Struct StoreLayerBuilder 

pub struct StoreLayerBuilder { /* private fields */ }

A wrapper over a SimpleLayerBuilder, providing a thread-safe sharable interface.

The SimpleLayerBuilder requires one to have a mutable reference to the underlying LayerBuilder, and on commit it will be consumed. This builder only requires an immutable reference, and uses a futures-aware read-write lock to synchronize access to it between threads. Also, rather than consuming itself on commit, this wrapper will simply mark itself as having committed, returning errors on further calls.

Implementations

impl StoreLayerBuilder

pub fn with_builder<R, F: FnOnce(&mut Box<dyn LayerBuilder>) -> R>( &self, f: F, ) -> Result<R, Error>

pub fn name(&self) -> [u32; 5]

Returns the name of the layer being built.

pub fn parent(&self) -> Option<Arc<dyn Layer>>

Returns the parent layer this builder is building on top of, if any.

If there’s no parent, this returns None.

pub fn add_value_triple(&self, triple: ValueTriple) -> Result<(), Error>

Add a string triple.

Examples found in repository

examples/write_to_graph.rs (line 87)

async fn process_commands(store_path: &str, graph: &str) -> io::Result<()> {
    let store = open_directory_store(store_path);
    let graph = store
        .open(graph)
        .await?
        .expect(&format!("expected graph {} to exist", graph));

    // There are two types of builders. One creates a new base layer,
    // which has no parent. The other creates a child layer, which has
    // another layer as its parent.
    let builder = match graph.head().await? {
        Some(layer) => layer.open_write().await?,
        None => store.create_base_layer().await?,
    };
    let mut stdin = io::BufReader::new(io::stdin()).lines();

    while let Some(line) = stdin.next_line().await? {
        let segment = line.trim();
        if segment.len() == 0 {
            continue;
        }

        let command = parse_command(segment).await?;

        // add all the input data into the builder.
        // The builder keeps an in-memory list of added and removed
        // triples. If the same triple is added and removed on the
        // same builder, it is a no-op. This is even the case when it
        // is then later re-added on the same builder.
        //
        // Since no io is happening, adding triples to the builder is
        // not a future.
        match command {
            Command::Add(triple) => builder.add_value_triple(triple)?,
            Command::Remove(triple) => builder.remove_value_triple(triple)?,
        }
    }

    // When commit is called, the builder writes its data to
    // persistent storage.
    let layer = builder.commit().await?;

    // While a layer exists now, it's not yet attached to anything,
    // and is therefore unusable unless you know the exact identifier
    // of the layer itself. To make this the graph data, we have to
    // set the grap head to this layer.
    graph.set_head(&layer).await?;

    println!(
        "Added: {}, removed: {}",
        layer.triple_layer_addition_count().await?,
        layer.triple_layer_removal_count().await?
    );

    Ok(())
}

pub fn add_id_triple(&self, triple: IdTriple) -> Result<(), Error>

Add an id triple.

pub fn remove_value_triple(&self, triple: ValueTriple) -> Result<(), Error>

Remove a string triple.

Examples found in repository

examples/write_to_graph.rs (line 88)

async fn process_commands(store_path: &str, graph: &str) -> io::Result<()> {
    let store = open_directory_store(store_path);
    let graph = store
        .open(graph)
        .await?
        .expect(&format!("expected graph {} to exist", graph));

    // There are two types of builders. One creates a new base layer,
    // which has no parent. The other creates a child layer, which has
    // another layer as its parent.
    let builder = match graph.head().await? {
        Some(layer) => layer.open_write().await?,
        None => store.create_base_layer().await?,
    };
    let mut stdin = io::BufReader::new(io::stdin()).lines();

    while let Some(line) = stdin.next_line().await? {
        let segment = line.trim();
        if segment.len() == 0 {
            continue;
        }

        let command = parse_command(segment).await?;

        // add all the input data into the builder.
        // The builder keeps an in-memory list of added and removed
        // triples. If the same triple is added and removed on the
        // same builder, it is a no-op. This is even the case when it
        // is then later re-added on the same builder.
        //
        // Since no io is happening, adding triples to the builder is
        // not a future.
        match command {
            Command::Add(triple) => builder.add_value_triple(triple)?,
            Command::Remove(triple) => builder.remove_value_triple(triple)?,
        }
    }

    // When commit is called, the builder writes its data to
    // persistent storage.
    let layer = builder.commit().await?;

    // While a layer exists now, it's not yet attached to anything,
    // and is therefore unusable unless you know the exact identifier
    // of the layer itself. To make this the graph data, we have to
    // set the grap head to this layer.
    graph.set_head(&layer).await?;

    println!(
        "Added: {}, removed: {}",
        layer.triple_layer_addition_count().await?,
        layer.triple_layer_removal_count().await?
    );

    Ok(())
}

pub fn remove_id_triple(&self, triple: IdTriple) -> Result<(), Error>

Remove an id triple.

pub fn committed(&self) -> bool

Returns true if this layer has been committed, and false otherwise.

pub async fn commit_no_load(&self) -> Result<()>

Commit the layer to storage without loading the resulting layer.

pub async fn commit(&self) -> Result<StoreLayer>

Commit the layer to storage.

Examples found in repository

examples/write_to_graph.rs (line 94)

async fn process_commands(store_path: &str, graph: &str) -> io::Result<()> {
    let store = open_directory_store(store_path);
    let graph = store
        .open(graph)
        .await?
        .expect(&format!("expected graph {} to exist", graph));

    // There are two types of builders. One creates a new base layer,
    // which has no parent. The other creates a child layer, which has
    // another layer as its parent.
    let builder = match graph.head().await? {
        Some(layer) => layer.open_write().await?,
        None => store.create_base_layer().await?,
    };
    let mut stdin = io::BufReader::new(io::stdin()).lines();

    while let Some(line) = stdin.next_line().await? {
        let segment = line.trim();
        if segment.len() == 0 {
            continue;
        }

        let command = parse_command(segment).await?;

        // add all the input data into the builder.
        // The builder keeps an in-memory list of added and removed
        // triples. If the same triple is added and removed on the
        // same builder, it is a no-op. This is even the case when it
        // is then later re-added on the same builder.
        //
        // Since no io is happening, adding triples to the builder is
        // not a future.
        match command {
            Command::Add(triple) => builder.add_value_triple(triple)?,
            Command::Remove(triple) => builder.remove_value_triple(triple)?,
        }
    }

    // When commit is called, the builder writes its data to
    // persistent storage.
    let layer = builder.commit().await?;

    // While a layer exists now, it's not yet attached to anything,
    // and is therefore unusable unless you know the exact identifier
    // of the layer itself. To make this the graph data, we have to
    // set the grap head to this layer.
    graph.set_head(&layer).await?;

    println!(
        "Added: {}, removed: {}",
        layer.triple_layer_addition_count().await?,
        layer.triple_layer_removal_count().await?
    );

    Ok(())
}

pub async fn apply_delta(&self, delta: &StoreLayer) -> Result<(), Error>

Apply all triples added and removed by a layer to this builder.

This is a way to ‘cherry-pick’ a layer on top of another layer, without caring about its history.

pub fn apply_diff(&self, other: &StoreLayer) -> Result<(), Error>

Apply the changes required to change our parent layer into the given layer.

Trait Implementations

impl Clone for StoreLayerBuilder

fn clone(&self) -> StoreLayerBuilder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.