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.h>
  31 #include <babeltrace2/graph/component-class.h>
  32 #include <babeltrace2/graph/query-executor.h>
  33 #include <babeltrace2/value.h>
  34 #include "lib/object.h"
  35 #include "compat/compiler.h"
  36
  37 #include "component-class.h"
  38 #include "query-executor.h"
  39 #include "interrupter.h"
  40 #include "lib/func-status.h"
  41
  42 static
  43 void bt_query_executor_destroy(struct bt_object *obj)
  44 {
  45         struct bt_query_executor *query_exec =
  46                 container_of(obj, struct bt_query_executor, base);
  47
  48         BT_LOGD("Destroying query executor: addr=%p", query_exec);
  49
  50         if (query_exec->interrupters) {
  51                 BT_LOGD_STR("Putting interrupters.");
  52                 g_ptr_array_free(query_exec->interrupters, TRUE);
  53                 query_exec->interrupters = NULL;
  54         }
  55
  56         BT_LOGD_STR("Putting component class.");
  57         BT_OBJECT_PUT_REF_AND_RESET(query_exec->comp_cls);
  58
  59         if (query_exec->object) {
  60                 g_string_free(query_exec->object, TRUE);
  61                 query_exec->object = NULL;
  62         }
  63
  64         BT_LOGD_STR("Putting parameters.");
  65         BT_OBJECT_PUT_REF_AND_RESET(query_exec->params);
  66         BT_OBJECT_PUT_REF_AND_RESET(query_exec->default_interrupter);
  67         g_free(query_exec);
  68 }
  69
  70 struct bt_query_executor *bt_query_executor_create_with_method_data(
  71                 const bt_component_class *comp_cls, const char *object,
  72                 const bt_value *params, void *method_data)
  73 {
  74         struct bt_query_executor *query_exec;
  75
  76         BT_ASSERT_PRE_NO_ERROR();
  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         BT_ASSERT_PRE_NO_ERROR();
 141         return bt_query_executor_create_with_method_data(comp_cls,
 142                 object, params, NULL);
 143 }
 144
 145 enum bt_query_executor_query_status bt_query_executor_query(
 146                 struct bt_query_executor *query_exec,
 147                 const struct bt_value **user_result)
 148 {
 149         typedef enum bt_component_class_query_method_status (*method_t)(
 150                 void * /* self component class */,
 151                 void * /* private query executor */,
 152                 const char * /* object */,
 153                 const struct bt_value * /* parameters */,
 154                 void * /* method data */,
 155                 const struct bt_value ** /* result */);
 156
 157         enum bt_query_executor_query_status status;
 158         enum bt_component_class_query_method_status query_status;
 159         method_t method = NULL;
 160
 161         BT_ASSERT_PRE_NO_ERROR();
 162         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 163         BT_ASSERT_PRE_NON_NULL(user_result, "Result (output)");
 164
 165         /*
 166          * Initial check: is the query executor already interrupted? If
 167          * so, return `BT_FUNC_STATUS_AGAIN`. Returning this status is
 168          * harmless: it's not `BT_FUNC_STATUS_OK` (there's no result),
 169          * and it's not `BT_FUNC_STATUS_ERROR` either (there's no
 170          * legitimate error). Since any query operation could return
 171          * `BT_FUNC_STATUS_AGAIN` when interrupted or instead of
 172          * blocking, the caller is responsible for checking the
 173          * interruption state of the query executor when getting this
 174          * status.
