Struct nats::kv::Store

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pub struct Store { /* private fields */ }

Available on crate feature unstable only.

Expand description

A key value store

Implementations

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impl Store

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pub fn status(&self) -> Result<BucketStatus>

Returns the status of the bucket

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pub fn entry(&self, key: &str) -> Result<Option<Entry>>

Returns the latest entry for the key, if any.

Examples

bucket.put("foo", b"bar")?;
let maybe_entry = bucket.entry("foo")?;
if let Some(entry) = maybe_entry {
  println!("Found entry {:?}", entry);
}

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pub fn get(&self, key: &str) -> Result<Option<Vec<u8>>>

Returns the latest value for the key, if any.

Examples

bucket.put("foo", b"bar")?;
let maybe_value = bucket.get("foo")?;
if let Some(value) = maybe_value {
  println!("Found value {:?}", value);
}

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pub fn put(&self, key: &str, value: impl AsRef<[u8 ]>) -> Result<u64>

Places the new value for the key into the bucket.

Examples

bucket.put("foo", b"bar")?;

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pub fn create(&self, key: &str, value: impl AsRef<[u8 ]>) -> Result<u64>

Creates the key/value pair if it does not exist or is marked for deletion.

Examples

bucket.purge("foo")?;
bucket.create("foo", b"bar")?;

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pub fn update(
 &self,
 key: &str,
 value: impl AsRef<[u8 ]>,
 revision: u64
) -> Result<u64>

Updates the value if the latest revision matches.

Examples

let revision = bucket.put("foo", b"bar")?;
let new_revision = bucket.update("foo", b"baz", revision)?;

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pub fn delete(&self, key: &str) -> Result<()>

Marks an entry as deleted by placing a delete marker but leaves the revision history intact.

Examples

bucket.create("foo", b"bar")?;
bucket.delete("foo")?;

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pub fn purge(&self, key: &str) -> Result<()>

Remove any entries associated with the key and all historical revisions.

Examples

bucket.create("foo", b"bar")?;
bucket.purge("foo")?;

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pub fn keys(&self) -> Result<Keys>

Returns an iterator which iterate over all the current keys.

Examples

bucket.put("foo", b"fizz")?;
bucket.put("bar", b"buzz")?;

let mut keys = bucket.keys()?;

assert_eq!(keys.next(), Some("foo".to_string()));
assert_eq!(keys.next(), Some("bar".to_string()));

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pub fn history(&self, key: &str) -> Result<History>

Returns an iterator which iterates over each entry in historical order.

Examples

let bucket = context.create_key_value(&Config {
  bucket: "history_iter".to_string(),
  history: 2,
  ..Default::default()
})?;

bucket.put("foo", b"fizz")?;
bucket.put("foo", b"buzz")?;

let mut history = bucket.history("foo")?;

let next = history.next().unwrap();
assert_eq!(next.key, "foo".to_string());
assert_eq!(next.value, b"fizz");

let next = history.next().unwrap();
assert_eq!(next.key, "foo".to_string());
assert_eq!(next.value, b"buzz");