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-pre.h"
  13 #include "lib/assert-post.h"
  14 #include <babeltrace2/graph/query-executor.h>
  15 #include <babeltrace2/graph/component-class.h>
  16 #include <babeltrace2/graph/query-executor.h>
  17 #include <babeltrace2/value.h>
  18 #include "lib/object.h"
  19 #include "compat/compiler.h"
  20
  21 #include "component-class.h"
  22 #include "query-executor.h"
  23 #include "interrupter.h"
  24 #include "lib/func-status.h"
  25
  26 static
  27 void bt_query_executor_destroy(struct bt_object *obj)
  28 {
  29         struct bt_query_executor *query_exec =
  30                 container_of(obj, struct bt_query_executor, base);
  31
  32         BT_LOGD("Destroying query executor: addr=%p", query_exec);
  33
  34         if (query_exec->interrupters) {
  35                 BT_LOGD_STR("Putting interrupters.");
  36                 g_ptr_array_free(query_exec->interrupters, TRUE);
  37                 query_exec->interrupters = NULL;
  38         }
  39
  40         BT_LOGD_STR("Putting component class.");
  41         BT_OBJECT_PUT_REF_AND_RESET(query_exec->comp_cls);
  42
  43         if (query_exec->object) {
  44                 g_string_free(query_exec->object, TRUE);
  45                 query_exec->object = NULL;
  46         }
  47
  48         BT_LOGD_STR("Putting parameters.");
  49         BT_OBJECT_PUT_REF_AND_RESET(query_exec->params);
  50         BT_OBJECT_PUT_REF_AND_RESET(query_exec->default_interrupter);
  51         g_free(query_exec);
  52 }
  53
  54 struct bt_query_executor *bt_query_executor_create_with_method_data(
  55                 const bt_component_class *comp_cls, const char *object,
  56                 const bt_value *params, void *method_data)
  57 {
  58         struct bt_query_executor *query_exec;
  59
  60         BT_ASSERT_PRE_NO_ERROR();
  61         BT_ASSERT_PRE_NON_NULL(comp_cls, "Component class");
  62         BT_ASSERT_PRE_NON_NULL(object, "Object");
  63         BT_LIB_LOGD("Creating query executor: "
  64                 "%![comp-cls-]+C, object=\"%s\", %![params-]+v",
  65                 comp_cls, object, params);
  66         query_exec = g_new0(struct bt_query_executor, 1);
  67         if (!query_exec) {
  68                 BT_LIB_LOGE_APPEND_CAUSE(
  69                         "Failed to allocate one query executor.");
  70                 goto end;
  71         }
  72
  73         query_exec->interrupters = g_ptr_array_new_with_free_func(
  74                 (GDestroyNotify) bt_object_put_ref_no_null_check);
  75         if (!query_exec->interrupters) {
  76                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GPtrArray.");
  77                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  78                 goto end;
  79         }
  80
  81         query_exec->default_interrupter = bt_interrupter_create();
  82         if (!query_exec->default_interrupter) {
  83                 BT_LIB_LOGE_APPEND_CAUSE(
  84                         "Failed to create one interrupter object.");
  85                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  86                 goto end;
  87         }
  88
  89         query_exec->object = g_string_new(object);
  90         if (!query_exec->object) {
  91                 BT_LIB_LOGE_APPEND_CAUSE("Failed to allocate one GString.");
  92                 BT_OBJECT_PUT_REF_AND_RESET(query_exec);
  93                 goto end;
  94         }
  95
  96         query_exec->comp_cls = comp_cls;
  97         bt_object_get_ref_no_null_check(query_exec->comp_cls);
  98
  99         if (!params) {
 100                 query_exec->params = bt_value_null;
 101         } else {
 102                 query_exec->params = params;
 103         }
 104
 105         bt_object_get_ref_no_null_check(query_exec->params);
 106         query_exec->method_data = method_data;
 107         query_exec->log_level = BT_LOGGING_LEVEL_NONE;
 108         bt_query_executor_add_interrupter(query_exec,
 109                 query_exec->default_interrupter);
 110         bt_object_init_shared(&query_exec->base,
 111                 bt_query_executor_destroy);
 112         BT_LIB_LOGD("Created query executor: "
 113                 "addr=%p, %![comp-cls-]+C, object=\"%s\", %![params-]+v",
 114                 query_exec, comp_cls, object, params);
 115
 116 end:
 117         return (void *) query_exec;
 118 }
 119
 120 struct bt_query_executor *bt_query_executor_create(
 121                 const bt_component_class *comp_cls, const char *object,
 122                 const bt_value *params)
 123 {
 124         BT_ASSERT_PRE_NO_ERROR();
 125         return bt_query_executor_create_with_method_data(comp_cls,
 126                 object, params, NULL);
 127 }
 128
 129 enum bt_query_executor_query_status bt_query_executor_query(
 130                 struct bt_query_executor *query_exec,
 131                 const struct bt_value **user_result)
 132 {
 133         typedef enum bt_component_class_query_method_status (*method_t)(
 134                 void * /* self component class */,
 135                 void * /* private query executor */,
 136                 const char * /* object */,
 137                 const struct bt_value * /* parameters */,
 138                 void * /* method data */,
