Reranko05 commented on code in PR #51038:
URL: https://github.com/apache/arrow/pull/51038#discussion_r4191867304
##########
cpp/src/arrow/json/parser.cc:
##########
@@ -762,102 +744,206 @@ class HandlerBase : public BlockParser,
}
protected:
- template <typename Handler, typename Stream>
- Status DoParse(Handler& handler, Stream&& json, size_t json_size) {
- constexpr auto parse_flags = rj::kParseIterativeFlag |
rj::kParseNanAndInfFlag |
- rj::kParseStopWhenDoneFlag |
- rj::kParseNumbersAsStringsFlag;
-
- rj::Reader reader;
- // ensure that the loop can exit when the block too large.
- for (; num_rows_ < std::numeric_limits<int32_t>::max(); ++num_rows_) {
- auto ok = reader.Parse<parse_flags>(json, handler);
- switch (ok.Code()) {
- case rj::kParseErrorNone:
- // parse the next object
- continue;
- case rj::kParseErrorDocumentEmpty:
- if (json.Tell() < json_size) {
- return ParseError(rj::GetParseError_En(ok.Code()));
- }
- // parsed all objects, finish
- return Status::OK();
- case rj::kParseErrorTermination:
- // handler emitted an error
- return handler.Error();
- default:
- // rj emitted an error
- return ParseError(rj::GetParseError_En(ok.Code()), " in row ",
num_rows_);
+ Status Parse(const std::shared_ptr<Buffer>& json) override {
+ RETURN_NOT_OK(ReserveScalarStorage(json->size()));
+
+ const std::string_view input(reinterpret_cast<const char*>(json->data()),
+ json->size());
+ // TODO(GH-51809): Remove this check once Arrow requires simdjson 5.0.2,
+ // which fixes truncated_bytes() for empty input.
+ const int64_t input_size = input.size();
+ if (internal::ConsumeJsonWhitespace(input, /*trailing=*/false) ==
input_size) {
+ return Status::OK();
+ }
+
+ auto parse = [&](const auto& input) -> Status {
+ ARROW_ASSIGN_OR_RAISE(auto stream,
arrow::internal::ResolveSimdjsonResult(
+ parser_.iterate_many(input),
+ "Failed to create JSON document
stream"));
+
+ for (auto document_result : stream) {
+ ARROW_ASSIGN_OR_RAISE(
+ auto document,
+ arrow::internal::ResolveSimdjsonResult(
+ document_result, "Failed to iterate JSON document stream"));
+
+ if (num_rows_ == std::numeric_limits<int32_t>::max()) {
+ return Status::Invalid("Row count overflowed int32_t");
+ }
+
+ ARROW_ASSIGN_OR_RAISE(
+ auto value,
+ arrow::internal::ResolveSimdjsonResult(
+ document.get_value(), "JSON parse error: Failed to get JSON
value"));
+
+ RETURN_NOT_OK(ParseValue(value));
+
+ ++num_rows_;
}
+
+ if (stream.truncated_bytes() != 0) {
+ return ParseError("JSON document was truncated");
+ }
+
+ return Status::OK();
+ };
+
+ if (json->capacity() - json->size() >=
+ static_cast<int64_t>(simdjson::SIMDJSON_PADDING)) {
+ const auto padded_json = simdjson::padded_string_view(
+ reinterpret_cast<const char*>(json->data()), json->size(),
json->capacity());
+ return parse(padded_json);
}
- return Status::Invalid("Row count overflowed int32_t");
+
+ // TODO(GH-51463): Investigate allocating input buffers with enough
capacity
+ // for SIMDJSON padding to avoid copying in this case.
