diff --git a/tests/src/unit-json_view.cpp b/tests/src/unit-json_view.cpp index e8d6871d2..1850d6deb 100644 --- a/tests/src/unit-json_view.cpp +++ b/tests/src/unit-json_view.cpp @@ -1321,488 +1321,3 @@ TEST_CASE("json_view JSON pointers") } #endif } - -TEST_CASE("json_view dump") -{ - SECTION("the output of ordered_json::dump()") - { - generator g; - for (int i = 0; i < 2000; ++i) - { - std::string text; - g.value(text, 0); - const ordered_json_document d = ordered_json_document::parse(text); - if (has_duplicate_keys(d.root())) - { - continue; - } - CAPTURE(text) - const ordered_json j = ordered_json::parse(text); - for (const int indent : - { - -1, 0, 2 - }) - { - for (const bool ensure_ascii : - { - false, true - }) - { - CHECK(d.root().dump(indent, i % 2 == 0 ? ' ' : '\t', ensure_ascii) == j.dump(indent, i % 2 == 0 ? ' ' : '\t', ensure_ascii)); - } - } - // also of each element - for (const ordered_json_view e : d.root()) - { - CHECK(e.dump() == e.materialize().dump()); - } - } - } - - SECTION("strings") - { - const std::string text = R"(["plain", "\u0000\u0001\u001f\u007f\u0080é€￿😀", "\"\\\/\b\f\n\r\t", "aéあ😀b", "long text beyond the eight bytes of a word \n with an escape in the middle"])"; - const ordered_json_document d = ordered_json_document::parse(text); - const ordered_json j = ordered_json::parse(text); - CHECK(d.root().dump() == j.dump()); - CHECK(d.root().dump(-1, ' ', true) == j.dump(-1, ' ', true)); - CHECK(d.root().dump(4, ' ', true) == j.dump(4, ' ', true)); - const ordered_json_document keys = ordered_json_document::parse(R"({"é\n": {"\"": [], "": {}}})"); - CHECK(keys.root().dump(2, ' ', true) == ordered_json::parse(R"({"é\n": {"\"": [], "": {}}})").dump(2, ' ', true)); - } - - SECTION("numbers") - { - const std::string text = "[1.50, 1E2, -0, -0.0, 123456789012345678901234567890, 18446744073709551615, -9223372036854775808, 0.1, 1e-7, 5e-324]"; - const json_document d = json_document::parse(text); - CHECK(d.root().dump() == json::parse(text).dump()); - CHECK(d.root().dump() == "[1.5,100.0,0,-0.0,1.2345678901234568e+29,18446744073709551615,-9223372036854775808,0.1,1e-07,5e-324]"); - CHECK(d.root().dump(-1, ' ', false, json_view::number_format::source) == "[1.50,1E2,-0,-0.0,123456789012345678901234567890,18446744073709551615,-9223372036854775808,0.1,1e-7,5e-324]"); - - // random doubles, written as parse() and dump() would - std::mt19937_64 rng(1170); // NOLINT(cert-msc32-c,cert-msc51-cpp,bugprone-random-generator-seed) - std::string many = "["; - for (int i = 0; i < 5000; ++i) - { - const std::uint64_t bits = rng(); - double x = 0; - std::memcpy(&x, &bits, sizeof(x)); - if (std::isfinite(x)) - { - many += (many.size() > 1 ? "," : "") + json(x).dump(); - } - } - many += ']'; - CHECK(json_document::parse(many).root().dump() == json::parse(many).dump()); - - using json_float = nlohmann::basic_json; - CHECK(nlohmann::basic_json_document::parse("[0.1, 1.5e10, 3.4028235e38]").root().dump() == json_float::parse("[0.1, 1.5e10, 3.4028235e38]").dump()); - } - - SECTION("members in document order, all of them") - { - const json_document d = json_document::parse(R"({"b": 1, "a": 2, "b": 3})"); - CHECK(d.root().dump() == R"({"b":1,"a":2,"b":3})"); - CHECK(d.root().dump(1) == "{\n \"b\": 1,\n \"a\": 2,\n \"b\": 3\n}"); - } - - SECTION("deep nesting") - { - const std::string deep = std::string(100000, '[') + std::string(100000, ']'); - const json_document deep_document = json_document::parse(deep); - CHECK(deep_document.root().dump() == deep); - } - - SECTION("the output buffer of a small value is small") - { - // an escaped key after the value: its node lies in the arena, so the - // source extent of the value cannot be read from the next node - const std::string big(100000, 'a'); - const