static void pg_output_begin(LogicalDecodingContext* ctx, DecodingJsonData* data, ReorderBufferTXN* txn, bool last_write) {
OutputPluginPrepareWrite(ctx, last_write);
appendStringInfo(
ctx->out,
"{\"type\":\"transaction.begin\",\"xid\":\"%u\",\"committed\":\"%s\"}",
txn->xid,
timestamptz_to_str(txn->commit_time)
);
OutputPluginWrite(ctx, last_write);
}
static void pg_decode_commit_txn(LogicalDecodingContext* ctx, ReorderBufferTXN* txn, XLogRecPtr commit_lsn) {
OutputPluginPrepareWrite(ctx, true);
appendStringInfo(
ctx->out,
"{\"type\":\"transaction.commit\",\"xid\":\"%u\",\"committed\":\"%s\"}",
txn->xid,
timestamptz_to_str(txn->commit_time)
);
OutputPluginWrite(ctx, true);
}
int write_frame(LogicalDecodingContext *ctx, plugin_state *state) {
int err = 0;
bytea *output = NULL;
check(err, try_writing(&output, &write_avro_binary, &state->frame_value));
OutputPluginPrepareWrite(ctx, true);
appendBinaryStringInfo(ctx->out, VARDATA(output), VARSIZE(output) - VARHDRSZ);
OutputPluginWrite(ctx, true);
pfree(output);
return err;
}
/* COMMIT callback */
static void
decoder_raw_commit_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
XLogRecPtr commit_lsn)
{
DecoderRawData *data = ctx->output_plugin_private;
if (!data->isLocal) {
XTM_INFO("Send commit of transaction %u to replica\n", txn->xid);
OutputPluginPrepareWrite(ctx, true);
appendStringInfoString(ctx->out, "COMMIT;");
OutputPluginWrite(ctx, true);
} else {
XTM_INFO("Skip commit of transaction %u\n", txn->xid);
}
}
static void
decoder_raw_begin_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn)
{
DecoderRawData *data = ctx->output_plugin_private;
Assert(lastXid != txn->xid);
lastXid = txn->xid;
if (MMIsLocalTransaction(txn->xid)) {
XTM_INFO("Skip local transaction %u\n", txn->xid);
data->isLocal = true;
} else {
OutputPluginPrepareWrite(ctx, true);
XTM_INFO("Send transaction %u to replica\n", txn->xid);
appendStringInfoString(ctx->out, "BEGIN;");
OutputPluginWrite(ctx, true);
data->isLocal = false;
}
}
static void pg_decode_change(LogicalDecodingContext* ctx, ReorderBufferTXN* txn, Relation relation, ReorderBufferChange* change) {
DecodingJsonData* data;
Form_pg_class class_form;
TupleDesc tupdesc;
HeapTuple tuple;
MemoryContext old;
data = ctx->output_plugin_private;
data->xact_wrote_changes = true;
class_form = RelationGetForm(relation);
tupdesc = RelationGetDescr(relation);
old = MemoryContextSwitchTo(data->context);
OutputPluginPrepareWrite(ctx, true);
appendStringInfoString(ctx->out, "{\"type\":\"table\"");
appendStringInfo(
ctx->out,
",\"schema\":\"%s\"",
get_namespace_name(
get_rel_namespace(
RelationGetRelid(relation)
)
)
);
appendStringInfo(ctx->out, ",\"name\":\"%s\"", NameStr(class_form->relname));
appendStringInfo(
ctx->out,
",\"change\":\"%s\"",
change->action == REORDER_BUFFER_CHANGE_INSERT
? "INSERT"
: change->action == REORDER_BUFFER_CHANGE_UPDATE
? "UPDATE"
: change->action == REORDER_BUFFER_CHANGE_DELETE
? "DELETE"
: "FIXME"
);
if (change->action == REORDER_BUFFER_CHANGE_UPDATE || change->action == REORDER_BUFFER_CHANGE_DELETE) {
appendStringInfoString(ctx->out, ",\"key\":{");
