BTreeMap binary serialization (#1489)

* btree map serializer

* serde tests

* fix styling
This commit is contained in:
Nikolay Volf 2016-07-01 23:27:50 +04:00 committed by Arkadiy Paronyan
parent d91e8ccd34
commit fa73ae17d9

View File

@ -19,7 +19,7 @@
use util::bytes::Populatable;
use util::numbers::{U256, U512, H256, H2048, Address};
use std::mem;
use std::collections::VecDeque;
use std::collections::{VecDeque, BTreeMap};
use std::ops::Range;
#[derive(Debug)]
@ -139,6 +139,92 @@ impl<R: BinaryConvertable, E: BinaryConvertable> BinaryConvertable for Result<R,
}
}
impl<K, V> BinaryConvertable for BTreeMap<K, V> where K : BinaryConvertable + Ord, V: BinaryConvertable {
fn size(&self) -> usize {
0usize + match K::len_params() {
0 => mem::size_of::<K>() * self.len(),
_ => self.iter().fold(0usize, |acc, (k, _)| acc + k.size())
} + match V::len_params() {
0 => mem::size_of::<V>() * self.len(),
_ => self.iter().fold(0usize, |acc, (_, v)| acc + v.size())
}
}
fn to_bytes(&self, buffer: &mut [u8], length_stack: &mut VecDeque<usize>) -> Result<(), BinaryConvertError> {
let mut offset = 0usize;
for (key, val) in self.iter() {
let key_size = match K::len_params() {
0 => mem::size_of::<K>(),
_ => { let size = key.size(); length_stack.push_back(size); size }
};
let val_size = match K::len_params() {
0 => mem::size_of::<V>(),
_ => { let size = val.size(); length_stack.push_back(size); size }
};
if key_size > 0 {
let item_end = offset + key_size;
try!(key.to_bytes(&mut buffer[offset..item_end], length_stack));
offset = item_end;
}
if val_size > 0 {
let item_end = offset + key_size;
try!(val.to_bytes(&mut buffer[offset..item_end], length_stack));
offset = item_end;
}
}
Ok(())
}
fn from_bytes(buffer: &[u8], length_stack: &mut VecDeque<usize>) -> Result<Self, BinaryConvertError> {
let mut index = 0;
let mut result = Self::new();
if buffer.len() == 0 { return Ok(result); }
loop {
let key_size = match K::len_params() {
0 => mem::size_of::<K>(),
_ => try!(length_stack.pop_front().ok_or(BinaryConvertError)),
};
let key = if key_size == 0 {
try!(K::from_empty_bytes())
} else {
try!(K::from_bytes(&buffer[index..index+key_size], length_stack))
};
index = index + key_size;
let val_size = match V::len_params() {
0 => mem::size_of::<V>(),
_ => try!(length_stack.pop_front().ok_or(BinaryConvertError)),
};
let val = if val_size == 0 {
try!(V::from_empty_bytes())
} else {
try!(V::from_bytes(&buffer[index..index+val_size], length_stack))
};
result.insert(key, val);
index = index + val_size;
if index == buffer.len() { break; }
if index > buffer.len() {
return Err(BinaryConvertError)
}
}
Ok(result)
}
fn from_empty_bytes() -> Result<Self, BinaryConvertError> {
Ok(Self::new())
}
fn len_params() -> usize {
1
}
}
impl<T> BinaryConvertable for Vec<T> where T: BinaryConvertable {
fn size(&self) -> usize {
match T::len_params() {
@ -652,3 +738,18 @@ fn serialize_err_opt_vec_in_out() {
assert!(vec.is_ok());
}
#[test]
fn serialize_btree() {
use std::io::{Cursor, SeekFrom, Seek};
let mut buff = Cursor::new(Vec::new());
let mut btree = BTreeMap::new();
btree.insert(1u64, 5u64);
serialize_into(&btree, &mut buff).unwrap();
buff.seek(SeekFrom::Start(0)).unwrap();
let res = deserialize_from::<BTreeMap<u64, u64>, _>(&mut buff).unwrap();
assert_eq!(res[&1u64], 5u64);
}