Struct wnfs_common::Metadata

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pub struct Metadata(pub BTreeMap<String, Ipld>);

Expand description

The metadata of a node in the WNFS file system.

§Examples

use wnfs_common::Metadata;
use chrono::Utc;

let metadata = Metadata::new(Utc::now());

println!("{:?}", metadata);

Tuple Fields§

§0: BTreeMap<String, Ipld>

Implementations§

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impl Metadata

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pub fn new(time: DateTime<Utc>) -> Self

Creates a new metadata.

§Examples

use wnfs_common::Metadata;
use chrono::Utc;

let metadata = Metadata::new(Utc::now());

println!("{:?}", metadata);

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pub fn upsert_mtime(&mut self, time: DateTime<Utc>)

Updates modified time.

§Examples

use wnfs_common::Metadata;
use chrono::{Utc, TimeZone, Duration};

let mut metadata = Metadata::new(Utc::now());
let time = Utc::now() + Duration::days(1);

metadata.upsert_mtime(time);

let imprecise_time = Utc.timestamp_opt(time.timestamp(), 0).single();
assert_eq!(metadata.get_modified(), imprecise_time);

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pub fn get_created(&self) -> Option<DateTime<Utc>>

Returns the created time.

§Examples

use wnfs_common::Metadata;
use chrono::{Utc, TimeZone};

let time = Utc::now();
let metadata = Metadata::new(time);

let imprecise_time = Utc.timestamp_opt(time.timestamp(), 0).single();
assert_eq!(metadata.get_created(), imprecise_time);

Will return None if there’s no created metadata on the node or if it’s not a second-based POSIX timestamp integer.

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pub fn get_modified(&self) -> Option<DateTime<Utc>>

Returns the modified time.

§Examples

use wnfs_common::Metadata;
use chrono::{Utc, TimeZone};

let time = Utc::now();
let metadata = Metadata::new(time);

let imprecise_time = Utc.timestamp_opt(time.timestamp(), 0).single();
assert_eq!(metadata.get_modified(), imprecise_time);

Will return None if there’s no created metadata on the node or if it’s not a second-based POSIX timestamp integer.

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pub fn put(&mut self, key: &str, value: Ipld) -> Option<Ipld>

Inserts a key-value pair into the metadata. If the key already existed, the value is updated, and the old value is returned.

§Examples

use wnfs_common::Metadata;
use chrono::Utc;
use libipld::Ipld;

let mut metadata = Metadata::new(Utc::now());
metadata.put("foo", Ipld::String("bar".into()));
assert_eq!(metadata.0.get("foo"), Some(&Ipld::String("bar".into())));
metadata.put("foo", Ipld::String("baz".into()));
assert_eq!(metadata.0.get("foo"), Some(&Ipld::String("baz".into())));

Returns (self, old_value), where old_value is None if the key did not exist prior to this call.

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pub fn get(&self, key: &str) -> Option<&Ipld>

Returns metadata value behind given key.

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pub fn put_serializable( &mut self, key: &str, value: impl Serialize ) -> Result<Option<Ipld>>

Serializes and inserts given value at given key in metadata.

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pub fn get_deserializable<D: DeserializeOwned>( &self, key: &str ) -> Option<Result<D>>

Returns deserialized metadata value behind given key.

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pub fn delete(&mut self, key: &str) -> Option<Ipld>

Deletes a key from the metadata.

§Examples

use wnfs_common::Metadata;
use chrono::Utc;
use libipld::Ipld;

let mut metadata = Metadata::new(Utc::now());
metadata.put("foo", Ipld::String("bar".into()));
assert_eq!(metadata.0.get("foo"), Some(&Ipld::String("bar".into())));
metadata.delete("foo");
assert_eq!(metadata.0.get("foo"), None);

Returns Some<Ipld> if the key existed prior to this call, otherwise None.

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pub fn update(&mut self, other: &Self)

Updates this metadata with the contents of another metadata. merge strategy is to take theirs.

§Examples

use wnfs_common::Metadata;
use chrono::Utc;
use libipld::Ipld;

let mut metadata1 = Metadata::new(Utc::now());
metadata1.put("foo", Ipld::String("bar".into()));
let mut metadata2 = Metadata::new(Utc::now());
metadata2.put("foo", Ipld::String("baz".into()));
metadata1.update(&metadata2);
assert_eq!(metadata1.0.get("foo"), Some(&Ipld::String("baz".into())));