liukun4515 commented on a change in pull request #941:
URL: https://github.com/apache/arrow-rs/pull/941#discussion_r749046645
##########
File path: arrow/src/csv/reader.rs
##########
@@ -728,6 +732,87 @@ fn parse_bool(string: &str) -> Option<bool> {
}
}
+// parse the column string to an Arrow Array
+fn build_decimal_array(
+ line_number: usize,
+ rows: &[StringRecord],
+ col_idx: usize,
+ precision: usize,
+ scale: usize,
+) -> Result<ArrayRef> {
+ let mut decimal_builder = DecimalBuilder::new(line_number, precision,
scale);
+ for row in rows {
+ let col_s = row.get(col_idx);
+ match col_s {
+ None => {
+ // No data for this row
+ decimal_builder.append_null()?;
+ }
+ Some(s) => {
+ if s.is_empty() {
+ // append null
+ decimal_builder.append_null()?;
+ } else {
+ let decimal_value: Result<i128> = parse_decimal(s);
+ match decimal_value {
+ Ok(v) => {
+ decimal_builder.append_value(v)?;
+ }
+ Err(e) => {
+ return Err(e);
+ }
+ }
+ }
+ }
+ }
+ }
+ Ok(Arc::new(decimal_builder.finish()))
+}
+
+// parse the string format decimal value to i128 format.
+// like "125.12" to 12512_i128.
+fn parse_decimal(s: &str) -> Result<i128> {
+ if DECIMAL_RE.is_match(s) {
+ let mut offset = s.len();
+ // each byte is digit、'-' or '.'
+ let bytes = s.as_bytes();
+ let mut negitive = false;
+ let mut result: i128 = 0;
Review comment:
This is a simple way to convert a string to i128, but we may meet some
corner case.
For example, we want to convert the value to decimal(10,2).
The string value (12.0000000000000000000000000000000000....000) (too may
'zero' after the decimal), if we remove the '.' and convert the value to i128,
we may meet the overflow error.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