std::string text = R"({"small":1,"list":[1,2,3],"k\n":")" + big + R"("})"; - const json_document d = json_document::parse(text); - const auto small = d.root()["small"].dump(); - CHECK(small == "1"); - CHECK(small.capacity() < 4096); - const auto list = d.root()["list"].dump(); - CHECK(list == "[1,2,3]"); - CHECK(list.capacity() < 4096); - CHECK(d.root()["list"].dump(2).capacity() < 4096); - - // the whole document and the large value are unaffected - CHECK(d.root().dump() == ordered_json::parse(text).dump()); - CHECK(d.root()["k\n"].dump() == "\"" + big + "\""); - } - - SECTION("output that outgrows the estimate") - { - // ensure_ascii writes six bytes for each two-byte character - std::string chars; - for (int i = 0; i < 5000; ++i) - { - chars += "\xC3\xA9"; - } - const json_document d = json_document::parse(R"({"a":")" + chars + R"(","k\n":1})"); - const json expected = json::parse("\"" + chars + "\""); - CHECK(d.root()["a"].dump(-1, ' ', true) == expected.dump(-1, ' ', true)); - CHECK(d.root()["a"].dump(-1, ' ', true).size() == 2 + (5000 * 6)); - } - - SECTION("streams and discarded views") - { - const json_document d = json_document::parse(R"({"a": [1, 2]})"); - std::ostringstream compact; - compact << d.root(); - CHECK(compact.str() == R"({"a":[1,2]})"); - std::ostringstream pretty; - pretty << std::setw(2) << std::setfill('.') << d.root() << d.root()["a"]; - CHECK(pretty.str() == "{\n..\"a\": [\n....1,\n....2\n..]\n}[1,2]"); - CHECK(json_view().dump() == json(json::value_t::discarded).dump()); - } -} - -TEST_CASE("json_view comparison") -{ - SECTION("equality of the values parse() produces") - { - generator g; - std::vector texts; - for (int i = 0; i < 600; ++i) - { - std::string text; - g.value(text, 0); - texts.push_back(text); - // the same value written differently: sorted keys, canonical numbers - texts.push_back(json::parse(text).dump(1)); - } - for (std::size_t i = 0; i + 2 < texts.size(); ++i) - { - for (std::size_t k = i; k < i + 3; ++k) - { - CAPTURE(texts[i]) - CAPTURE(texts[k]) - const json_document a = json_document::parse(texts[i]); - const json_document b = json_document::parse(texts[k]); - const json ja = json::parse(texts[i]); - const json jb = json::parse(texts[k]); - CHECK((a.root() == b.root()) == (ja == jb)); - CHECK((a.root() != b.root()) == (ja != jb)); - CHECK((a.root() == jb) == (ja == jb)); - CHECK((jb == a.root()) == (ja == jb)); - CHECK((a.root() != jb) == (ja != jb)); - CHECK((jb != a.root()) == (ja != jb)); - - // ordered_json compares members in order - const ordered_json_document oa = ordered_json_document::parse(texts[i]); - const ordered_json_document ob = ordered_json_document::parse(texts[k]); - const ordered_json oja = ordered_json::parse(texts[i]); - const ordered_json ojb = ordered_json::parse(texts[k]); - CHECK((oa.root() == ob.root()) == (oja == ojb)); - CHECK((oa.root() == ojb) == (oja == ojb)); - } - } - } - - SECTION("numbers, duplicate keys, member order") - { - const auto same = [](const char* x, const char* y) - { - return json_document::parse(x).root() == json_document::parse(y).root(); - }; - CHECK(same("1", "1.0")); - CHECK(same("[1, -1, 2.5]", "[1.0, -1.0, 25e-1]")); - CHECK(!same("1", "1.5")); - CHECK(same("18446744073709551615", "18446744073709551615")); - CHECK(same(R"({"a": 1, "a": 2})", R"({"a": 2})")); - CHECK(!same(R"({"a": 1, "a": 2})", R"({"a": 1})")); - CHECK(same(R"({"a": 1, "b": 2})", R"({"b": 2, "a": 1})")); - CHECK(!same(R"({"a": 1})", R"({"a": 1, "b": 2})")); - CHECK(!same("[1, 2]", "[2, 1]")); - CHECK(!same("\"a\"", "\"b\"")); - CHECK(same("\"\\u00e9\"", "\"\xc3\xa9\"")); - CHECK(!same("null", "false")); - CHECK(!same("[]", "{}")); - CHECK(ordered_json_document::parse(R"({"a": 1, "b": 2, "a": 3})").root() == ordered_json_document::parse(R"({"a": 