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postgres-decoderbufs/src/decoderbufs.c

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/*
* decoderbufs - PostgreSQL output plug-in for logical replication to Protocol
* Buffers
*
* Copyright (c) 2014 Xavier Stevens
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#if defined(__linux__)
#include <endian.h>
#elif defined(__APPLE__)
#include <machine/endian.h>
#include <libkern/OSByteOrder.h>
#define htobe64(x) OSSwapHostToBigInt64(x)
#endif
#include <inttypes.h>
#include "postgres.h"
#include "funcapi.h"
#include "catalog/pg_class.h"
#include "catalog/pg_type.h"
#include "catalog/namespace.h"
#include "executor/spi.h"
#include "replication/output_plugin.h"
#include "replication/logical.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/geo_decls.h"
#include "utils/json.h"
#include "utils/memutils.h"
#include "utils/numeric.h"
#include "utils/rel.h"
#include "utils/relcache.h"
#include "utils/syscache.h"
#include "utils/typcache.h"
#include "utils/uuid.h"
#include "utils/timestamp.h"
#include "utils/date.h"
#include "utils/cash.h"
#include "proto/pg_logicaldec.pb-c.h"
#ifndef HAVE_INT64_TIMESTAMP
#error Expecting timestamps to be represented as integers, not as floating-point.
#endif
#ifdef USE_POSTGIS
/* POSTGIS version define so it doesn't redef macros */
#define POSTGIS_PGSQL_VERSION 94
#include "liblwgeom.h"
#endif
PG_MODULE_MAGIC;
/* define a time macro to convert TimestampTz into something more sane,
* which in this case is microseconds since epoch. This is because PG stores internally the timestamps relative to
* 2000-01-01T00:00:00Z and not the Unix epoch.
*/
#define TIMESTAMPTZ_TO_USEC_SINCE_EPOCH(t) t + (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * USECS_PER_DAY;
#define DATE_TO_DAYS_SINCE_EPOCH(t) t + (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE);
typedef struct {
MemoryContext context;
bool debug_mode;
} DecoderData;
/* GLOBALs for PostGIS dynamic OIDs */
Oid geometry_oid = InvalidOid;
Oid geography_oid = InvalidOid;
/* these must be available to pg_dlsym() */
extern void _PG_init(void);
extern void _PG_output_plugin_init(OutputPluginCallbacks *cb);
static void pg_decode_startup(LogicalDecodingContext *ctx,
OutputPluginOptions *opt, bool is_init);
static void pg_decode_shutdown(LogicalDecodingContext *ctx);
static void pg_decode_begin_txn(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn);
static void pg_decode_commit_txn(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn, XLogRecPtr commit_lsn);
static void pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
Relation rel, ReorderBufferChange *change);
void _PG_init(void) {}
/* specify output plugin callbacks */
void _PG_output_plugin_init(OutputPluginCallbacks *cb) {
AssertVariableIsOfType(&_PG_output_plugin_init, LogicalOutputPluginInit);
cb->startup_cb = pg_decode_startup;
cb->begin_cb = pg_decode_begin_txn;
cb->change_cb = pg_decode_change;
cb->commit_cb = pg_decode_commit_txn;
cb->shutdown_cb = pg_decode_shutdown;
}
/* initialize this plugin */
static void pg_decode_startup(LogicalDecodingContext *ctx,
OutputPluginOptions *opt, bool is_init) {
ListCell *option;
DecoderData *data;
elog(DEBUG1, "Entering startup callback");
data = palloc(sizeof(DecoderData));
data->context = AllocSetContextCreate(
ctx->context, "decoderbufs context", ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE);
data->debug_mode = false;
opt->output_type = OUTPUT_PLUGIN_BINARY_OUTPUT;
