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Transforms for jsonb to PL/Perl

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Add a new contrib module jsonb_plperl that provides a transform between
jsonb and PL/Perl.  jsonb values are converted to appropriate Perl types
such as arrays and hashes, and vice versa.

Author: Anthony Bykov <a.bykov@postgrespro.ru>
Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Reviewed-by: Aleksander Alekseev <a.alekseev@postgrespro.ru>
Reviewed-by: Nikita Glukhov <n.gluhov@postgrespro.ru>
This commit is contained in:
Peter Eisentraut
2018-04-03 09:47:18 -04:00
parent a08dc71195
commit 341e166180
13 changed files with 963 additions and 4 deletions
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262
contrib/jsonb_plperl/jsonb_plperl.c Normal file
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#include "postgres.h"
#undef _
#include "fmgr.h"
#include "plperl.h"
#include "plperl_helpers.h"
#include "utils/jsonb.h"
#include "utils/fmgrprotos.h"
PG_MODULE_MAGIC;
static SV *Jsonb_to_SV(JsonbContainer *jsonb);
static JsonbValue *SV_to_JsonbValue(SV *obj, JsonbParseState **ps, bool is_elem);
static SV *
JsonbValue_to_SV(JsonbValue *jbv)
{
dTHX;
switch (jbv->type)
{
case jbvBinary:
return newRV(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;
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 newRV(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 (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 (SV *) hv;
}
default:
elog(ERROR, "unexpected jsonb token: %d", r);
return NULL;
}
}
static JsonbValue *
AV_to_JsonbValue(AV *in, JsonbParseState **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)
(void) SV_to_JsonbValue(*value, jsonb_state, true);
}
return pushJsonbValue(jsonb_state, WJB_END_ARRAY, NULL);
}
static JsonbValue *
HV_to_JsonbValue(HV *obj, JsonbParseState **jsonb_state)
{
dTHX;
JsonbValue key;
SV *val;
key.type = jbvString;
pushJsonbValue(jsonb_state, WJB_BEGIN_OBJECT, NULL);
(void) hv_iterinit(obj);
while ((val = hv_iternextsv(obj, &key.val.string.val, &key.val.string.len)))
{
key.val.string.val = pnstrdup(key.val.string.val, key.val.string.len);
pushJsonbValue(jsonb_state, WJB_KEY, &key);
(void) SV_to_JsonbValue(val, jsonb_state, false);
}
return pushJsonbValue(jsonb_state, WJB_END_OBJECT, NULL);
}
static JsonbValue *
SV_to_JsonbValue(SV *in, JsonbParseState **jsonb_state, bool is_elem)
{
dTHX;
JsonbValue out; /* result */
/* Dereference references recursively. */
while (SvROK(in))
in = SvRV(in);
switch (SvTYPE(in))
{
case SVt_PVAV:
return AV_to_JsonbValue((AV *) in, jsonb_state);
case SVt_PVHV:
return HV_to_JsonbValue((HV *) in, jsonb_state);
case SVt_NV:
case SVt_IV:
{
char *str = sv2cstr(in);
/*
* Use case-insensitive comparison because infinity
* representation varies across Perl versions.
*/
if (pg_strcasecmp(str, "inf") == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
(errmsg("cannot convert infinite value to jsonb"))));
out.type = jbvNumeric;
out.val.numeric = DatumGetNumeric(DirectFunctionCall3(numeric_in,
CStringGetDatum(str), 0, -1));
}
break;
case SVt_NULL:
out.type = jbvNull;
break;
case SVt_PV: /* string */
out.type = jbvString;
out.val.string.val = sv2cstr(in);
out.val.string.len = strlen(out.val.string.val);
break;
default:
/*
* 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"))));
return NULL;
}
/* Push result into 'jsonb_state' unless it is a raw scalar. */
return *jsonb_state
? pushJsonbValue(jsonb_state, is_elem ? WJB_ELEM : WJB_VALUE, &out)
: memcpy(palloc(sizeof(JsonbValue)), &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(newRV(sv));
}
PG_FUNCTION_INFO_V1(plperl_to_jsonb);
Datum
plperl_to_jsonb(PG_FUNCTION_ARGS)
{
dTHX;
JsonbParseState *jsonb_state = NULL;
SV *in = (SV *) PG_GETARG_POINTER(0);
JsonbValue *out = SV_to_JsonbValue(in, &jsonb_state, true);
Jsonb *result = JsonbValueToJsonb(out);
PG_RETURN_JSONB_P(result);
}