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/assert.h"
  11 #include "common/common.h"
  12 #include "lib/assert-cond.h"
  13 #include <babeltrace2/graph/query-executor.h>
  14 #include <babeltrace2/graph/component-class.h>
  15 #include <babeltrace2/graph/query-executor.h>
  16 #include <babeltrace2/value.h>
  17 #include "lib/object.h"
  18 #include "compat/compiler.h"
  19
  20 #include "component-class.h"
  21 #include "query-executor.h"
  22 #include "interrupter.h"
  23 #include "lib/func-status.h"
  24
  25 static
  26 void bt_query_executor_destroy(struct bt_object *obj)
  27 {
  28         struct bt_query_executor *query_exec =
  29                 container_of(obj, struct bt_query_executor, base);
  30
  31         BT_LOGD("Destroying query executor: addr=%p", query_exec);
  32
  33         if (query_exec->interrupters) {
  34                 BT_LOGD_STR("Putting interrupters.");
  35                 g_ptr_array_free(query_exec->interrupters, TRUE);
  36                 query_exec->interrupters = NULL;
  37         }
  38
  39         BT_LOGD_STR("Putting component class.");
  40         BT_OBJECT_PUT_REF_AND_RESET(query_exec->comp_cls);
  41
  42         if (query_exec->object) {
  43                 g_string_free(query_exec->object, TRUE);
  44                 query_exec->object = NULL;
  45         }
  46
  47         BT_LOGD_STR("Putting parameters.");
  48         BT_OBJECT_PUT_REF_AND_RESET(query_exec->params);
  49         BT_OBJECT_PUT_REF_AND_RESET(query_exec->default_interrupter);
  50         g_free(query_exec);
  51 }
  52
  53 BT_EXPORT
  54 struct bt_query_executor *bt_query_executor_create_with_method_data(
  55                 const bt_component_class *comp_cls, const char *object,
  56                 const bt_value *params, void *method_data)
  57 {
  58         struct bt_query_executor *query_exec;
  59
  60         BT_ASSERT_PRE_NO_ERROR();
  61         BT_ASSERT_PRE_COMP_CLS_NON_NULL(comp_cls);
  62         BT_ASSERT_PRE_NON_NULL("object", object, "Object");
  63         BT_LIB_LOGD("Creating query executor: "
  64                 "%![comp-cls-]+C, object=\"%s\", %![params-]+v",
  65                 comp_cls, object, params);
  66         query_exec = g_new0(struct bt_query_executor, 1);
  67         if (!query_exec) {
  68                 BT_LIB_LOGE_APPEND_CAUSE(
  69                         "Failed to allocate one query executor.");
  70                 goto end;
  71         }
  72
  73         query_exec->interrupters = g_ptr_array_new_with_free_func(
  74                 (GDestroyNotify) bt_object_put_ref_no_null_check);
  75         if (!query_exec->interrupters) {
  76                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GPtrArray.");
  77                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  78                 goto end;
  79         }
  80
  81         query_exec->default_interrupter = bt_interrupter_create();
  82         if (!query_exec->default_interrupter) {
  83                 BT_LIB_LOGE_APPEND_CAUSE(
  84                         "Failed to create one interrupter object.");
  85                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  86                 goto end;
  87         }
  88
  89         query_exec->object = g_string_new(object);
  90         if (!query_exec->object) {
  91                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GString.");
  92                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  93                 goto end;
  94         }
  95
  96         query_exec->comp_cls = comp_cls;
  97         bt_object_get_ref_no_null_check(query_exec->comp_cls);
  98
  99         if (!params) {
 100                 query_exec->params = bt_value_null;
 101         } else {
 102                 query_exec->params = params;
 103         }
 104
 105         bt_object_get_ref_no_null_check(query_exec->params);
 106         query_exec->method_data = method_data;
 107         query_exec->log_level = BT_LOGGING_LEVEL_NONE;
 108         bt_query_executor_add_interrupter(query_exec,
 109                 query_exec->default_interrupter);
 110         bt_object_init_shared(&query_exec->base,
 111                 bt_query_executor_destroy);
 112         BT_LIB_LOGD("Created query executor: "
 113                 "addr=%p, %![comp-cls-]+C, object=\"%s\", %![params-]+v",
 114                 query_exec, comp_cls, object, params);
 115
 116 end:
 117         return (void *) query_exec;
 118 }
 119
 120 BT_EXPORT
 121 struct bt_query_executor *bt_query_executor_create(
 122                 const bt_component_class *comp_cls, const char *object,
 123                 const bt_value *params)
 124 {
 125         BT_ASSERT_PRE_NO_ERROR();
 126         return bt_query_executor_create_with_method_data(comp_cls,
 127                 object, params, NULL);
 128 }
 129
 130 BT_EXPORT
 131 enum bt_query_executor_query_status bt_query_executor_query(
 132                 struct bt_query_executor *query_exec,
 133                 const struct bt_value **user_result)
 134 {
 135         typedef enum bt_component_class_query_method_status (*method_t)(
 136                 void * /* self component class */,
 137                 void * /* private query executor */,
 138                 const char * /* object */,
 139                 const struct bt_value * /* parameters */,
 140                 void * /* method data */,
 141                 const struct bt_value ** /* result */);
 142
 143         enum bt_query_executor_query_status status;
 144         enum bt_component_class_query_method_status query_status;
 145         method_t method = NULL;
 146         const char *method_name = NULL;
 147
 148         BT_ASSERT_PRE_NO_ERROR();
 149         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 150         BT_ASSERT_PRE_RES_OUT_NON_NULL(user_result);
 151
 152         /*
 153          * Initial check: is the query executor already interrupted? If
 154          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 155          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 156          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 157          * legitimate error). Since any query operation could return
 158          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 159          * blocking, the caller is responsible for checking the
 160          * interruption state of the query executor when getting this
 161          * status.
