Skip to content

Using encode_arrow_schema from arrow-rs. #17543

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Sep 12, 2025
Merged

Using encode_arrow_schema from arrow-rs. #17543

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 0 additions & 1 deletion Cargo.lock
View file
Open in desktop

Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.

1 change: 0 additions & 1 deletion datafusion/common/Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -60,7 +60,6 @@ apache-avro = { version = "0.20", default-features = false, features = [
], optional = true }
arrow = { workspace = true }
arrow-ipc = { workspace = true }
base64 = "0.22.1"
chrono = { workspace = true }
half = { workspace = true }
hashbrown = { workspace = true }
Expand Down
27 changes: 1 addition & 26 deletions datafusion/common/src/file_options/parquet_writer.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -17,7 +17,6 @@

//! Options related to how parquet files should be written

use base64::Engine;
use std::sync::Arc;

use crate::{
Expand All @@ -26,6 +25,7 @@ use crate::{
};

use arrow::datatypes::Schema;
use parquet::arrow::encode_arrow_schema;
// TODO: handle once deprecated
#[allow(deprecated)]
use parquet::{
Expand Down Expand Up @@ -166,31 +166,6 @@ impl TryFrom<&TableParquetOptions> for WriterPropertiesBuilder {
}
}

/// Encodes the Arrow schema into the IPC format, and base64 encodes it
///
/// TODO: use extern parquet's private method, once publicly available.
/// Refer to <https://github.com/apache/arrow-rs/pull/6916>
fn encode_arrow_schema(schema: &Arc<Schema>) -> String {
let options = arrow_ipc::writer::IpcWriteOptions::default();
let mut dictionary_tracker = arrow_ipc::writer::DictionaryTracker::new(true);
let data_gen = arrow_ipc::writer::IpcDataGenerator::default();
let mut serialized_schema = data_gen.schema_to_bytes_with_dictionary_tracker(
schema,
&mut dictionary_tracker,
&options,
);

// manually prepending the length to the schema as arrow uses the legacy IPC format
// TODO: change after addressing ARROW-9777
let schema_len = serialized_schema.ipc_message.len();
let mut len_prefix_schema = Vec::with_capacity(schema_len + 8);
len_prefix_schema.append(&mut vec![255u8, 255, 255, 255]);
len_prefix_schema.append((schema_len as u32).to_le_bytes().to_vec().as_mut());
len_prefix_schema.append(&mut serialized_schema.ipc_message);

base64::prelude::BASE64_STANDARD.encode(&len_prefix_schema)
}

impl ParquetOptions {
/// Convert the global session options, [`ParquetOptions`], into a single write action's [`WriterPropertiesBuilder`].
///
Expand Down