public:

static constexpr int kStackTraceInitialSize = 30;

StackTrace() = default;

StackTrace(StackTrace&& other) = default;

// Returns `StackTrace` object that captures the current Python stack trace.

// `limit` determines how many stack frames at most are returned: set to -1

// for "no limit".

// Python GIL must be acquired beforehand.

ABSL_MUST_USE_RESULT

ABSL_ATTRIBUTE_HOT

static std::shared_ptr<StackTrace> Capture(int limit);

uint64_t hash() const {

uint64_t hash = 0;

for (const auto& p : code_objs_) {

hash = tsl::FingerprintCat64(hash,

reinterpret_cast<const uint64_t>(p.first));

hash = tsl::FingerprintCat64(hash, p.second);

}

return hash;

}

~StackTrace() override { Clear(); }

// Returns a structured representation of the captured stack trace.

// `source_map` provides a custom mapping for translating stack frames,

// `filter` returns `true` for the stack frames which should be omitted.

//

// `reverse_traversal` changes the traversal order of the stack trace, and

// `limit` bounds the number of returned frames (after filtering).

std::vector<StackFrame> ToStackFrames(const SourceMap& source_map,

const StackTraceFilter& filtered,

bool reverse_traversal,

int limit) const override;

private:

void Clear() {

auto gil_state = PyGILState_Ensure();

for (const auto& p : code_objs_) Py_DECREF(p.first);

code_objs_.clear();

PyGILState_Release(gil_state);

}

absl::InlinedVector<std::pair<PyCodeObject*, int>, 16> code_objs_;

StackTrace(const StackTrace&) = delete;

StackTrace& operator=(const StackTrace&) = delete;