Introduce a ScyllaDB driver for userver

CMakeLists.txt

@@ -291,6 +291,13 @@ if(USERVER_FEATURE_GRPC)
     list(APPEND USERVER_AVAILABLE_COMPONENTS grpc)
 endif()
 
+if(USERVER_FEATURE_SCYLLADB)
+    _require_userver_core("USERVER_FEATURE_SCYLLADB")
+    add_subdirectory(scylla)
+    list(APPEND USERVER_AVAILABLE_COMPONENTS scylla)
+endif()
+
+
 if(USERVER_FEATURE_OTLP)
     if(NOT USERVER_FEATURE_GRPC)
         message(FATAL_ERROR "'USERVER_FEATURE_OTLP' requires 'USERVER_FEATURE_GRPC=ON'")

cmake/SetupScyllaDeps.cmake

@@ -0,0 +1,16 @@
+include_guard(GLOBAL)
+
+find_library(SCYLLA_CPP_DRIVER_LIB scylla-cpp-driver)
+find_path(SCYLLA_CPP_DRIVER_INCLUDE cassandra.h)
+
+if(NOT SCYLLA_CPP_DRIVER_LIB OR NOT SCYLLA_CPP_DRIVER_INCLUDE)
+    message(FATAL_ERROR "ScyllaDB cpp-driver not found")
+endif()
+
+message(STATUS "ScyllaDB cpp-driver: ${SCYLLA_CPP_DRIVER_LIB}")
+
+add_library(scylla_cpp_driver SHARED IMPORTED)
+set_target_properties(scylla_cpp_driver PROPERTIES
+    IMPORTED_LOCATION "${SCYLLA_CPP_DRIVER_LIB}"
+    INTERFACE_INCLUDE_DIRECTORIES "${SCYLLA_CPP_DRIVER_INCLUDE}"
+)

cmake/install/userver-scylla-config.cmake

@@ -0,0 +1,11 @@
+include_guard(GLOBAL)
+
+if(userver_scylla_FOUND)
+    return()
+endif()
+
+find_package(userver REQUIRED COMPONENTS core)
+
+include("${USERVER_CMAKE_DIR}/SetupScyllaDeps.cmake")
+
+set(userver_scylla_FOUND TRUE)

mongo/src/storages/mongo/stats.cpp

@@ -187,9 +187,7 @@ void OperationStopwatch::Account(ErrorType error_type) noexcept {
         UASSERT(ms >= 0);
         stats_item->timings.GetCurrentCounter().Account(ms);
         stats_item->timings_sum += utils::statistics::Rate{static_cast<utils::statistics::Rate::ValueType>(ms)};
-    } catch (const std::exception&) {
-        // ignore
-    }
+    } catch (const std::exception&) {}
 }
 
 ConnectionWaitStopwatch::ConnectionWaitStopwatch(std::shared_ptr<PoolConnectStatistics> stats_ptr)
@@ -201,9 +199,7 @@ ConnectionWaitStopwatch::~ConnectionWaitStopwatch() {
     try {
         ++stats_ptr_->requested;
         stats_ptr_->request_timings_agg.GetCurrentCounter().Account(GetMilliseconds(scope_time_.Reset()));
-    } catch (const std::exception&) {
-        // ignore
-    }
+    } catch (const std::exception&) {}
 }
 
 ConnectionThrottleStopwatch::ConnectionThrottleStopwatch(std::shared_ptr<PoolConnectStatistics> stats_ptr)
@@ -225,9 +221,7 @@ void ConnectionThrottleStopwatch::Stop() noexcept {
 
     try {
         stats_ptr->queue_wait_timings_agg.GetCurrentCounter().Account(GetMilliseconds(scope_time_.Reset()));
-    } catch (const std::exception&) {
-        // ignore
-    }
+    } catch (const std::exception&) {}
 }
 
 }  // namespace storages::mongo::stats

samples/scylla_service/CMakeLists.txt

@@ -0,0 +1,10 @@
+cmake_minimum_required(VERSION 3.14)
+project(userver-samples-scylla_service CXX)
+
+find_package(userver COMPONENTS scylla REQUIRED)
+userver_setup_environment()
+
+add_executable(${PROJECT_NAME} src/main.cpp src/helpers.cpp)
+target_link_libraries(${PROJECT_NAME} userver::scylla)
+
+userver_testsuite_add_simple()

