Merge pull request #364 from RoloEdits/perf/pre_alloc_buf

perf: pre-allocate buffers with `with_capacity()`

src/ods.rs

@@ -209,7 +209,7 @@ fn parse_content<RS: Read + Seek>(mut zip: ZipArchive<RS>) -> Result<Content, Od
  Err(ZipError::FileNotFound) => return Err(OdsError::FileNotFound("content.xml")),
  Err(e) => return Err(OdsError::Zip(e)),
  };
- let mut buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
  let mut sheets = BTreeMap::new();
  let mut defined_names = Vec::new();
  let mut sheets_metadata = Vec::new();
@@ -292,9 +292,9 @@ fn read_table(reader: &mut OdsReader<'_>) -> Result<(Range<DataType>, Range<Stri
  let mut rows_repeats = Vec::new();
  let mut formulas = Vec::new();
  let mut cols = Vec::new();
- let mut buf = Vec::new();
- let mut row_buf = Vec::new();
- let mut cell_buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
+ let mut row_buf = Vec::with_capacity(1024);
+ let mut cell_buf = Vec::with_capacity(1024);
  cols.push(0);
  loop {
  match reader.read_event_into(&mut buf) {
@@ -587,7 +587,7 @@ fn get_datatype(
 
 fn read_named_expressions(reader: &mut OdsReader<'_>) -> Result<Vec<(String, String)>, OdsError> {
  let mut defined_names = Vec::new();
- let mut buf = Vec::new();
+ let mut buf = Vec::with_capacity(512);
  loop {
  buf.clear();
  match reader.read_event_into(&mut buf) {

src/xlsb.rs

@@ -146,7 +146,7 @@ impl<RS: Read + Seek> Xlsb<RS> {
  .trim_text(false)
  .check_comments(false)
  .expand_empty_elements(true);
- let mut buf = Vec::new();
+ let mut buf: Vec<u8> = Vec::with_capacity(64);
 
  loop {
  match xml.read_event_into(&mut buf) {
@@ -193,7 +193,7 @@ impl<RS: Read + Seek> Xlsb<RS> {
  Ok(iter) => iter,
  Err(_) => return Ok(()), // it is fine if path does not exists
  };
- let mut buf = vec![0; 1024];
+ let mut buf = Vec::with_capacity(1024);
  let mut number_formats = BTreeMap::new();
 
  loop {
@@ -248,7 +248,7 @@ impl<RS: Read + Seek> Xlsb<RS> {
  Ok(iter) => iter,
  Err(_) => return Ok(()), // it is fine if path does not exists
  };
- let mut buf = vec![0; 1024];
+ let mut buf = Vec::with_capacity(1024);
 
  let _ = iter.next_skip_blocks(0x009F, &[], &mut buf)?; // BrtBeginSst
  let len = read_usize(&buf[4..8]);
@@ -273,7 +273,7 @@ impl<RS: Read + Seek> Xlsb<RS> {
  relationships: &BTreeMap<Vec<u8>, String>,
  ) -> Result<(), XlsbError> {
  let mut iter = RecordIter::from_zip(&mut self.zip, "xl/workbook.bin")?;
- let mut buf = vec![0; 1024];
+ let mut buf = Vec::with_capacity(1024);
 
  loop {
  match iter.read_type()? {
@@ -379,7 +379,7 @@ impl<RS: Read + Seek> Xlsb<RS> {
 
  fn worksheet_range_from_path(&mut self, path: &str) -> Result<Range<DataType>, XlsbError> {
  let mut iter = RecordIter::from_zip(&mut self.zip, &path)?;
- let mut buf = vec![0; 1024];
+ let mut buf = Vec::with_capacity(1024);
  let formats = &self.formats;
  // BrtWsDim
  let _ = iter.next_skip_blocks(
@@ -492,7 +492,7 @@ impl<RS: Read + Seek> Xlsb<RS> {
 
  fn worksheet_formula_from_path(&mut self, path: String) -> Result<Range<String>, XlsbError> {
  let mut iter = RecordIter::from_zip(&mut self.zip, &path)?;
- let mut buf = vec![0; 1024];
+ let mut buf = Vec::with_capacity(1024);
 
  // BrtWsDim
  let _ = iter.next_skip_blocks(

src/xlsx.rs

@@ -191,7 +191,7 @@ impl<RS: Read + Seek> Xlsx<RS> {
  None => return Ok(()),
  Some(x) => x?,
  };
- let mut buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
  loop {
  buf.clear();
  match xml.read_event_into(&mut buf) {
@@ -217,8 +217,8 @@ impl<RS: Read + Seek> Xlsx<RS> {
 
  let mut number_formats = BTreeMap::new();
 
- let mut buf = Vec::new();
- let mut inner_buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
+ let mut inner_buf = Vec::with_capacity(1024);
  loop {
  buf.clear();
  match xml.read_event_into(&mut buf) {
@@ -291,8 +291,8 @@ impl<RS: Read + Seek> Xlsx<RS> {
  Some(x) => x?,
  };
  let mut defined_names = Vec::new();
- let mut buf = Vec::new();
- let mut val_buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
+ let mut val_buf = Vec::with_capacity(1024);
  loop {
  buf.clear();
  match xml.read_event_into(&mut buf) {
@@ -417,7 +417,7 @@ impl<RS: Read + Seek> Xlsx<RS> {
  Some(x) => x?,
  };
  let mut relationships = BTreeMap::new();
- let mut buf = Vec::new();
+ let mut buf = Vec::with_capacity(64);
  loop {
  buf.clear();
  match xml.read_event_into(&mut buf) {
@@ -456,7 +456,7 @@ impl<RS: Read + Seek> Xlsx<RS> {
  let rel_path = format!("{}/_rels{}.rels", base_folder, file_name);
 
  let mut table_locations = Vec::new();
- let mut buf = Vec::new();
+ let mut buf = Vec::with_capacity(64);
  // we need another mutable borrow of self.zip later so we enclose this borrow within braces
  {
  let mut xml = match xml_reader(&mut self.zip, &rel_path) {
@@ -732,8 +732,8 @@ where
  &mut Vec<Cell<T>>,
  ) -> Result<(), XlsxError>,
 {
- let mut cells = Vec::new();
- let mut buf = Vec::new();
+ let mut cells = Vec::with_capacity(1024);
+ let mut buf = Vec::with_capacity(1024);
  'xml: loop {
  buf.clear();
  match xml.read_event_into(&mut buf) {
@@ -841,7 +841,7 @@ impl<RS: Read + Seek> Reader<RS> for Xlsx<RS> {
  xml.read_to_end_into(e.name(), &mut Vec::new())?;
  }
  b"f" => {
- let mut f_buf = Vec::new();
+ let mut f_buf = Vec::with_capacity(512);
  let mut f = String::new();
  loop {
  match xml.read_event_into(&mut f_buf)? {
@@ -937,8 +937,8 @@ where
  &BytesStart<'_>,
  ) -> Result<(), XlsxError>,
 {
- let mut buf = Vec::new();
- let mut cell_buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
+ let mut cell_buf = Vec::with_capacity(1024);
 
  let mut row_index = 0;
  let mut col_index = 0;
@@ -1222,8 +1222,8 @@ fn read_string(
  xml: &mut XlsReader<'_>,
  QName(closing): QName,
 ) -> Result<Option<String>, XlsxError> {
- let mut buf = Vec::new();
- let mut val_buf = Vec::new();
+ let mut buf = Vec::with_capacity(1024);
+ let mut val_buf = Vec::with_capacity(1024);
  let mut rich_buffer: Option<String> = None;
  let mut is_phonetic_text = false;
  loop {