foreach(option, ctx->output_plugin_options) {
DefElem *elem = lfirst(option);
Assert(elem->arg == NULL || IsA(elem->arg, String));
if (strcmp(elem->defname, "debug-mode") == 0) {
if (elem->arg == NULL) {
data->debug_mode = false;
} else if (!parse_bool(strVal(elem->arg), &data->debug_mode)) {
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
if (data->debug_mode) {
elog(NOTICE, "Decoderbufs DEBUG MODE is ON.");
opt->output_type = OUTPUT_PLUGIN_TEXTUAL_OUTPUT;
} else {
elog(NOTICE, "Decoderbufs DEBUG MODE is OFF.");
}
} else {
ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("option \"%s\" = \"%s\" is unknown", elem->defname,
elem->arg ? strVal(elem->arg) : "(null)")));
}
}
ctx->output_plugin_private = data;
elog(INFO, "Exiting startup callback");
}
/* cleanup this plugin's resources */
static void pg_decode_shutdown(LogicalDecodingContext *ctx) {
DecoderData *data;
elog(DEBUG1, "Entering decode_shutdown callback");
data = ctx->output_plugin_private;
/* cleanup our own resources via memory context reset */
MemoryContextDelete(data->context);
}
/* BEGIN callback */
static void pg_decode_begin_txn(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn) {
#ifdef USE_POSTGIS
// set PostGIS geometry type id (these are dynamic)
// TODO: Figure out how to make sure we get the typid's from postgis extension namespace
if (geometry_oid == InvalidOid) {
geometry_oid = TypenameGetTypid("geometry");
if (geometry_oid != InvalidOid) {
elog(DEBUG1, "PostGIS geometry type detected: %u", geometry_oid);
}
}
if (geography_oid == InvalidOid) {
geography_oid = TypenameGetTypid("geography");
if (geography_oid != InvalidOid) {
elog(DEBUG1, "PostGIS geometry type detected: %u", geography_oid);
}
}
#endif
}
/* COMMIT callback */
static void pg_decode_commit_txn(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn, XLogRecPtr commit_lsn) {
}
/* convenience method to free up sub-messages */
static void row_message_destroy(Decoderbufs__RowMessage *msg) {
if (!msg) {
return;
}
if (msg->table) {
pfree(msg->table);
}
if (msg->n_new_tuple > 0) {
for (int i = 0; i < msg->n_new_tuple; i++) {
if (msg->new_tuple[i]) {
switch (msg->new_tuple[i]->datum_case) {
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_STRING:
if (msg->new_tuple[i]->datum_string) {
pfree(msg->new_tuple[i]->datum_string);
}
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BYTES:
if (msg->new_tuple[i]->datum_bytes.data) {
pfree(msg->new_tuple[i]->datum_bytes.data);
msg->new_tuple[i]->datum_bytes.data = NULL;
msg->new_tuple[i]->datum_bytes.len = 0;
}
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_POINT:
if (msg->new_tuple[i]->datum_point) {
pfree(msg->new_tuple[i]->datum_point);
}
break;
default:
break;
}
pfree(msg->new_tuple[i]);
}
}
pfree(msg->new_tuple);
}
if (msg->n_old_tuple > 0) {
for (int i = 0; i < msg->n_old_tuple; i++) {
if (msg->old_tuple[i]) {
switch (msg->old_tuple[i]->datum_case) {
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_STRING:
if (msg->old_tuple[i]->datum_string) {
pfree(msg->old_tuple[i]->datum_string);
}
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BYTES:
if (msg->old_tuple[i]->datum_bytes.data) {
pfree(msg->old_tuple[i]->datum_bytes.data);
msg->old_tuple[i]->datum_bytes.data = NULL;
msg->old_tuple[i]->datum_bytes.len = 0;
}
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_POINT:
if (msg->old_tuple[i]->datum_point) {
pfree(msg->old_tuple[i]->datum_point);
}
break;
default:
break;
}
