src/lib/graph/query-executor.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  */
   6
   7 #define BT_LOG_TAG "LIB/QUERY-EXECUTOR"
   8 #include "lib/logging.h"
   9
  10 #include "common/common.h"
  11 #include "lib/assert-cond.h"
  12 #include <babeltrace2/graph/query-executor.h>
  13 #include <babeltrace2/graph/component-class.h>
  14 #include <babeltrace2/graph/query-executor.h>
  15 #include <babeltrace2/value.h>
  16 #include "lib/object.h"
  17 #include "compat/compiler.h"
  18
  19 #include "component-class.h"
  20 #include "query-executor.h"
  21 #include "interrupter.h"
  22 #include "lib/func-status.h"
  23
  24 static
  25 void bt_query_executor_destroy(struct bt_object *obj)
  26 {
  27         struct bt_query_executor *query_exec =
  28                 container_of(obj, struct bt_query_executor, base);
  29
  30         BT_LOGD("Destroying query executor: addr=%p", query_exec);
  31
  32         if (query_exec->interrupters) {
  33                 BT_LOGD_STR("Putting interrupters.");
  34                 g_ptr_array_free(query_exec->interrupters, TRUE);
  35                 query_exec->interrupters = NULL;
  36         }
  37
  38         BT_LOGD_STR("Putting component class.");
  39         BT_OBJECT_PUT_REF_AND_RESET(query_exec->comp_cls);
  40
  41         if (query_exec->object) {
  42                 g_string_free(query_exec->object, TRUE);
  43                 query_exec->object = NULL;
  44         }
  45
  46         BT_LOGD_STR("Putting parameters.");
  47         BT_OBJECT_PUT_REF_AND_RESET(query_exec->params);
  48         BT_OBJECT_PUT_REF_AND_RESET(query_exec->default_interrupter);
  49         g_free(query_exec);
  50 }
  51
  52 BT_EXPORT
  53 struct bt_query_executor *bt_query_executor_create_with_method_data(
  54                 const bt_component_class *comp_cls, const char *object,
  55                 const bt_value *params, void *method_data)
  56 {
  57         struct bt_query_executor *query_exec;
  58
  59         BT_ASSERT_PRE_NO_ERROR();
  60         BT_ASSERT_PRE_COMP_CLS_NON_NULL(comp_cls);
  61         BT_ASSERT_PRE_NON_NULL("object", object, "Object");
  62         BT_LIB_LOGD("Creating query executor: "
  63                 "%![comp-cls-]+C, object=\"%s\", %![params-]+v",
  64                 comp_cls, object, params);
  65         query_exec = g_new0(struct bt_query_executor, 1);
  66         if (!query_exec) {
  67                 BT_LIB_LOGE_APPEND_CAUSE(
  68                         "Failed to allocate one query executor.");
  69                 goto end;
  70         }
  71
  72         query_exec->interrupters = g_ptr_array_new_with_free_func(
  73                 (GDestroyNotify) bt_object_put_ref_no_null_check);
  74         if (!query_exec->interrupters) {
  75                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GPtrArray.");
  76                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  77                 goto end;
  78         }
  79
  80         query_exec->default_interrupter = bt_interrupter_create();
  81         if (!query_exec->default_interrupter) {
  82                 BT_LIB_LOGE_APPEND_CAUSE(
  83                         "Failed to create one interrupter object.");
  84                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  85                 goto end;
  86         }
  87
  88         query_exec->object = g_string_new(object);
  89         if (!query_exec->object) {
  90                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GString.");
  91                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  92                 goto end;
  93         }
  94
  95         query_exec->comp_cls = comp_cls;
  96         bt_object_get_ref_no_null_check(query_exec->comp_cls);
  97
  98         if (!params) {
  99                 query_exec->params = bt_value_null;
 100         } else {
 101                 query_exec->params = params;
 102         }
 103
 104         bt_object_get_ref_no_null_check(query_exec->params);
 105         query_exec->method_data = method_data;
 106         query_exec->log_level = BT_LOGGING_LEVEL_NONE;
 107         bt_query_executor_add_interrupter(query_exec,
 108                 query_exec->default_interrupter);
 109         bt_object_init_shared(&query_exec->base,
 110                 bt_query_executor_destroy);
 111         BT_LIB_LOGD("Created query executor: "
 112                 "addr=%p, %![comp-cls-]+C, object=\"%s\", %![params-]+v",
 113                 query_exec, comp_cls, object, params);
 114
 115 end:
 116         return (void *) query_exec;
 117 }
 118
 119 BT_EXPORT
 120 struct bt_query_executor *bt_query_executor_create(
 121                 const bt_component_class *comp_cls, const char *object,
 122                 const bt_value *params)
 123 {
 124         BT_ASSERT_PRE_NO_ERROR();
 125         return bt_query_executor_create_with_method_data(comp_cls,
 126                 object, params, NULL);
 127 }
 128
 129 BT_EXPORT
 130 enum bt_query_executor_query_status bt_query_executor_query(
 131                 struct bt_query_executor *query_exec,
 132                 const struct bt_value **user_result)
 133 {
 134         typedef enum bt_component_class_query_method_status (*method_t)(
 135                 void * /* self component class */,
 136                 void * /* private query executor */,
 137                 const char * /* object */,
 138                 const struct bt_value * /* parameters */,
 139                 void * /* method data */,
 140                 const struct bt_value ** /* result */);
 141
 142         enum bt_query_executor_query_status status;
 143         enum bt_component_class_query_method_status query_status;
 144         method_t method = NULL;
 145         const char *method_name = NULL;
 146
 147         BT_ASSERT_PRE_NO_ERROR();
 148         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 149         BT_ASSERT_PRE_RES_OUT_NON_NULL(user_result);
 150
 151         /*
 152          * Initial check: is the query executor already interrupted? If
 153          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 154          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 155          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 156          * legitimate error). Since any query operation could return
 157          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 158          * blocking, the caller is responsible for checking the
 159          * interruption state of the query executor when getting this
 160          * status.
