Counter (JSimpleDB Main Classes 2.1.2 API)

java.lang.Object
- org.jsimpledb.Counter

```
public class Counter
extends Object
```
Represents a 64-bit counter value that can be adjusted concurrently by multiple transactions, typically without locking (depending on the underlying key/value store).
To define a field of type Counter, annotate the field's getter method as a normal field using @JField. No setter method should be defined. Counter fields do not support indexing or change listeners.
Note: during schema version change notification, counter field values appear as plain long values.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`adjust(long offset)` Adjust this counter's value by the specified amount.
`void`	`decrement()` Decrement this counter's value by one.
`long`	`get()` Read this counter's current value.
`void`	`increment()` Increment this counter's value by one.
`void`	`set(long value)` Set this counter's value.

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

- Method Detail
  - get
```
public long get()
```
    Read this counter's current value. Invoking this method will typically disable the lock-free behavior of adjust() in the current transaction.
    
    Returns:
    current value of the counter
    
    Throws:
    
    StaleTransactionException - if the transaction from which this instance was read is no longer usable
    
    DeletedObjectException - if the object from which this instance was read no longer exists
  - set
```
public void set(long value)
```
    Set this counter's value. Invoking this method will typically disable the lock-free behavior of adjust() in the current transaction.
    
    Parameters:
    value - new value for the counter
    
    Throws:
    
    StaleTransactionException - if the transaction from which this instance was read is no longer usable
    
    DeletedObjectException - if the object from which this instance was read no longer exists
  - adjust
```
public void adjust(long offset)
```
    Adjust this counter's value by the specified amount.
    
    Parameters:
    offset - amount to add to counter
    
    Throws:
    
    StaleTransactionException - if the transaction from which this instance was read is no longer usable
    
    DeletedObjectException - if the object from which this instance was read no longer exists
  - increment
```
public void increment()
```
    Increment this counter's value by one.
    
    Throws:
    
    StaleTransactionException - if the transaction from which this instance was read is no longer usable
    
    DeletedObjectException - if the object from which this instance was read no longer exists
  - decrement
```
public void decrement()
```
    Decrement this counter's value by one.
    
    Throws:
    
    StaleTransactionException - if the transaction from which this instance was read is no longer usable
    
    DeletedObjectException - if the object from which this instance was read no longer exists

Class Counter

Method Summary

Methods inherited from class java.lang.Object

Method Detail

get

set

adjust

increment

decrement