C++ MethodTableBucket类代码示例

  Object* System::vm_check_super_callable(STATE, CallFrame* call_frame) {
    if(call_frame->native_method_p()) return Qtrue;

    Module* mod = call_frame->module()->superclass();

    MethodTableBucket* entry;
    Symbol* sym = call_frame->original_name();

    while(!mod->nil_p()) {
      entry = mod->method_table()->find_entry(state, sym);

      if(entry) {
        if(entry->undef_p(state)) return Qfalse;

        // It's callable, ok, but see if we should see if it's just a stub
        // to change the visibility of another method.
        if(!entry->method()->nil_p()) {
          return Qtrue;
        }
      }

      mod = mod->superclass();
    }

    return Qfalse;
  }

  MethodTable* MethodTable::duplicate(STATE) {
    size_t size, i;
    MethodTable* dup = 0;

    utilities::thread::SpinLock::LockGuard lg(lock_);

    size = bins_->to_native();
    dup = MethodTable::create(state, size);

    // Allow for subclassing.
    dup->klass(state, class_object(state));

    size_t num = bins_->to_native();

    MethodTableBucket* entry = 0;

    for(i = 0; i < num; i++) {
      entry = try_as<MethodTableBucket>(values_->at(state, i));

      while(entry) {
        dup->store(state, entry->name(), entry->method(), entry->visibility());
        entry = try_as<MethodTableBucket>(entry->next());
      }
    }

    return dup;
  }

  Object* System::vm_check_callable(STATE, Object* obj, Symbol* sym, Object* self) {
    Module* mod = obj->lookup_begin(state);

    MethodTableBucket* entry;
    bool skip_vis_check = false;

    while(!mod->nil_p()) {
      entry = mod->method_table()->find_entry(state, sym);

      if(entry) {
        if(entry->undef_p(state)) return Qfalse;
        if(!skip_vis_check) {
          if(entry->private_p(state)) return Qfalse;
          if(entry->protected_p(state)) {
            if(!self->kind_of_p(state, mod)) return Qfalse;
          }
        }

        // It's callable, ok, but see if we should see if it's just a stub
        // to change the visibility of another method.
        if(entry->method()->nil_p()) {
          skip_vis_check = true;
        } else {
          return Qtrue;
        }
      }

      mod = mod->superclass();
    }

    return Qfalse;
  }

  void MethodTable::Info::show(STATE, Object* self, int level) {
    MethodTable* tbl = as<MethodTable>(self);
    size_t size = tbl->bins()->to_native();

    if(size == 0) {
      class_info(state, self, true);
      return;
    }

    class_info(state, self);
    std::cout << ": " << size << std::endl;
    indent(++level);
    for(size_t i = 0; i < size; i++) {
      MethodTableBucket* entry = try_as<MethodTableBucket>(tbl->values()->at(state, i));

      while(entry) {
       if(Symbol* sym = try_as<Symbol>(entry->name())) {
          std::cout << ":" << sym->debug_str(state);
        } else if(Fixnum* fix = try_as<Fixnum>(entry->name())) {
          std::cout << fix->to_native();
        }
        entry = try_as<MethodTableBucket>(entry->next());
      }
      if(i < size - 1) std::cout << ", ";
    }
    std::cout << std::endl;
    close_body(level);
  }

  Object* MethodTable::alias(STATE, Symbol* name, Symbol* vis,
                             Symbol* orig_name, Object* orig_method,
                             Module* orig_mod)
  {
    check_frozen(state);

    utilities::thread::SpinLock::LockGuard lg(lock_);

    Executable* orig_exec;

    if(Alias* alias = try_as<Alias>(orig_method)) {
      orig_exec = alias->original_exec();
      orig_mod = alias->original_module();
      orig_name = alias->original_name();
    } else if(orig_method->nil_p()) {
      orig_exec = nil<Executable>();
    } else {
      orig_exec = as<Executable>(orig_method);
    }

    Alias* method = Alias::create(state, orig_name, orig_mod, orig_exec);

    native_int num_entries = entries_->to_native();
    native_int num_bins = bins_->to_native();

    if(max_density_p(num_entries, num_bins)) {
      redistribute(state, num_bins <<= 1);
    }

    native_int bin = find_bin(key_hash(name), num_bins);

