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_NON_NULL(comp_cls, "Component class");
  78         BT_ASSERT_PRE_NON_NULL(object, "Object");
  79         BT_LIB_LOGD("Creating query executor: "
  80                 "%![comp-cls-]+C, object=\"%s\", %![params-]+v",
  81                 comp_cls, object, params);
  82         query_exec = g_new0(struct bt_query_executor, 1);
  83         if (!query_exec) {
  84                 BT_LIB_LOGE_APPEND_CAUSE(
  85                         "Failed to allocate one query executor.");
  86                 goto end;
  87         }
  88
  89         query_exec->interrupters = g_ptr_array_new_with_free_func(
  90                 (GDestroyNotify) bt_object_put_ref_no_null_check);
  91         if (!query_exec->interrupters) {
  92                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GPtrArray.");
  93                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  94                 goto end;
  95         }
  96
  97         query_exec->default_interrupter = bt_interrupter_create();
  98         if (!query_exec->default_interrupter) {
  99                 BT_LIB_LOGE_APPEND_CAUSE(
 100                         "Failed to create one interrupter object.");
 101                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
 102                 goto end;
 103         }
 104
 105         query_exec->object = g_string_new(object);
 106         if (!query_exec->object) {
 107                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GString.");
 108                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
 109                 goto end;
 110         }
 111
 112         query_exec->comp_cls = comp_cls;
 113         bt_object_get_ref_no_null_check(query_exec->comp_cls);
 114
 115         if (!params) {
 116                 query_exec->params = bt_value_null;
 117         } else {
 118                 query_exec->params = params;
 119         }
 120
 121         bt_object_get_ref_no_null_check(query_exec->params);
 122         query_exec->method_data = method_data;
 123         query_exec->log_level = BT_LOGGING_LEVEL_NONE;
 124         bt_query_executor_add_interrupter(query_exec,
 125                 query_exec->default_interrupter);
 126         bt_object_init_shared(&query_exec->base,
 127                 bt_query_executor_destroy);
 128         BT_LIB_LOGD("Created query executor: "
 129                 "addr=%p, %![comp-cls-]+C, object=\"%s\", %![params-]+v",
 130                 query_exec, comp_cls, object, params);
 131
 132 end:
 133         return (void *) query_exec;
 134 }
 135
 136 struct bt_query_executor *bt_query_executor_create(
 137                 const bt_component_class *comp_cls, const char *object,
 138                 const bt_value *params)
 139 {
 140         return bt_query_executor_create_with_method_data(comp_cls,
 141                 object, params, NULL);
 142 }
 143
 144 enum bt_query_executor_query_status bt_query_executor_query(
 145                 struct bt_query_executor *query_exec,
 146                 const struct bt_value **user_result)
 147 {
 148         typedef enum bt_component_class_query_method_status (*method_t)(
 149                 void * /* self component class */,
 150                 void * /* private query executor */,
 151                 const char * /* object */,
 152                 const struct bt_value * /* parameters */,
 153                 void * /* method data */,
 154                 const struct bt_value ** /* result */);
 155
 156         enum bt_query_executor_query_status status;
 157         enum bt_component_class_query_method_status query_status;
 158         method_t method = NULL;
 159
 160         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 161         BT_ASSERT_PRE_NON_NULL(user_result, "Result (output)");
 162
 163         /*
 164          * Initial check: is the query executor already interrupted? If
 165          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 166          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 167          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 168          * legitimate error). Since any query operation could return
 169          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 170          * blocking, the caller is responsible for checking the
 171          * interruption state of the query executor when getting this
 172          * status.