+ simdjson::padded_string padded_json(reinterpret_cast<const
char*>(json->data()),
+ json->size());
+ return parse(padded_json);
}
- template <typename Handler>
- Status DoParse(Handler& handler, const std::shared_ptr<Buffer>& json) {
- RETURN_NOT_OK(ReserveScalarStorage(json->size()));
- rj::MemoryStream ms(reinterpret_cast<const char*>(json->data()),
json->size());
- using InputStream = rj::EncodedInputStream<rj::UTF8<>, rj::MemoryStream>;
- return DoParse(handler, InputStream(ms),
static_cast<size_t>(json->size()));
+ template <Kind::type kind>
+ Status MaybePromoteFromNull() {
+ if (builder_.kind != Kind::kNull) {
+ return Status::OK();
+ }
+
+ auto parent = builder_stack_.back();
+
+ if (parent.kind == Kind::kArray) {
+ auto list_builder = Cast<Kind::kArray>(parent);
+ DCHECK_EQ(list_builder->value_builder(), builder_);
+
+ RETURN_NOT_OK(builder_set_.MakeBuilder<kind>(builder_.index, &builder_));
+
+ list_builder = Cast<Kind::kArray>(parent);
+ list_builder->value_builder(builder_);
+ } else {
+ auto struct_builder = Cast<Kind::kObject>(parent);
+ DCHECK_EQ(struct_builder->field_builder(field_index_), builder_);
+
+ RETURN_NOT_OK(builder_set_.MakeBuilder<kind>(builder_.index, &builder_));
+
+ struct_builder = Cast<Kind::kObject>(parent);
+ struct_builder->field_builder(field_index_, builder_);
+ }
+
+ return Status::OK();
}
- /// \defgroup handlerbase-append-methods append non-nested values
- ///
- /// @{
+ Status ParseValue(sj::value value) {
+ ARROW_ASSIGN_OR_RAISE(auto type, arrow::internal::ResolveSimdjsonResult(
+ value.type(), "Failed to determine
JSON type"));
- template <Kind::type kind>
- Status AppendScalar(BuilderPtr builder, std::string_view scalar) {
- if (ARROW_PREDICT_FALSE(builder.kind != kind)) {
- return IllegallyChangedTo(kind);
+ switch (type) {
+ case sj::json_type::null: {
+ ARROW_ASSIGN_OR_RAISE([[maybe_unused]] auto is_null,
+ arrow::internal::ResolveSimdjsonResult(
+ value.is_null(), "Failed to validate JSON
null"));
+ return Null();
+ }
+
+ case sj::json_type::boolean: {
+ RETURN_NOT_OK(MaybePromoteFromNull<Kind::kBoolean>());
+
+ ARROW_ASSIGN_OR_RAISE(auto boolean,
+ arrow::internal::ResolveSimdjsonResult(
+ value.get_bool(), "Failed to get JSON
boolean"));
+ return Bool(boolean);
+ }
+
+ case sj::json_type::string: {
+ RETURN_NOT_OK(MaybePromoteFromNull<Kind::kString>());
+
+ ARROW_ASSIGN_OR_RAISE(auto string,
+ arrow::internal::ResolveSimdjsonResult(
+ value.get_string(), "Failed to get JSON
string"));
+ return String(string);
+ }
+
+ case sj::json_type::number: {
+ RETURN_NOT_OK(MaybePromoteFromNull<Kind::kNumber>());
+ auto raw_number = value.raw_json_token();
+ RETURN_NOT_OK(arrow::internal::ResolveSimdjsonResult(
+ value.get_number(), "Failed to parse JSON number"));
+ raw_number.remove_suffix(
+ internal::ConsumeJsonWhitespace(raw_number, /*trailing=*/true));
+ return RawNumber(raw_number);
+ }
+
+ case sj::json_type::array:
+ RETURN_NOT_OK(MaybePromoteFromNull<Kind::kArray>());
+ return ParseArray(value);
+
+ case sj::json_type::object:
+ RETURN_NOT_OK(MaybePromoteFromNull<Kind::kObject>());
+ return ParseObject(value);
+
+ case sj::json_type::unknown:
+ return ParseError("Invalid JSON value");
Review Comment:
@taepper Currently Arrow supports simdjson v4.6.4, and unless this issue is
resolved simdjson is being pinned to `simdjson < 5`
https://github.com/apache/arrow/issues/51690#issuecomment-5949233460, so we
need to wait for the issue to resolved to bump up the simdjson version, as we
also need the `truncated_bytes()` fix that is released in simdjson v5.0.2. So
could you open a follow up issue for this and we can work on it after we bump
the simdjson version.
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