KuduScanToken (Kudu 1.0.1 API)

java.lang.Object
- org.apache.kudu.client.KuduScanToken

All Implemented Interfaces:

Comparable<KuduScanToken>
```
@InterfaceAudience.Public
@InterfaceStability.Unstable
public class KuduScanToken
extends Object
implements Comparable<KuduScanToken>
```
A scan token describes a partial scan of a Kudu table limited to a single contiguous physical location. Using the KuduScanToken.KuduScanTokenBuilder, clients can describe the desired scan, including predicates, bounds, timestamps, and caching, and receive back a collection of scan tokens. Each scan token may be separately turned into a scanner using intoScanner(org.apache.kudu.client.KuduClient), with each scanner responsible for a disjoint section of the table. Scan tokens may be serialized using the serialize() method and deserialized back into a scanner using the deserializeIntoScanner(byte[], org.apache.kudu.client.KuduClient) method. This allows use cases such as generating scan tokens in the planner component of a query engine, then sending the tokens to execution nodes based on locality, and then instantiating the scanners on those nodes. Scan token locality information can be inspected using the getTablet() method.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class KuduScanToken.KuduScanTokenBuilder
Builds a sequence of scan tokens.

Nested Classes
Modifier and Type	Class and Description
`static class`	`KuduScanToken.KuduScanTokenBuilder` Builds a sequence of scan tokens.

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`compareTo(KuduScanToken other)`
`static KuduScanner`	`deserializeIntoScanner(byte[] buf, KuduClient client)` Deserializes a `KuduScanToken` into a `KuduScanner`.
`LocatedTablet`	`getTablet()` Returns the tablet which the scanner created from this token will access.
`KuduScanner`	`intoScanner(KuduClient client)` Creates a `KuduScanner` from this scan token.
`byte[]`	`serialize()` Serializes this `KuduScanToken` into a byte array.
`static String`	`stringifySerializedToken(byte[] buf, KuduClient client)` Formats the serialized token for debug printing.

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

- Method Detail
  - getTablet
```
public LocatedTablet getTablet()
```
    Returns the tablet which the scanner created from this token will access.
    
    Returns:
    the located tablet
  - intoScanner
```
public KuduScanner intoScanner(KuduClient client)
                        throws Exception
```
    Creates a KuduScanner from this scan token.
    
    Parameters:
    client - a Kudu client for the cluster
    
    Returns:
    a scanner for the scan token
    
    Throws:
    
    Exception
  - serialize
```
public byte[] serialize()
                 throws IOException
```
    Serializes this KuduScanToken into a byte array.
    
    Returns:
    the serialized scan token
    
    Throws:
    
    IOException
  - deserializeIntoScanner
```
public static KuduScanner deserializeIntoScanner(byte[] buf,
                                 KuduClient client)
                                          throws IOException
```
    Deserializes a KuduScanToken into a KuduScanner.
    
    Parameters:
    buf - a byte array containing the serialized scan token.
    client - a Kudu client for the cluster
    
    Returns:
    a scanner for the serialized scan token
    
    Throws:
    
    IOException
  - stringifySerializedToken
```
public static String stringifySerializedToken(byte[] buf,
                              KuduClient client)
                                       throws IOException
```
    Formats the serialized token for debug printing.
    
    Parameters:
    buf - the serialized token
    client - a Kudu client for the cluster to which the token belongs
    
    Returns:
    a debug string
    
    Throws:
    
    IOException
  - compareTo
```
public int compareTo(KuduScanToken other)
```
    Specified by:
    
    compareTo in interface Comparable<KuduScanToken>

Class KuduScanToken

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getTablet

intoScanner

serialize

deserializeIntoScanner

stringifySerializedToken

compareTo