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wal2json.c
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/*-------------------------------------------------------------------------
*
* wal2json.c
* JSON output plugin for changeset extraction
*
* Copyright (c) 2013-2018, Euler Taveira de Oliveira
*
* IDENTIFICATION
* contrib/wal2json/wal2json.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_type.h"
#include "replication/logical.h"
#include "utils/builtins.h"
#include "utils/guc.h"
#include "utils/json.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/pg_lsn.h"
#include "utils/rel.h"
#include "utils/syscache.h"
#define WAL2JSON_FORMAT_VERSION 1
#define WAL2JSON_FORMAT_MIN_VERSION 1
PG_MODULE_MAGIC;
extern void _PG_init(void);
extern void PGDLLEXPORT _PG_output_plugin_init(OutputPluginCallbacks *cb);
typedef struct
{
MemoryContext context;
bool include_xids; /* include transaction ids */
bool include_timestamp; /* include transaction timestamp */
bool include_schemas; /* qualify tables */
bool include_types; /* include data types */
bool include_type_oids; /* include data type oids */
bool include_typmod; /* include typmod in types */
bool include_not_null; /* include not-null constraints */
bool include_missing_toast; /* include list of missing toast columns */
bool pretty_print; /* pretty-print JSON? */
bool write_in_chunks; /* write in chunks? */
List *filter_tables; /* filter out tables */
List *add_tables; /* add only these tables */
int format_version; /* support different formats */
/*
* LSN pointing to the end of commit record + 1 (txn->end_lsn)
* It is useful for tools that wants a position to restart from.
*/
bool include_lsn; /* include LSNs */
uint64 nr_changes; /* # of passes in pg_decode_change() */
/* FIXME replace with txn->nentries */
/* pretty print */
char ht[2]; /* horizontal tab, if pretty print */
char nl[2]; /* new line, if pretty print */
char sp[2]; /* space, if pretty print */
} JsonDecodingData;
typedef struct SelectTable
{
char *schemaname;
char *tablename;
bool allschemas; /* true means any schema */
bool alltables; /* true means any table */
} SelectTable;
/* These must be available to pg_dlsym() */
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);
#if PG_VERSION_NUM >= 90600
static void pg_decode_message(LogicalDecodingContext *ctx,
ReorderBufferTXN *txn, XLogRecPtr lsn,
bool transactional, const char *prefix,
Size content_size, const char *content);
#endif
static bool parse_table_identifier(List *qualified_tables, char separator, List **select_tables);
static bool string_to_SelectTable(char *rawstring, char separator, List **select_tables);
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;
#if PG_VERSION_NUM >= 90600
cb->message_cb = pg_decode_message;
#endif
}
/* Initialize this plugin */
static void
pg_decode_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt, bool is_init)
{
ListCell *option;
JsonDecodingData *data;
SelectTable *t;
data = palloc0(sizeof(JsonDecodingData));
data->context = AllocSetContextCreate(TopMemoryContext,
"wal2json output context",
#if PG_VERSION_NUM >= 90600
ALLOCSET_DEFAULT_SIZES
#else
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE
#endif
);
data->include_xids = false;
data->include_timestamp = false;
data->include_schemas = true;
data->include_types = true;
data->include_type_oids = false;
data->include_typmod = true;
data->pretty_print = false;
data->write_in_chunks = false;
data->include_lsn = false;
data->include_not_null = false;
data->include_missing_toast = false;
data->filter_tables = NIL;
data->format_version = WAL2JSON_FORMAT_VERSION;
/* pretty print */
strcpy(data->ht, "");
strcpy(data->nl, "");
strcpy(data->sp, "");
/* add all tables in all schemas by default */
t = palloc0(sizeof(SelectTable));
t->allschemas = true;
t->alltables = true;
data->add_tables = lappend(data->add_tables, t);
data->nr_changes = 0;
ctx->output_plugin_private = data;
opt->output_type = OUTPUT_PLUGIN_TEXTUAL_OUTPUT;
