support_for_serde.md

Support For Serde

We can save and load an RTree by serde. To use serde, we need to add feature serde to rstar.

cargo add rstar -F serde

In this tutorial, we use serde_json to do the (de)serialization.

cargo add serde_json

The dependencies in Cargo.toml should look like this:

[dependencies]
rstar = { version = "0.12.0", features = ["serde"] }
serde_json = "1.0.131"

Now, we can use serde_json::to_string_pretty and serde_json::from_str to save and load an RTree.

use rstar::RTree;

fn main() {
    let tree = RTree::bulk_load(vec![(0, 0), (1, 2), (8, 5)]);

    let json = serde_json::to_string_pretty(&tree).unwrap();
    println!("{}", json);

    let tree2: RTree<(i32, i32)> = serde_json::from_str(&json).unwrap();
    println!("Points in tree2:");
    for point in &tree2 {
        println!("{:?}", point);
    }
}

Output:

{
    "root": {
    "children": [
        {
        "Leaf": [
            0,
            0
        ]
        },
        {
        "Leaf": [
            1,
            2
        ]
        },
        {
        "Leaf": [
            8,
            5
        ]
        }
    ],
    "envelope": {
        "lower": [
        0,
        0
        ],
        "upper": [
        8,
        5
        ]
    }
    },
    "size": 3,
    "_params": null
}
Points in tree2:
(8, 5)
(1, 2)
(0, 0)

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