voxelize 1.0.0

A fast multiplayer voxel engine.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107

use bincode;
use blake3::Hash;
use hashbrown::HashMap;
use log::info;
use serde::{de::DeserializeOwned, Deserialize, Serialize};
use serde_json::{json, Value};
use specs::{Component, VecStorage};

/// A list of chunks that the entity is requesting to generate.
#[derive(Debug, Default, Component, Serialize, Deserialize, Clone)]
#[storage(VecStorage)]
pub struct MetadataComp {
    pub map: HashMap<String, Value>,

    #[serde(skip_serializing)]
    #[serde(skip_deserializing)]
    cache_hash: Option<Hash>,

    #[serde(skip_serializing)]
    #[serde(skip_deserializing)]
    cached_json: Option<String>,
}

impl MetadataComp {
    /// Create a component of a new list of chunk requests.
    pub fn new() -> Self {
        Self::default()
    }

    pub fn from_map(map: HashMap<String, Value>) -> Self {
        Self {
            map,
            cache_hash: None,
            cached_json: None,
        }
    }

    /// Set a component's metadata
    pub fn set<T: Component + Serialize>(&mut self, component: &str, data: &T) {
        let value = json!(data);
        self.map.insert(component.to_owned(), value);
        // Invalidate caches when data changes
        self.cached_json = None;
    }

    /// Get a component's metadata
    pub fn get<T: Component + DeserializeOwned>(&self, component: &str) -> Option<T> {
        if let Some(component) = self.map.get(component) {
            return Some(serde_json::from_value(component.to_owned()).unwrap());
        }

        None
    }

    /// Calculate hash of the current metadata map
    fn calculate_hash(&self) -> Hash {
        // Serialize to binary format which is more efficient than JSON string
        let bytes = bincode::serialize(&self.map).unwrap_or_default();
        blake3::hash(&bytes)
    }

    /// Convert metadata to JSON string, also caches is current state using hash.
    pub fn to_cached_str(&mut self) -> (String, bool) {
        let current_hash = self.calculate_hash();

        let mut updated = false;
        if let Some(cache_hash) = self.cache_hash {
            if cache_hash != current_hash {
                updated = true;
                self.cache_hash = Some(current_hash);
                // Invalidate JSON cache when hash changes
                self.cached_json = None;
            }
        } else {
            updated = true;
            self.cache_hash = Some(current_hash);
            // Invalidate JSON cache for first update
            self.cached_json = None;
        }

        // Use cached JSON if available and not updated
        if !updated && self.cached_json.is_some() {
            return (self.cached_json.clone().unwrap(), updated);
        }

        // Generate and cache the JSON string
        let json_str = self.to_string();
        self.cached_json = Some(json_str.clone());
        
        (json_str, updated)
    }

    /// Get a clean JSON string with no side-effects.
    pub fn to_string(&self) -> String {
        serde_json::to_string(&self.map).unwrap()
    }

    /// Is the metadata empty?
    pub fn is_empty(&self) -> bool {
        self.map.is_empty()
    }

    /// Reset this metadata
    pub fn reset(&mut self) {
        self.map.clear();
    }
}