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use super::builder::*;
use super::list::List;
pub struct ListBuilder<T> {
data: Builder<T>,
offsets: Builder<i32>,
}
impl<T> ListBuilder<T> {
pub fn new() -> Self {
ListBuilder::with_capacity(64)
}
pub fn with_capacity(n: usize) -> Self {
let data = Builder::with_capacity(n);
let mut offsets = Builder::with_capacity(n);
offsets.push(0_i32);
ListBuilder { data, offsets }
}
pub fn push(&mut self, slice: &[T]) {
self.data.push_slice(slice);
self.offsets.push(self.data.len() as i32);
}
pub fn finish(&mut self) -> List<T> {
List::from_raw_parts(self.data.finish(), self.offsets.finish())
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_list_u8_default_capacity() {
let mut b: ListBuilder<u8> = ListBuilder::new();
b.push("Hello, ".as_bytes());
b.push("World!".as_bytes());
let buffer = b.finish();
assert_eq!(2, buffer.len());
assert_eq!("Hello, ".as_bytes(), buffer.slice(0));
assert_eq!("World!".as_bytes(), buffer.slice(1));
}
#[test]
fn test_list_u8_zero_capacity() {
let mut b: ListBuilder<u8> = ListBuilder::with_capacity(0);
b.push("Hello, ".as_bytes());
b.push("World!".as_bytes());
let buffer = b.finish();
assert_eq!(2, buffer.len());
assert_eq!("Hello, ".as_bytes(), buffer.slice(0));
assert_eq!("World!".as_bytes(), buffer.slice(1));
}
}