polyglot_common_context.h

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#ifndef MYSQLSHDK_SCRIPTING_POLYGLOT_LANGUAGES_POLYGLOT_COMMON_CONTEXT_H_
#define MYSQLSHDK_SCRIPTING_POLYGLOT_LANGUAGES_POLYGLOT_COMMON_CONTEXT_H_
 
#include "utils/polyglot_api_clean.h"
 
#include <memory>
#include <optional>
 
#include "languages/polyglot_garbage_collector.h"
#include "native_wrappers/polyglot_collectable.h"
#include "utils/polyglot_scope.h"
#include "utils/polyglot_store.h"
 
namespace shcore {
namespace polyglot {
 
struct IsolateArgs {
 public:
  std::optional<uint64_t> min_heap_size;
  std::optional<uint64_t> max_heap_size;
  std::optional<uint64_t> max_new_size;
};
 
/**
 * Common context for GraalVM Languages
 *
 * Encloses the following global routines/components:
 *
 * - Initialization/TearDown of the GraalVM Isolate.
 * - Registration of global logging callbacks.
 * - Setup of the global engine.
 * - Provides access to the garbage collector for event registration.
 *
 * This class can be specialized to:
 *
 * - Provide custom callbacks for the global logging functions.
 * - Create a custom Engine to be used in the contexts created from this class.
 * - Provide custom configuration for the garbage collector.
 */
class Polyglot_common_context {
 public:
  Polyglot_common_context() = default;
  virtual ~Polyglot_common_context() = default;
 
  virtual void initialize(const IsolateArgs &isolate_args);
  virtual void finalize();
 
  poly_reference engine() const { return m_engine.get(); }
  poly_isolate isolate() const { return m_isolate; }
  poly_thread thread() const { return m_thread; }
 
  void clean_collectables();
 
  Collectable_registry *collectable_registry() { return &m_registry; }
 
  double get_heap_usage_percent();
  std::string get_gc_status();
 
 protected:
  poly_isolate m_isolate = nullptr;
  poly_thread m_thread = nullptr;
 
 private:
  void init_engine();
  static void fatal_error_callback(void *data);
  static void flush_callback(void *data);
  static void log_callback(const char *bytes, size_t length, void *data);
  virtual void fatal_error() = 0;
  virtual void flush() = 0;
  virtual void log(const char *bytes, size_t length) = 0;
  virtual poly_engine create_engine() { return nullptr; }
  virtual Garbage_collector::Config gc_config() { return {}; }
 
  Store m_engine;
  std::unique_ptr<Polyglot_scope> m_scope;
  Collectable_registry m_registry;
  int64_t m_max_heap_size = 0;
  int64_t *m_heap_status = nullptr;
 
  // Holds the used capacity for each generation
  std::vector<int64_t *> m_generation_used;
};
 
}  // namespace polyglot
}  // namespace shcore
 
#endif  // MYSQLSHDK_SCRIPTING_POLYGLOT_LANGUAGES_POLYGLOT_COMMON_CONTEXT_H_