liwe 0.3.2

IWE core library
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

use rayon::prelude::*;
use serde_yaml::Mapping;

use crate::graph::{Graph, GraphContext};
use crate::model::node::{Node, NodeIter};
use crate::model::Key;
use crate::query::document::{CountOp, DeleteOp, Filter, FindOp, Limit, Operation, Sort, UpdateOp};
use crate::query::eval;
use crate::query::frontmatter::strip_reserved;
use crate::query::project::{apply_projection, ProjectionContext};
use crate::query::sort::sort_in_place;
use crate::query::update;

#[derive(Debug)]
pub enum Outcome {
    Find { matches: Vec<FindMatch> },
    Count(usize),
    Update { changes: Vec<(Key, String)> },
    Delete { removed: Vec<Key> },
}

#[derive(Debug, Clone)]
pub struct FindMatch {
    pub key: Key,
    pub document: Mapping,
}

pub fn execute(op: &Operation, graph: &Graph) -> Outcome {
    match op {
        Operation::Find(find) => execute_find(find, graph),
        Operation::Count(count) => execute_count(count, graph),
        Operation::Update(upd) => execute_update(upd, graph),
        Operation::Delete(del) => execute_delete(del, graph),
    }
}

fn select(filter: Option<&Filter>, graph: &Graph) -> Vec<(Key, Mapping)> {
    let keys: Vec<Key> = match filter {
        None => {
            let mut k = graph.keys();
            k.sort_by(|a, b| a.to_string().cmp(&b.to_string()));
            k
        }
        Some(f) => eval::evaluate(f, graph),
    };
    keys.into_par_iter()
        .map(|key| {
            let mapping = graph.frontmatter(&key).cloned().unwrap_or_default();
            (key, mapping)
        })
        .collect()
}

fn apply_sort_and_limit(
    mut rows: Vec<(Key, Mapping)>,
    sort: Option<&Sort>,
    limit: Option<&Limit>,
) -> Vec<(Key, Mapping)> {
    rows.sort_by(|a, b| a.0.to_string().cmp(&b.0.to_string()));
    if let Some(s) = sort {
        sort_in_place(&mut rows, s);
    }
    if let Some(l) = limit {
        if !l.is_unbounded() {
            rows.truncate(l.0 as usize);
        }
    }
    rows
}

fn execute_find(op: &FindOp, graph: &Graph) -> Outcome {
    let rows = select(op.filter.as_ref(), graph);
    let rows = apply_sort_and_limit(rows, op.sort.as_ref(), op.limit.as_ref());
    let matches: Vec<FindMatch> = rows
        .into_iter()
        .map(|(key, mut m)| {
            let document = match &op.project {
                Some(p) => {
                    let ctx = ProjectionContext { graph, key: &key };
                    apply_projection(&ctx, p)
                }
                None => {
                    strip_reserved(&mut m);
                    m
                }
            };
            FindMatch { key, document }
        })
        .collect();
    Outcome::Find { matches }
}

fn execute_count(op: &CountOp, graph: &Graph) -> Outcome {
    let rows = select(op.filter.as_ref(), graph);
    let rows = apply_sort_and_limit(rows, op.sort.as_ref(), op.limit.as_ref());
    Outcome::Count(rows.len())
}

fn execute_update(op: &UpdateOp, graph: &Graph) -> Outcome {
    let rows = select(Some(&op.filter), graph);
    let rows = apply_sort_and_limit(rows, op.sort.as_ref(), op.limit.as_ref());
    let mut changes = Vec::new();
    for (key, mut mapping) in rows {
        update::apply(&op.update, &mut mapping);
        strip_reserved(&mut mapping);
        let markdown = render_with_frontmatter(graph, &key, mapping);
        changes.push((key, markdown));
    }
    Outcome::Update { changes }
}

fn execute_delete(op: &DeleteOp, graph: &Graph) -> Outcome {
    let rows = select(Some(&op.filter), graph);
    let rows = apply_sort_and_limit(rows, op.sort.as_ref(), op.limit.as_ref());
    let removed = rows.into_iter().map(|(k, _)| k).collect();
    Outcome::Delete { removed }
}

fn render_with_frontmatter(graph: &Graph, key: &Key, mapping: Mapping) -> String {
    let mut tree = graph.collect(key);
    let frontmatter = if mapping.is_empty() {
        None
    } else {
        Some(mapping)
    };
    tree.node = Node::Document(key.clone(), frontmatter);
    tree.iter()
        .to_markdown(&key.parent(), &graph.markdown_options())
}