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Improve the efficiency of certain jsonb get operations.

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Instead of iterating over jsonb structures, use the inbuilt functions
findJsonbValueFromContainerLen() and getIthJsonbValueFromContainer() to
extract values directly. These functions use algorithms that are O(n log
n) and O(1) respectively, whereas iterating is O(n), so we should see
considerable speedup here.

Teodor Sigaev.
This commit is contained in:
Andrew Dunstan 2014-06-01 19:04:02 -04:00
parent a57509821c
commit 1a4174a498
1 changed files with 65 additions and 113 deletions
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178
src/backend/utils/adt/jsonfuncs.c
View File

@ -466,12 +466,8 @@ Datum
jsonb_object_field(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB(0);
char *key = text_to_cstring(PG_GETARG_TEXT_P(1));
int klen = strlen(key);
JsonbIterator *it;
JsonbValue v;
int r;
bool skipNested = false;
text *key = PG_GETARG_TEXT_PP(1);
JsonbValue *v;
if (JB_ROOT_IS_SCALAR(jb))
ereport(ERROR,
@ -484,25 +480,11 @@ jsonb_object_field(PG_FUNCTION_ARGS)
Assert(JB_ROOT_IS_OBJECT(jb));
it = JsonbIteratorInit(&jb->root);
v = findJsonbValueFromContainerLen(&jb->root, JB_FOBJECT,
VARDATA_ANY(key), VARSIZE_ANY_EXHDR(key));
while ((r = JsonbIteratorNext(&it, &v, skipNested)) != WJB_DONE)
{
skipNested = true;
if (r == WJB_KEY)
{
if (klen == v.val.string.len && strncmp(key, v.val.string.val, klen) == 0)
{
/*
* The next thing the iterator fetches should be the value, no
* matter what shape it is.
*/
(void) JsonbIteratorNext(&it, &v, skipNested);
PG_RETURN_JSONB(JsonbValueToJsonb(&v));
}
}
}
if (v != NULL)
PG_RETURN_JSONB(JsonbValueToJsonb(v));
PG_RETURN_NULL();
}
@ -527,12 +509,8 @@ Datum
jsonb_object_field_text(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB(0);
char *key = text_to_cstring(PG_GETARG_TEXT_P(1));
int klen = strlen(key);
JsonbIterator *it;
JsonbValue v;
int r;
bool skipNested = false;
text *key = PG_GETARG_TEXT_PP(1);
JsonbValue *v;
if (JB_ROOT_IS_SCALAR(jb))
ereport(ERROR,
@ -545,47 +523,41 @@ jsonb_object_field_text(PG_FUNCTION_ARGS)
Assert(JB_ROOT_IS_OBJECT(jb));
it = JsonbIteratorInit(&jb->root);
v = findJsonbValueFromContainerLen(&jb->root, JB_FOBJECT,
VARDATA_ANY(key), VARSIZE_ANY_EXHDR(key));
while ((r = JsonbIteratorNext(&it, &v, skipNested)) != WJB_DONE)
if (v != NULL)
{
skipNested = true;
text *result = NULL;
if (r == WJB_KEY)
switch(v->type)
{
if (klen == v.val.string.len && strncmp(key, v.val.string.val, klen) == 0)
{
text *result;
/*
* The next thing the iterator fetches should be the value, no
* matter what shape it is.
*/
r = JsonbIteratorNext(&it, &v, skipNested);
/*
* if it's a scalar string it needs to be de-escaped,
* otherwise just return the text
*/
if (v.type == jbvString)
case jbvNull:
break;
case jbvBool:
result = cstring_to_text(v->val.boolean ? "true" : "false");
break;
case jbvString:
result = cstring_to_text_with_len(v->val.string.val, v->val.string.len);
break;
case jbvNumeric:
