Compare Exchange in Cluster-Wide Session
-
Compare-Exchange items can be created and managed on the advanced session (
session.advanced
).
Other options are listed in this compare-exchange overview. -
When working with compare-exchange items from the session,
the session must be opened as a cluster-wide session. -
In this page:
Create compare-exchange
Example
// The session must be first opened with cluster-wide mode
$session->advanced()->clusterTransaction()->createCompareExchangeValue(
key: "Best NoSQL Transactional Database",
value: "RavenDB"
);
$session->saveChanges();
saveChanges()
throws aConcurrencyException
if the key already exists.- An
InvalidOperationException
exception is thrown if the session was Not opened as cluster-wide.
Syntax
$session->advanced()->clusterTransaction()->createCompareExchangeValue($key, $value);
Parameters | Type | Description |
---|---|---|
key | string |
The compare-exchange item key. This string can be up to 512 bytes. |
value | T |
The associated value to store for the key |
Return Value | Description |
---|---|
CompareExchangeValue<T> |
The new compare-exchange item is returned |
The CompareExchangeValue
Parameters | Type | Description |
---|---|---|
key | string |
The compare-exchange item key. This string can be up to 512 bytes. |
value | T |
The value associated with the key |
index | long |
Index for concurrency control |
Get compare-exchange
Get single value
$session->advanced()->clusterTransaction()->getCompareExchangeValue(null, $key);
Parameters | Type | Description |
---|---|---|
key | string |
The key to retrieve |
Return Value | Description |
---|---|
CompareExchangeValue<T> |
The compare exchange value, or null if it doesn't exist |
Get multiple values
$session->advanced()->clusterTransaction()->getCompareExchangeValues(null, $keys);
Parameters | Type | Description |
---|---|---|
keys | string[] |
Array of keys to retrieve |
Return Value | Description |
---|---|
Dictionary<string, CompareExchangeValue<T>> |
If a key doesn't exists the associate value will be null |
Get compare-exchange lazily
// Single value
$session->advanced()->clusterTransaction()->lazily()->getCompareExchangeValue(null, $key);
// Multiple values
$session->advanced()->clusterTransaction()->lazily()->getCompareExchangeValues(null, $keys);
Parameters | Type | Description |
---|---|---|
key | string |
The key to retrieve |
keys | string[] |
Array of keys to retrieve |
Return Value | Description |
---|---|
Lazy<CompareExchangeValue<T>> |
If the key doesn't exist it will return null |
Lazy<Dictionary<string, CompareExchangeValue<T>>> |
If a key doesn't exists the associate value will be null |
Delete compare-exchange
// Delete by key & index
$session->advanced()->clusterTransaction()->deleteCompareExchangeValue($key, $index);
// Delete by compare-exchange item
$session->advanced()->clusterTransaction()->deleteCompareExchangeValue($item);
Parameters | Type | Description |
---|---|---|
key | string |
The key of the compare-exchange item to delete |
index | long |
The index of this compare-exchange item |
item | CompareExchangeValue<T> |
The compare-exchange item to delete |