foreach(option, ctx->output_plugin_options)
{
DefElem *elem = lfirst(option);
Assert(elem->arg == NULL || IsA(elem->arg, String));
if (strcmp(elem->defname, "include-xids") == 0)
{
/* If option does not provide a value, it means its value is true */
if (elem->arg == NULL)
{
elog(DEBUG1, "include-xids argument is null");
data->include_xids = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_xids))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-timestamp") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-timestamp argument is null");
data->include_timestamp = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_timestamp))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-schemas") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-schemas argument is null");
data->include_schemas = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_schemas))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-types") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-types argument is null");
data->include_types = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_types))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-type-oids") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-type-oids argument is null");
data->include_type_oids = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_type_oids))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-typmod") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-typmod argument is null");
data->include_typmod = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_typmod))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-not-null") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-not-null argument is null");
data->include_not_null = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_not_null))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "pretty-print") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "pretty-print argument is null");
data->pretty_print = true;
}
else if (!parse_bool(strVal(elem->arg), &data->pretty_print))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
if (data->pretty_print)
{
strncpy(data->ht, "\t", 1);
strncpy(data->nl, "\n", 1);
strncpy(data->sp, " ", 1);
}
}
else if (strcmp(elem->defname, "write-in-chunks") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "write-in-chunks argument is null");
data->write_in_chunks = true;
}
else if (!parse_bool(strVal(elem->arg), &data->write_in_chunks))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-lsn") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-lsn argument is null");
data->include_lsn = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_lsn))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "include-unchanged-toast") == 0)
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("parameter \"%s\" was deprecated", elem->defname)));
}
else if (strcmp(elem->defname, "filter-tables") == 0)
{
char *rawstr;
if (elem->arg == NULL)
{
elog(DEBUG1, "filter-tables argument is null");
data->filter_tables = NIL;
}
else
{
rawstr = pstrdup(strVal(elem->arg));
if (!string_to_SelectTable(rawstr, ',', &data->filter_tables))
{
pfree(rawstr);
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
pfree(rawstr);
}
}
else if (strcmp(elem->defname, "add-tables") == 0)
{
char *rawstr;
/*
* If this parameter is specified, remove 'all tables in all
* schemas' value from list.
*/
list_free_deep(data->add_tables);
data->add_tables = NIL;
if (elem->arg == NULL)
{
elog(DEBUG1, "add-tables argument is null");
data->add_tables = NIL;
}
else
{
rawstr = pstrdup(strVal(elem->arg));
if (!string_to_SelectTable(rawstr, ',', &data->add_tables))
{
pfree(rawstr);
ereport(ERROR,
(errcode(ERRCODE_INVALID_NAME),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
pfree(rawstr);
}
}
else if (strcmp(elem->defname, "include-missing-toast") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "include-missing-toast argument is null");
data->include_missing_toast = true;
}
