src/cpp-common/bt2/query-executor.hpp

   1 /*
   2  * Copyright (c) 2024 EfficiOS, Inc.
   3  *
   4  * SPDX-License-Identifier: MIT
   5  */
   6
   7 #ifndef BABELTRACE_CPP_COMMON_BT2_QUERY_EXECUTOR_HPP
   8 #define BABELTRACE_CPP_COMMON_BT2_QUERY_EXECUTOR_HPP
   9
  10 #include <babeltrace2/babeltrace.h>
  11
  12 #include "cpp-common/bt2c/c-string-view.hpp"
  13
  14 #include "borrowed-object.hpp"
  15 #include "component-class.hpp"
  16 #include "shared-object.hpp"
  17 #include "value.hpp"
  18
  19 namespace bt2 {
  20 namespace internal {
  21
  22 struct QueryExecutorRefFuncs final
  23 {
  24     static void get(const bt_query_executor * const libObjPtr) noexcept
  25     {
  26         bt_query_executor_get_ref(libObjPtr);
  27     }
  28
  29     static void put(const bt_query_executor * const libObjPtr) noexcept
  30     {
  31         bt_query_executor_put_ref(libObjPtr);
  32     }
  33 };
  34
  35 } /* namespace internal */
  36
  37 template <typename LibObjT>
  38 class CommonQueryExecutor final : public BorrowedObject<LibObjT>
  39 {
  40 private:
  41     using typename BorrowedObject<LibObjT>::_ThisBorrowedObject;
  42
  43 public:
  44     using typename _ThisBorrowedObject::LibObjPtr;
  45     using Shared = SharedObject<CommonQueryExecutor, LibObjT, internal::QueryExecutorRefFuncs>;
  46
  47     explicit CommonQueryExecutor(const LibObjPtr libObjPtr) noexcept :
  48         _ThisBorrowedObject {libObjPtr}
  49     {
  50     }
  51
  52     template <typename OtherLibObjT>
  53     CommonQueryExecutor(const CommonQueryExecutor<OtherLibObjT> queryExec) noexcept :
  54         _ThisBorrowedObject {queryExec}
  55     {
  56     }
  57
  58     template <typename OtherLibObjT>
  59     CommonQueryExecutor operator=(const CommonQueryExecutor<OtherLibObjT> queryExec) noexcept
  60     {
  61         _ThisBorrowedObject::operator=(queryExec);
  62         return *this;
  63     }
  64
  65     static Shared create(const ConstComponentClass compCls, const bt2c::CStringView objectName,
  66                          const OptionalBorrowedObject<ConstMapValue> params = {})
  67     {
  68         return CommonQueryExecutor::_create(compCls, objectName, params,
  69                                             static_cast<void *>(nullptr));
  70     }
  71
  72     template <typename QueryDataT>
  73     static Shared create(const ConstComponentClass compCls, const bt2c::CStringView objectName,
  74                          QueryDataT& queryData,
  75                          const OptionalBorrowedObject<ConstMapValue> params = {})
  76     {
  77         return CommonQueryExecutor::_create(compCls, objectName, params, &queryData);
  78     }
  79
  80     ConstValue::Shared query() const
  81     {
  82         static_assert(!std::is_const<LibObjT>::value,
  83                       "Not available with `bt2::ConstQueryExecutor`.");
  84
  85         const bt_value *res;
  86         const auto status = bt_query_executor_query(this->libObjPtr(), &res);
  87
  88         if (status == BT_QUERY_EXECUTOR_QUERY_STATUS_ERROR) {
  89             throw Error {};
  90         } else if (status == BT_QUERY_EXECUTOR_QUERY_STATUS_MEMORY_ERROR) {
  91             throw MemoryError {};
  92         } else if (status == BT_QUERY_EXECUTOR_QUERY_STATUS_AGAIN) {
  93             throw TryAgain {};
  94         } else if (status == BT_QUERY_EXECUTOR_QUERY_STATUS_UNKNOWN_OBJECT) {
  95             throw UnknownObject {};
  96         }
  97
  98         return ConstValue::Shared::createWithoutRef(res);
  99     }
 100
 101 private:
 102     template <typename QueryDataT>
 103     static Shared _create(const ConstComponentClass compCls, const bt2c::CStringView objectName,
 104                           const OptionalBorrowedObject<ConstMapValue> params,
 105                           QueryDataT * const queryData)
 106     {
 107         const auto libObjPtr = bt_query_executor_create_with_method_data(
 108             compCls.libObjPtr(), objectName, params ? params->libObjPtr() : nullptr,
 109             const_cast<void *>(static_cast<const void *>(queryData)));
 110
 111         if (!libObjPtr) {
 112             throw MemoryError {};
 113         }
 114
 115         return Shared::createWithoutRef(libObjPtr);
 116     }
 117 };
 118
 119 using QueryExecutor = CommonQueryExecutor<bt_query_executor>;
 120 using ConstQueryExecutor = CommonQueryExecutor<const bt_query_executor>;
 121
 122 } /* namespace bt2 */
 123
 124 #endif /* BABELTRACE_CPP_COMMON_BT2_QUERY_EXECUTOR_HPP  */