(arrow-rs) branch main updated: fix: reset the offset of 'file_for_view' (#8381)

[alamb]

This is an automated email from the ASF dual-hosted git repository.

alamb pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/main by this push:
     new 138368cc9c fix: reset the offset of 'file_for_view' (#8381)
138368cc9c is described below

commit 138368cc9c9aec2fd40afe2050b1054caaa3dd55
Author: Van De Bio <trevora...@gmail.com>
AuthorDate: Sat Sep 20 02:58:26 2025 +0800

    fix: reset the offset of 'file_for_view' (#8381)
    
    # Which issue does this PR close?
    
    - Closes #8380
    
    # Rationale for this change
    
    It will fix the example to help user get the result of utf8view
    performance.
    
    # What changes are included in this PR?
    
    Reset the file handle's offset before using it in next time.
    
    # Are these changes tested?
    
    ```
    arrow-avro/examples/read_with_utf8view.rs
    ```
    
    The example can run successfully
    ```shell
    (base) ➜  arrow-avro git:(fix/example_of_utf8view) cargo run --package 
arrow-avro --example read_with_utf8view -- test/data/nested_record_reuse.avro
        Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
         Running 
`/Users/trevor.wang/Workspace/rust/fix-arrow-rs/arrow-rs/target/debug/examples/read_with_utf8view
 test/data/nested_record_reuse.avro`
    Read 2 rows from test/data/nested_record_reuse.avro
    Reading with StringArray: 2.095417ms
    Reading with StringViewArray: 179.333µs
    StringViewArray was 11.68x faster
    ```
    
    # Are there any user-facing changes?
    
    Every user will get the right result and run the example to get the
    perfomrance data.
    
    ---------
    
    Co-authored-by: Trevor Wang <trevor.w...@shopee.com>
---
 arrow-avro/examples/read_with_utf8view.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arrow-avro/examples/read_with_utf8view.rs 
b/arrow-avro/examples/read_with_utf8view.rs
index 707be57516..85b07c8d03 100644
--- a/arrow-avro/examples/read_with_utf8view.rs
+++ b/arrow-avro/examples/read_with_utf8view.rs
@@ -22,7 +22,7 @@
 
 use std::env;
 use std::fs::File;
-use std::io::BufReader;
+use std::io::{BufReader, Seek, SeekFrom};
 use std::time::Instant;
 
 use arrow_array::{RecordBatch, StringArray, StringViewArray};
@@ -39,7 +39,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     };
 
     let file = File::open(file_path)?;
-    let file_for_view = file.try_clone()?;
+    let mut file_for_view = file.try_clone()?;
 
     let start = Instant::now();
     let reader = BufReader::new(file);
@@ -48,6 +48,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let batches: Vec<RecordBatch> = avro_reader.collect::<Result<_, _>>()?;
     let regular_duration = start.elapsed();
 
+    file_for_view.seek(SeekFrom::Start(0))?;
     let start = Instant::now();
     let reader_view = BufReader::new(file_for_view);
     let avro_reader_view = ReaderBuilder::new()