lwgeom_out_geobuf.c

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/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * PostGIS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * PostGIS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with PostGIS.  If not, see <http://www.gnu.org/licenses/>.
 *
 **********************************************************************
 *
 * Copyright (C) 2016-2017 Björn Harrtell <bjorn@wololo.org>
 *
 **********************************************************************/
 
#include "geobuf.h"
 
#include "postgres.h"
#include "utils/builtins.h"
#include "executor/spi.h"
 
#include "../postgis_config.h"
#include "lwgeom_pg.h"
#include "lwgeom_log.h"
#include "liblwgeom.h"
#include "geobuf.h"
 
PG_FUNCTION_INFO_V1(pgis_asgeobuf_transfn);
Datum pgis_asgeobuf_transfn(PG_FUNCTION_ARGS)
{
#if !(defined HAVE_LIBPROTOBUF)
        elog(ERROR, "ST_AsGeobuf: Compiled without protobuf-c support");
        PG_RETURN_NULL();
#else
        MemoryContext aggcontext, oldcontext;
        struct geobuf_agg_context *ctx;
 
        /* We need to initialize the internal cache to access it later via postgis_oid() */
        postgis_initialize_cache();
 
        if (!AggCheckCallContext(fcinfo, &aggcontext))
                elog(ERROR, "pgis_asgeobuf_transfn: called in non-aggregate context");
        oldcontext = MemoryContextSwitchTo(aggcontext);
 
        if (PG_ARGISNULL(0)) {
                ctx = palloc(sizeof(*ctx));
 
                ctx->geom_name = NULL;
                if (PG_NARGS() > 2 && !PG_ARGISNULL(2))
                        ctx->geom_name = text_to_cstring(PG_GETARG_TEXT_P(2));
                geobuf_agg_init_context(ctx);
        } else {
                ctx = (struct geobuf_agg_context *) PG_GETARG_POINTER(0);
        }
 
        if (!type_is_rowtype(get_fn_expr_argtype(fcinfo->flinfo, 1)))
                elog(ERROR, "pgis_asgeobuf_transfn: parameter row cannot be other than a rowtype");
 
        /* Null input tuple => null result */
        if (PG_ARGISNULL(1)) {
                PG_RETURN_NULL();
        }
 
        ctx->row = PG_GETARG_HEAPTUPLEHEADER(1);
 
        geobuf_agg_transfn(ctx);
        MemoryContextSwitchTo(oldcontext);
        PG_RETURN_POINTER(ctx);
#endif
}
 
PG_FUNCTION_INFO_V1(pgis_asgeobuf_finalfn);
Datum pgis_asgeobuf_finalfn(PG_FUNCTION_ARGS)
{
#if !(defined HAVE_LIBPROTOBUF)
        elog(ERROR, "ST_AsGeobuf: Compiled without protobuf-c support");
        PG_RETURN_NULL();
#else
        uint8_t *buf;
        struct geobuf_agg_context *ctx;
        if (!AggCheckCallContext(fcinfo, NULL))
                elog(ERROR, "pgis_asmvt_finalfn called in non-aggregate context");
 
        if (PG_ARGISNULL(0))
                PG_RETURN_NULL();
 
        ctx = (struct geobuf_agg_context *) PG_GETARG_POINTER(0);
        buf = geobuf_agg_finalfn(ctx);
        PG_RETURN_BYTEA_P(buf);
#endif
}