else if (!parse_bool(strVal(elem->arg), &data->include_missing_toast))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
}
else if (strcmp(elem->defname, "format-version") == 0)
{
if (elem->arg == NULL)
{
elog(DEBUG1, "format-version argument is null");
data->format_version = WAL2JSON_FORMAT_VERSION;
}
else if (!parse_int(strVal(elem->arg), &data->format_version, 0, NULL))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not parse value \"%s\" for parameter \"%s\"",
strVal(elem->arg), elem->defname)));
if (data->format_version > WAL2JSON_FORMAT_VERSION)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("client sent format_version=%d but we only support format %d or lower",
data->format_version, WAL2JSON_FORMAT_VERSION)));
if (data->format_version < WAL2JSON_FORMAT_MIN_VERSION)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("client sent format_version=%d but we only support format %d or higher",
data->format_version, WAL2JSON_FORMAT_MIN_VERSION)));
}
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("option \"%s\" = \"%s\" is unknown",
elem->defname,
elem->arg ? strVal(elem->arg) : "(null)")));
}
}
elog(DEBUG2, "format version: %d", data->format_version);
}
/* cleanup this plugin's resources */
static void
pg_decode_shutdown(LogicalDecodingContext *ctx)
{
JsonDecodingData *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)
{
JsonDecodingData *data = ctx->output_plugin_private;
data->nr_changes = 0;
/* Transaction starts */
OutputPluginPrepareWrite(ctx, true);
appendStringInfo(ctx->out, "{%s", data->nl);
if (data->include_xids)
appendStringInfo(ctx->out, "%s\"xid\":%s%u,%s", data->ht, data->sp, txn->xid, data->nl);
if (data->include_lsn)
{
char *lsn_str = DatumGetCString(DirectFunctionCall1(pg_lsn_out, txn->end_lsn));
appendStringInfo(ctx->out, "%s\"nextlsn\":%s\"%s\",%s", data->ht, data->sp, lsn_str, data->nl);
pfree(lsn_str);
}
if (data->include_timestamp)
appendStringInfo(ctx->out, "%s\"timestamp\":%s\"%s\",%s", data->ht, data->sp, timestamptz_to_str(txn->commit_time), data->nl);
appendStringInfo(ctx->out, "%s\"change\":%s[", data->ht, data->sp);
if (data->write_in_chunks)
OutputPluginWrite(ctx, true);
}
/* COMMIT callback */
static void
pg_decode_commit_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
XLogRecPtr commit_lsn)
{
JsonDecodingData *data = ctx->output_plugin_private;
if (txn->has_catalog_changes)
elog(DEBUG2, "txn has catalog changes: yes");
else
elog(DEBUG2, "txn has catalog changes: no");
elog(DEBUG2, "my change counter: %lu ; # of changes: %lu ; # of changes in memory: %lu", data->nr_changes, txn->nentries, txn->nentries_mem);
elog(DEBUG2, "# of subxacts: %d", txn->nsubtxns);
/* Transaction ends */
if (data->write_in_chunks)
OutputPluginPrepareWrite(ctx, true);
/* if we don't write in chunks, we need a newline here */
if (!data->write_in_chunks)
appendStringInfo(ctx->out, "%s", data->nl);
appendStringInfo(ctx->out, "%s]%s}", data->ht, data->nl);
OutputPluginWrite(ctx, true);
}
/*
* Accumulate tuple information and stores it at the end
*
* replident: is this tuple a replica identity?
* hasreplident: does this tuple has an associated replica identity?
*/
static void
tuple_to_stringinfo(LogicalDecodingContext *ctx, TupleDesc tupdesc, HeapTuple tuple, TupleDesc indexdesc, bool replident, bool hasreplident)
{
JsonDecodingData *data;
int natt;
StringInfoData colnames;
StringInfoData missingtoastcols;
StringInfoData coltypes;
StringInfoData coltypeoids;
StringInfoData colnotnulls;
StringInfoData colvalues;
char comma[3] = "";
char toastcomma[3] = "";
data = ctx->output_plugin_private;
initStringInfo(&colnames);
initStringInfo(&coltypes);
if (data->include_type_oids)
initStringInfo(&coltypeoids);
if (data->include_not_null)
initStringInfo(&colnotnulls);
if (data->include_missing_toast)
initStringInfo(&missingtoastcols);
initStringInfo(&colvalues);
/*
* If replident is true, it will output info about replica identity. In this
* case, there are special JSON objects for it. Otherwise, it will print new
* tuple data.
