearch in interface Dataset
    
    Returns:
    
    index of the search key, if it is contained in the list; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the list: the index of the first element greater than the key, or list.size(), if all elements in the list are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.
  - initialize
```
public void initialize(java.lang.String[] columnNames,
                       java.lang.Class<?>[] columnTypes,
                       boolean supportsQuality,
                       int expectedRows)
```
    Description copied from interface: StreamingDatasetWriter
    
    Initializes the streaming dataset with important information, primarily the column names and types. If supportsQuality is true, it is expected that every value added has an associated quality. expectedRows gives an idea as to how many rows will be returned- useful for progress indication. Should be -1 if the number cannot be known in advance.
    
    Specified by:
    
    initialize in interface StreamingDatasetWriter
    
    expectedRows - -1 if not known, otherwise the number of rows that will be in the dataset.
  - write
```
public void write(java.lang.Object[] data,
                  QualityCode[] quality)
           throws java.io.IOException
```
    Description copied from interface: StreamingDatasetWriter
    
    Writes a row with the given data. Bounds and order of arrays must match that used to call initialize. quality may be null if dataset does not support quality.
    
    Specified by:
    
    write in interface StreamingDatasetWriter
    
    Throws:
    
    java.io.IOException
  - write
```
public void write(StreamingDataset.Row row)
```
  - finish
```
public void finish()
```
    Description copied from interface: StreamingDatasetWriter
    
    Notifies the writer to close- all data has been written. Should be called from a finally block.
    
    Specified by:
    
    finish in interface StreamingDatasetWriter
  - finishWithError
```
public void finishWithError(java.lang.Exception e)
```
    Description copied from interface: StreamingDatasetWriter
    
    Finishes the stream while indicating an error occurred. Either this, or the successful finish(), must be called.
    
    Specified by:
    
    finishWithError in interface StreamingDatasetWriter
  - getInternalRowCount
```
public int getInternalRowCount()
```
    Mostly for unit testing

Class StreamingDataset

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface com.inductiveautomation.ignition.common.Dataset

Constructor Detail

StreamingDataset

StreamingDataset

Method Detail

setTransientMode

newWriter

setBlockingWrites

readFully

isClosed

hasRow

checkError

waitForColumns

getColumnNames

getColumnTypes

getColumnCount

getRowCount

getColumnIndex

getColumnName

getColumnType

waitFor

getValueAt

getQualityAt

getValueAt

getPrimitiveValueAt

getRow

binarySearch

initialize

write

write

finish

finishWithError

getInternalRowCount