    MethodTableBucket* entry = try_as<MethodTableBucket>(values_->at(state, bin));
    MethodTableBucket* last = NULL;

    while(entry) {
      if(entry->name() == name) {
        entry->method_id(state, nil<String>());
        entry->method(state, method);
        entry->scope(state, cNil);
        entry->serial(state, Fixnum::from(0));
        entry->visibility(state, vis);
        return name;
      }

      last = entry;
      entry = try_as<MethodTableBucket>(entry->next());
    }

    if(last) {
      last->next(state, MethodTableBucket::create(
            state, name, nil<String>(), method, cNil, Fixnum::from(0), vis));
    } else {
      values_->put(state, bin, MethodTableBucket::create(
            state, name, nil<String>(), method, cNil, Fixnum::from(0), vis));
    }

    entries(state, Fixnum::from(num_entries + 1));
    return name;
  }

  MethodTableBucket* MethodTableBucket::create(STATE, Symbol* name,
      Executable* method, Symbol* vis)
  {
    MethodTableBucket *entry =
      state->new_object<MethodTableBucket>(G(methtblbucket));

    entry->name(state, name);
    entry->method(state, method);
    entry->visibility(state, vis);
    return entry;
  }

  bool InlineCache::fill_private(STATE, Symbol* name, Module* start) {
    MethodTableBucket* entry;

    Module* module = start;

    // Check the global cache first!
    GlobalCache::cache_entry* global_entry =
      state->global_cache->lookup(module, name);

    if(global_entry && !global_entry->method_missing) {
      this->method = global_entry->method;
      this->module = global_entry->module;

      return true;
    }

    do {
      entry = module->method_table()->find_entry(state, name);

      /* Nothing, there? Ok, keep looking. */
      if(entry) {

        /* A 'false' method means to terminate method lookup.
         * (eg. undef_method) */
        if(entry->undef_p(state)) return false;

        /* The method was callable, but we need to keep looking
         * for the implementation, so make the invocation bypass all further
         * visibility checks.
         *
         * This is pretty much always where a subclass marks a superclass
         * method as public. We don't move the method, we just put this
         * marker into the method table. */
        if(!entry->method()->nil_p()) {
          this->method = entry->method();
          this->module = module;
          state->global_cache->retain(state, start, name, this->module,
              this->method, false,
              !entry->public_p(state));

          return true;
        }
      }

      module = module->superclass();

      /* No more places to look, we couldn't find it. */
      if(module->nil_p()) return false;
    } while(1);

    // Shouldn't be here!
    rubinius::abort();
  }

  Object* MethodTableBucket::append(STATE, MethodTableBucket* nxt) {
    MethodTableBucket* cur = try_as<MethodTableBucket>(this->next());
    MethodTableBucket* last = this;

    while(cur) {
      last = cur;
      cur = try_as<MethodTableBucket>(cur->next());
    }

    last->next(state, nxt);
    return nxt;
  }

  bool InlineCache::fill_method_missing(STATE, Class* klass,
                                        MethodCacheEntry*& mce)
  {
    MethodTableBucket* entry;

    Module* module = klass;

    Symbol* name = G(sym_method_missing);

    do {
      entry = module->method_table()->find_entry(state, name);

      /* Nothing, there? Ok, keep looking. */
      if(entry) {

        /* A 'false' method means to terminate method lookup.
         * (eg. undef_method) */
        if(entry->undef_p(state)) return false;

        /* The method was callable, but we need to keep looking
         * for the implementation, so make the invocation bypass all further
         * visibility checks.
         *
         * This is pretty much always where a subclass marks a superclass
         * method as public. We don't move the method, we just put this
         * marker into the method table. */
        if(!entry->method()->nil_p()) {
          if(Alias* alias = try_as<Alias>(entry->method())) {
            mce = MethodCacheEntry::create(state, klass,
                                           alias->original_module(),
                                           alias->original_exec());
          } else {
            mce = MethodCacheEntry::create(state, klass,
                                           module,
                                           entry->method());
          }

          return true;
        }
      }

      module = module->superclass();

      /* No more places to look, we couldn't find it. */
      if(module->nil_p()) return false;
    } while(1);

