// Copyright 2024 The TCMalloc Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <algorithm>
#include <cstddef>
#include <cstring>
#include <string>

#include "gtest/gtest.h"
#include "fuzztest/fuzztest.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "tcmalloc/internal/memory_stats.h"

namespace tcmalloc::tcmalloc_internal {
namespace {

void ParseInput(absl::string_view s) {
  const char* data = s.data();
  size_t size = s.size();

  MemoryStats stats;
  bool r = GetMemoryStatsFromCallback(stats,
                                      [&](char* buf, size_t count) -> ssize_t {
                                        size_t to_read = std::min(size, count);
                                        if (to_read > 0) {
                                          memcpy(buf, data, to_read);
                                          data += to_read;
                                          size -= to_read;
                                        }
                                        return to_read;
                                      });
  if (!r) {
    return;
  }

  // Validate the results in the fuzztest to ensure we can read all of the
  // fields without UB or MSan poison, even if they contain arbitrary fuzzed
  // values.
  std::string formatted =
      absl::StrCat(stats.vss, "-", stats.rss, "-", stats.shared, "-",
                   stats.code, "-", stats.data);
  EXPECT_GT(formatted.size(), 0);
}

FUZZ_TEST(MemoryStatsTest, ParseInput);

}  // namespace
}  // namespace tcmalloc::tcmalloc_internal
