wmi 0.3.0

WMI crate for rust. 
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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148

use crate::safearray::safe_array_to_vec;
use failure::{bail, Error, format_err};
use widestring::WideCStr;
use winapi::{
    shared::wtypes::*,
    um::{oaidl::SAFEARRAY, oaidl::VARIANT},
};
use std::convert::TryFrom;

// See: https://msdn.microsoft.com/en-us/library/cc237864.aspx
const VARIANT_FALSE: i16 = 0x0000;

#[derive(Debug, PartialEq, Hash)]
pub enum Variant {
    Empty,
    Null,

    String(String),

    I1(i8),
    I2(i16),
    I4(i32),
    I8(i64),

    Bool(bool),

    UI1(u8),
    UI2(u16),
    UI4(u32),
    UI8(u64),

    Array(Vec<Variant>),
}

impl Variant {
    pub fn from_variant(vt: VARIANT) -> Result<Variant, Error> {
        let variant_type: VARTYPE = unsafe { vt.n1.n2().vt };

        // variant_type has two 'forms':
        // 1. A simple type like `VT_BSTR` .
        // 2. An array of certain type like `VT_ARRAY | VT_BSTR`.
        if variant_type as u32 & VT_ARRAY == VT_ARRAY {
            let array: &*mut SAFEARRAY = unsafe { vt.n1.n2().n3.parray() };

            let item_type = variant_type as u32 & VT_TYPEMASK;

            return Ok(Variant::Array(safe_array_to_vec(*array, item_type as u32)?));
        }

        // See https://msdn.microsoft.com/en-us/library/cc237865.aspx for more info.
        // Rust can infer the return type of `vt.*Val()` calls,
        // but it's easier to read when the type is named explicitly.
        let variant_value = match variant_type as u32 {
            VT_BSTR => {
                let bstr_ptr: &BSTR = unsafe { vt.n1.n2().n3.bstrVal() };

                let prop_val: &WideCStr = unsafe { WideCStr::from_ptr_str(*bstr_ptr) };

                let property_value_as_string = prop_val.to_string()?;

                Variant::String(property_value_as_string)
            }
            VT_I1 => {
                let num: &i8 = unsafe { vt.n1.n2().n3.cVal() };

                Variant::I1(*num)
            }
            VT_I2 => {
                let num: &i16 = unsafe { vt.n1.n2().n3.iVal() };

                Variant::I2(*num)
            }
            VT_I4 => {
                let num: &i32 = unsafe { vt.n1.n2().n3.lVal() };

                Variant::I4(*num)
            }
            VT_I8 => {
                let num: &i64 = unsafe { vt.n1.n2().n3.llVal() };

                Variant::I8(*num)
            }
            VT_BOOL => {
                let value: &i16 = unsafe { vt.n1.n2().n3.boolVal() };

                match *value {
                    VARIANT_FALSE => Variant::Bool(false),
                    VARIANT_TRUE => Variant::Bool(true),
                    _ => bail!("Invalid bool value: {:#X}", value),
                }
            }
            VT_UI1 => {
                let num: &u8 = unsafe { vt.n1.n2().n3.bVal() };

                Variant::UI1(*num)
            }
            VT_UI2 => {
                let num: &u16 = unsafe { vt.n1.n2().n3.uiVal() };

                Variant::UI2(*num)
            }
            VT_UI4 => {
                let num: &u32 = unsafe { vt.n1.n2().n3.ulVal() };

                Variant::UI4(*num)
            }
            VT_UI8 => {
                let num: &u64 = unsafe { vt.n1.n2().n3.ullVal() };

                Variant::UI8(*num)
            }
            VT_EMPTY => Variant::Empty,
            VT_NULL => Variant::Null,
            _ => bail!(
                "Converting from variant type {:#X} is not implemented yet",
                variant_type
            ),
        };

        Ok(variant_value)
    }
}

macro_rules! impl_try_from_variant {
    ($target_type:ty, $variant_type:ident) => {
        impl TryFrom<Variant> for $target_type {
            type Error = Error;

            fn try_from(value: Variant) -> Result<$target_type, Self::Error> {
                match value {
                    Variant::$variant_type(item) => Ok(item),
                    other => Err(format_err!("Variant {:?} cannot be turned into a {}", &other, stringify!($target_type)))
                }
            }
        }
    }
}

impl_try_from_variant!(String, String);
impl_try_from_variant!(i8, I1);
impl_try_from_variant!(i16, I2);
impl_try_from_variant!(i32, I4);
impl_try_from_variant!(i64, I8);
impl_try_from_variant!(u8, UI1);
impl_try_from_variant!(u16, UI2);
impl_try_from_variant!(u32, UI4);
impl_try_from_variant!(u64, UI8);
impl_try_from_variant!(bool, Bool);