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
149
150
151
152
153
154
155
156
157
158
159
160

//! Helper struct that manages attributes.
//! It creates an `Attribute` instance if it does not exists or uses a cached one.

use std::cell::RefCell;
use std::collections::HashMap;
use std::fmt::{self, Debug};
use std::fs;
use std::string::String;

use crate::{utils::OrErr, Attribute, Ev3Error, Ev3Result, Port};

/// The root driver path `/sys/class/`.
const ROOT_PATH: &str = "/sys/class/";

/// Helper struct that manages attributes.
/// It creates an `Attribute` instance if it does not exists or uses a cached one.
pub struct Driver {
    class_name: String,
    name: String,
    attributes: RefCell<HashMap<String, Attribute>>,
}

impl Driver {
    /// Returns a new `Driver`.
    /// All attributes created by this driver will use the path `/sys/class/{class_name}/{name}`.
    pub fn new(class_name: &str, name: &str) -> Driver {
        Driver {
            class_name: class_name.to_owned(),
            name: name.to_owned(),
            attributes: RefCell::new(HashMap::new()),
        }
    }

    /// Returns the name of the device with the given `class_name`, `driver_name` and at the given `port`.
    ///
    /// Returns `Ev3Error::NotFound` if no such device exists.
    pub fn find_name_by_port_and_driver(
        class_name: &str,
        port: &dyn Port,
        driver_name: &str,
    ) -> Ev3Result<String> {
        let port_address = port.address();

        let paths = fs::read_dir(format!("{}{}", ROOT_PATH, class_name))?;

        for path in paths {
            let file_name = path?.file_name();
            let name = file_name.to_str().or_err()?;

            let address = Attribute::new(class_name, name, "address")?;

            if address.get::<String>()?.contains(&port_address) {
                let driver = Attribute::new(class_name, name, "driver_name")?;

                if driver.get::<String>()? == driver_name {
                    return Ok(name.to_owned());
                }
            }
        }

        Err(Ev3Error::NotFound)
    }

    /// Returns the name of the device with the given `class_name` and at the given `port`.
    ///
    /// Returns `Ev3Error::NotFound` if no such device exists.
    /// Returns `Ev3Error::MultipleMatches` if more then one matching device exists.
    pub fn find_name_by_port(class_name: &str, port: &dyn Port) -> Ev3Result<String> {
        let port_address = port.address();

        let paths = fs::read_dir(format!("{}{}", ROOT_PATH, class_name))?;

        for path in paths {
            let file_name = path?.file_name();
            let name = file_name.to_str().or_err()?;

            let address = Attribute::new(class_name, name, "address")?;

            if address.get::<String>()?.contains(&port_address) {
                return Ok(name.to_owned());
            }
        }

        Err(Ev3Error::NotFound)
    }

    /// Returns the name of the device with the given `class_name`.
    ///
    /// Returns `Ev3Error::NotFound` if no such device exists.
    /// Returns `Ev3Error::MultipleMatches` if more then one matching device exists.
    pub fn find_name_by_driver(class_name: &str, driver_name: &str) -> Ev3Result<String> {
        let mut names = Driver::find_names_by_driver(class_name, driver_name)?;

        match names.len() {
            0 => Err(Ev3Error::NotFound),
            1 => Ok(names
                .pop()
                .expect("Name vector contains exactly one element")),
            _ => Err(Ev3Error::MultipleMatches),
        }
    }

    /// Returns the names of the devices with the given `class_name`.
    pub fn find_names_by_driver(class_name: &str, driver_name: &str) -> Ev3Result<Vec<String>> {
        let paths = fs::read_dir(format!("{}{}", ROOT_PATH, class_name))?;

        let mut found_names = Vec::new();
        for path in paths {
            let file_name = path?.file_name();
            let name = file_name.to_str().or_err()?;

            let driver = Attribute::new(class_name, name, "driver_name")?;

            if driver.get::<String>()? == driver_name {
                found_names.push(name.to_owned());
            }
        }

        Ok(found_names)
    }

    /// Return the `Attribute` wrapper for the given `attribute_name`.
    /// Creates a new one if it does not exist.
    pub fn get_attribute(&self, attribute_name: &str) -> Attribute {
        let mut attributes = self.attributes.borrow_mut();

        if !attributes.contains_key(attribute_name) {
            if let Ok(v) =
                Attribute::new(self.class_name.as_ref(), self.name.as_ref(), attribute_name)
            {
                attributes.insert(attribute_name.to_owned(), v);
            };
        };

        attributes
            .get(attribute_name)
            .expect("Internal error in the attribute map")
            .clone()
    }
}

impl Clone for Driver {
    fn clone(&self) -> Self {
        Driver {
            class_name: self.class_name.clone(),
            name: self.name.clone(),
            attributes: RefCell::new(HashMap::new()),
        }
    }
}

impl Debug for Driver {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(
            f,
            "Driver {{ class_name: {}, name: {} }}",
            self.class_name, self.name
        )
    }
}