Initialize vectors with a capacity

dremio · Feb 24, 2019 · 344379a · 344379a
1 parent 257d235
commit 344379a
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/rust/arrow/src/array.rs b/rust/arrow/src/array.rs
@@ -609,8 +609,8 @@ impl From<ArrayDataRef> for BinaryArray {
 
 impl<'a> From<Vec<&'a str>> for BinaryArray {
  fn from(v: Vec<&'a str>) -> Self {
- let mut offsets = vec![];
- let mut values = vec![];
+ let mut offsets = Vec::with_capacity(v.len() + 1);
+ let mut values = Vec::new();
  let mut length_so_far = 0;
  offsets.push(length_so_far);
  for s in &v {
@@ -629,8 +629,8 @@ impl<'a> From<Vec<&'a str>> for BinaryArray {
 
 impl<'a> From<Vec<&[u8]>> for BinaryArray {
  fn from(v: Vec<&[u8]>) -> Self {
- let mut offsets = vec![];
- let mut values = vec![];
+ let mut offsets = Vec::with_capacity(v.len() + 1);
+ let mut values = Vec::new();
  let mut length_so_far = 0;
  offsets.push(length_so_far);
  for s in &v {