jsonb_plperl.c

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#include "postgres.h"
 
#include <math.h>
 
#include "fmgr.h"
#include "miscadmin.h"
#include "plperl.h"
#include "utils/fmgrprotos.h"
#include "utils/jsonb.h"
 
PG_MODULE_MAGIC_EXT(
                    .name = "jsonb_plperl",
                    .version = PG_VERSION
);
 
static SV  *Jsonb_to_SV(JsonbContainer *jsonb);
static void SV_to_JsonbValue(SV *in, JsonbInState *jsonb_state, bool is_elem);
 
 
static SV  *
JsonbValue_to_SV(JsonbValue *jbv)
{
    dTHX;
 
    switch (jbv->type)
    {
        case jbvBinary:
            return Jsonb_to_SV(jbv->val.binary.data);
 
        case jbvNumeric:
            {
                char       *str = DatumGetCString(DirectFunctionCall1(numeric_out,
                                                                      NumericGetDatum(jbv->val.numeric)));
                SV         *result = newSVnv(SvNV(cstr2sv(str)));
 
                pfree(str);
                return result;
            }
 
        case jbvString:
            {
                char       *str = pnstrdup(jbv->val.string.val,
                                           jbv->val.string.len);
                SV         *result = cstr2sv(str);
 
                pfree(str);
                return result;
            }
 
        case jbvBool:
            return newSVnv(SvNV(jbv->val.boolean ? &PL_sv_yes : &PL_sv_no));
 
        case jbvNull:
            return newSV(0);
 
        default:
            elog(ERROR, "unexpected jsonb value type: %d", jbv->type);
            return NULL;
    }
}
 
static SV  *
Jsonb_to_SV(JsonbContainer *jsonb)
{
    dTHX;
    JsonbValue  v;
    JsonbIterator *it;
    JsonbIteratorToken r;
 
    /* this can recurse via JsonbValue_to_SV() */
    check_stack_depth();
 
    it = JsonbIteratorInit(jsonb);
    r = JsonbIteratorNext(&it, &v, true);
 
    switch (r)
    {
        case WJB_BEGIN_ARRAY:
            if (v.val.array.rawScalar)
            {
                JsonbValue  tmp;
 
                if ((r = JsonbIteratorNext(&it, &v, true)) != WJB_ELEM ||
                    (r = JsonbIteratorNext(&it, &tmp, true)) != WJB_END_ARRAY ||
                    (r = JsonbIteratorNext(&it, &tmp, true)) != WJB_DONE)
                    elog(ERROR, "unexpected jsonb token: %d", r);
 
                return JsonbValue_to_SV(&v);
            }
            else
            {
                AV         *av = newAV();
 
                while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
                {
                    if (r == WJB_ELEM)
                        av_push(av, JsonbValue_to_SV(&v));
                }
 
                return newRV((SV *) av);
            }
 
        case WJB_BEGIN_OBJECT:
            {
                HV         *hv = newHV();
 
                while ((r = JsonbIteratorNext(&it, &v, true)) != WJB_DONE)
                {
                    if (r == WJB_KEY)
                    {
                        /* json key in v, json value in val */
                        JsonbValue  val;
 
                        if (JsonbIteratorNext(&it, &val, true) == WJB_VALUE)
                        {
                            SV         *value = JsonbValue_to_SV(&val);
 
                            (void) hv_store(hv,
                                            v.val.string.val, v.val.string.len,
                                            value, 0);
                        }
                    }
                }
 
                return newRV((SV *) hv);
            }
 
        default:
            elog(ERROR, "unexpected jsonb token: %d", r);
            return NULL;
    }
}
 
static void
AV_to_JsonbValue(AV *in, JsonbInState *jsonb_state)
{
    dTHX;
    SSize_t     pcount = av_len(in) + 1;
    SSize_t     i;
 
    pushJsonbValue(jsonb_state, WJB_BEGIN_ARRAY, NULL);
 
    for (i = 0; i < pcount; i++)
    {
        SV        **value = av_fetch(in, i, FALSE);
 
        if (value)
            SV_to_JsonbValue(*value, jsonb_state, true);
    }
 
    pushJsonbValue(jsonb_state, WJB_END_ARRAY, NULL);
}
 
static void
HV_to_JsonbValue(HV *obj, JsonbInState *jsonb_state)
{
    dTHX;
    JsonbValue  key;
    SV         *val;
    char       *kstr;
    I32         klen;
 
    key.type = jbvString;
 
    pushJsonbValue(jsonb_state, WJB_BEGIN_OBJECT, NULL);
 