3, "b": 2})").root()); - CHECK(ordered_json_document::parse(R"({"a": 1, "b": 2})").root() != ordered_json_document::parse(R"({"b": 2, "a": 1})").root()); - - // discarded values compare as basic_json's do - const json discarded(json::value_t::discarded); - CHECK((json_view() == json_view()) == (discarded == discarded)); // NOLINT(readability-container-size-empty): operator== is tested - CHECK((json_view() == discarded) == (discarded == discarded)); // NOLINT(readability-container-size-empty) - const json_document null_document = json_document::parse("null"); - CHECK(!(json_view() == null_document.root())); // NOLINT(readability-container-size-empty) - CHECK(!(null_document.root() == discarded)); - } - - SECTION("deep nesting") - { - const std::string deep = std::string(100000, '[') + std::string(100000, ']'); - const json_document a = json_document::parse(deep); - const json_document b = json_document::parse(deep); - CHECK(a.root() == b.root()); - CHECK(a.root() == json::parse(deep)); - const std::string other = std::string(100000, '[') + "1" + std::string(100000, ']'); - CHECK(a.root() != json_document::parse(other).root()); - } -} - -TEST_CASE("json_view large objects") -{ - // objects with 128 members or more are looked up with a hash index - for (const std::size_t members : - { - 127u, 128u, 129u, 10000u - }) - { - CAPTURE(members) - std::string text = "{"; - for (std::size_t i = 0; i < members; ++i) - { - text += (i != 0 ? ",\"" : "\"") + std::string(i % 23, 'k') + std::to_string(i) + (i % 7 == 0 ? "\\n" : "") + "\":" + std::to_string(i); - } - text += R"(,"":"empty key","k1":"a duplicate of an earlier key"})"; - const json_document d = json_document::parse(text); - const json_view v = d.root(); - const json j = json::parse(text); - for (std::size_t i = 0; i < members; ++i) - { - const std::string key = std::string(i % 23, 'k') + std::to_string(i) + (i % 7 == 0 ? "\n" : ""); - CHECK(v[key].get() == i); - CHECK(v.contains(key)); - CHECK(v.find(key).key() == key); - CHECK(v.at(key).get() == i); - CHECK(!v.contains(key + "x")); - } - CHECK(v[""].get_string() == "empty key"); - CHECK(v["k1"].get() == 1); // the first of duplicate keys, as for small objects - CHECK(!v.contains("missing")); - CHECK_THROWS_WITH_AS(v.at("missing"), "[json.exception.out_of_range.403] key 'missing' not found", json::out_of_range&); - CHECK(v == j); - CHECK(v.materialize() == j); - } - - SECTION("duplicate keys: the first member wins, with and without a table") - { - // an object of `total` members: the keys "k0".."k" in order, then - // three keys repeated twice more (one copy in the middle, one at the - // end), and two keys repeated once; the value of a member is its - // position, so that the first member of a key can be told apart - struct member - { - std::string key; - std::size_t position; - }; - const auto make_members = [](std::size_t total) - { - std::vector keys; - for (std::size_t i = 0; i + 8 < total; ++i) - { - keys.push_back("k" + std::to_string(i)); - } - const std::size_t n = keys.size(); - const std::array triple = {{3, 17, n - 1}}; - const std::array twice = {{5, n / 2}}; - std::vector ordered = keys; - for (const std::size_t i : triple) - { - ordered.insert(ordered.begin() + static_cast(ordered.size() / 2), keys[i]); - } - for (const std::size_t i : twice) - { - ordered.insert(ordered.begin() + static_cast(ordered.size() / 3), keys[i]); - } - for (const std::size_t i : triple) - { - ordered.push_back(keys[i]); - } - std::vector result; - result.reserve(ordered.size()); - for (std::size_t i = 0; i < ordered.size(); ++i) - { - result.push_back({ordered[i], i}); - } - return result; - }; - - // 100 and 127 members: no table; 128 members and more: a table - for (const