/*
* Create a textual representation of a JsonbValue that will serve as a GIN
* key in a jsonb_ops index. is_key is true if the JsonbValue is a key,
* or if it is a string array element (since we pretend those are keys,
* see jsonb.h).
*/
static Datum
make_scalar_key(const JsonbValue *scalarVal, bool is_key)
{
Datum item;
char *cstr;
switch (scalarVal->type)
{
case jbvNull:
Assert(!is_key);
item = make_text_key(JGINFLAG_NULL, "", 0);
break;
case jbvBool:
Assert(!is_key);
item = make_text_key(JGINFLAG_BOOL,
scalarVal->val.boolean ? "t" : "f", 1);
break;
case jbvNumeric:
Assert(!is_key);
/*
* A normalized textual representation, free of trailing zeroes,
* is required so that numerically equal values will produce equal
* strings.
*
* It isn't ideal that numerics are stored in a relatively bulky
* textual format. However, it's a notationally convenient way of
* storing a "union" type in the GIN B-Tree, and indexing Jsonb
* strings takes precedence.
*/
cstr = numeric_normalize(scalarVal->val.numeric);
item = make_text_key(JGINFLAG_NUM, cstr, strlen(cstr));
pfree(cstr);
break;
case jbvString:
item = make_text_key(is_key ? JGINFLAG_KEY : JGINFLAG_STR,
scalarVal->val.string.val,
scalarVal->val.string.len);
break;
default:
elog(ERROR, "unrecognized jsonb scalar type: %d", scalarVal->type);
item = 0; /* keep compiler quiet */
break;
}
return item;
}
/*
* Create a textual representation of a jsonbValue for GIN storage.
*/
static text *
make_scalar_key(const JsonbValue * scalarVal, char flag)
{
text *item;
char *cstr;
switch (scalarVal->type)
{
case jbvNull:
item = make_text_key("n", 1, flag);
break;
case jbvBool:
item = make_text_key(scalarVal->val.boolean ? "t" : "f", 1, flag);
break;
case jbvNumeric:
/*
* A normalized textual representation, free of trailing zeroes is
* is required.
*
* It isn't ideal that numerics are stored in a relatively bulky
* textual format. However, it's a notationally convenient way of
* storing a "union" type in the GIN B-Tree, and indexing Jsonb
* strings takes precedence.
*/
cstr = numeric_normalize(scalarVal->val.numeric);
item = make_text_key(cstr, strlen(cstr), flag);
pfree(cstr);
break;
case jbvString:
item = make_text_key(scalarVal->val.string.val, scalarVal->val.string.len,
flag);
break;
default:
elog(ERROR, "invalid jsonb scalar type");
}
return item;
}
/* Append JsonPathGinPathItem to JsonPathGinPath (jsonb_ops) */
static bool
jsonb_ops__add_path_item(JsonPathGinPath *path, JsonPathItem *jsp)
{
JsonPathGinPathItem *pentry;
Datum keyName;
switch (jsp->type)
{
case jpiRoot:
path->items = NULL; /* reset path */
return true;
case jpiKey:
{
int len;
char *key = jspGetString(jsp, &len);
keyName = make_text_key(JGINFLAG_KEY, key, len);
break;
}
case jpiAny:
case jpiAnyKey:
case jpiAnyArray:
case jpiIndexArray:
keyName = PointerGetDatum(NULL);
break;
default:
/* other path items like item methods are not supported */
return false;
}
pentry = palloc(sizeof(*pentry));
pentry->type = jsp->type;
pentry->keyName = keyName;
pentry->parent = path->items;
path->items = pentry;
return true;
}
Datum
gin_extract_jsonb_query(PG_FUNCTION_ARGS)
{
int32 *nentries = (int32 *) PG_GETARG_POINTER(1);
StrategyNumber strategy = PG_GETARG_UINT16(2);
int32 *searchMode = (int32 *) PG_GETARG_POINTER(6);
Datum *entries;
if (strategy == JsonbContainsStrategyNumber)
{
/* Query is a jsonb, so just apply gin_extract_jsonb... */
entries = (Datum *)
DatumGetPointer(DirectFunctionCall2(gin_extract_jsonb,
PG_GETARG_DATUM(0),
PointerGetDatum(nentries)));
/* ...although "contains {}" requires a full index scan */
if (*nentries == 0)
*searchMode = GIN_SEARCH_MODE_ALL;
}
else if (strategy == JsonbExistsStrategyNumber)
{
/* Query is a text string, which we treat as a key */
text *query = PG_GETARG_TEXT_PP(0);
*nentries = 1;
entries = (Datum *) palloc(sizeof(Datum));
entries[0] = make_text_key(JGINFLAG_KEY,
VARDATA_ANY(query),
VARSIZE_ANY_EXHDR(query));
}
else if (strategy == JsonbExistsAnyStrategyNumber ||
strategy == JsonbExistsAllStrategyNumber)
{
/* Query is a text array; each element is treated as a key */
ArrayType *query = PG_GETARG_ARRAYTYPE_P(0);
Datum *key_datums;
bool *key_nulls;
int key_count;
int i,
j;
deconstruct_array(query,
TEXTOID, -1, false, 'i',
&key_datums, &key_nulls, &key_count);
entries = (Datum *) palloc(sizeof(Datum) * key_count);
for (i = 0, j = 0; i < key_count; i++)
{
/* Nulls in the array are ignored */
if (key_nulls[i])
continue;
entries[j++] = make_text_key(JGINFLAG_KEY,
VARDATA(key_datums[i]),
VARSIZE(key_datums[i]) - VARHDRSZ);
}
*nentries = j;
/* ExistsAll with no keys should match everything */
if (j == 0 && strategy == JsonbExistsAllStrategyNumber)
*searchMode = GIN_SEARCH_MODE_ALL;
}
else
{
elog(ERROR, "unrecognized strategy number: %d", strategy);
entries = NULL; /* keep compiler quiet */
}
PG_RETURN_POINTER(entries);
}