*/
if (replident)
{
appendStringInfo(&colnames, "%s%s%s\"oldkeys\":%s{%s", data->ht, data->ht, data->ht, data->sp, data->nl);
appendStringInfo(&colnames, "%s%s%s%s\"keynames\":%s[", data->ht, data->ht, data->ht, data->ht, data->sp);
appendStringInfo(&coltypes, "%s%s%s%s\"keytypes\":%s[", data->ht, data->ht, data->ht, data->ht, data->sp);
if (data->include_type_oids)
appendStringInfo(&coltypeoids, "%s%s%s%s\"keytypeoids\":%s[", data->ht, data->ht, data->ht, data->ht, data->sp);
appendStringInfo(&colvalues, "%s%s%s%s\"keyvalues\":%s[", data->ht, data->ht, data->ht, data->ht, data->sp);
}
else
{
appendStringInfo(&colnames, "%s%s%s\"columnnames\":%s[", data->ht, data->ht, data->ht, data->sp);
appendStringInfo(&coltypes, "%s%s%s\"columntypes\":%s[", data->ht, data->ht, data->ht, data->sp);
if (data->include_type_oids)
appendStringInfo(&coltypeoids, "%s%s%s\"columntypeoids\":%s[", data->ht, data->ht, data->ht, data->sp);
if (data->include_not_null)
appendStringInfo(&colnotnulls, "%s%s%s\"columnoptionals\":%s[", data->ht, data->ht, data->ht, data->sp);
if (data->include_missing_toast)
appendStringInfo(&missingtoastcols, "%s%s%s\"missingtoastcols\":%s[", data->ht, data->ht, data->ht, data->sp);
appendStringInfo(&colvalues, "%s%s%s\"columnvalues\":%s[", data->ht, data->ht, data->ht, data->sp);
}
/* Print column information (name, type, value) */
for (natt = 0; natt < tupdesc->natts; natt++)
{
Form_pg_attribute attr; /* the attribute itself */
Oid typid; /* type of current attribute */
HeapTuple type_tuple; /* information about a type */
Oid typoutput; /* output function */
bool typisvarlena;
Datum origval; /* possibly toasted Datum */
Datum val; /* definitely detoasted Datum */
char *outputstr = NULL;
bool isnull; /* column is null? */
/*
* Commit d34a74dd064af959acd9040446925d9d53dff15b introduced
* TupleDescAttr() in back branches. If the version supports
* this macro, use it. Version 10 and later already support it.
*/
#if (PG_VERSION_NUM >= 90600 && PG_VERSION_NUM < 90605) || (PG_VERSION_NUM >= 90500 && PG_VERSION_NUM < 90509) || (PG_VERSION_NUM >= 90400 && PG_VERSION_NUM < 90414)
attr = tupdesc->attrs[natt];
#else
attr = TupleDescAttr(tupdesc, natt);
#endif
elog(DEBUG1, "attribute \"%s\" (%d/%d)", NameStr(attr->attname), natt, tupdesc->natts);
/* Do not print dropped or system columns */
if (attr->attisdropped || attr->attnum < 0)
continue;
/* Search indexed columns in whole heap tuple */
if (indexdesc != NULL)
{
int j;
bool found_col = false;
for (j = 0; j < indexdesc->natts; j++)
{
Form_pg_attribute iattr;
/* See explanation a few lines above. */
#if (PG_VERSION_NUM >= 90600 && PG_VERSION_NUM < 90605) || (PG_VERSION_NUM >= 90500 && PG_VERSION_NUM < 90509) || (PG_VERSION_NUM >= 90400 && PG_VERSION_NUM < 90414)
iattr = indexdesc->attrs[j];
#else
iattr = TupleDescAttr(indexdesc, j);
#endif
if (strcmp(NameStr(attr->attname), NameStr(iattr->attname)) == 0)
found_col = true;
}
/* Print only indexed columns */
if (!found_col)
continue;
}
/* Get Datum from tuple */
origval = heap_getattr(tuple, natt + 1, tupdesc, &isnull);
/* Skip nulls iif printing key/identity */
if (isnull && replident)
continue;
typid = attr->atttypid;
/* Figure out type name */
type_tuple = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
if (!HeapTupleIsValid(type_tuple))
elog(ERROR, "cache lookup failed for type %u", typid);
/* Get information needed for printing values of a type */
getTypeOutputInfo(typid, &typoutput, &typisvarlena);
/* XXX Unchanged TOAST Datum does not need to be output */
if (!isnull && typisvarlena && VARATT_IS_EXTERNAL_ONDISK(origval))
