WriterImpl (hive-dwrf 0.8.5 API)

java.lang.Object
- com.facebook.hive.orc.WriterImpl

All Implemented Interfaces:

MemoryManager.Callback, Writer
```
public class WriterImpl
extends Object
implements Writer, MemoryManager.Callback
```
An ORC file writer. The file is divided into stripes, which is the natural unit of work when reading. Each stripe is buffered in memory until the memory reaches the stripe size and then it is written out broken down by columns. Each column is written by a TreeWriter that is specific to that type of column. TreeWriters may have children TreeWriters that handle the sub-types. Each of the TreeWriters writes the column's data as a set of streams. This class is synchronized so that multi-threaded access is ok. In particular, because the MemoryManager is shared between writers, this class assumes that checkMemory may be called from a separate thread.

Field Summary

Fields
Modifier and Type	Field and Description
`static long`	`BASE_TIMESTAMP`
`static int`	`COMPRESSED_PRESENT_STREAM_INDEX_ENTRIES`
`static int`	`INT_BYTE_SIZE`
`static int`	`LONG_BYTE_SIZE`
`static int`	`MILLIS_PER_SECOND`
`static int`	`SHORT_BYTE_SIZE`
`static int`	`UNCOMPRESSED_PRESENT_STREAM_INDEX_ENTRIES`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addRow(Object row)` Add a row to the ORC file.
`void`	`addStripe(StripeInformation si, byte[] data)`
`void`	`addUserMetadata(String name, ByteBuffer value)` Add arbitrary meta-data to the ORC file.
`boolean`	`checkMemory(double newScale)` The writer needs to check its memory usage
`void`	`close()` Flush all of the buffers and close the file.
`void`	`close(ColumnStatisticsImpl[] columnStats)`
`void`	`enterLowMemoryMode()` If the initial amount of memory needed by a writer is greater than the amount allocated, call this to try to get the writers to use less memory to avoid an OOM
`long`	`getRowRawDataSize()` Get the raw data size of the last row added

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

- Field Detail
  - SHORT_BYTE_SIZE
```
public static final int SHORT_BYTE_SIZE
```
    See Also:
    
    Constant Field Values
  - INT_BYTE_SIZE
```
public static final int INT_BYTE_SIZE
```
    See Also:
    
    Constant Field Values
  - LONG_BYTE_SIZE
```
public static final int LONG_BYTE_SIZE
```
    See Also:
    
    Constant Field Values
  - UNCOMPRESSED_PRESENT_STREAM_INDEX_ENTRIES
```
public static final int UNCOMPRESSED_PRESENT_STREAM_INDEX_ENTRIES
```
    See Also:
    
    Constant Field Values
  - COMPRESSED_PRESENT_STREAM_INDEX_ENTRIES
```
public static final int COMPRESSED_PRESENT_STREAM_INDEX_ENTRIES
```
    See Also:
    
    Constant Field Values
  - MILLIS_PER_SECOND
```
public static final int MILLIS_PER_SECOND
```
    See Also:
    
    Constant Field Values
  - BASE_TIMESTAMP
```
public static final long BASE_TIMESTAMP
```
- Method Detail
  - enterLowMemoryMode
```
public void enterLowMemoryMode()
                        throws IOException
```
    Description copied from interface: MemoryManager.Callback
    
    If the initial amount of memory needed by a writer is greater than the amount allocated, call this to try to get the writers to use less memory to avoid an OOM
    
    Specified by:
    
    enterLowMemoryMode in interface MemoryManager.Callback
    
    Throws:
    
    IOException
  - checkMemory
```
public boolean checkMemory(double newScale)
                    throws IOException
```
    Description copied from interface: MemoryManager.Callback
    
    The writer needs to check its memory usage
    
    Specified by:
    
    checkMemory in interface MemoryManager.Callback
    
    Parameters:
    
    newScale - the current scale factor for memory allocations
    
    Returns:
    
    true if the writer was over the limit
    
    Throws:
    
    IOException
  - addStripe
```
public void addStripe(StripeInformation si,
                      byte[] data)
               throws IOException
```
    Throws:
    
    IOException
  - addUserMetadata
```
public void addUserMetadata(String name,
                            ByteBuffer value)
```
    Description copied from interface: Writer
    
    Add arbitrary meta-data to the ORC file. This may be called at any point until the Writer is closed. If the same key is passed a second time, the second value will replace the first.
    
    Specified by:
    
    addUserMetadata in interface Writer
    
    Parameters:
    
    name - a key to label the data with.
    
    value - the contents of the metadata.
  - addRow
```
public void addRow(Object row)
            throws IOException
```
    Description copied from interface: Writer
    
    Add a row to the ORC file.
    
    Specified by:
    
    addRow in interface Writer
    
    Parameters:
    
    row - the row to add
    
    Throws:
    
    IOException
  - getRowRawDataSize
```
public long getRowRawDataSize()
```
    Description copied from interface: Writer
    
    Get the raw data size of the last row added
    
    Specified by:
    
    getRowRawDataSize in interface Writer
  - close
```
public void close()
           throws IOException
```
    Description copied from interface: Writer
    
    Flush all of the buffers and close the file. No methods on this writer should be called afterwards.
    
    Specified by:
    
    close in interface Writer
    
    Throws:
    
    IOException
  - close
```
public void close(ColumnStatisticsImpl[] columnStats)
           throws IOException
```
    Throws:
    
    IOException

Class WriterImpl

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SHORT_BYTE_SIZE

INT_BYTE_SIZE

LONG_BYTE_SIZE

UNCOMPRESSED_PRESENT_STREAM_INDEX_ENTRIES

COMPRESSED_PRESENT_STREAM_INDEX_ENTRIES

MILLIS_PER_SECOND

BASE_TIMESTAMP

Method Detail

enterLowMemoryMode

checkMemory

addStripe

addUserMetadata

addRow

getRowRawDataSize

close

close