feat: Implement GC for Column Families.

Includes a full coverage test suite.

Author: marete

.bazelignore

@@ -5,3 +5,4 @@ cmake-build-debug/
 cmake-build-coverage/
 cmake-build-release/
 .build/
+build/

.gitignore

@@ -42,3 +42,4 @@ CMakeUserPresets.json
 
 # Lock files created by bzlmod. We do not want to accidentally commit these.
 MODULE.bazel.lock
+Testing/

CMakeLists.txt

@@ -81,6 +81,8 @@ FetchContent_Declare(
 
 FetchContent_MakeAvailable(google-cloud-cpp)
 
+find_package(Protobuf REQUIRED)
+
 add_library(
     bigtable_emulator_common # cmake-format: sort
     cell_view.h
@@ -110,7 +112,8 @@ target_link_libraries(
     google-cloud-cpp::bigtable
     google-cloud-cpp::bigtable_protos
     google-cloud-cpp::common
-    google-cloud-cpp::grpc_utils)
+    google-cloud-cpp::grpc_utils
+    ${PROTOBUF_LIBRARIES})
 
 google_cloud_cpp_add_common_options(bigtable_emulator_common)
 
@@ -128,6 +131,7 @@ if (BUILD_TESTING)
         drop_row_range_test.cc
         filter_test.cc
         filtered_map_test.cc
+        gc_test.cc
         mutations_test.cc
         range_set_test.cc
         server_test.cc

bigtable_emulator_unit_tests.bzl

@@ -22,6 +22,7 @@ bigtable_emulator_unit_tests = [
     "drop_row_range_test.cc",
     "filter_test.cc",
     "filtered_map_test.cc",
+    "gc_test.cc",
     "mutations_test.cc",
     "range_set_test.cc",
     "server_test.cc",

bigtable_limits.h

@@ -21,6 +21,7 @@ namespace cloud {
 namespace bigtable {
 namespace emulator {
 constexpr std::size_t kMaxRowLen = 2 << 11;
+constexpr std::size_t kMaxGCRuleSize = 500;
 }  // namespace emulator
 }  // namespace bigtable
 }  // namespace cloud

cluster.cc

@@ -13,11 +13,11 @@
 // limitations under the License.
 
 #include "cluster.h"
-#include "table.h"
 #include "google/cloud/internal/make_status.h"
 #include "google/cloud/status.h"
 #include "google/cloud/status_or.h"
 #include "absl/strings/match.h"
+#include "table.h"
 #include <google/bigtable/admin/v2/table.pb.h>
 #include <iostream>
 #include <map>

cluster.h

@@ -15,9 +15,9 @@
 #ifndef GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_BIGTABLE_EMULATOR_CLUSTER_H
 #define GOOGLE_CLOUD_CPP_GOOGLE_CLOUD_BIGTABLE_EMULATOR_CLUSTER_H
 
-#include "table.h"
 #include "google/cloud/status.h"
 #include "google/cloud/status_or.h"
+#include "table.h"
 #include <google/bigtable/admin/v2/table.pb.h>
 #include <map>
 #include <memory>