{
if (data->include_missing_toast)
{
appendStringInfo(&missingtoastcols, "%s", toastcomma);
escape_json(&missingtoastcols, NameStr(attr->attname));
}
/* first missing toast has no comma */
if (strcmp(toastcomma, "") == 0)
snprintf(toastcomma, 3, ",%s", data->sp);
elog(DEBUG1, "column \"%s\" has an unchanged TOAST", NameStr(attr->attname));
continue;
}
/* Accumulate each column info */
appendStringInfo(&colnames, "%s", comma);
escape_json(&colnames, NameStr(attr->attname));
if (data->include_types)
{
if (data->include_typmod)
{
char *type_str;
type_str = TextDatumGetCString(DirectFunctionCall2(format_type, attr->atttypid, attr->atttypmod));
appendStringInfo(&coltypes, "%s", comma);
escape_json(&coltypes, type_str);
pfree(type_str);
}
else
{
Form_pg_type type_form = (Form_pg_type) GETSTRUCT(type_tuple);
appendStringInfo(&coltypes, "%s", comma);
escape_json(&coltypes, NameStr(type_form->typname));
}
/* oldkeys doesn't print not-null constraints */
if (!replident && data->include_not_null)
{
if (attr->attnotnull)
appendStringInfo(&colnotnulls, "%sfalse", comma);
else
appendStringInfo(&colnotnulls, "%strue", comma);
}
}
if (data->include_type_oids)
appendStringInfo(&coltypeoids, "%s%u", comma, typid);
ReleaseSysCache(type_tuple);
if (isnull)
{
appendStringInfo(&colvalues, "%snull", comma);
}
else
{
if (typisvarlena)
val = PointerGetDatum(PG_DETOAST_DATUM(origval));
else
val = origval;
/* Finally got the value */
outputstr = OidOutputFunctionCall(typoutput, val);
/*
* Data types are printed with quotes unless they are number, true,
* false, null, an array or an object.
*
* The NaN and Infinity are not valid JSON symbols. Hence,
* regardless of sign they are represented as the string null.
*/
switch (typid)
{
case INT2OID:
case INT4OID:
case INT8OID:
case OIDOID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
if (pg_strncasecmp(outputstr, "NaN", 3) == 0 ||
pg_strncasecmp(outputstr, "Infinity", 8) == 0 ||
pg_strncasecmp(outputstr, "-Infinity", 9) == 0)
{
appendStringInfo(&colvalues, "%snull", comma);
elog(DEBUG1, "attribute \"%s\" is special: %s", NameStr(attr->attname), outputstr);
}
else if (strspn(outputstr, "0123456789+-eE.") == strlen(outputstr))
appendStringInfo(&colvalues, "%s%s", comma, outputstr);
else
elog(ERROR, "%s is not a number", outputstr);
break;
case BOOLOID:
if (strcmp(outputstr, "t") == 0)
appendStringInfo(&colvalues, "%strue", comma);
else
appendStringInfo(&colvalues, "%sfalse", comma);
break;
case BYTEAOID:
appendStringInfo(&colvalues, "%s", comma);
/* string is "\x54617069727573", start after "\x" */
escape_json(&colvalues, (outputstr + 2));
break;
default:
appendStringInfo(&colvalues, "%s", comma);
escape_json(&colvalues, outputstr);
break;
}
}
/* The first column does not have comma */
if (strcmp(comma, "") == 0)
snprintf(comma, 3, ",%s", data->sp);
}
/* Column info ends */
if (replident)
{
appendStringInfo(&colnames, "],%s", data->nl);
if (data->include_types)
appendStringInfo(&coltypes, "],%s", data->nl);
if (data->include_type_oids)
appendStringInfo(&coltypeoids, "],%s", data->nl);
appendStringInfo(&colvalues, "]%s", data->nl);
appendStringInfo(&colvalues, "%s%s%s}%s", data->ht, data->ht, data->ht, data->nl);
}
else
{
appendStringInfo(&colnames, "],%s", data->nl);
if (data->include_types)
appendStringInfo(&coltypes, "],%s", data->nl);
if (data->include_type_oids)
appendStringInfo(&coltypeoids, "],%s", data->nl);
if (data->include_not_null)
appendStringInfo(&colnotnulls, "],%s", data->nl);
if (data->include_missing_toast)
appendStringInfo(&missingtoastcols, "],%s", data->nl);