    (void) hv_iterinit(obj);
 
    while ((val = hv_iternextsv(obj, &kstr, &klen)))
    {
        key.val.string.val = pnstrdup(kstr, klen);
        key.val.string.len = klen;
        pushJsonbValue(jsonb_state, WJB_KEY, &key);
        SV_to_JsonbValue(val, jsonb_state, false);
    }
 
    pushJsonbValue(jsonb_state, WJB_END_OBJECT, NULL);
}
 
static void
SV_to_JsonbValue(SV *in, JsonbInState *jsonb_state, bool is_elem)
{
    dTHX;
    JsonbValue  out;            /* result */
 
    /* this can recurse via AV_to_JsonbValue() or HV_to_JsonbValue() */
    check_stack_depth();
 
    /* Dereference references recursively. */
    while (SvROK(in))
    {
        /*
         * It's possible for circular references to make this an infinite
         * loop.  Checking for such a situation seems like much more trouble
         * than it's worth, but let's provide a way to break out of the loop.
         */
        CHECK_FOR_INTERRUPTS();
        in = SvRV(in);
    }
 
    switch (SvTYPE(in))
    {
        case SVt_PVAV:
            AV_to_JsonbValue((AV *) in, jsonb_state);
            return;
 
        case SVt_PVHV:
            HV_to_JsonbValue((HV *) in, jsonb_state);
            return;
 
        default:
            if (!SvOK(in))
            {
                out.type = jbvNull;
            }
            else if (SvUOK(in))
            {
                /*
                 * If UV is >=64 bits, we have no better way to make this
                 * happen than converting to text and back.  Given the low
                 * usage of UV in Perl code, it's not clear it's worth working
                 * hard to provide alternate code paths.
                 */
                const char *strval = SvPV_nolen(in);
 
                out.type = jbvNumeric;
                out.val.numeric =
                    DatumGetNumeric(DirectFunctionCall3(numeric_in,
                                                        CStringGetDatum(strval),
                                                        ObjectIdGetDatum(InvalidOid),
                                                        Int32GetDatum(-1)));
            }
            else if (SvIOK(in))
            {
                IV          ival = SvIV(in);
 
                out.type = jbvNumeric;
                out.val.numeric = int64_to_numeric(ival);
            }
            else if (SvNOK(in))
            {
                double      nval = SvNV(in);
 
                /*
                 * jsonb doesn't allow infinity or NaN (per JSON
                 * specification), but the numeric type that is used for the
                 * storage accepts those, so we have to reject them here
                 * explicitly.
                 */
                if (isinf(nval))
                    ereport(ERROR,
                            (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                             errmsg("cannot convert infinity to jsonb")));
                if (isnan(nval))
                    ereport(ERROR,
                            (errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
                             errmsg("cannot convert NaN to jsonb")));
 
                out.type = jbvNumeric;
                out.val.numeric =
                    DatumGetNumeric(DirectFunctionCall1(float8_numeric,
                                                        Float8GetDatum(nval)));
            }
            else if (SvPOK(in))
            {
                out.type = jbvString;
                out.val.string.val = sv2cstr(in);
                out.val.string.len = strlen(out.val.string.val);
            }
            else
            {
                /*
                 * XXX It might be nice if we could include the Perl type in
                 * the error message.
                 */
                ereport(ERROR,
                        (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                         errmsg("cannot transform this Perl type to jsonb")));
            }
    }
 
    if (jsonb_state->parseState)
    {
        /* We're in an array or object, so push value as element or field. */
        pushJsonbValue(jsonb_state, is_elem ? WJB_ELEM : WJB_VALUE, &out);
    }
    else
    {
        /*
         * We are at top level, so it's a raw scalar.  If we just shove the
         * scalar value into jsonb_state->result, JsonbValueToJsonb will take
         * care of wrapping it into a dummy array.
         */
        jsonb_state->result = palloc_object(JsonbValue);
        memcpy(jsonb_state->result, &out, sizeof(JsonbValue));
    }
}
 
 
PG_FUNCTION_INFO_V1(jsonb_to_plperl);
 
Datum
jsonb_to_plperl(PG_FUNCTION_ARGS)
{
    dTHX;
    Jsonb      *in = PG_GETARG_JSONB_P(0);
    SV         *sv = Jsonb_to_SV(&in->root);
 
    return PointerGetDatum(sv);
}
 
 
PG_FUNCTION_INFO_V1(plperl_to_jsonb);
 
Datum
plperl_to_jsonb(PG_FUNCTION_ARGS)
{
    dTHX;
    SV         *in = (SV *) PG_GETARG_POINTER(0);
    JsonbInState jsonb_state = {0};
 
    SV_to_JsonbValue(in, &jsonb_state, true);
    PG_RETURN_JSONB_P(JsonbValueToJsonb(jsonb_state.result));
}