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