pfree(msg->old_tuple[i]);
}
}
pfree(msg->old_tuple);
}
}
/* print tuple datums (only used for debug-mode) */
static void print_tuple_datums(StringInfo out, Decoderbufs__DatumMessage **tup,
size_t n) {
if (tup) {
for (int i = 0; i < n; i++) {
Decoderbufs__DatumMessage *dmsg = tup[i];
if (dmsg->column_name)
appendStringInfo(out, "column_name[%s]", dmsg->column_name);
if (dmsg->has_column_type)
appendStringInfo(out, ", column_type[%" PRId64 "]", dmsg->column_type);
switch (dmsg->datum_case) {
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT32:
appendStringInfo(out, ", datum[%d]", dmsg->datum_int32);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT64:
appendStringInfo(out, ", datum[%" PRId64 "]", dmsg->datum_int64);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_FLOAT:
appendStringInfo(out, ", datum[%f]", dmsg->datum_float);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_DOUBLE:
appendStringInfo(out, ", datum[%f]", dmsg->datum_double);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BOOL:
appendStringInfo(out, ", datum[%d]", dmsg->datum_bool);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_STRING:
appendStringInfo(out, ", datum[%s]", dmsg->datum_string);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BYTES:
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_POINT:
appendStringInfo(out, ", datum[POINT(%f, %f)]",
dmsg->datum_point->x, dmsg->datum_point->y);
break;
case DECODERBUFS__DATUM_MESSAGE__DATUM__NOT_SET:
// intentional fall-through
default:
appendStringInfo(out, ", datum[!NOT SET!]");
break;
}
appendStringInfo(out, "\n");
}
}
}
/* print a row message (only used for debug-mode) */
static void print_row_msg(StringInfo out, Decoderbufs__RowMessage *rmsg) {
if (!rmsg)
return;
if (rmsg->has_transaction_id)
appendStringInfo(out, "txid[%d]", rmsg->transaction_id);
if (rmsg->has_commit_time)
appendStringInfo(out, ", commit_time[%" PRId64 "]", rmsg->commit_time);
if (rmsg->table)
appendStringInfo(out, ", table[%s]", rmsg->table);
if (rmsg->has_op)
appendStringInfo(out, ", op[%d]", rmsg->op);
if (rmsg->old_tuple) {
appendStringInfo(out, "\nOLD TUPLE: \n");
print_tuple_datums(out, rmsg->old_tuple, rmsg->n_old_tuple);
appendStringInfo(out, "\n");
}
if (rmsg->new_tuple) {
appendStringInfo(out, "\nNEW TUPLE: \n");
print_tuple_datums(out, rmsg->new_tuple, rmsg->n_new_tuple);
appendStringInfo(out, "\n");
}
}
/* this doesn't seem to be available in the public api (unfortunate) */
static double numeric_to_double_no_overflow(Numeric num) {
char *tmp;
double val;
char *endptr;
tmp = DatumGetCString(DirectFunctionCall1(numeric_out, NumericGetDatum(num)));
/* unlike float8in, we ignore ERANGE from strtod */
val = strtod(tmp, &endptr);
if (*endptr != '\0') {
/* shouldn't happen ... */
ereport(ERROR,
(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
errmsg("invalid input syntax for type double precision: \"%s\"",
tmp)));
}
pfree(tmp);
return val;
}
static bool geography_point_as_decoderbufs_point(Datum datum,
Decoderbufs__Point *p) {
#ifdef USE_POSTGIS
GSERIALIZED *geom;
LWGEOM *lwgeom;
LWPOINT *point = NULL;
POINT2D p2d;
geom = (GSERIALIZED *)PG_DETOAST_DATUM(datum);
if (gserialized_get_type(geom) != POINTTYPE) {
return false;
}
lwgeom = lwgeom_from_gserialized(geom);
point = lwgeom_as_lwpoint(lwgeom);
if (lwgeom_is_empty(lwgeom)) {
return false;
}
getPoint2d_p(point->point, 0, &p2d);
if (p != NULL) {
Decoderbufs__Point dp = DECODERBUFS__POINT__INIT;
dp.x = p2d.x;
dp.y = p2d.y;