std::size_t total : - { - 100u, 127u, 128u, 200u, 5000u - }) - { - CAPTURE(total) - const std::vector members = make_members(total); - REQUIRE(members.size() >= total); - REQUIRE(members.size() >= 100); - std::string text = "{"; - std::map first; - std::map last; - for (const member& m : members) - { - text += (text.size() > 1 ? ",\"" : "\"") + m.key + "\":" + std::to_string(m.position); - first.insert({m.key, m.position}); - last[m.key] = m.position; - } - text += '}'; - REQUIRE(first.size() < members.size()); - - const json_document d = json_document::parse(text); - const json_view v = d.root(); - const json j = json::parse(text); - CHECK(v.size() == members.size()); // every occurrence is visited - const json m = v.materialize(); - for (const auto& entry : first) - { - CAPTURE(entry.first) - const std::size_t expected = entry.second; - CHECK(v[entry.first].get() == expected); - CHECK(v.at(entry.first).get() == expected); - CHECK(v.find(entry.first).value().get() == expected); - CHECK(v.value(entry.first, std::size_t{0}) == expected); - CHECK(v.contains(entry.first)); - CHECK(v.count(entry.first) == 1); - const std::string pointer = "/" + entry.first; - CHECK(v[json::json_pointer(pointer)].get() == expected); - CHECK(v.at(json::json_pointer(pointer)).get() == expected); - CHECK(v.value(json::json_pointer(pointer), std::size_t{0}) == expected); - CHECK(v.contains(json::json_pointer(pointer))); - // materialize() and parse() keep the last value instead - CHECK(j[entry.first].get() == last.at(entry.first)); - CHECK(m[entry.first].get() == last.at(entry.first)); - } - CHECK(!v.contains("k")); - CHECK(v["missing"].is_discarded()); - CHECK(v.materialize() == j); - CHECK(v == j); - } - } - - SECTION("colliding keys") - { - // the hash is not seeded, so keys that all land in one place must not - // make the table build quadratic: such an object gets no table and is - // searched linearly - constexpr std::size_t members = 300; - constexpr std::size_t slots = 1024; // the table size for 300 members: the next power of two >= 600 - std::vector colliding; - std::vector spread; - for (std::uint64_t counter = 0; colliding.size() < members || spread.size() < members; ++counter) - { - std::string key(8, 'a'); - std::uint64_t x = counter; - for (std::size_t i = 0; i < 8; ++i, x /= 26) - { - key[i] = static_cast('a' + (x % 26)); - } - const bool lands_in_slot_zero = (nlohmann::detail::view::key_hash(key.data(), key.size()) & (slots - 1)) == 0; - if (lands_in_slot_zero && colliding.size() < members) - { - colliding.push_back(key); - } - else if (!lands_in_slot_zero && spread.size() < members) - { - spread.push_back(key); - } - } - - const auto make_text = [](const std::vector& keys) - { - std::string text = "{"; - for (std::size_t i = 0; i < keys.size(); ++i) - { - text += (i != 0 ? ",\"" : "\"") + keys[i] + "\":" + std::to_string(i % 10); - } - return text + "}"; - }; - const std::string colliding_text = make_text(colliding); - const std::string spread_text = make_text(spread); - - json_document with_collisions = json_document::parse(colliding_text); - json_document without_collisions = json_document::parse(spread_text); - for (const auto* pair : - { - &colliding, &spread - }) - { - const json_view v = (pair == &colliding ? with_collisions : without_collisions).root(); - for (std::size_t i = 0; i < members; ++i) - { - CAPTURE(i) - CHECK(v[(*pair)[i]].get() == i % 10); - CHECK(v.at((*pair)[i]).get() == i % 10); - CHECK(v.find((*pair)[i]).key() == (*pair)[i]); - CHECK(!v.contains((*pair)[i] + "x")); - } - CHECK(!v.contains("missing")); - } - CHECK(with_collisions.root() == json::parse(colliding_text)); - - // only the object with the spread keys got a table (both texts have the - // same length, so the tables are the