 175          */
 176         if (bt_query_executor_is_interrupted(query_exec)) {
 177                 BT_LIB_LOGD("Query executor is interrupted: "
 178                         "not performing the query operation: "
 179                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 180                         "%![params-]+v, log-level=%s",
 181                         query_exec, query_exec->comp_cls,
 182                         query_exec->object->str, query_exec->params,
 183                         bt_common_logging_level_string(query_exec->log_level));
 184                 status = BT_FUNC_STATUS_AGAIN;
 185                 goto end;
 186         }
 187
 188         switch (query_exec->comp_cls->type) {
 189         case BT_COMPONENT_CLASS_TYPE_SOURCE:
 190         {
 191                 struct bt_component_class_source *src_cc = (void *)
 192                         query_exec->comp_cls;
 193
 194                 method = (method_t) src_cc->methods.query;
 195                 break;
 196         }
 197         case BT_COMPONENT_CLASS_TYPE_FILTER:
 198         {
 199                 struct bt_component_class_filter *flt_cc = (void *)
 200                         query_exec->comp_cls;
 201
 202                 method = (method_t) flt_cc->methods.query;
 203                 break;
 204         }
 205         case BT_COMPONENT_CLASS_TYPE_SINK:
 206         {
 207                 struct bt_component_class_sink *sink_cc = (void *)
 208                         query_exec->comp_cls;
 209
 210                 method = (method_t) sink_cc->methods.query;
 211                 break;
 212         }
 213         default:
 214                 bt_common_abort();
 215         }
 216
 217         if (!method) {
 218                 /* Not an error: nothing to query */
 219                 BT_LIB_LOGD("Component class has no registered query method: "
 220                         "%!+C", query_exec->comp_cls);
 221                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 222                 goto end;
 223         }
 224
 225         BT_LIB_LOGD("Calling user's query method: "
 226                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 227                 "log-level=%s",
 228                 query_exec, query_exec->comp_cls, query_exec->object->str,
 229                 query_exec->params,
 230                 bt_common_logging_level_string(query_exec->log_level));
 231         *user_result = NULL;
 232         query_status = method((void *) query_exec->comp_cls,
 233                 (void *) query_exec, query_exec->object->str,
 234                 query_exec->params, query_exec->method_data, user_result);
 235         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 236                 bt_common_func_status_string(query_status), *user_result);
 237         BT_ASSERT_POST(query_status != BT_FUNC_STATUS_OK || *user_result,
 238                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 239         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(query_status);
 240         status = (int) query_status;
 241
 242         if (status < 0) {
 243                 BT_LIB_LOGW_APPEND_CAUSE(
 244                         "Component class's \"query\" method failed: "
 245                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 246                         "%![params-]+v, log-level=%s", query_exec,
 247                         query_exec->comp_cls, query_exec->object->str,
 248                         query_exec->params,
 249                         bt_common_logging_level_string(query_exec->log_level));
 250                 goto end;
 251         }
 252
 253 end:
 254         return status;
 255 }
 256
 257 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 258                 struct bt_query_executor *query_exec,
 259                 const struct bt_interrupter *intr)
 260 {
 261         BT_ASSERT_PRE_NO_ERROR();
 262         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 263         BT_ASSERT_PRE_NON_NULL(intr, "Interrupter");
 264         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 265         bt_object_get_ref_no_null_check(intr);
 266         BT_LIB_LOGD("Added interrupter to query executor: "
 267                 "query-exec-addr=%p, %![intr-]+z",
 268                 query_exec, intr);
 269         return BT_FUNC_STATUS_OK;
 270 }
 271
 272 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 273 {
 274         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 275         return (bt_bool) bt_interrupter_array_any_is_set(
 276                 query_exec->interrupters);
 277 }
 278
 279 struct bt_interrupter *bt_query_executor_borrow_default_interrupter(
 280                 struct bt_query_executor *query_exec)
 281 {
 282         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 283         return query_exec->default_interrupter;
 284 }
 285
 286 enum bt_query_executor_set_logging_level_status
 287 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 288                 enum bt_logging_level log_level)
 289 {
 290         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 291         query_exec->log_level = log_level;
 292         return BT_FUNC_STATUS_OK;
 293 }
 294
 295 enum bt_logging_level bt_query_executor_get_logging_level(
 296                 const struct bt_query_executor *query_exec)
 297 {
 298         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 299         return query_exec->log_level;
 300 }
 301
 302 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 303 {
 304         bt_object_get_ref(query_executor);
 305 }
 306
 307 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 308 {
 309         bt_object_put_ref(query_executor);
 310 }