memcpy(p, &dp, sizeof(dp));
elog(DEBUG1, "Translating geography to point: (x,y) = (%f,%f)", p->x, p->y);
}
return true;
#else
elog(DEBUG1, "PostGIS support is off, recompile decoderbufs with USE_POSTGIS option!");
return false;
#endif
}
/* set a datum value based on its OID specified by typid */
static void set_datum_value(Decoderbufs__DatumMessage *datum_msg, Oid typid,
Oid typoutput, Datum datum) {
Numeric num;
bytea *valptr = NULL;
const char *output = NULL;
Point *p = NULL;
Timestamp ts;
double duration;
TimeTzADT *timetz = NULL;
Interval *interval = NULL;
Decoderbufs__Point dp = DECODERBUFS__POINT__INIT;
int size = 0;
switch (typid) {
case BOOLOID:
datum_msg->datum_bool = DatumGetBool(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BOOL;
break;
case INT2OID:
datum_msg->datum_int32 = DatumGetInt16(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT32;
break;
case INT4OID:
datum_msg->datum_int32 = DatumGetInt32(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT32;
break;
case INT8OID:
case OIDOID:
datum_msg->datum_int64 = DatumGetInt64(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT64;
break;
case FLOAT4OID:
datum_msg->datum_float = DatumGetFloat4(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_FLOAT;
break;
case FLOAT8OID:
datum_msg->datum_double = DatumGetFloat8(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_DOUBLE;
break;
case NUMERICOID:
num = DatumGetNumeric(datum);
if (!numeric_is_nan(num)) {
datum_msg->datum_double = numeric_to_double_no_overflow(num);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_DOUBLE;
}
break;
case CASHOID:
datum_msg->datum_int64 = DatumGetCash(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT64;
break;
case CHAROID:
case VARCHAROID:
case BPCHAROID:
case TEXTOID:
case JSONOID:
case JSONBOID:
case XMLOID:
case BITOID:
case VARBITOID:
case UUIDOID:
output = OidOutputFunctionCall(typoutput, datum);
datum_msg->datum_string = pnstrdup(output, strlen(output));
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_STRING;
break;
case TIMESTAMPOID:
ts = DatumGetTimestamp(datum);
if (TIMESTAMP_NOT_FINITE(ts)) {
ereport(ERROR, (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp \'%s\'out of range", ts ? strVal(ts) : "(null)")));
} else {
datum_msg->datum_int64 = TIMESTAMPTZ_TO_USEC_SINCE_EPOCH(ts);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT64;
break;
}
case TIMESTAMPTZOID:
ts = DatumGetTimestampTz(datum);
if (TIMESTAMP_NOT_FINITE(ts)) {
ereport(ERROR, (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp \'%s\'out of range", ts ? strVal(ts) : "(null)")));
} else {
datum_msg->datum_int64 = TIMESTAMPTZ_TO_USEC_SINCE_EPOCH(ts);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT64;
break;
}
case DATEOID:
/* simply get the number of days as the stored 32 bit value and convert to EPOCH */
datum_msg->datum_int32 = DATE_TO_DAYS_SINCE_EPOCH(DatumGetDateADT(datum));
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT32;
break;
case TIMEOID:
datum_msg->datum_int64 = DatumGetTimeADT(datum);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_INT64;
break;
case TIMETZOID:
timetz = DatumGetTimeTzADTP(datum);
/* use GMT-equivalent time */
datum_msg->datum_double = (double) (timetz->time + (timetz->zone * 1000000.0));
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_DOUBLE;
break;
case INTERVALOID:
interval = DatumGetIntervalP(datum);
/*
Convert the month part of Interval to days using assumed average month length of 365.25/12.0 days.