only difference) - with_collisions.shrink_to_fit(); - without_collisions.shrink_to_fit(); - CHECK(without_collisions.memory_usage() >= with_collisions.memory_usage() + (slots * sizeof(std::uint32_t))); - } - - SECTION("shrink_to_fit releases the tables' spare capacity") - { - const auto make_text = [](int objects, int members) - { - std::string text = "["; - for (int object = 0; object < objects; ++object) - { - text += object != 0 ? ",{" : "{"; - for (int i = 0, n = members + object; i < n; ++i) - { - text += (i != 0 ? ",\"" : "\"") + std::to_string(i) + "\":" + std::to_string(i); - } - text += '}'; - } - return text + "]"; - }; - const std::string small_text = make_text(5, 150); - const std::string big_text = make_text(40, 400); - - // reading a big text, and then a small one, leaves the spare capacity - // of the big one: shrink_to_fit() brings the document to the size of - // one parsed from the small text alone - json_document d = json_document::parse(big_text); - const std::size_t big = d.memory_usage(); - d.read(small_text); - CHECK(d.memory_usage() >= big); - d.shrink_to_fit(); - json_document fresh = json_document::parse(small_text); - fresh.shrink_to_fit(); - CHECK(d.memory_usage() == fresh.memory_usage()); - CHECK(d.memory_usage() < big / 2); - CHECK(d.root() == json::parse(small_text)); - for (int object = 0; object < 5; ++object) - { - const json_view v = d.root()[static_cast(object)]; - for (int i = 0, n = 150 + object; i < n; ++i) - { - CHECK(v[std::to_string(i)].get() == i); - } - } - } - - SECTION("nested, reused, and in arrays") - { - std::string inner = "{"; - for (int i = 0; i < 300; ++i) - { - inner += (i != 0 ? ",\"m" : "\"m") + std::to_string(i) + "\":" + std::to_string(i); - } - inner += '}'; - const std::string text = "[" + inner + ",{\"x\":" + inner + "}," + inner + "]"; - json_document d = json_document::parse(text); - CHECK(d.root()[0]["m299"].get() == 299); - CHECK(d.root()[1]["x"]["m150"].get() == 150); - CHECK(d.root()[2]["m0"].get() == 0); - const std::size_t with_index = d.memory_usage(); - d.read(std::string("{\"small\": 1}")); - CHECK(d.root()["small"].get() == 1); - d.read(text); - CHECK(d.root()[2]["m7"].get() == 7); - CHECK(d.memory_usage() >= with_index / 2); - } -} diff --git a/tests/src/unit-json_view_dump.cpp b/tests/src/unit-json_view_dump.cpp index ac3133e17..1a9f59f51 100644 --- a/tests/src/unit-json_view_dump.cpp +++ b/tests/src/unit-json_view_dump.cpp @@ -20,6 +20,7 @@ using nlohmann::ordered_json_view; using json_view_test::generator; using json_view_test::has_duplicate_keys; +#include #include #include #include @@ -273,3 +274,265 @@ TEST_CASE("json_view comparison") CHECK(a.root() != c.root()); } } + +TEST_CASE("json_view large objects") +{ + // objects with 128 members or more are looked up with a hash index + for (const std::size_t members : + { + 127u, 128u, 129u, 10000u + }) + { + CAPTURE(members) + std::string text = "{"; + for (std::size_t i = 0; i < members; ++i) + { + text += (i != 0 ? ",\"" : "\"") + std::string(i % 23, 'k') + std::to_string(i) + (i % 7 == 0 ? "\\n" : "") + "\":" + std::to_string(i); + } + text += R"(,"":"empty key","k1":"a duplicate of an earlier key"})"; + const json_document d = json_document::parse(text); + const json_view v = d.root(); + const json j = json::parse(text); + for (std::size_t i = 0; i < members; ++i) + { + const std::string key = std::string(i % 23, 'k') + std::to_string(i) + (i % 7 == 0 ? "\n" : ""); + CHECK(v[key].get() == i); + CHECK(v.contains(key)); + CHECK(v.find(key).key() == key); + CHECK(v.at(key).get() == i); + CHECK(!v.contains(key + "x")); + } + CHECK(v[""].get_string() == "empty key"); + CHECK(v["k1"].get() == 1); // the first of duplicate keys, as for small objects + CHECK(!v.contains("missing")); + CHECK_THROWS_WITH_AS(v.at("missing"), "[json.exception.out_of_range.403] key 'missing' not found", json::out_of_range&); + CHECK(v == j); + CHECK(v.materialize() == j); + } + + SECTION("duplicate keys: the first member wins, with and without a table") + { + // an object of `total` members: the keys "k0".."k" in order, then + // three keys repeated twice more (one copy in the middle, one at the + // end), and two keys repeated once; the value of a member is its + // position, so that the first member of a key can be told apart + struct member + { + std::string key; + std::size_t position; + }; + const auto make_members = [](std::size_t total) + { + std::vector keys; + for (std::size_t i = 0; i + 8 < total; ++i) + { + keys.push_back("k" + std::to_string(i)); + } + const std::size_t n = keys.size(); + const std::array triple = {{3, 17, n - 1}}; + const std::array twice = {{5, n / 2}}; + std::vector ordered = keys; + for (const std::size_t i : triple) + { + ordered.insert(ordered.begin() + static_cast(ordered.size() / 2), keys[i]); + } + for (const std::size_t i : twice) + { + ordered.insert(ordered.begin() + static_cast(ordered.size() / 3), keys[i]); + } + for (const std::size_t i : triple) + { + ordered.push_back(keys[i]); + } + std::vector result; + result.reserve(ordered.size()); + for (std::size_t i = 0; i < ordered.size(); ++i) + { + result.push_back({ordered[i], i}); + } + return result; + }; + + // 100 and 127 members: no table; 128 members and more: a table + for (const std::size_t total : + { + 100u, 127u, 128u, 200u, 5000u + }) + { + CAPTURE(total) + const std::vector members = make_members(total); + REQUIRE(members.size() >= total); + REQUIRE(members.size() >= 100); + std::string text = "{"; + std::map first; + std::map last; + for (const member& m : members) + { + text += (text.size() > 1 ? ",\"" : "\"") + m.key + "\":" + std::to_string(m.position); + first.insert({m.key, m.position}); + last[m.key] = m.position; + } + text += '}'; + REQUIRE(first.size() < members.size()); + + const json_document d = json_document::parse(text); + const json_view v = d.root(); + const json j = json::parse(text); + CHECK(v.size() == members.size()); // every occurrence is visited + const json m = v.materialize(); + for (const auto& entry : first) + { + CAPTURE(entry.first) + const std::size_t expected = entry.second; + CHECK(v[entry.first].get() == expected); + CHECK(v.at(entry.first).get() == expected); + CHECK(v.find(entry.first).value().get() == expected); + CHECK(v.value(entry.first, std::size_t{0}) == expected); + CHECK(v.contains(entry.first)); + CHECK(v.count(entry.first) == 1); + const std::string pointer = "/" + entry.first; + CHECK(v[json::json_pointer(pointer)].get() == expected); + CHECK(v.at(json::json_pointer(pointer)).get() == expected); + CHECK(v.value(json::json_pointer(pointer), std::size_t{0}) == expected); + CHECK(v.contains(json::json_pointer(pointer))); + // materialize() and parse() keep the last value instead + CHECK(j[entry.first].get() == last.at(entry.first)); + CHECK(m[entry.first].get() == last.at(entry.first)); + } + CHECK(!v.contains("k")); + CHECK(v["missing"].is_discarded()); + CHECK(v.materialize() == j); + CHECK(v == j); + } + } + + SECTION("colliding keys") + { + // the hash is not seeded, so keys that all land in one place must not + // make the table build quadratic: such an object gets no table and is + // searched linearly + constexpr std::size_t members = 300; + constexpr std::size_t slots = 1024; // the table size for 300 members: the next power of two >= 600 + std::vector colliding; + std::vector spread; + for (std::uint64_t counter = 0; colliding.size() < members || spread.size() < members; ++counter) + { + std::string key(8, 'a'); + std::uint64_t