src/lib/graph/query-executor.c

   1 /*
   2  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #define BT_LOG_TAG "LIB/QUERY-EXECUTOR"
  24 #include "lib/logging.h"
  25
  26 #include "common/assert.h"
  27 #include "common/common.h"
  28 #include "lib/assert-pre.h"
  29 #include "lib/assert-post.h"
  30 #include <babeltrace2/graph/query-executor-const.h>
  31 #include <babeltrace2/graph/query-executor.h>
  32 #include <babeltrace2/graph/component-class.h>
  33 #include <babeltrace2/value.h>
  34 #include <babeltrace2/value-const.h>
  35 #include "lib/object.h"
  36 #include "compat/compiler.h"
  37
  38 #include "component-class.h"
  39 #include "query-executor.h"
  40 #include "interrupter.h"
  41 #include "lib/func-status.h"
  42
  43 static
  44 void bt_query_executor_destroy(struct bt_object *obj)
  45 {
  46         struct bt_query_executor *query_exec =
  47                 container_of(obj, struct bt_query_executor, base);
  48
  49         BT_LOGD("Destroying query executor: addr=%p", query_exec);
  50
  51         if (query_exec->interrupters) {
  52                 BT_LOGD_STR("Putting interrupters.");
  53                 g_ptr_array_free(query_exec->interrupters, TRUE);
  54                 query_exec->interrupters = NULL;
  55         }
  56
  57         BT_LOGD_STR("Putting component class.");
  58         BT_OBJECT_PUT_REF_AND_RESET(query_exec->comp_cls);
  59
  60         if (query_exec->object) {
  61                 g_string_free(query_exec->object, TRUE);
  62                 query_exec->object = NULL;
  63         }
  64
  65         BT_LOGD_STR("Putting parameters.");
  66         BT_OBJECT_PUT_REF_AND_RESET(query_exec->params);
  67         BT_OBJECT_PUT_REF_AND_RESET(query_exec->default_interrupter);
  68         g_free(query_exec);
  69 }
  70
  71 struct bt_query_executor *bt_query_executor_create_with_method_data(
  72                 const bt_component_class *comp_cls, const char *object,
  73                 const bt_value *params, void *method_data)
  74 {
  75         struct bt_query_executor *query_exec;
  76
  77         BT_ASSERT_PRE_NO_ERROR();
  78         BT_ASSERT_PRE_NON_NULL(comp_cls, "Component class");
  79         BT_ASSERT_PRE_NON_NULL(object, "Object");
  80         BT_LIB_LOGD("Creating query executor: "
  81                 "%![comp-cls-]+C, object=\"%s\", %![params-]+v",
  82                 comp_cls, object, params);
  83         query_exec = g_new0(struct bt_query_executor, 1);
  84         if (!query_exec) {
  85                 BT_LIB_LOGE_APPEND_CAUSE(
  86                         "Failed to allocate one query executor.");
  87                 goto end;
  88         }
  89
  90         query_exec->interrupters = g_ptr_array_new_with_free_func(
  91                 (GDestroyNotify) bt_object_put_ref_no_null_check);
  92         if (!query_exec->interrupters) {
  93                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GPtrArray.");
  94                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  95                 goto end;
  96         }
  97
  98         query_exec->default_interrupter = bt_interrupter_create();
  99         if (!query_exec->default_interrupter) {
 100                 BT_LIB_LOGE_APPEND_CAUSE(
 101                         "Failed to create one interrupter object.");
 102                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
 103                 goto end;
 104         }
 105
 106         query_exec->object = g_string_new(object);
 107         if (!query_exec->object) {
 108                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GString.");
 109                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
 110                 goto end;
 111         }
 112
 113         query_exec->comp_cls = comp_cls;
 114         bt_object_get_ref_no_null_check(query_exec->comp_cls);
 115
 116         if (!params) {
 117                 query_exec->params = bt_value_null;
 118         } else {
 119                 query_exec->params = params;
 120         }
 121
 122         bt_object_get_ref_no_null_check(query_exec->params);
 123         query_exec->method_data = method_data;
 124         query_exec->log_level = BT_LOGGING_LEVEL_NONE;
 125         bt_query_executor_add_interrupter(query_exec,
 126                 query_exec->default_interrupter);
 127         bt_object_init_shared(&query_exec->base,
 128                 bt_query_executor_destroy);
 129         BT_LIB_LOGD("Created query executor: "
 130                 "addr=%p, %![comp-cls-]+C, object=\"%s\", %![params-]+v",
 131                 query_exec, comp_cls, object, params);
 132
 133 end:
 134         return (void *) query_exec;
 135 }
 136
 137 struct bt_query_executor *bt_query_executor_create(
 138                 const bt_component_class *comp_cls, const char *object,
 139                 const bt_value *params)
 140 {
 141         BT_ASSERT_PRE_NO_ERROR();
 142         return bt_query_executor_create_with_method_data(comp_cls,
 143                 object, params, NULL);
 144 }
 145
 146 enum bt_query_executor_query_status bt_query_executor_query(
 147                 struct bt_query_executor *query_exec,
 148                 const struct bt_value **user_result)
 149 {
 150         typedef enum bt_component_class_query_method_status (*method_t)(
 151                 void * /* self component class */,
 152                 void * /* private query executor */,
 153                 const char * /* object */,
 154                 const struct bt_value * /* parameters */,
 155                 void * /* method data */,
 156                 const struct bt_value ** /* result */);
 157
 158         enum bt_query_executor_query_status status;
 159         enum bt_component_class_query_method_status query_status;
 160         method_t method = NULL;
 161
 162         BT_ASSERT_PRE_NO_ERROR();
 163         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 164         BT_ASSERT_PRE_NON_NULL(user_result, "Result (output)");
 165
 166         /*
 167          * Initial check: is the query executor already interrupted? If
 168          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 169          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 170          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 171          * legitimate error). Since any query operation could return
 172          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 173          * blocking, the caller is responsible for checking the
 174          * interruption state of the query executor when getting this
 175          * status.