if (hasreplident)
appendStringInfo(&colvalues, "],%s", data->nl);
else
appendStringInfo(&colvalues, "]%s", data->nl);
}
/* Print data */
appendStringInfoString(ctx->out, colnames.data);
if (data->include_types)
appendStringInfoString(ctx->out, coltypes.data);
if (data->include_type_oids)
appendStringInfoString(ctx->out, coltypeoids.data);
if (data->include_not_null)
appendStringInfoString(ctx->out, colnotnulls.data);
if (data->include_missing_toast)
appendStringInfoString(ctx->out, missingtoastcols.data);
appendStringInfoString(ctx->out, colvalues.data);
pfree(colnames.data);
pfree(coltypes.data);
if (data->include_type_oids)
pfree(coltypeoids.data);
if (data->include_not_null)
pfree(colnotnulls.data);
if (data->include_missing_toast)
pfree(missingtoastcols.data);
pfree(colvalues.data);
}
/* Print columns information */
static void
columns_to_stringinfo(LogicalDecodingContext *ctx, TupleDesc tupdesc, HeapTuple tuple, bool hasreplident)
{
tuple_to_stringinfo(ctx, tupdesc, tuple, NULL, false, hasreplident);
}
/* Print replica identity information */
static void
identity_to_stringinfo(LogicalDecodingContext *ctx, TupleDesc tupdesc, HeapTuple tuple, TupleDesc indexdesc)
{
/* Last parameter does not matter */
tuple_to_stringinfo(ctx, tupdesc, tuple, indexdesc, true, false);
}
/* Callback for individual changed tuples */
static void
pg_decode_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
Relation relation, ReorderBufferChange *change)
{
JsonDecodingData *data;
Form_pg_class class_form;
TupleDesc tupdesc;
MemoryContext old;
Relation indexrel;
TupleDesc indexdesc;
char *schemaname;
char *tablename;
AssertVariableIsOfType(&pg_decode_change, LogicalDecodeChangeCB);
data = ctx->output_plugin_private;
class_form = RelationGetForm(relation);
tupdesc = RelationGetDescr(relation);
/* Avoid leaking memory by using and resetting our own context */
old = MemoryContextSwitchTo(data->context);
/* schema and table names are used for select tables */
schemaname = get_namespace_name(class_form->relnamespace);
tablename = NameStr(class_form->relname);
if (data->write_in_chunks)
OutputPluginPrepareWrite(ctx, true);
/* Make sure rd_replidindex is set */
RelationGetIndexList(relation);
/* Filter tables, if available */
if (list_length(data->filter_tables) > 0)
{
ListCell *lc;
foreach(lc, data->filter_tables)
{
SelectTable *t = lfirst(lc);
if (t->allschemas || strcmp(t->schemaname, schemaname) == 0)
{
if (t->alltables || strcmp(t->tablename, tablename) == 0)
{
elog(DEBUG2, "\"%s\".\"%s\" was filtered out",
((t->allschemas) ? "*" : t->schemaname),
((t->alltables) ? "*" : t->tablename));
return;
}
}
}
}
/* Add tables */
if (list_length(data->add_tables) > 0)
{
ListCell *lc;
bool skip = true;
/* all tables in all schemas are added by default */
foreach(lc, data->add_tables)
{
SelectTable *t = lfirst(lc);
if (t->allschemas || strcmp(t->schemaname, schemaname) == 0)
{
if (t->alltables || strcmp(t->tablename, tablename) == 0)
{
elog(DEBUG2, "\"%s\".\"%s\" was added",
((t->allschemas) ? "*" : t->schemaname),
((t->alltables) ? "*" : t->tablename));
skip = false;
}
}
}
/* table was not found */
if (skip)
return;
}
/* Sanity checks */
switch (change->action)
{
case REORDER_BUFFER_CHANGE_INSERT:
if (change->data.tp.newtuple == NULL)
{
elog(WARNING, "no tuple data for INSERT in table \"%s\"", NameStr(class_form->relname));
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
return;
}
break;
case REORDER_BUFFER_CHANGE_UPDATE:
/*
* Bail out iif:
* (i) doesn't have a pk and replica identity is not full;
* (ii) replica identity is nothing.