 173          */
 174         if (bt_query_executor_is_interrupted(query_exec)) {
 175                 BT_LIB_LOGD("Query executor is interrupted: "
 176                         "not performing the query operation: "
 177                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 178                         "%![params-]+v, log-level=%s",
 179                         query_exec, query_exec->comp_cls,
 180                         query_exec->object->str, query_exec->params,
 181                         bt_common_logging_level_string(query_exec->log_level));
 182                 status = BT_FUNC_STATUS_AGAIN;
 183                 goto end;
 184         }
 185
 186         switch (query_exec->comp_cls->type) {
 187         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 188         {
 189                 struct bt_component_class_source *src_cc = (void *)
 190                         query_exec->comp_cls;
 191
 192                 method = (method_t) src_cc->methods.query;
 193                 break;
 194         }
 195         case BT_COMPONENT_CLASS_TYPE_FILTER:
 196         {
 197                 struct bt_component_class_filter *flt_cc = (void *)
 198                         query_exec->comp_cls;
 199
 200                 method = (method_t) flt_cc->methods.query;
 201                 break;
 202         }
 203         case BT_COMPONENT_CLASS_TYPE_SINK:
 204         {
 205                 struct bt_component_class_sink *sink_cc = (void *)
 206                         query_exec->comp_cls;
 207
 208                 method = (method_t) sink_cc->methods.query;
 209                 break;
 210         }
 211         default:
 212                 abort();
 213         }
 214
 215         if (!method) {
 216                 /* Not an error: nothing to query */
 217                 BT_LIB_LOGD("Component class has no registered query method: "
 218                         "%!+C", query_exec->comp_cls);
 219                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 220                 goto end;
 221         }
 222
 223         BT_LIB_LOGD("Calling user's query method: "
 224                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 225                 "log-level=%s",
 226                 query_exec, query_exec->comp_cls, query_exec->object->str,
 227                 query_exec->params,
 228                 bt_common_logging_level_string(query_exec->log_level));
 229         *user_result = NULL;
 230         query_status = method((void *) query_exec->comp_cls,
 231                 (void *) query_exec, query_exec->object->str,
 232                 query_exec->params, query_exec->method_data, user_result);
 233         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 234                 bt_common_func_status_string(query_status), *user_result);
 235         BT_ASSERT_POST(query_status != BT_FUNC_STATUS_OK || *user_result,
 236                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 237         status = (int) query_status;
 238
 239         if (status < 0) {
 240                 BT_LIB_LOGW_APPEND_CAUSE(
 241                         "Component class's \"query\" method failed: "
 242                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 243                         "%![params-]+v, log-level=%s", query_exec,
 244                         query_exec->comp_cls, query_exec->object->str,
 245                         query_exec->params,
 246                         bt_common_logging_level_string(query_exec->log_level));
 247                 goto end;
 248         }
 249
 250 end:
 251         return status;
 252 }
 253
 254 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 255                 struct bt_query_executor *query_exec,
 256                 const struct bt_interrupter *intr)
 257 {
 258         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 259         BT_ASSERT_PRE_NON_NULL(intr, "Interrupter");
 260         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 261         bt_object_get_ref_no_null_check(intr);
 262         BT_LIB_LOGD("Added interrupter to query executor: "
 263                 "query-exec-addr=%p, %![intr-]+z",
 264                 query_exec, intr);
 265         return BT_FUNC_STATUS_OK;
 266 }
 267
 268 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 269 {
 270         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 271         return (bt_bool) bt_interrupter_array_any_is_set(
 272                 query_exec->interrupters);
 273 }
 274
 275 void bt_query_executor_interrupt(struct bt_query_executor *query_exec)
 276 {
 277         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 278         bt_interrupter_set(query_exec->default_interrupter);
 279         BT_LIB_LOGI("Interrupted query executor: query-exec-addr=%p",
 280                 query_exec);
 281 }
 282
 283 enum bt_query_executor_set_logging_level_status
 284 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 285                 enum bt_logging_level log_level)
 286 {
 287         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 288         query_exec->log_level = log_level;
 289         return BT_FUNC_STATUS_OK;
 290 }
 291
 292 enum bt_logging_level bt_query_executor_get_logging_level(
 293                 const struct bt_query_executor *query_exec)
 294 {
 295         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 296         return query_exec->log_level;
 297 }
 298
 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 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 305 {
 306         bt_object_put_ref(query_executor);
 307 }