 176          */
 177         if (bt_query_executor_is_interrupted(query_exec)) {
 178                 BT_LIB_LOGD("Query executor is interrupted: "
 179                         "not performing the query operation: "
 180                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 181                         "%![params-]+v, log-level=%s",
 182                         query_exec, query_exec->comp_cls,
 183                         query_exec->object->str, query_exec->params,
 184                         bt_common_logging_level_string(query_exec->log_level));
 185                 status = BT_FUNC_STATUS_AGAIN;
 186                 goto end;
 187         }
 188
 189         switch (query_exec->comp_cls->type) {
 190         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 191         {
 192                 struct bt_component_class_source *src_cc = (void *)
 193                         query_exec->comp_cls;
 194
 195                 method = (method_t) src_cc->methods.query;
 196                 break;
 197         }
 198         case BT_COMPONENT_CLASS_TYPE_FILTER:
 199         {
 200                 struct bt_component_class_filter *flt_cc = (void *)
 201                         query_exec->comp_cls;
 202
 203                 method = (method_t) flt_cc->methods.query;
 204                 break;
 205         }
 206         case BT_COMPONENT_CLASS_TYPE_SINK:
 207         {
 208                 struct bt_component_class_sink *sink_cc = (void *)
 209                         query_exec->comp_cls;
 210
 211                 method = (method_t) sink_cc->methods.query;
 212                 break;
 213         }
 214         default:
 215                 bt_common_abort();
 216         }
 217
 218         if (!method) {
 219                 /* Not an error: nothing to query */
 220                 BT_LIB_LOGD("Component class has no registered query method: "
 221                         "%!+C", query_exec->comp_cls);
 222                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 223                 goto end;
 224         }
 225
 226         BT_LIB_LOGD("Calling user's query method: "
 227                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 228                 "log-level=%s",
 229                 query_exec, query_exec->comp_cls, query_exec->object->str,
 230                 query_exec->params,
 231                 bt_common_logging_level_string(query_exec->log_level));
 232         *user_result = NULL;
 233         query_status = method((void *) query_exec->comp_cls,
 234                 (void *) query_exec, query_exec->object->str,
 235                 query_exec->params, query_exec->method_data, user_result);
 236         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 237                 bt_common_func_status_string(query_status), *user_result);
 238         BT_ASSERT_POST(query_status != BT_FUNC_STATUS_OK || *user_result,
 239                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 240         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(query_status);
 241         status = (int) query_status;
 242
 243         if (status < 0) {
 244                 BT_LIB_LOGW_APPEND_CAUSE(
 245                         "Component class's \"query\" method failed: "
 246                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 247                         "%![params-]+v, log-level=%s", query_exec,
 248                         query_exec->comp_cls, query_exec->object->str,
 249                         query_exec->params,
 250                         bt_common_logging_level_string(query_exec->log_level));
 251                 goto end;
 252         }
 253
 254 end:
 255         return status;
 256 }
 257
 258 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 259                 struct bt_query_executor *query_exec,
 260                 const struct bt_interrupter *intr)
 261 {
 262         BT_ASSERT_PRE_NO_ERROR();
 263         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 264         BT_ASSERT_PRE_NON_NULL(intr, "Interrupter");
 265         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 266         bt_object_get_ref_no_null_check(intr);
 267         BT_LIB_LOGD("Added interrupter to query executor: "
 268                 "query-exec-addr=%p, %![intr-]+z",
 269                 query_exec, intr);
 270         return BT_FUNC_STATUS_OK;
 271 }
 272
 273 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 274 {
 275         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 276         return (bt_bool) bt_interrupter_array_any_is_set(
 277                 query_exec->interrupters);
 278 }
 279
 280 void bt_query_executor_interrupt(struct bt_query_executor *query_exec)
 281 {
 282         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 283         bt_interrupter_set(query_exec->default_interrupter);
 284         BT_LIB_LOGI("Interrupted query executor: query-exec-addr=%p",
 285                 query_exec);
 286 }
 287
 288 enum bt_query_executor_set_logging_level_status
 289 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 290                 enum bt_logging_level log_level)
 291 {
 292         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 293         query_exec->log_level = log_level;
 294         return BT_FUNC_STATUS_OK;
 295 }
 296
 297 enum bt_logging_level bt_query_executor_get_logging_level(
 298                 const struct bt_query_executor *query_exec)
 299 {
 300         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 301         return query_exec->log_level;
 302 }
 303
 304 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 305 {
 306         bt_object_get_ref(query_executor);
 307 }
 308
 309 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 310 {
 311         bt_object_put_ref(query_executor);
 312 }