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 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 struct bt_query_executor *bt_query_executor_create(
 120                 const bt_component_class *comp_cls, const char *object,
 121                 const bt_value *params)
 122 {
 123         BT_ASSERT_PRE_NO_ERROR();
 124         return bt_query_executor_create_with_method_data(comp_cls,
 125                 object, params, NULL);
 126 }
 127
 128 enum bt_query_executor_query_status bt_query_executor_query(
 129                 struct bt_query_executor *query_exec,
 130                 const struct bt_value **user_result)
 131 {
 132         typedef enum bt_component_class_query_method_status (*method_t)(
 133                 void * /* self component class */,
 134                 void * /* private query executor */,
 135                 const char * /* object */,
 136                 const struct bt_value * /* parameters */,
 137                 void * /* method data */,
 138                 const struct bt_value ** /* result */);
 139
 140         enum bt_query_executor_query_status status;
 141         enum bt_component_class_query_method_status query_status;
 142         method_t method = NULL;
 143         const char *method_name = NULL;
 144
 145         BT_ASSERT_PRE_NO_ERROR();
 146         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 147         BT_ASSERT_PRE_RES_OUT_NON_NULL(user_result);
 148
 149         /*
 150          * Initial check: is the query executor already interrupted? If
 151          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 152          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 153          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 154          * legitimate error). Since any query operation could return
 155          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 156          * blocking, the caller is responsible for checking the
 157          * interruption state of the query executor when getting this
 158          * status.
 159          */
 160         if (bt_query_executor_is_interrupted(query_exec)) {
 161                 BT_LIB_LOGD("Query executor is interrupted: "
 162                         "not performing the query operation: "
 163                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 164                         "%![params-]+v, log-level=%s",
 165                         query_exec, query_exec->comp_cls,
 166                         query_exec->object->str, query_exec->params,
 167                         bt_common_logging_level_string(query_exec->log_level));
 168                 status = BT_FUNC_STATUS_AGAIN;
 169                 goto end;
 170         }
 171
 172         switch (query_exec->comp_cls->type) {
 173         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 174         {
 175                 struct bt_component_class_source *src_cc = (void *)
 176                         query_exec->comp_cls;
 177
 178                 method = (method_t) src_cc->methods.query;
 179                 method_name = "bt_component_class_source_query_method";
 180                 break;
 181         }
 182         case BT_COMPONENT_CLASS_TYPE_FILTER:
 183         {
 184                 struct bt_component_class_filter *flt_cc = (void *)
 185                         query_exec->comp_cls;
 186
 187                 method = (method_t) flt_cc->methods.query;
 188                 method_name = "bt_component_class_filter_query_method";
 189                 break;
 190         }
 191         case BT_COMPONENT_CLASS_TYPE_SINK:
 192         {
 193                 struct bt_component_class_sink *sink_cc = (void *)
 194                         query_exec->comp_cls;
 195
 196                 method = (method_t) sink_cc->methods.query;
 197                 method_name = "bt_component_class_sink_query_method";
 198                 break;
 199         }
 200         default:
 201                 bt_common_abort();
 202         }
 203
 204         if (!method) {
 205                 /* Not an error: nothing to query */
 206                 BT_LIB_LOGD("Component class has no registered query method: "
 207                         "%!+C", query_exec->comp_cls);
 208                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 209                 goto end;
 210         }
 211
 212         BT_LIB_LOGD("Calling user's query method: "
 213                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 214                 "log-level=%s",
 215                 query_exec, query_exec->comp_cls, query_exec->object->str,
 216                 query_exec->params,
 217                 bt_common_logging_level_string(query_exec->log_level));
 218         *user_result = NULL;
 219         query_status = method((void *) query_exec->comp_cls,
 220                 (void *) query_exec, query_exec->object->str,
 221                 query_exec->params, query_exec->method_data, user_result);
 222         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 223                 bt_common_func_status_string(query_status), *user_result);
 224         BT_ASSERT_POST(method_name, "status-ok-with-result",
 225                 query_status != BT_FUNC_STATUS_OK || *user_result,
 226                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 227         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(method_name, query_status);
 228         status = (int) query_status;
 229
 230         if (status < 0) {
 231                 BT_LIB_LOGW_APPEND_CAUSE(
 232                         "Component class's \"query\" method failed: "
 233                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 234                         "%![params-]+v, log-level=%s", query_exec,
 235                         query_exec->comp_cls, query_exec->object->str,
 236                         query_exec->params,
 237                         bt_common_logging_level_string(query_exec->log_level));
 238                 goto end;
 239         }
 240
 241 end:
 242         return status;
 243 }
 244
 245 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 246                 struct bt_query_executor *query_exec,
 247                 const struct bt_interrupter *intr)
 248 {
 249         BT_ASSERT_PRE_NO_ERROR();
 250         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 251         BT_ASSERT_PRE_INTR_NON_NULL(intr);
 252         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 253         bt_object_get_ref_no_null_check(intr);
 254         BT_LIB_LOGD("Added interrupter to query executor: "
 255                 "query-exec-addr=%p, %![intr-]+z",
 256                 query_exec, intr);
 257         return BT_FUNC_STATUS_OK;
 258 }
 259
 260 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 261 {
 262         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 263         return (bt_bool) bt_interrupter_array_any_is_set(
 264                 query_exec->interrupters);
 265 }
 266
 267 struct bt_interrupter *bt_query_executor_borrow_default_interrupter(
 268                 struct bt_query_executor *query_exec)
 269 {
 270         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 271         return query_exec->default_interrupter;
 272 }
 273
 274 enum bt_query_executor_set_logging_level_status
 275 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 276                 enum bt_logging_level log_level)
 277 {
 278         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 279         query_exec->log_level = log_level;
 280         return BT_FUNC_STATUS_OK;
 281 }
 282
 283 enum bt_logging_level bt_query_executor_get_logging_level(
 284                 const struct bt_query_executor *query_exec)
 285 {
 286         BT_ASSERT_PRE_QUERY_EXEC_NON_NULL(query_exec);
 287         return query_exec->log_level;
 288 }
 289
 290 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 291 {
 292         bt_object_get_ref(query_executor);
 293 }
 294
 295 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 296 {
 297         bt_object_put_ref(query_executor);
 298 }