DBZ-1052 Emit tx BEGIN/END messages

Author: jpechane

proto/pg_logicaldec.proto

@@ -8,6 +8,8 @@ enum Op {
     INSERT = 0;
     UPDATE = 1;
     DELETE = 2;
+    BEGIN  = 3;
+    COMMIT = 4;
 }
 
 message Point {

src/decoderbufs.c

@@ -164,16 +164,6 @@ static void pg_decode_shutdown(LogicalDecodingContext *ctx) {
   MemoryContextDelete(data->context);
 }
 
-/* BEGIN callback */
-static void pg_decode_begin_txn(LogicalDecodingContext *ctx,
-                                ReorderBufferTXN *txn) {
-}
-
-/* COMMIT callback */
-static void pg_decode_commit_txn(LogicalDecodingContext *ctx,
-                                 ReorderBufferTXN *txn, XLogRecPtr commit_lsn) {
-}
-
 /* print tuple datums (only used for debug-mode) */
 static void print_tuple_datums(StringInfo out, Decoderbufs__DatumMessage **tup,
                                size_t n) {
@@ -491,6 +481,82 @@ static void add_metadata_to_msg(Decoderbufs__TypeInfo **tmsg,
   }
 }
 
+/* BEGIN callback */
+static void pg_decode_begin_txn(LogicalDecodingContext *ctx,
+                                ReorderBufferTXN *txn) {
+
+  DecoderData *data;
+  MemoryContext old;
+  Decoderbufs__RowMessage rmsg = DECODERBUFS__ROW_MESSAGE__INIT;
+  elog(DEBUG1, "Entering begin callback");
+
+
+  /* Avoid leaking memory by using and resetting our own context */
+  data = ctx->output_plugin_private;
+  old = MemoryContextSwitchTo(data->context);
+
+  rmsg.op = DECODERBUFS__OP__BEGIN;
+  rmsg.has_op = true;
+  rmsg.transaction_id = txn->xid;
+  rmsg.has_transaction_id = true;
+  rmsg.commit_time = TIMESTAMPTZ_TO_USEC_SINCE_EPOCH(txn->commit_time);
+  rmsg.has_commit_time = true;
+
+  /* write msg */
+  OutputPluginPrepareWrite(ctx, true);
+  if (data->debug_mode) {
+    print_row_msg(ctx->out, &rmsg);
+  } else {
+    size_t psize = decoderbufs__row_message__get_packed_size(&rmsg);
+    void *packed = palloc(psize);
+    size_t ssize = decoderbufs__row_message__pack(&rmsg, packed);
+    appendBinaryStringInfo(ctx->out, packed, ssize);
+  }
+  OutputPluginWrite(ctx, true);
+
+  /* Cleanup, freeing memory */
+  MemoryContextSwitchTo(old);
+  MemoryContextReset(data->context);
+}
+
+/* COMMIT callback */
+static void pg_decode_commit_txn(LogicalDecodingContext *ctx,
+                                 ReorderBufferTXN *txn, XLogRecPtr commit_lsn) {
+
+  DecoderData *data;
+  MemoryContext old;
+  Decoderbufs__RowMessage rmsg = DECODERBUFS__ROW_MESSAGE__INIT;
+  elog(DEBUG1, "Entering commit callback");
+
+
+  /* Avoid leaking memory by using and resetting our own context */
+  data = ctx->output_plugin_private;
+  old = MemoryContextSwitchTo(data->context);
+
+  rmsg.op = DECODERBUFS__OP__COMMIT;
+  rmsg.has_op = true;
+  rmsg.transaction_id = txn->xid;
+  rmsg.has_transaction_id = true;
+  rmsg.commit_time = TIMESTAMPTZ_TO_USEC_SINCE_EPOCH(txn->commit_time);
+  rmsg.has_commit_time = true;
+
+  /* write msg */
+  OutputPluginPrepareWrite(ctx, true);
+  if (data->debug_mode) {
+    print_row_msg(ctx->out, &rmsg);
+  } else {
+    size_t psize = decoderbufs__row_message__get_packed_size(&rmsg);
+    void *packed = palloc(psize);
+    size_t ssize = decoderbufs__row_message__pack(&rmsg, packed);
+    appendBinaryStringInfo(ctx->out, packed, ssize);
+  }
+  OutputPluginWrite(ctx, true);
+
+  /* Cleanup, freeing memory */
+  MemoryContextSwitchTo(old);
+  MemoryContextReset(data->context);
+}
+
 /* callback for individual changed tuples */
 static void pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
                              Relation relation, ReorderBufferChange *change) {

src/proto/pg_logicaldec.pb-c.c

@@ -565,17 +565,21 @@ const ProtobufCMessageDescriptor decoderbufs__row_message__descriptor =
   (ProtobufCMessageInit) decoderbufs__row_message__init,
   NULL,NULL,NULL    /* reserved[123] */
 };
-static const ProtobufCEnumValue decoderbufs__op__enum_values_by_number[3] =
+static const ProtobufCEnumValue decoderbufs__op__enum_values_by_number[5] =
 {
   { "INSERT", "DECODERBUFS__OP__INSERT", 0 },
   { "UPDATE", "DECODERBUFS__OP__UPDATE", 1 },
   { "DELETE", "DECODERBUFS__OP__DELETE", 2 },
+  { "BEGIN", "DECODERBUFS__OP__BEGIN", 3 },
+  { "COMMIT", "DECODERBUFS__OP__COMMIT", 4 },
 };
 static const ProtobufCIntRange decoderbufs__op__value_ranges[] = {
-{0, 0},{0, 3}
+{0, 0},{0, 5}
 };
-static const ProtobufCEnumValueIndex decoderbufs__op__enum_values_by_name[3] =
+static const ProtobufCEnumValueIndex decoderbufs__op__enum_values_by_name[5] =
 {
+  { "BEGIN", 3 },
+  { "COMMIT", 4 },
   { "DELETE", 2 },
   { "INSERT", 0 },
   { "UPDATE", 1 },
@@ -587,9 +591,9 @@ const ProtobufCEnumDescriptor decoderbufs__op__descriptor =
   "Op",
   "Decoderbufs__Op",
   "decoderbufs",
-  3,
+  5,
   decoderbufs__op__enum_values_by_number,
-  3,
+  5,
   decoderbufs__op__enum_values_by_name,
   1,
   decoderbufs__op__value_ranges,