edf_reader/
async_reader.rs

1//! Read an EDF file asynhronously (with futures)
2
3use crate::file_reader::AsyncFileReader;
4use crate::model::{EDFHeader, EDF_HEADER_BYTE_SIZE};
5
6use futures::future::err;
7use futures::Future;
8use std::io::Error;
9
10pub struct AsyncEDFReader<T: AsyncFileReader> {
11    pub edf_header: EDFHeader,
12    file_reader: T,
13}
14
15impl<T: 'static + AsyncFileReader> AsyncEDFReader<T> {
16    /**
17    Init an EDFReader with a custom FileReader.
18    It can be usefull if the EDF file is not located in the system file. (ie : we cannot use RandomAccessFile).
19    An example of use : read the file with DOM FileAPI in Webassembly
20    */
21    pub fn init_with_file_reader(
22        file_reader: T,
23    ) -> Box<Future<Item = AsyncEDFReader<T>, Error = std::io::Error>> {
24        Box::new(
25            file_reader
26                .read_async(0, 256)
27                .map(|general_header_raw: Vec<u8>| {
28                    let mut edf_header = EDFHeader::build_general_header(general_header_raw);
29
30                    file_reader
31                        .read_async(
32                            256,
33                            edf_header.number_of_signals * EDF_HEADER_BYTE_SIZE as u64,
34                        )
35                        .map(|channel_headers_raw| {
36                            edf_header.build_channel_headers(channel_headers_raw);
37
38                            AsyncEDFReader {
39                                edf_header: edf_header,
40                                file_reader,
41                            }
42                        })
43                })
44                .flatten(),
45        )
46    }
47
48    /// Says "Hello, [name]" to the `Person` it is called on.
49    pub fn read_data_window(
50        &self,
51        start_time_ms: u64, // in mS
52        duration_ms: u64,   // in mS
53    ) -> Box<Future<Item = Vec<Vec<f32>>, Error = std::io::Error>> {
54        // check boundaries
55        if let Err(e) = super::check_bounds(start_time_ms, duration_ms, &self.edf_header) {
56            return Box::new(err::<Vec<Vec<f32>>, Error>(e));
57        }
58
59        // calculate the corresponding blocks to get
60
61        let first_block_start_time = start_time_ms - start_time_ms % self.edf_header.block_duration;
62
63        let first_block_index = first_block_start_time / self.edf_header.block_duration;
64
65        let number_of_blocks_to_get =
66            (duration_ms as f64 / self.edf_header.block_duration as f64).ceil() as u64;
67
68        let offset = self.edf_header.byte_size_header
69            + first_block_index * self.edf_header.get_size_of_data_block();
70
71        let header = self.edf_header.clone();
72
73        Box::new(
74            self.file_reader
75                .read_async(
76                    offset,
77                    number_of_blocks_to_get * self.edf_header.get_size_of_data_block(),
78                )
79                .map(move |data: Vec<u8>| {
80                    let mut result: Vec<Vec<f32>> = Vec::new();
81
82                    for _ in 0..header.number_of_signals {
83                        result.push(Vec::new());
84                    }
85
86                    let mut index = 0;
87
88                    for _ in 0..number_of_blocks_to_get {
89                        for (j, channel) in header.channels.iter().enumerate() {
90                            for _ in 0..channel.number_of_samples_in_data_record {
91                                let sample = super::get_sample(&data, index) as f32;
92                                result[j].push(
93                                    (sample - channel.digital_minimum as f32)
94                                        * channel.scale_factor
95                                        + channel.physical_minimum,
96                                );
97                                index += 1;
98                            }
99                        }
100                    }
101
102                    result
103                }),
104        )
105    }
106}
107
108// impl<T: AsyncFileReader> AsyncEDFReader<T> {
109
110// }
edf_reader/async_reader.rs

edf_reader/
async_reader.rs
