automerge 0.10.0

A JSON-like data structure (a CRDT) that can be modified concurrently by different users, and merged again automatically
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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

use std::collections::HashMap;
use std::ops::{Deref, DerefMut};

use crate::exid::ExId;
use crate::types::Prop;
use crate::{PatchAction, ScalarValue, TextEncoding};

use super::{HydrateError, Value};

#[derive(Clone, Debug, Default, PartialEq)]
pub struct Map(HashMap<String, MapValue>);

#[derive(Clone, Debug, PartialEq)]
pub struct MapValue {
    pub value: Value,
    pub conflict: bool,
}

impl Map {
    pub fn iter(&self) -> impl Iterator<Item = (&String, &MapValue)> {
        self.0.iter()
    }

    pub(crate) fn apply(
        &mut self,
        text_encoding: TextEncoding,
        patch: PatchAction,
    ) -> Result<(), HydrateError> {
        match patch {
            PatchAction::DeleteMap { key } => {
                self.0.remove(&key);
                Ok(())
            }
            PatchAction::PutMap {
                key,
                value,
                conflict,
            } => {
                let h_value = Value::new(value.0, text_encoding);
                self.0
                    .insert(key, MapValue::new(h_value, value.1, conflict));
                Ok(())
            }
            PatchAction::Increment {
                prop: Prop::Map(key),
                value,
            } => {
                self.0
                    .get_mut(&key)
                    .ok_or(HydrateError::InvalidKey(key))?
                    .increment(value)?;
                Ok(())
            }
            _ => Err(HydrateError::InvalidMapOp),
        }
    }

    pub fn get(&self, key: &str) -> Option<&Value> {
        self.0.get(key).map(|mv| &mv.value)
    }

    pub fn get_mut(&mut self, key: &str) -> Option<&mut Value> {
        self.0.get_mut(key).map(|mv| &mut mv.value)
    }

    pub(crate) fn new() -> Self {
        Self(Default::default())
    }
}

impl MapValue {
    pub(crate) fn new(value: Value, _id: ExId, conflict: bool) -> Self {
        Self { value, conflict }
    }

    pub(crate) fn increment(&mut self, n: i64) -> Result<(), HydrateError> {
        if let Value::Scalar(ScalarValue::Counter(c)) = &mut self.value {
            c.increment(n);
            Ok(())
        } else {
            Err(HydrateError::BadIncrement)
        }
    }
}

impl Deref for Map {
    type Target = HashMap<String, MapValue>;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl DerefMut for Map {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

impl From<HashMap<&str, Value>> for Map {
    fn from(value: HashMap<&str, Value>) -> Self {
        Map(value
            .into_iter()
            .map(|(k, value)| {
                (
                    k.to_string(),
                    MapValue {
                        value,
                        conflict: false,
                    },
                )
            })
            .collect())
    }
}

impl From<HashMap<String, Value>> for Map {
    fn from(value: HashMap<String, Value>) -> Self {
        Map(value
            .into_iter()
            .map(|(k, value)| {
                (
                    k,
                    MapValue {
                        value,
                        conflict: false,
                    },
                )
            })
            .collect())
    }
}