 139                 const struct bt_value ** /* result */);
 140
 141         enum bt_query_executor_query_status status;
 142         enum bt_component_class_query_method_status query_status;
 143         method_t method = NULL;
 144
 145         BT_ASSERT_PRE_NO_ERROR();
 146         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 147         BT_ASSERT_PRE_NON_NULL(user_result, "Result (output)");
 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                 break;
 180         }
 181         case BT_COMPONENT_CLASS_TYPE_FILTER:
 182         {
 183                 struct bt_component_class_filter *flt_cc = (void *)
 184                         query_exec->comp_cls;
 185
 186                 method = (method_t) flt_cc->methods.query;
 187                 break;
 188         }
 189         case BT_COMPONENT_CLASS_TYPE_SINK:
 190         {
 191                 struct bt_component_class_sink *sink_cc = (void *)
 192                         query_exec->comp_cls;
 193
 194                 method = (method_t) sink_cc->methods.query;
 195                 break;
 196         }
 197         default:
 198                 bt_common_abort();
 199         }
 200
 201         if (!method) {
 202                 /* Not an error: nothing to query */
 203                 BT_LIB_LOGD("Component class has no registered query method: "
 204                         "%!+C", query_exec->comp_cls);
 205                 status = BT_FUNC_STATUS_UNKNOWN_OBJECT;
 206                 goto end;
 207         }
 208
 209         BT_LIB_LOGD("Calling user's query method: "
 210                 "query-exec-addr=%p, %![cc-]+C, object=\"%s\", %![params-]+v, "
 211                 "log-level=%s",
 212                 query_exec, query_exec->comp_cls, query_exec->object->str,
 213                 query_exec->params,
 214                 bt_common_logging_level_string(query_exec->log_level));
 215         *user_result = NULL;
 216         query_status = method((void *) query_exec->comp_cls,
 217                 (void *) query_exec, query_exec->object->str,
 218                 query_exec->params, query_exec->method_data, user_result);
 219         BT_LIB_LOGD("User method returned: status=%s, %![res-]+v",
 220                 bt_common_func_status_string(query_status), *user_result);
 221         BT_ASSERT_POST(query_status != BT_FUNC_STATUS_OK || *user_result,
 222                 "User method returned `BT_FUNC_STATUS_OK` without a result.");
 223         BT_ASSERT_POST_NO_ERROR_IF_NO_ERROR_STATUS(query_status);
 224         status = (int) query_status;
 225
 226         if (status < 0) {
 227                 BT_LIB_LOGW_APPEND_CAUSE(
 228                         "Component class's \"query\" method failed: "
 229                         "query-exec-addr=%p, %![cc-]+C, object=\"%s\", "
 230                         "%![params-]+v, log-level=%s", query_exec,
 231                         query_exec->comp_cls, query_exec->object->str,
 232                         query_exec->params,
 233                         bt_common_logging_level_string(query_exec->log_level));
 234                 goto end;
 235         }
 236
 237 end:
 238         return status;
 239 }
 240
 241 enum bt_query_executor_add_interrupter_status bt_query_executor_add_interrupter(
 242                 struct bt_query_executor *query_exec,
 243                 const struct bt_interrupter *intr)
 244 {
 245         BT_ASSERT_PRE_NO_ERROR();
 246         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 247         BT_ASSERT_PRE_NON_NULL(intr, "Interrupter");
 248         g_ptr_array_add(query_exec->interrupters, (void *) intr);
 249         bt_object_get_ref_no_null_check(intr);
 250         BT_LIB_LOGD("Added interrupter to query executor: "
 251                 "query-exec-addr=%p, %![intr-]+z",
 252                 query_exec, intr);
 253         return BT_FUNC_STATUS_OK;
 254 }
 255
 256 bt_bool bt_query_executor_is_interrupted(const struct bt_query_executor *query_exec)
 257 {
 258         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 259         return (bt_bool) bt_interrupter_array_any_is_set(
 260                 query_exec->interrupters);
 261 }
 262
 263 struct bt_interrupter *bt_query_executor_borrow_default_interrupter(
 264                 struct bt_query_executor *query_exec)
 265 {
 266         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 267         return query_exec->default_interrupter;
 268 }
 269
 270 enum bt_query_executor_set_logging_level_status
 271 bt_query_executor_set_logging_level(struct bt_query_executor *query_exec,
 272                 enum bt_logging_level log_level)
 273 {
 274         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 275         query_exec->log_level = log_level;
 276         return BT_FUNC_STATUS_OK;
 277 }
 278
 279 enum bt_logging_level bt_query_executor_get_logging_level(
 280                 const struct bt_query_executor *query_exec)
 281 {
 282         BT_ASSERT_PRE_NON_NULL(query_exec, "Query executor");
 283         return query_exec->log_level;
 284 }
 285
 286 void bt_query_executor_get_ref(const struct bt_query_executor *query_executor)
 287 {
 288         bt_object_get_ref(query_executor);
 289 }
 290
 291 void bt_query_executor_put_ref(const struct bt_query_executor *query_executor)
 292 {
 293         bt_object_put_ref(query_executor);
 294 }