arrow-avro 56.2.1

// 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::compression::{CompressionCodec, CODEC_METADATA_KEY};
use crate::schema::{AvroSchema, SCHEMA_METADATA_KEY};
use crate::writer::encoder::write_long;
use arrow_schema::{ArrowError, Schema};
use rand::RngCore;
use std::fmt::Debug;
use std::io::Write;

/// Format abstraction implemented by each container‐level writer.
pub trait AvroFormat: Debug + Default {
    /// Write any bytes required at the very beginning of the output stream
    /// Implementations **must not** write any record data.
    fn start_stream<W: Write>(
        &mut self,
        writer: &mut W,
        schema: &Schema,
        compression: Option<CompressionCodec>,
    ) -> Result<(), ArrowError>;

    /// Return the 16‑byte sync marker (OCF) or `None` (binary stream).
    fn sync_marker(&self) -> Option<&[u8; 16]>;
}

/// Avro Object Container File (OCF) format writer.
#[derive(Debug, Default)]
pub struct AvroOcfFormat {
    sync_marker: [u8; 16],
}

impl AvroFormat for AvroOcfFormat {
    fn start_stream<W: Write>(
        &mut self,
        writer: &mut W,
        schema: &Schema,
        compression: Option<CompressionCodec>,
    ) -> Result<(), ArrowError> {
        let mut rng = rand::rng();
        rng.fill_bytes(&mut self.sync_marker);
        let avro_schema = AvroSchema::try_from(schema)?;
        writer
            .write_all(b"Obj\x01")
            .map_err(|e| ArrowError::IoError(format!("write OCF magic: {e}"), e))?;
        let codec_str = match compression {
            Some(CompressionCodec::Deflate) => "deflate",
            Some(CompressionCodec::Snappy) => "snappy",
            Some(CompressionCodec::ZStandard) => "zstandard",
            Some(CompressionCodec::Bzip2) => "bzip2",
            Some(CompressionCodec::Xz) => "xz",
            None => "null",
        };
        write_long(writer, 2)?;
        write_string(writer, SCHEMA_METADATA_KEY)?;
        write_bytes(writer, avro_schema.json_string.as_bytes())?;
        write_string(writer, CODEC_METADATA_KEY)?;
        write_bytes(writer, codec_str.as_bytes())?;
        write_long(writer, 0)?;
        // Sync marker (16 bytes)
        writer
            .write_all(&self.sync_marker)
            .map_err(|e| ArrowError::IoError(format!("write OCF sync marker: {e}"), e))?;

        Ok(())
    }

    fn sync_marker(&self) -> Option<&[u8; 16]> {
        Some(&self.sync_marker)
    }
}

/// Raw Avro binary streaming format (no header or footer).
#[derive(Debug, Default)]
pub struct AvroBinaryFormat;

impl AvroFormat for AvroBinaryFormat {
    fn start_stream<W: Write>(
        &mut self,
        _writer: &mut W,
        _schema: &Schema,
        _compression: Option<CompressionCodec>,
    ) -> Result<(), ArrowError> {
        Err(ArrowError::NotYetImplemented(
            "avro binary format not yet implemented".to_string(),
        ))
    }

    fn sync_marker(&self) -> Option<&[u8; 16]> {
        None
    }
}

#[inline]
fn write_string<W: Write>(writer: &mut W, s: &str) -> Result<(), ArrowError> {
    write_bytes(writer, s.as_bytes())
}

#[inline]
fn write_bytes<W: Write>(writer: &mut W, bytes: &[u8]) -> Result<(), ArrowError> {
    write_long(writer, bytes.len() as i64)?;
    writer
        .write_all(bytes)
        .map_err(|e| ArrowError::IoError(format!("write bytes: {e}"), e))
}