*/
duration = interval->time + interval->day * (double) USECS_PER_DAY + interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
datum_msg->datum_double = duration;
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_DOUBLE;
break;
case BYTEAOID:
valptr = DatumGetByteaPCopy(datum);
size = VARSIZE(valptr) - VARHDRSZ;
datum_msg->datum_bytes.data = palloc(size);
memcpy(datum_msg->datum_bytes.data, (uint8_t *)VARDATA(valptr), size);
datum_msg->datum_bytes.len = size;
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BYTES;
break;
case POINTOID:
p = DatumGetPointP(datum);
dp.x = p->x;
dp.y = p->y;
datum_msg->datum_point = palloc(sizeof(Decoderbufs__Point));
memcpy(datum_msg->datum_point, &dp, sizeof(dp));
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_POINT;
break;
default:
// PostGIS uses dynamic OIDs so we need to check the type again here
if (typid == geometry_oid || typid == geography_oid) {
elog(DEBUG1, "Converting geography point to datum_point");
datum_msg->datum_point = palloc(sizeof(Decoderbufs__Point));
geography_point_as_decoderbufs_point(datum, datum_msg->datum_point);
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_POINT;
} else {
int len;
elog(DEBUG1, "Encountered unknown typid: %d, using bytes", typid);
output = OidOutputFunctionCall(typoutput, datum);
len = strlen(output);
size = sizeof(char) * len;
datum_msg->datum_bytes.data = palloc(size);
memcpy(datum_msg->datum_bytes.data, (uint8_t *)output, size);
datum_msg->datum_bytes.len = len;
datum_msg->datum_case = DECODERBUFS__DATUM_MESSAGE__DATUM_DATUM_BYTES;
}
break;
}
}
/* return the number of valid attributes from the tuple */
static int valid_attributes_count_from(TupleDesc tupdesc) {
int natt;
int count = 0;
for (natt = 0; natt < tupdesc->natts; natt++) {
Form_pg_attribute attr = tupdesc->attrs[natt];
/* skip dropped columns and system columns */
if (attr->attisdropped || attr->attnum < 0) {
continue;
}
count++;
}
return count;
}
/* convert a PG tuple to an array of DatumMessage(s) */
static void tuple_to_tuple_msg(Decoderbufs__DatumMessage **tmsg,
Relation relation, HeapTuple tuple,
TupleDesc tupdesc) {
int natt;
int valid_attr_cnt = 0;
elog(DEBUG1, "processing tuple with %d columns", tupdesc->natts);
/* build column names and values */
for (natt = 0; natt < tupdesc->natts; natt++) {
Form_pg_attribute attr;
Datum origval;
bool isnull;
const char *attrName;
Oid typoutput;
bool typisvarlena;
Decoderbufs__DatumMessage datum_msg = DECODERBUFS__DATUM_MESSAGE__INIT;
attr = tupdesc->attrs[natt];
/* skip dropped columns and system columns */
if (attr->attisdropped || attr->attnum < 0) {
elog(DEBUG1, "skipping column %d because %s", natt + 1, attr->attisdropped ? "it's a dropped column" : "it's a system column");
continue;
}
attrName = quote_identifier(NameStr(attr->attname));
elog(DEBUG1, "processing column %d with name %s", natt + 1, attrName);
/* set the column name */
datum_msg.column_name = (char *)attrName;
/* set datum from tuple */
origval = heap_getattr(tuple, natt + 1, tupdesc, &isnull);
/* get output function */
datum_msg.column_type = attr->atttypid;
datum_msg.has_column_type = true;
/* query output function */
getTypeOutputInfo(attr->atttypid, &typoutput, &typisvarlena);
if (!isnull) {
if (typisvarlena && VARATT_IS_EXTERNAL_ONDISK(origval)) {
// TODO: Is there a way we can handle this?
elog(DEBUG1, "Not handling external on disk varlena at the moment.");
} else if (!typisvarlena) {
set_datum_value(&datum_msg, attr->atttypid, typoutput, origval);
} else {
Datum val = PointerGetDatum(PG_DETOAST_DATUM(origval));
set_datum_value(&datum_msg, attr->atttypid, typoutput, val);
}
} else {
elog(DEBUG1, "column %s is null, ignoring value", attrName);
}
tmsg[valid_attr_cnt] = palloc(sizeof(datum_msg));
memcpy(tmsg[valid_attr_cnt], &datum_msg, sizeof(datum_msg));
valid_attr_cnt++;
}
}
/* callback for individual changed tuples */