 161          */
 162         if (bt_query_executor_is_interrupted(query_exec)) {
 163                 BT_LIB_LOGD("Query executor is interrupted: "
 164                         "not performing the query operation: "
 165                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 166                         "%![params-]+v, log-level=%s",
 167                         query_exec, query_exec->comp_cls,
 168                         query_exec->object->str, query_exec->params,
 169                         bt_common_logging_level_string(query_exec->log_level));
 170                 status = BT_FUNC_STATUS_AGAIN;
 171                 goto end;
 172         }
 173
 174         switch (query_exec->comp_cls->type) {
 175         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 176         {
 177                 struct bt_component_class_source *src_cc = (void *)
 178                         query_exec->comp_cls;
 179
 180                 method = (method_t) src_cc->methods.query;
 181                 method_name = "bt_component_class_source_query_method";
 182                 break;
 183         }
 184         case BT_COMPONENT_CLASS_TYPE_FILTER:
 185         {
 186                 struct bt_component_class_filter *flt_cc = (void *)
 187                         query_exec->comp_cls;
 188
 189                 method = (method_t) flt_cc->methods.query;
 190                 method_name = "bt_component_class_filter_query_method";
 191                 break;
 192         }
 193         case BT_COMPONENT_CLASS_TYPE_SINK:
 194         {
 195                 struct bt_component_class_sink *sink_cc = (void *)
 196                         query_exec->comp_cls;
 197
 198                 method = (method_t) sink_cc->methods.query;
 199                 method_name = "bt_component_class_sink_query_method";
 200                 break;
 201         }
 202         default:
 203                 bt_common_abort();
 204         }
 205
 206         if (!method) {
 207                 /* Not an error: nothing to query */
 208                 BT_LIB_LOGD("Component class has no registered query method: "
 209                         "%!+C", query_exec->comp_cls);
 210                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 211                 goto end;
 212         }
 213
 214         BT_LIB_LOGD("Calling user's query method: "
 215                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 216                 "log-level=%s",
 217                 query_exec, query_exec->comp_cls, query_exec->object->str,
 218                 query_exec->params,
 219                 bt_common_logging_level_string(query_exec->log_level));
 220         *user_result = NULL;
 221         query_status = method((void *) query_exec->comp_cls,
 222                 (void *) query_exec, query_exec->object->str,
 223                 query_exec->params, query_exec->method_data, user_result);
 224         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 225                 bt_common_func_status_string(query_status), *user_result);
 226         BT_ASSERT_POST(method_name, "status-ok-with-result",
 227                 query_status != BT_FUNC_STATUS_OK || *user_result,
 228                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 229         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(method_name, query_status);
 230         status = (int) query_status;
 231
 232         if (status < 0) {
 233                 BT_LIB_LOGW_APPEND_CAUSE(
 234                         "Component class's \"query\" method failed: "
 235                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 236                         "%![params-]+v, log-level=%s", query_exec,
 237                         query_exec->comp_cls, query_exec->object->str,
 238                         query_exec->params,
 239                         bt_common_logging_level_string(query_exec->log_level));
 240                 goto end;
 241         }
 242
 243 end:
 244         return status;
 245 }
 246
 247 BT_EXPORT
 248 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 249                 struct bt_query_executor *query_exec,
 250                 const struct bt_interrupter *intr)
 251 {
 252         BT_ASSERT_PRE_NO_ERROR();
 253         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 254         BT_ASSERT_PRE_INTR_NON_NULL(intr);
 255         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 256         bt_object_get_ref_no_null_check(intr);
 257         BT_LIB_LOGD("Added interrupter to query executor: "
 258                 "query-exec-addr=%p, %![intr-]+z",
 259                 query_exec, intr);
 260         return BT_FUNC_STATUS_OK;
 261 }
 262
 263 BT_EXPORT
 264 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 265 {
 266         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 267         return (bt_bool) bt_interrupter_array_any_is_set(
 268                 query_exec->interrupters);
 269 }
 270
 271 BT_EXPORT
 272 struct bt_interrupter *bt_query_executor_borrow_default_interrupter(
 273                 struct bt_query_executor *query_exec)
 274 {
 275         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 276         return query_exec->default_interrupter;
 277 }
 278
 279 BT_EXPORT
 280 enum bt_query_executor_set_logging_level_status
 281 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 282                 enum bt_logging_level log_level)
 283 {
 284         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 285         query_exec->log_level = log_level;
 286         return BT_FUNC_STATUS_OK;
 287 }
 288
 289 BT_EXPORT
 290 enum bt_logging_level bt_query_executor_get_logging_level(
 291                 const struct bt_query_executor *query_exec)
 292 {
 293         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 294         return query_exec->log_level;
 295 }
 296
 297 BT_EXPORT
 298 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 299 {
 300         bt_object_get_ref(query_executor);
 301 }
 302
 303 BT_EXPORT
 304 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 305 {
 306         bt_object_put_ref(query_executor);
 307 }