    // Shouldn't be here!
    rubinius::bug("Control flow bug in method lookup");
  }

  Executable* MethodTable::remove(STATE, Symbol* name) {
    hashval bin;
    MethodTableBucket* entry;
    MethodTableBucket* last = NULL;

    size_t num_entries = entries_->to_native();
    size_t num_bins = bins_->to_native();

    if(min_density_p(num_entries, num_bins) && (num_bins >> 1) >= METHODTABLE_MIN_SIZE) {
      redistribute(state, num_bins >>= 1);
    }

    bin = find_bin(key_hash(name), num_bins);
    entry = try_as<MethodTableBucket>(values_->at(state, bin));

    while(entry) {
      if(entry->name() == name) {
        Executable* val = entry->method();
        if(last) {
          last->next(state, entry->next());
        } else {
          values_->put(state, bin, entry->next());
        }
        entries(state, Fixnum::from(entries_->to_native() - 1));
        return val;
      }

      last = entry;
      entry = try_as<MethodTableBucket>(entry->next());
    }

    return reinterpret_cast<Executable*>(Qnil);
  }

  MethodTableBucket* MethodTable::find_entry(Symbol* name) {
    unsigned int bin;

    bin = find_bin(key_hash(name), bins_->to_native());
    MethodTableBucket *entry = try_as<MethodTableBucket>(values_->at(bin));

    while(entry) {
      if(entry->name() == name) {
        return entry;
      }
      entry = try_as<MethodTableBucket>(entry->next());
    }

    return 0;
  }

  MethodTable* MethodTable::duplicate(STATE) {
    size_t size, i;
    MethodTable *dup;

    size = bins_->to_native();
    dup = MethodTable::create(state, size);

    // Allow for subclassing.
    dup->klass(state, class_object(state));

    size_t num = entries_->to_native();

    Array* entries = all_entries(state);
    for(i = 0; i < num; i++) {
      MethodTableBucket* entry = as<MethodTableBucket>(entries->get(state, i));
      dup->store(state, entry->name(), entry->method(), entry->visibility());
    }
    return dup;
  }

  Array* MethodTable::collect(STATE, MethodTable* tbl,
                              Object* (*action)(STATE, MethodTableBucket*))
  {
    size_t i, j;
    Tuple* values;
    MethodTableBucket* entry;

    Array* ary = Array::create(state, tbl->entries()->to_native());
    size_t num_bins = tbl->bins()->to_native();
    values = tbl->values();

    for(i = j = 0; i < num_bins; i++) {
      entry = try_as<MethodTableBucket>(values->at(state, i));

      while(entry) {
        ary->set(state, j++, action(state, entry));
        entry = try_as<MethodTableBucket>(entry->next());
      }
    }
    return ary;
  }

  bool InlineCache::fill_method_missing(STATE, Module* module) {
    MethodTableBucket* entry;

    Symbol* name = G(sym_method_missing);

    do {
      entry = module->method_table()->find_entry(state, name);

      /* Nothing, there? Ok, keep looking. */
      if(entry) {

        /* A 'false' method means to terminate method lookup.
         * (eg. undef_method) */
        if(entry->undef_p(state)) return false;

        /* The method was callable, but we need to keep looking
         * for the implementation, so make the invocation bypass all further
         * visibility checks.
         *
         * This is pretty much always where a subclass marks a superclass
         * method as public. We don't move the method, we just put this
         * marker into the method table. */
        if(!entry->method()->nil_p()) {
          this->method = entry->method();
          this->module = module;

          return true;
        }
      }

      module = module->superclass();

      /* No more places to look, we couldn't find it. */
      if(module->nil_p()) return false;
    } while(1);

    // Shouldn't be here!
    rubinius::abort();
  }

  MethodTableBucket* MethodTableBucket::create(STATE, Symbol* name, Object* method_id,
      Object* method, Object* scope, Fixnum* serial, Symbol* vis)
  {
    MethodTableBucket *entry =
      state->new_object<MethodTableBucket>(G(methtblbucket));

    entry->name(state, name);
    entry->method_id(state, method_id);
    entry->method(state, method);
    entry->scope(state, scope);
    entry->serial(state, serial);
    entry->visibility(state, vis);

    return entry;
  }