static void pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
Relation relation, ReorderBufferChange *change) {
DecoderData *data;
MemoryContext old;
Form_pg_class class_form;
char replident;
bool is_rel_non_selective;
const char *selectiveInfo;
TupleDesc tupdesc;
Decoderbufs__RowMessage rmsg = DECODERBUFS__ROW_MESSAGE__INIT;
elog(DEBUG1, "Entering decode_change callback");
replident = relation->rd_rel->relreplident;
class_form = RelationGetForm(relation);
data = ctx->output_plugin_private;
/* Avoid leaking memory by using and resetting our own context */
old = MemoryContextSwitchTo(data->context);
RelationGetIndexList(relation);
is_rel_non_selective = (replident == REPLICA_IDENTITY_NOTHING ||
(replident == REPLICA_IDENTITY_DEFAULT &&
!OidIsValid(relation->rd_replidindex)));
selectiveInfo = is_rel_non_selective ? "non selective" : "selective";
/* set common fields */
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;
rmsg.table = pstrdup(quote_qualified_identifier(get_namespace_name(get_rel_namespace(RelationGetRelid(relation))),
NameStr(class_form->relname)));
/* decode different operation types */
switch (change->action) {
case REORDER_BUFFER_CHANGE_INSERT:
elog(DEBUG1, "decoding INSERT for table %s; relation is %s", rmsg.table, selectiveInfo);
rmsg.op = DECODERBUFS__OP__INSERT;
rmsg.has_op = true;
if (change->data.tp.newtuple != NULL) {
elog(DEBUG1, "decoding new tuple information");
tupdesc = RelationGetDescr(relation);
rmsg.n_new_tuple = valid_attributes_count_from(tupdesc);
rmsg.new_tuple =
palloc(sizeof(Decoderbufs__DatumMessage*) * rmsg.n_new_tuple);
tuple_to_tuple_msg(rmsg.new_tuple, relation,
&change->data.tp.newtuple->tuple, tupdesc);
}
break;
case REORDER_BUFFER_CHANGE_UPDATE:
rmsg.op = DECODERBUFS__OP__UPDATE;
rmsg.has_op = true;
elog(DEBUG1, "decoding UPDATE for table %s; relation is %s", rmsg.table, selectiveInfo);
if (!is_rel_non_selective) {
if (change->data.tp.oldtuple != NULL) {
elog(DEBUG1, "decoding old tuple information");
tupdesc = RelationGetDescr(relation);
rmsg.n_old_tuple = valid_attributes_count_from(tupdesc);
rmsg.old_tuple =
palloc(sizeof(Decoderbufs__DatumMessage*) * rmsg.n_old_tuple);
tuple_to_tuple_msg(rmsg.old_tuple, relation,
&change->data.tp.oldtuple->tuple, tupdesc);
}
if (change->data.tp.newtuple != NULL) {
elog(DEBUG1, "decoding new tuple information");
tupdesc = RelationGetDescr(relation);
rmsg.n_new_tuple = valid_attributes_count_from(tupdesc);
rmsg.new_tuple =
palloc(sizeof(Decoderbufs__DatumMessage*) * rmsg.n_new_tuple);
tuple_to_tuple_msg(rmsg.new_tuple, relation,
&change->data.tp.newtuple->tuple, tupdesc);
}
}
break;
case REORDER_BUFFER_CHANGE_DELETE:
rmsg.op = DECODERBUFS__OP__DELETE;
rmsg.has_op = true;
elog(DEBUG1, "decoding DELETE for table %s; relation is %s", rmsg.table, selectiveInfo);
/* if there was no PK, we only know that a delete happened */
if (!is_rel_non_selective && change->data.tp.oldtuple != NULL) {
elog(DEBUG1, "decoding old tuple information");
tupdesc = RelationGetDescr(relation);
rmsg.n_old_tuple = valid_attributes_count_from(tupdesc);
rmsg.old_tuple =
palloc(sizeof(Decoderbufs__DatumMessage*) * rmsg.n_old_tuple);
tuple_to_tuple_msg(rmsg.old_tuple, relation,
&change->data.tp.oldtuple->tuple, tupdesc);
} else {
elog(DEBUG1, "no information to decode from DELETE because either no PK is present or REPLICA IDENTITY NOTHING or invalid ");
}
break;
default:
elog(WARNING, "unknown change action");
Assert(0);
break;
}
/* write msg */
OutputPluginPrepareWrite(ctx, true);
if (data->debug_mode) {
//protobuf_c_text_to_string(ctx->out, (ProtobufCMessage*)&rmsg);
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);
/* free packed buffer */
pfree(packed);
}
OutputPluginWrite(ctx, true);
/* cleanup msg */
row_message_destroy(&rmsg);
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
}
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