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use crate::error::Result;
use crate::monitoring::{MetricsCollector, MetricsCollectorTrait};
use crate::transaction_manager::{PendingTransactionFile, TransactionManager};
use crate::types::{EventType, Lsn};
use chrono::{DateTime, Utc};
use pg_walstream::LogicalReplicationStream;
use std::collections::HashMap;
use std::sync::Arc;
use tokio::sync::{mpsc, oneshot, Mutex};
use tokio_util::sync::CancellationToken;
use tracing::{debug, error, info, warn};
/// Commit a transaction file and notify the consumer.
///
/// Moves the transaction from `sql_received_tx/` to `sql_pending_tx/`, reads the
/// resulting metadata, and sends a notification through the mpsc channel so the
/// consumer can pick it up for execution.
pub(crate) async fn handle_transaction_commit(
transaction_id: u32,
event_lsn: Option<Lsn>,
transaction_type: &str,
transaction_file_manager: &Arc<TransactionManager>,
commit_notifier: &mpsc::Sender<PendingTransactionFile>,
metrics_collector: &Arc<MetricsCollector>,
) -> Result<()> {
match transaction_file_manager
.commit_transaction(transaction_id, event_lsn)
.await
{
Ok((pending_path, metadata)) => {
info!(
"Committed {} transaction file to: {:?} (commit_lsn: {:?})",
transaction_type, pending_path, event_lsn
);
let notification = PendingTransactionFile {
file_path: pending_path,
metadata,
};
if let Err(e) = commit_notifier.send(notification).await {
warn!(
"Failed to send commit notification to consumer: {}. Consumer may have stopped.",
e
);
}
Ok(())
}
Err(e) => {
error!(
"Failed to commit {} transaction file for tx {}: {}",
transaction_type, transaction_id, e
);
metrics_collector.record_error("transaction_file_commit_failed", "producer");
Err(e)
}
}
}
/// File-based producer task: reads events from the PostgreSQL replication stream
/// and persists them as transaction files.
///
/// The producer collects events between BEGIN and COMMIT, writing them to
/// transaction files in `sql_data_tx/`. On COMMIT the metadata is moved from
/// `sql_received_tx/` to `sql_pending_tx/`, making it available for the consumer.
///
/// ## Shutdown Coordination
///
/// When the cancellation token fires:
/// 1. Producer flushes buffers and drops the mpsc sender ("no more messages")
/// 2. Sends oneshot signal to notify consumer it has stopped
/// 3. Consumer then drains mpsc channel and processes remaining transactions
pub(crate) async fn run_producer(
replication_stream: Arc<Mutex<LogicalReplicationStream>>,
cancellation_token: CancellationToken,
start_lsn: Lsn,
metrics_collector: Arc<MetricsCollector>,
transaction_file_manager: Arc<TransactionManager>,
commit_notifier: mpsc::Sender<PendingTransactionFile>,
producer_shutdown_signal: oneshot::Sender<()>,
) -> Result<()> {
info!(
"Starting replication producer, last time start_lsn: {}",
start_lsn
);
metrics_collector.update_source_connection_status(true);
// Restore active transaction files from sql_received_tx/
let active_tx_files = transaction_file_manager
.restore_received_transactions()
.await?;
info!(
"Producer starting with {} active transaction file(s) from sql_received_tx/",
active_tx_files.len()
);
let mut current_normal_tx: Option<(u32, DateTime<Utc>)> = None;
let mut streaming_txs: HashMap<u32, DateTime<Utc>> = HashMap::new();
let mut active_streaming_dml_txid: Option<u32> = None;
// Restore transactions from active_tx_files based on their type
for metadata in active_tx_files {
let tx_id = metadata.transaction_id;
let timestamp = metadata.commit_timestamp;
if metadata.transaction_type == "streaming" {
streaming_txs.insert(tx_id, timestamp);
info!(
"Restored streaming transaction {} from sql_received_tx/",
tx_id
);
} else {
if current_normal_tx.is_some() {
warn!(
"Multiple normal transactions found in sql_received_tx/, only one expected. Keeping tx {}",
tx_id
);
}
current_normal_tx = Some((tx_id, timestamp));
info!(
"Restored normal transaction {} from sql_received_tx/",
tx_id
);
}
}
while !cancellation_token.is_cancelled() {
let event_result = {
let mut stream = replication_stream.lock().await;
stream.next_event_with_retry(&cancellation_token).await
};
match event_result {
Ok(event) => {
metrics_collector.record_received_lsn(event.lsn.0);
metrics_collector.record_event(&event);
match &event.event_type {
EventType::Begin {
transaction_id,
commit_timestamp,
..