 162          */
 163         if (bt_query_executor_is_interrupted(query_exec)) {
 164                 BT_LIB_LOGD("Query executor is interrupted: "
 165                         "not performing the query operation: "
 166                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 167                         "%![params-]+v, log-level=%s",
 168                         query_exec, query_exec->comp_cls,
 169                         query_exec->object->str, query_exec->params,
 170                         bt_common_logging_level_string(query_exec->log_level));
 171                 status = BT_FUNC_STATUS_AGAIN;
 172                 goto end;
 173         }
 174
 175         switch (query_exec->comp_cls->type) {
 176         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 177         {
 178                 struct bt_component_class_source *src_cc = (void *)
 179                         query_exec->comp_cls;
 180
 181                 method = (method_t) src_cc->methods.query;
 182                 method_name = "bt_component_class_source_query_method";
 183                 break;
 184         }
 185         case BT_COMPONENT_CLASS_TYPE_FILTER:
 186         {
 187                 struct bt_component_class_filter *flt_cc = (void *)
 188                         query_exec->comp_cls;
 189
 190                 method = (method_t) flt_cc->methods.query;
 191                 method_name = "bt_component_class_filter_query_method";
 192                 break;
 193         }
 194         case BT_COMPONENT_CLASS_TYPE_SINK:
 195         {
 196                 struct bt_component_class_sink *sink_cc = (void *)
 197                         query_exec->comp_cls;
 198
 199                 method = (method_t) sink_cc->methods.query;
 200                 method_name = "bt_component_class_sink_query_method";
 201                 break;
 202         }
 203         default:
 204                 bt_common_abort();
 205         }
 206
 207         if (!method) {
 208                 /* Not an error: nothing to query */
 209                 BT_LIB_LOGD("Component class has no registered query method: "
 210                         "%!+C", query_exec->comp_cls);
 211                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 212                 goto end;
 213         }
 214
 215         BT_LIB_LOGD("Calling user's query method: "
 216                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 217                 "log-level=%s",
 218                 query_exec, query_exec->comp_cls, query_exec->object->str,
 219                 query_exec->params,
 220                 bt_common_logging_level_string(query_exec->log_level));
 221         *user_result = NULL;
 222         query_status = method((void *) query_exec->comp_cls,
 223                 (void *) query_exec, query_exec->object->str,
 224                 query_exec->params, query_exec->method_data, user_result);
 225         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 226                 bt_common_func_status_string(query_status), *user_result);
 227         BT_ASSERT_POST(method_name, "status-ok-with-result",
 228                 query_status != BT_FUNC_STATUS_OK || *user_result,
 229                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 230         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(method_name, query_status);
 231         status = (int) query_status;
 232
 233         if (status < 0) {
 234                 BT_LIB_LOGW_APPEND_CAUSE(
 235                         "Component class's \"query\" method failed: "
 236                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 237                         "%![params-]+v, log-level=%s", query_exec,
 238                         query_exec->comp_cls, query_exec->object->str,
 239                         query_exec->params,
 240                         bt_common_logging_level_string(query_exec->log_level));
 241                 goto end;
 242         }
 243
 244 end:
 245         return status;
 246 }
 247
 248 BT_EXPORT
 249 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 250                 struct bt_query_executor *query_exec,
 251                 const struct bt_interrupter *intr)
 252 {
 253         BT_ASSERT_PRE_NO_ERROR();
 254         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 255         BT_ASSERT_PRE_INTR_NON_NULL(intr);
 256         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 257         bt_object_get_ref_no_null_check(intr);
 258         BT_LIB_LOGD("Added interrupter to query executor: "
 259                 "query-exec-addr=%p, %![intr-]+z",
 260                 query_exec, intr);
 261         return BT_FUNC_STATUS_OK;
 262 }
 263
 264 BT_EXPORT
 265 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 266 {
 267         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 268         return (bt_bool) bt_interrupter_array_any_is_set(
 269                 query_exec->interrupters);
 270 }
 271
 272 BT_EXPORT
 273 struct bt_interrupter *bt_query_executor_borrow_default_interrupter(
 274                 struct bt_query_executor *query_exec)
 275 {
 276         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 277         return query_exec->default_interrupter;
 278 }
 279
 280 BT_EXPORT
 281 enum bt_query_executor_set_logging_level_status
 282 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 283                 enum bt_logging_level log_level)
 284 {
 285         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 286         query_exec->log_level = log_level;
 287         return BT_FUNC_STATUS_OK;
 288 }
 289
 290 BT_EXPORT
 291 enum bt_logging_level bt_query_executor_get_logging_level(
 292                 const struct bt_query_executor *query_exec)
 293 {
 294         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 295         return query_exec->log_level;
 296 }
 297
 298 BT_EXPORT
 299 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 300 {
 301         bt_object_get_ref(query_executor);
 302 }
 303
 304 BT_EXPORT
 305 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 306 {
 307         bt_object_put_ref(query_executor);
 308 }