tustvold commented on code in PR #2378: URL: https://github.com/apache/arrow-rs/pull/2378#discussion_r940578202
########## parquet/src/util/cursor.rs: ########## @@ -1,284 +0,0 @@ -// Licensed to the Apache Software Foundation (ASF) under one -// or more contributor license agreements. See the NOTICE file -// distributed with this work for additional information -// regarding copyright ownership. The ASF licenses this file -// to you under the Apache License, Version 2.0 (the -// "License"); you may not use this file except in compliance -// with the License. You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, -// software distributed under the License is distributed on an -// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY -// KIND, either express or implied. See the License for the -// specific language governing permissions and limitations -// under the License. - -use crate::util::io::TryClone; -use std::io::{self, Cursor, Error, ErrorKind, Read, Seek, SeekFrom, Write}; -use std::sync::{Arc, Mutex}; -use std::{cmp, fmt}; - -/// This is object to use if your file is already in memory. -/// The sliceable cursor is similar to std::io::Cursor, except that it makes it easy to create "cursor slices". -/// To achieve this, it uses Arc instead of shared references. Indeed reference fields are painful -/// because the lack of Generic Associated Type implies that you would require complex lifetime propagation when -/// returning such a cursor. -#[allow(clippy::rc_buffer)] -#[deprecated = "use bytes::Bytes instead"] -pub struct SliceableCursor { - inner: Arc<Vec<u8>>, - start: u64, - length: usize, - pos: u64, -} - -#[allow(deprecated)] -impl fmt::Debug for SliceableCursor { - fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { - f.debug_struct("SliceableCursor") - .field("start", &self.start) - .field("length", &self.length) - .field("pos", &self.pos) - .field("inner.len", &self.inner.len()) - .finish() - } -} - -#[allow(deprecated)] -impl SliceableCursor { - pub fn new(content: impl Into<Arc<Vec<u8>>>) -> Self { - let inner = content.into(); - let size = inner.len(); - SliceableCursor { - inner, - start: 0, - pos: 0, - length: size, - } - } - - /// Create a slice cursor using the same data as a current one. - pub fn slice(&self, start: u64, length: usize) -> io::Result<Self> { - let new_start = self.start + start; - if new_start >= self.inner.len() as u64 - || new_start as usize + length > self.inner.len() - { - return Err(Error::new(ErrorKind::InvalidInput, "out of bound")); - } - Ok(SliceableCursor { - inner: Arc::clone(&self.inner), - start: new_start, - pos: new_start, - length, - }) - } - - fn remaining_slice(&self) -> &[u8] { - let end = self.start as usize + self.length; - let offset = cmp::min(self.pos, end as u64) as usize; - &self.inner[offset..end] - } - - /// Get the length of the current cursor slice - pub fn len(&self) -> u64 { - self.length as u64 - } - - /// return true if the cursor is empty (self.len() == 0) - pub fn is_empty(&self) -> bool { - self.len() == 0 - } -} - -/// Implementation inspired by std::io::Cursor -#[allow(deprecated)] -impl Read for SliceableCursor { - fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { - let n = Read::read(&mut self.remaining_slice(), buf)?; - self.pos += n as u64; - Ok(n) - } -} - -#[allow(deprecated)] -impl Seek for SliceableCursor { - fn seek(&mut self, pos: SeekFrom) -> io::Result<u64> { - let new_pos = match pos { - SeekFrom::Start(pos) => pos as i64, - SeekFrom::End(pos) => self.inner.len() as i64 + pos as i64, - SeekFrom::Current(pos) => self.pos as i64 + pos as i64, - }; - - if new_pos < 0 { - Err(Error::new( - ErrorKind::InvalidInput, - format!( - "Request out of bounds: cur position {} + seek {:?} < 0: {}", - self.pos, pos, new_pos - ), - )) - } else if new_pos >= self.inner.len() as i64 { - Err(Error::new( - ErrorKind::InvalidInput, - format!( - "Request out of bounds: cur position {} + seek {:?} >= length {}: {}", - self.pos, - pos, - self.inner.len(), - new_pos - ), - )) - } else { - self.pos = new_pos as u64; - Ok(self.start) - } - } -} - -/// Use this type to write Parquet to memory rather than a file. -#[deprecated = "use Vec<u8> instead"] Review Comment: This was always an experimental API, and so can also go -- 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]
