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use util::migration::SimpleMigration;
pub struct ToV6;
impl ToV6 {
fn migrate_old_key(&self, old_key: Vec<u8>, index: u8, len: usize) -> Vec<u8> {
let mut result = vec![];
result.reserve(len);
unsafe {
result.set_len(len);
}
result[0] = index;
let old_key_start = 33 - len;
result[1..].clone_from_slice(&old_key[old_key_start..32]);
result
}
}
impl SimpleMigration for ToV6 {
fn columns(&self) -> Option<u32> { None }
fn version(&self) -> u32 { 6 }
fn simple_migrate(&mut self, key: Vec<u8>, value: Vec<u8>) -> Option<(Vec<u8>, Vec<u8>)> {
if key.len() == 33 {
if key[32] == 0 {
return Some((self.migrate_old_key(key, 0, 33), value));
}
if key[32] == 1 {
return Some((self.migrate_old_key(key, 1, 5), value));
}
if key[32] == 2 {
return Some((self.migrate_old_key(key, 2, 33), value));
}
if key[32] == 3 {
return None;
}
if key[32] == 4 {
let reverse = key.into_iter().rev().collect::<Vec<_>>();
let mut result = [0u8; 6];
result[0] = 3;
result[1] = reverse[9];
result[2] = reverse[4];
result[3] = reverse[3];
result[4] = reverse[2];
result[5] = reverse[1];
return Some((result.to_vec(), value));
}
if key[32] == 5 {
return Some((self.migrate_old_key(key, 4, 33), value));
}
}
Some((key, value))
}
}