} => {
debug!(
"BEGIN: transaction_id={}, commit_timestamp={}",
transaction_id, commit_timestamp
);
if current_normal_tx.is_some() {
warn!("BEGIN received while normal transaction already active - replacing");
}
match transaction_file_manager
.begin_transaction(*transaction_id, *commit_timestamp, "normal")
.await
{
Ok(_) => {
current_normal_tx = Some((*transaction_id, *commit_timestamp));
debug!("Created normal transaction file for tx {}", transaction_id);
}
Err(e) => {
error!(
"Failed to create transaction file for tx {}: {}",
transaction_id, e
);
metrics_collector
.record_error("transaction_file_create_failed", "producer");
return Err(e);
}
}
}
EventType::Commit { .. } => {
if let Some((tx_id, _)) = current_normal_tx.take() {
info!("Producer: Committing normal transaction {}", tx_id);
if let Err(e) = handle_transaction_commit(
tx_id,
Some(event.lsn),
"normal",
&transaction_file_manager,
&commit_notifier,
&metrics_collector,
)
.await
{
error!(
"Failed to handle normal transaction commit for tx {}: {}",
tx_id, e
);
return Err(e);
}
} else {
warn!("Received COMMIT without active normal transaction, ignoring");
}
}
EventType::StreamStart {
transaction_id,
first_segment,
} => {
debug!(
"StreamStart: transaction_id={}, first_segment={}",
transaction_id, first_segment
);
active_streaming_dml_txid = Some(*transaction_id);
if *first_segment {
let timestamp = chrono::Utc::now();
match transaction_file_manager
.begin_transaction(*transaction_id, timestamp, "streaming")
.await
{
Ok(_) => {
debug!(
"Created streaming transaction file for tx {}",
transaction_id
);
streaming_txs.insert(*transaction_id, timestamp);
}
Err(e) => {
error!(
"Failed to create streaming transaction file for tx {}: {}",
transaction_id, e
);
metrics_collector
.record_error("transaction_file_create_failed", "producer");
return Err(e);
}
}
}
}
EventType::StreamStop => {
if let Some(txid) = active_streaming_dml_txid {
info!("Producer: StreamStop for streaming transaction {}", txid);
active_streaming_dml_txid = None;
} else {
warn!("Producer: StreamStop received but no active streaming DML transaction");
}
}
EventType::StreamCommit {
transaction_id,
commit_timestamp: _,
..
} => {
info!("Producer: StreamCommit for transaction {}", transaction_id);
if streaming_txs.remove(transaction_id).is_some() {
if let Err(e) = handle_transaction_commit(
*transaction_id,
Some(event.lsn),
"streaming",
&transaction_file_manager,
&commit_notifier,
&metrics_collector,
)
.await
{
error!(
"Failed to handle streaming transaction commit for tx {}: {}",
transaction_id, e
);
return Err(e);
}
} else {
warn!("StreamCommit for unknown transaction {}", transaction_id);
}
}
EventType::StreamAbort { transaction_id, .. } => {
debug!("StreamAbort: transaction_id={}", transaction_id);
if let Some(timestamp) = streaming_txs.remove(transaction_id) {
match transaction_file_manager
.abort_transaction(*transaction_id, timestamp)
.await
{
Ok(_) => {
debug!(
"Aborted streaming transaction file for tx {}",
transaction_id
);
}
Err(e) => {
error!(
"Failed to abort transaction file for tx {}: {}",
transaction_id, e
);
metrics_collector
.record_error("transaction_file_abort_failed", "producer");
}
}
} else {
warn!("StreamAbort for unknown transaction {}", transaction_id);
}
}
EventType::Insert { .. }
| EventType::Update { .. }
| EventType::Delete { .. }
| EventType::Truncate(_) => {
let target_tx_id = if let Some((tx_id, _)) = current_normal_tx {
debug!("Appending DML to normal transaction {}", tx_id);
Some(tx_id)
} else if let Some(streaming_txid) = active_streaming_dml_txid {
if streaming_txs.contains_key(&streaming_txid) {
debug!("Appending DML to streaming transaction {}", streaming_txid);
Some(streaming_txid)
} else {
error!(
"Active streaming DML txid {} not found in streaming_txs map",
streaming_txid
);
None
}
} else {
warn!(
"Received DML event with no active transaction (normal or streaming): {:?}",
event.event_type
);
None
};
if let Some(tx_id) = target_tx_id {
if let Err(e) =
transaction_file_manager.append_event(tx_id, &event).await
{
error!("Failed to append event to transaction {}: {}", tx_id, e);
metrics_collector
.record_error("transaction_file_append_failed", "producer");
return Err(e);
}
}
}
_ => {
debug!("Skipping metadata event: {:?}", event.event_type);
}
}
}
Err(e) => {
error!("Error reading from replication stream: {}", e);
metrics_collector.record_error("replication_stream_error", "producer");
break;
}
}
}
info!("File-based producer shutting down");
if let Err(e) = transaction_file_manager.flush_all_buffers().await {
error!("Failed to flush buffers during shutdown: {}", e);
metrics_collector.record_error("buffer_flush_failed", "producer");
} else {
info!("Successfully flushed all buffers");
}
let total_incomplete = if let Some((tx_id, _)) = current_normal_tx {
info!(
"Producer shutdown with incomplete normal transaction {}",
tx_id
);
1 + streaming_txs.len()
} else {
streaming_txs.len()
};
if total_incomplete > 0 {
info!(
"Producer shutdown with {} incomplete transaction(s) in sql_received_tx/ (will be recovered on restart)",
total_incomplete
);
}
metrics_collector.update_source_connection_status(false);
if producer_shutdown_signal.send(()).is_err() {
warn!("Producer: Failed to send shutdown signal (consumer may have already stopped)");
} else {
info!("Producer: Sent shutdown notification to consumer");
}
info!("Producer shutdown complete");
Ok(())
}