RelationGetIndexList(relation);
if (OidIsValid(relation->rd_replidindex)) {
int i;
Relation index = index_open(relation->rd_replidindex, ShareLock);
tuple =
change->data.tp.oldtuple
? &change->data.tp.oldtuple->tuple
: &change->data.tp.newtuple->tuple;
for (i = 0; i < index->rd_index->indnatts; i++) {
int j = index->rd_index->indkey.values[i];
Form_pg_attribute attr = tupdesc->attrs[j - 1];
if (i > 0) appendStringInfoChar(ctx->out, ',');
appendStringInfo(ctx->out, "\"%s\":", NameStr(attr->attname));
print_value(ctx->out, tupdesc, tuple, j - 1);
}
index_close(index, NoLock);
} else {
appendStringInfoString(ctx->out, "\"***FIXME***\"");
}
appendStringInfoChar(ctx->out, '}');
}
if (change->action == REORDER_BUFFER_CHANGE_UPDATE || change->action == REORDER_BUFFER_CHANGE_INSERT) {
appendStringInfoString(ctx->out, ",\"data\":{");
tuple_to_stringinfo(ctx->out, tupdesc, &change->data.tp.newtuple->tuple, false);
appendStringInfoChar(ctx->out, '}');
}
appendStringInfoChar(ctx->out, '}');
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
OutputPluginWrite(ctx, true);
}
/*
* Callback for individual changed tuples
*/
static void
decoder_raw_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
Relation relation, ReorderBufferChange *change)
{
DecoderRawData *data;
MemoryContext old;
char replident = relation->rd_rel->relreplident;
bool is_rel_non_selective;
data = ctx->output_plugin_private;
if (data->isLocal) {
XTM_INFO("Skip action %d in transaction %u\n", change->action, txn->xid);
return;
}
XTM_INFO("Send action %d in transaction %u to replica\n", change->action, txn->xid);
/* Avoid leaking memory by using and resetting our own context */
old = MemoryContextSwitchTo(data->context);
/*
* Determine if relation is selective enough for WHERE clause generation
* in UPDATE and DELETE cases. A non-selective relation uses REPLICA
* IDENTITY set as NOTHING, or DEFAULT without an available replica
* identity index.
*/
RelationGetIndexList(relation);
is_rel_non_selective = (replident == REPLICA_IDENTITY_NOTHING ||
(replident == REPLICA_IDENTITY_DEFAULT &&
!OidIsValid(relation->rd_replidindex)));
/* Decode entry depending on its type */
switch (change->action)
{
case REORDER_BUFFER_CHANGE_INSERT:
if (change->data.tp.newtuple != NULL)
{
OutputPluginPrepareWrite(ctx, true);
decoder_raw_insert(ctx->out,
relation,
&change->data.tp.newtuple->tuple);
OutputPluginWrite(ctx, true);
}
break;
case REORDER_BUFFER_CHANGE_UPDATE:
if (!is_rel_non_selective)
{
HeapTuple oldtuple = change->data.tp.oldtuple != NULL ?
&change->data.tp.oldtuple->tuple : NULL;
HeapTuple newtuple = change->data.tp.newtuple != NULL ?
&change->data.tp.newtuple->tuple : NULL;
OutputPluginPrepareWrite(ctx, true);
decoder_raw_update(ctx->out,
relation,
oldtuple,
newtuple);
OutputPluginWrite(ctx, true);
}
break;
case REORDER_BUFFER_CHANGE_DELETE:
if (!is_rel_non_selective)
{
OutputPluginPrepareWrite(ctx, true);
decoder_raw_delete(ctx->out,
relation,
&change->data.tp.oldtuple->tuple);
OutputPluginWrite(ctx, true);
}
break;
default:
/* Should not come here */
Assert(0);
break;
}
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
}
