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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201

#![allow(dead_code)]
pub const SBX_LARGEST_BLOCK_SIZE: usize = 4096;

pub const SBX_FIRST_DATA_SEQ_NUM: u32 = 1;

pub const SBX_LAST_SEQ_NUM: u32 = u32::max_value();

pub const SBX_METADATA_BLOCK_COUNT: usize = 1;

pub const SBX_SCAN_BLOCK_SIZE: usize = 128;

pub const SBX_FILE_UID_LEN: usize = common_params::FILE_UID_LEN;

pub const SBX_SIGNATURE: &[u8] = common_params::SIGNATURE;

pub const SBX_HEADER_SIZE: usize = common_params::HEADER_SIZE;

pub const SBX_MAX_DATA_BLOCK_COUNT: u32 = u32::max_value();

pub const SBX_MAX_BURST_ERR_RESISTANCE: usize = 1000;

#[derive(Clone, Copy, Debug, PartialEq)]
pub enum Version {
    V1,
    V2,
    V3,
    V17,
    V18,
    V19,
}

mod common_params {
    use std::u32;

    pub const FILE_UID_LEN: usize = 6;
    pub const SIGNATURE: &[u8] = b"SBx";
    pub const HEADER_SIZE: usize = 16;
    pub const MAX_BLOCK_NUM: u64 = u32::MAX as u64;
}

mod params_for_v1 {
    use super::common_params;

    pub const BLOCK_SIZE: usize = 512;
    pub const DATA_SIZE: usize = BLOCK_SIZE - common_params::HEADER_SIZE;
}

mod params_for_v2 {
    use super::common_params;

    pub const BLOCK_SIZE: usize = 128;
    pub const DATA_SIZE: usize = BLOCK_SIZE - common_params::HEADER_SIZE;
}

mod params_for_v3 {
    use super::common_params;

    pub const BLOCK_SIZE: usize = 4096;
    pub const DATA_SIZE: usize = BLOCK_SIZE - common_params::HEADER_SIZE;
}

mod params_for_v17 {
    use super::params_for_v1;

    pub const BLOCK_SIZE: usize = params_for_v1::BLOCK_SIZE;
    pub const DATA_SIZE: usize = params_for_v1::DATA_SIZE;
}

mod params_for_v18 {
    use super::params_for_v2;

    pub const BLOCK_SIZE: usize = params_for_v2::BLOCK_SIZE;
    pub const DATA_SIZE: usize = params_for_v2::DATA_SIZE;
}

mod params_for_v19 {
    use super::params_for_v3;

    pub const BLOCK_SIZE: usize = params_for_v3::BLOCK_SIZE;
    pub const DATA_SIZE: usize = params_for_v3::DATA_SIZE;
}

pub fn ver_to_usize(version: Version) -> usize {
    use self::Version::*;
    match version {
        V1 => 1,
        V2 => 2,
        V3 => 3,
        V17 => 17,
        V18 => 18,
        V19 => 19,
    }
}

pub fn string_to_ver(string: &str) -> Result<Version, ()> {
    use self::Version::*;
    match string {
        "1" => Ok(V1),
        "2" => Ok(V2),
        "3" => Ok(V3),
        "17" => Ok(V17),
        "18" => Ok(V18),
        "19" => Ok(V19),
        _ => Err(()),
    }
}

pub fn ver_to_block_size(version: Version) -> usize {
    use self::Version::*;
    match version {
        V1 => params_for_v1::BLOCK_SIZE,
        V2 => params_for_v2::BLOCK_SIZE,
        V3 => params_for_v3::BLOCK_SIZE,
        V17 => params_for_v17::BLOCK_SIZE,
        V18 => params_for_v18::BLOCK_SIZE,
        V19 => params_for_v19::BLOCK_SIZE,
    }
}

pub fn ver_to_data_size(version: Version) -> usize {
    use self::Version::*;
    match version {
        V1 => params_for_v1::DATA_SIZE,
        V2 => params_for_v2::DATA_SIZE,
        V3 => params_for_v3::DATA_SIZE,
        V17 => params_for_v17::DATA_SIZE,
        V18 => params_for_v18::DATA_SIZE,
        V19 => params_for_v19::DATA_SIZE,
    }
}

pub fn ver_uses_rs(version: Version) -> bool {
    use self::Version::*;
    match version {
        V1 | V2 | V3 => false,
        V17 | V18 | V19 => true,
    }
}

pub fn ver_forces_meta_enabled(version: Version) -> bool {
    use self::Version::*;
    match version {
        V1 | V2 | V3 => false,
        V17 | V18 | V19 => true,
    }
}

pub fn ver_to_max_block_set_count(
    version: Version,
    data_par_burst: Option<(usize, usize, usize)>,
) -> Option<u32> {
    if ver_uses_rs(version) {
        let (data, parity, _) = data_par_burst.unwrap();

        let block_set_size = (data + parity) as u32;

        Some(SBX_MAX_DATA_BLOCK_COUNT / block_set_size)
    } else {
        assert!(data_par_burst == None);

        None
    }
}

pub fn ver_to_last_data_seq_num_exc_parity(
    version: Version,
    data_par_burst: Option<(usize, usize, usize)>,
) -> u32 {
    if ver_uses_rs(version) {
        let (data, parity, _) = data_par_burst.unwrap();

        let block_set_size = data + parity;
        let max_block_set_count = ver_to_max_block_set_count(version, data_par_burst).unwrap();

        max_block_set_count * block_set_size as u32 - parity as u32
    } else {
        assert!(data_par_burst == None);

        SBX_LAST_SEQ_NUM
    }
}

pub fn ver_to_max_data_file_size(
    version: Version,
    data_par_burst: Option<(usize, usize, usize)>,
) -> u64 {
    let data_size = ver_to_data_size(version) as u64;

    if ver_uses_rs(version) {
        let (data, _, _) = data_par_burst.unwrap();

        let max_block_set_count =
            ver_to_max_block_set_count(version, data_par_burst).unwrap() as u64;

        max_block_set_count * data as u64 * data_size
    } else {
        assert!(data_par_burst == None);

        SBX_MAX_DATA_BLOCK_COUNT as u64 * data_size
    }
}