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GH-50654: [C++] Support simdjson without exceptions #50672

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GH-50654: [C++] Support simdjson without exceptions #50672

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2 changes: 2 additions & 0 deletions cpp/cmake_modules/ThirdpartyToolchain.cmake
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Original file line number Diff line number Diff line change
Expand Up @@ -2823,6 +2823,8 @@ function(build_simdjson)

fetchcontent_makeavailable(simdjson)

target_compile_definitions(simdjson PUBLIC SIMDJSON_EXCEPTIONS=0)

# The macOS 11.3 SDK has incomplete C++20 concepts support, which prevents
# simdjson headers from compiling. Disable simdjson concepts for this SDK.
if(CMAKE_OSX_SYSROOT AND CMAKE_OSX_SYSROOT MATCHES "MacOSX11\\.3\\.sdk$")
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38 changes: 27 additions & 11 deletions cpp/src/arrow/json/object_parser.cc
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Expand Up @@ -30,7 +30,9 @@ class ObjectParser::Impl {
padded_json_ = simdjson::padded_string(json);

// Store parsed document
document_ = parser_.iterate(padded_json_);
if (auto error = parser_.iterate(padded_json_).get(document_)) {
return Status::Invalid("JSON parse error: ", simdjson::error_message(error));
}

// Validate root is an object
auto object = document_.get_object();
Expand Down Expand Up @@ -69,7 +71,12 @@ class ObjectParser::Impl {
"': ", simdjson::error_message(str_result.error()));
}

return std::string(str_result.value());
std::string_view str;
if (auto error = std::move(str_result).get(str)) {
return Status::Invalid("Error getting string for key '", key,
"': ", simdjson::error_message(error));
}
return std::string(str);
Comment on lines +74 to +79

@taepper taepper Jul 28, 2026

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#50653 adds

template <typename SimdjsonValueType>
Result<SimdjsonValueType> GetJsonAs(sj::value& value) {

that already returns arrow::Results instead of error codes. This might simplify these type-casts

@Reranko05 Reranko05 Jul 28, 2026 •
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Thanks for the suggestions! I opened #50693 to track this cleanup after #50672 is merged.

@pitrou pitrou Jul 28, 2026

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Well, #50653 is merged now :)

@Reranko05 Reranko05 Jul 28, 2026

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I wanted to write after this PR is merged. Referenced the wrong PR. Fixed it.

}

Result<std::unordered_map<std::string, std::string>> GetStringMap() {
Expand All @@ -80,13 +87,10 @@ class ObjectParser::Impl {
auto object = document_.get_object();

for (auto field : object) {
auto key_result = field.unescaped_key();

auto key = key_result.value();

if (key_result.error()) {
return Status::Invalid("Error getting value for key '", std::string(key),
"': ", simdjson::error_message(key_result.error()));
std::string_view key;
if (auto error = field.unescaped_key().get(key)) {
return Status::Invalid("Error getting object key: ",
simdjson::error_message(error));
}

auto value = field.value();
Expand All @@ -102,7 +106,13 @@ class ObjectParser::Impl {
"': (code=", static_cast<int>(str_result.error()), ")");
}

map.emplace(std::string(key), std::string(str_result.value()));
std::string_view str;
if (auto error = std::move(str_result).get(str)) {
return Status::Invalid("Error getting value for key '", std::string(key),
"': ", simdjson::error_message(error));
}

map.emplace(std::string(key), std::string(str));
Comment on lines 90 to +115

@taepper taepper Jul 28, 2026

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auto field has type simdjson_result<sj::field>. If we first resolve this to a sj::field, we do not need duplicated value checks for the unescaped_key and value.

Also, first asserting the value (L110), then type-checking the value (L98), is cleaner IMO. (It also works the other way around because simdjson provides overloads for many methods on its result type)

Note that for asserting the value and type-checking the value #50653 adds helper methods we might want to reuse

}

return map;
Expand Down Expand Up @@ -132,7 +142,13 @@ class ObjectParser::Impl {
"': ", simdjson::error_message(bool_result.error()));
}

return bool_result.value();
bool value;
if (auto error = std::move(bool_result).get(value)) {
return Status::Invalid("Error getting bool for key '", key,
"': ", simdjson::error_message(error));
}
Comment on lines +145 to +149

@taepper taepper Jul 28, 2026

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#50653 adds

template <typename SimdjsonValueType>
Result<SimdjsonValueType> GetJsonAs(sj::value& value) {

that already returns arrow::Results instead of error codes. This might simplify these type-casts


return value;
}

private:
Expand Down
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