*/
if (!OidIsValid(relation->rd_replidindex) && relation->rd_rel->relreplident != REPLICA_IDENTITY_FULL)
{
/* FIXME this sentence is imprecise */
elog(WARNING, "table \"%s\" without primary key or replica identity is nothing", NameStr(class_form->relname));
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
return;
}
if (change->data.tp.newtuple == NULL)
{
elog(WARNING, "no tuple data for UPDATE in table \"%s\"", NameStr(class_form->relname));
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
return;
}
break;
case REORDER_BUFFER_CHANGE_DELETE:
/*
* Bail out iif:
* (i) doesn't have a pk and replica identity is not full;
* (ii) replica identity is nothing.
*/
if (!OidIsValid(relation->rd_replidindex) && relation->rd_rel->relreplident != REPLICA_IDENTITY_FULL)
{
/* FIXME this sentence is imprecise */
elog(WARNING, "table \"%s\" without primary key or replica identity is nothing", NameStr(class_form->relname));
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
return;
}
if (change->data.tp.oldtuple == NULL)
{
elog(WARNING, "no tuple data for DELETE in table \"%s\"", NameStr(class_form->relname));
MemoryContextSwitchTo(old);
MemoryContextReset(data->context);
return;
}
break;
default:
Assert(false);
}
/* Change counter */
data->nr_changes++;
/* if we don't write in chunks, we need a newline here */
if (!data->write_in_chunks)
appendStringInfo(ctx->out, "%s", data->nl);
appendStringInfo(ctx->out, "%s%s", data->ht, data->ht);
if (data->nr_changes > 1)
appendStringInfoChar(ctx->out, ',');
appendStringInfo(ctx->out, "{%s", data->nl);
/* Print change kind */
switch (change->action)
{
case REORDER_BUFFER_CHANGE_INSERT:
appendStringInfo(ctx->out, "%s%s%s\"kind\":%s\"insert\",%s", data->ht, data->ht, data->ht, data->sp, data->nl);
break;
case REORDER_BUFFER_CHANGE_UPDATE:
appendStringInfo(ctx->out, "%s%s%s\"kind\":%s\"update\",%s", data->ht, data->ht, data->ht, data->sp, data->nl);
break;
case REORDER_BUFFER_CHANGE_DELETE:
appendStringInfo(ctx->out, "%s%s%s\"kind\":%s\"delete\",%s", data->ht, data->ht, data->ht, data->sp, data->nl);
break;
default:
Assert(false);
}
/* Print table name (possibly) qualified */
if (data->include_schemas)
{
appendStringInfo(ctx->out, "%s%s%s\"schema\":%s", data->ht, data->ht, data->ht, data->sp);
escape_json(ctx->out, get_namespace_name(class_form->relnamespace));
appendStringInfo(ctx->out, ",%s", data->nl);
}
appendStringInfo(ctx->out, "%s%s%s\"table\":%s", data->ht, data->ht, data->ht, data->sp);