result = cstring_to_text(DatumGetCString(DirectFunctionCall1(numeric_out,
PointerGetDatum(v->val.numeric))));
break;
case jbvBinary:
{
result = cstring_to_text_with_len(v.val.string.val, v.val.string.len);
}
else if (v.type == jbvNull)
{
PG_RETURN_NULL();
}
else
{
StringInfo jtext = makeStringInfo();
Jsonb *tjb = JsonbValueToJsonb(&v);
StringInfo jtext = makeStringInfo();
(void) JsonbToCString(jtext, &tjb->root , -1);
(void) JsonbToCString(jtext, v->val.binary.data, -1);
result = cstring_to_text_with_len(jtext->data, jtext->len);
}
PG_RETURN_TEXT_P(result);
}
break;
default:
elog(ERROR, "Wrong jsonb type: %d", v->type);
}
if (result)
PG_RETURN_TEXT_P(result);
}
PG_RETURN_NULL();
@ -611,11 +583,7 @@ jsonb_array_element(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB(0);
int element = PG_GETARG_INT32(1);
JsonbIterator *it;
JsonbValue v;
int r;
bool skipNested = false;
int element_number = 0;
JsonbValue *v;
if (JB_ROOT_IS_SCALAR(jb))
ereport(ERROR,
@ -628,18 +596,9 @@ jsonb_array_element(PG_FUNCTION_ARGS)
Assert(JB_ROOT_IS_ARRAY(jb));
it = JsonbIteratorInit(&jb->root);
while ((r = JsonbIteratorNext(&it, &v, skipNested)) != WJB_DONE)
{
skipNested = true;
if (r == WJB_ELEM)
{
if (element_number++ == element)
PG_RETURN_JSONB(JsonbValueToJsonb(&v));
}
}
v = getIthJsonbValueFromContainer(&jb->root, element);
if (v != NULL)
PG_RETURN_JSONB(JsonbValueToJsonb(v));
PG_RETURN_NULL();
}
@ -664,12 +623,7 @@ jsonb_array_element_text(PG_FUNCTION_ARGS)
{
Jsonb *jb = PG_GETARG_JSONB(0);
int element = PG_GETARG_INT32(1);
JsonbIterator *it;
JsonbValue v;
int r;
bool skipNested = false;
int element_number = 0;
JsonbValue *v;
if (JB_ROOT_IS_SCALAR(jb))
ereport(ERROR,
@ -682,41 +636,39 @@ jsonb_array_element_text(PG_FUNCTION_ARGS)
Assert(JB_ROOT_IS_ARRAY(jb));
it = JsonbIteratorInit(&jb->root);
while ((r = JsonbIteratorNext(&it, &v, skipNested)) != WJB_DONE)
v = getIthJsonbValueFromContainer(&jb->root, element);
if (v != NULL)
{
skipNested = true;
text *result = NULL;
if (r == WJB_ELEM)
switch(v->type)
{
if (element_number++ == element)
{
/*
* if it's a scalar string it needs to be de-escaped,
* otherwise just return the text
*/
text *result;
case jbvNull:
break;
case jbvBool:
result = cstring_to_text(v->val.boolean ? "true" : "false");
break;
case jbvString:
result = cstring_to_text_with_len(v->val.string.val, v->val.string.len);
break;
case jbvNumeric:
result = cstring_to_text(DatumGetCString(DirectFunctionCall1(numeric_out,
PointerGetDatum(v->val.numeric))));
break;
case jbvBinary:
{
StringInfo jtext = makeStringInfo();
if (v.type == jbvString)
{
result = cstring_to_text_with_len(v.val.string.val, v.val.string.len);
}
else if (v.type == jbvNull)
{
PG_RETURN_NULL();
}
else
{
StringInfo jtext = makeStringInfo();
Jsonb *tjb = JsonbValueToJsonb(&v);
(void) JsonbToCString(jtext, &tjb->root, -1);
(void) JsonbToCString(jtext, v->val.binary.data, -1);
result = cstring_to_text_with_len(jtext->data, jtext->len);
}
PG_RETURN_TEXT_P(result);
}
break;
default:
elog(ERROR, "Wrong jsonb type: %d", v->type);
}
if (result)
PG_RETURN_TEXT_P(result);
}
PG_RETURN_NULL();