samples/scylla_service/README.md

@@ -0,0 +1,157 @@
+# scylla_service demo
+
+Enter the ScyllaDB container and open cqlsh
+
+```shell
+docker exec -it scylla cqlsh
+```
+
+Create the keyspace and table
+
+```sql
+CREATE KEYSPACE IF NOT EXISTS examples
+    WITH REPLICATION = { 'class' : 'SimpleStrategy', 'replication_factor' : 1 };
+
+CREATE TABLE IF NOT EXISTS examples.basic (
+    key text PRIMARY KEY,
+    bln boolean,
+    flt float,
+    dbl double,
+    i32 int,
+    i64 bigint
+);
+```
+
+
+---
+
+```shell
+docker exec -it scylla-dev-1 bash
+```
+
+## Operations
+
+
+### InsertOne
+
+```bash
+curl -sS -X POST "http://localhost:8080/v1/kv" \
+    -H 'Content-Type: application/json' \
+    -d '{"key":"alpha","bln":true,"i32":1,"i64":42,"flt":1.5,"dbl":2.5}'
+```
+
+### 2. SelectOne
+
+```bash
+curl -sS "http://localhost:8080/v1/kv?key=alpha"
+
+# should return 404
+curl -sS -w '\n%{http_code}\n' "http://localhost:8080/v1/kv?key=does-not-exist"
+```
+
+### 3. UpdateOne
+
+```bash
+curl -sS -X PATCH "http://localhost:8080/v1/kv?key=alpha" \
+    -H 'Content-Type: application/json' \
+    -d '{"bln":false,"i32":99}'
+
+curl -sS "http://localhost:8080/v1/kv?key=alpha"
+```
+
+### 4. DeleteOne
+
+```bash
+curl -sS -X DELETE "http://localhost:8080/v1/kv?key=alpha"
+```
+
+### 5. InsertMany
+
+```bash
+curl -sS -X POST "http://localhost:8080/v1/kv/bulk" \
+    -H 'Content-Type: application/json' \
+    -d '[
+          {"key":"bulk-1","i32":1,"bln":true},
+          {"key":"bulk-2","i32":2,"bln":true},
+          {"key":"bulk-3","i32":3,"bln":false}
+        ]'
+```
+
+### 6. SelectMany
+
+```bash
+curl -sS "http://localhost:8080/v1/kv/list"
+
+curl -sS "http://localhost:8080/v1/kv/list?limit=2"
+```
+
+### 7. Count
+
+```bash
+curl -sS "http://localhost:8080/v1/kv/count"
+
+curl -sS "http://localhost:8080/v1/kv/count?key=bulk-1"
+```
+
+### 8. Truncate
+
+```bash
+curl -sS -X POST "http://localhost:8080/v1/kv/truncate"
+
+curl -sS "http://localhost:8080/v1/kv/count"
+```
+
+### 9. InsertOne IF NOT EXISTS (LWT)
+
+```bash
+curl -sS -X POST "http://localhost:8080/v1/kv/create_if_absent" \
+    -H 'Content-Type: application/json' \
+    -d '{"key":"lwt-1","i32":100}'
+
+curl -sS -w '\n%{http_code}\n' -X POST "http://localhost:8080/v1/kv/create_if_absent" \
+    -H 'Content-Type: application/json' \
+    -d '{"key":"lwt-1","i32":999}'
+```
+
+### 10. UpdateOne IF col = ? (Compare-And-Set)
+
+```bash
+curl -sS -X POST "http://localhost:8080/v1/kv/cas?key=lwt-1" \
+    -H 'Content-Type: application/json' \
+    -d '{"expect":{"i32":100},"set":{"i32":101}}'
+
+curl -sS -w '\n%{http_code}\n' -X POST "http://localhost:8080/v1/kv/cas?key=lwt-1" \
+    -H 'Content-Type: application/json' \
+    -d '{"expect":{"i32":100},"set":{"i32":200}}'
+```
+
+### 11. DeleteOne IF EXISTS
+
+```bash
+curl -sS -X DELETE "http://localhost:8080/v1/kv/delete_if_exists?key=lwt-1"
+
+curl -sS -w '\n%{http_code}\n' -X DELETE "http://localhost:8080/v1/kv/delete_if_exists?key=lwt-1"
+```
+
+
+---
+
+Current `static_config.yaml`
+
+```yaml
+scylla-db:
+    dbconnection: scylla
+    consistency: local_quorum
+    serial_consistency: local_serial
+    request_timeout: 10s
+    pool_size: 16
+    app_name: scylla_sample
+    shard_awareness: true
+    retry_policy: default
+    load_balancing_policy: round_robin
+    speculative_execution:
+        enabled: false
+        max_attempts: 2
+        delay: 100ms
+    default_keyspace: examples
+```

samples/scylla_service/secdist.json

@@ -0,0 +1,7 @@
+{
+    "scylla_settings": {
+        "scylla_example": {
+            "hosts": "scylla"
+        }
+    }
+}