parallel_disk_usage/data_tree/reflection/
par_methods.rs

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
use super::{ConversionError, Reflection};
use crate::{data_tree::DataTree, size};
use rayon::prelude::*;
use std::{ffi::OsStr, iter::once};

impl<Name, Size> Reflection<Name, Size>
where
    Name: Send,
    Size: size::Size + Send,
{
    /// Attempting to convert a [`Reflection`] into a valid [`DataTree`].
    pub fn par_try_into_tree(self) -> Result<DataTree<Name, Size>, ConversionError<Name, Size>> {
        let Reflection {
            name,
            size,
            children,
        } = self;
        let children_sum = children.iter().map(|child| child.size).sum();
        if size < children_sum {
            return Err(ConversionError::ExcessiveChildren {
                path: once(name).collect(),
                size,
                children,
                children_sum,
            });
        }
        let children: Result<Vec<_>, _> = children
            .into_par_iter()
            .map(Self::par_try_into_tree)
            .collect();
        let children = match children {
            Ok(children) => children,
            Err(ConversionError::ExcessiveChildren {
                mut path,
                size,
                children,
                children_sum,
            }) => {
                path.push_front(name);
                return Err(ConversionError::ExcessiveChildren {
                    path,
                    size,
                    children,
                    children_sum,
                });
            }
        };
        Ok(DataTree {
            name,
            size,
            children,
        })
    }

    /// Attempt to transform names and sizes.
    pub fn par_try_map<TargetName, TargetSize, Error, Transform>(
        self,
        transform: Transform,
    ) -> Result<Reflection<TargetName, TargetSize>, Error>
    where
        TargetName: Send,
        TargetSize: size::Size + Send + Sync,
        Error: Send,
        Transform: Fn(Name, Size) -> Result<(TargetName, TargetSize), Error> + Copy + Sync,
    {
        let Reflection {
            name,
            size,
            children,
        } = self;
        let children = children
            .into_par_iter()
            .map(|child| child.par_try_map(transform))
            .collect::<Result<Vec<_>, _>>()?;
        let (name, size) = transform(name, size)?;
        Ok(Reflection {
            name,
            size,
            children,
        })
    }

    /// Attempt to convert all names from `OsString` to `String`.
    pub fn par_convert_names_to_utf8(self) -> Result<Reflection<String, Size>, Name>
    where
        Name: AsRef<OsStr>,
        Size: Sync,
    {
        self.par_try_map(|name, size| {
            name.as_ref()
                .to_str()
                .map(|name| (name.to_string(), size))
                .ok_or(name)
        })
    }
}