x = counter; + for (std::size_t i = 0; i < 8; ++i, x /= 26) + { + key[i] = static_cast('a' + (x % 26)); + } + const bool lands_in_slot_zero = (nlohmann::detail::view::key_hash(key.data(), key.size()) & (slots - 1)) == 0; + if (lands_in_slot_zero && colliding.size() < members) + { + colliding.push_back(key); + } + else if (!lands_in_slot_zero && spread.size() < members) + { + spread.push_back(key); + } + } + + const auto make_text = [](const std::vector& keys) + { + std::string text = "{"; + for (std::size_t i = 0; i < keys.size(); ++i) + { + text += (i != 0 ? ",\"" : "\"") + keys[i] + "\":" + std::to_string(i % 10); + } + return text + "}"; + }; + const std::string colliding_text = make_text(colliding); + const std::string spread_text = make_text(spread); + + json_document with_collisions = json_document::parse(colliding_text); + json_document without_collisions = json_document::parse(spread_text); + for (const auto* pair : + { + &colliding, &spread + }) + { + const json_view v = (pair == &colliding ? with_collisions : without_collisions).root(); + for (std::size_t i = 0; i < members; ++i) + { + CAPTURE(i) + CHECK(v[(*pair)[i]].get() == i % 10); + CHECK(v.at((*pair)[i]).get() == i % 10); + CHECK(v.find((*pair)[i]).key() == (*pair)[i]); + CHECK(!v.contains((*pair)[i] + "x")); + } + CHECK(!v.contains("missing")); + } + CHECK(with_collisions.root() == json::parse(colliding_text)); + + // only the object with the spread keys got a table (both texts have the + // same length, so the tables are the only difference) + with_collisions.shrink_to_fit(); + without_collisions.shrink_to_fit(); + CHECK(without_collisions.memory_usage() >= with_collisions.memory_usage() + (slots * sizeof(std::uint32_t))); + } + + SECTION("shrink_to_fit releases the tables' spare capacity") + { + const auto make_text = [](int objects, int members) + { + std::string text = "["; + for (int object = 0; object < objects; ++object) + { + text += object != 0 ? ",{" : "{"; + for (int i = 0, n = members + object; i < n; ++i) + { + text += (i != 0 ? ",\"" : "\"") + std::to_string(i) + "\":" + std::to_string(i); + } + text += '}'; + } + return text + "]"; + }; + const std::string small_text = make_text(5, 150); + const std::string big_text = make_text(40, 400); + + // reading a big text, and then a small one, leaves the spare capacity + // of the big one: shrink_to_fit() brings the document to the size of + // one parsed from the small text alone + json_document d = json_document::parse(big_text); + const std::size_t big = d.memory_usage(); + d.read(small_text); + CHECK(d.memory_usage() >= big); + d.shrink_to_fit(); + json_document fresh = json_document::parse(small_text); + fresh.shrink_to_fit(); + CHECK(d.memory_usage() == fresh.memory_usage()); + CHECK(d.memory_usage() < big / 2); + CHECK(d.root() == json::parse(small_text)); + for (int object = 0; object < 5; ++object) + { + const json_view v = d.root()[static_cast(object)]; + for (int i = 0, n = 150 + object; i < n; ++i) + { + CHECK(v[std::to_string(i)].get() == i); + } + } + } + + SECTION("nested, reused, and in arrays") + { + std::string inner = "{"; + for (int i = 0; i < 300; ++i) + { + inner += (i != 0 ? ",\"m" : "\"m") + std::to_string(i) + "\":" + std::to_string(i); + } + inner += '}'; + const std::string text = "[" + inner + ",{\"x\":" + inner + "}," + inner + "]"; + json_document d = json_document::parse(text); + CHECK(d.root()[0]["m299"].get() == 299); + CHECK(d.root()[1]["x"]["m150"].get() == 150); + CHECK(d.root()[2]["m0"].get() == 0); + const std::size_t with_index = d.memory_usage(); + d.read(std::string("{\"small\": 1}")); + CHECK(d.root()["small"].get() == 1); + d.read(text); + CHECK(d.root()[2]["m7"].get() == 7); + CHECK(d.memory_usage() >= with_index / 2); + } +}