bench: add support for custom data directory

Expands the benchmark framework with the existing '-testdatadir' arg,
enabling the ability to change the benchmark data directory.

This is useful for running benchmarks on different storage devices, and
not just under the OS /tmp/ directory.

Author: furszy

src/bench/bench.cpp

@@ -27,7 +27,16 @@ using util::Join;
 
 const std::function<void(const std::string&)> G_TEST_LOG_FUN{};
 
-const std::function<std::vector<const char*>()> G_TEST_COMMAND_LINE_ARGUMENTS{};
+/**
+ * Retrieves the available test setup command line arguments that may be used
+ * in the benchmark. They will be used only if the benchmark utilizes a
+ * 'BasicTestingSetup' or any child of it.
+ */
+static std::function<std::vector<const char*>()> g_bench_command_line_args{};
+
+const std::function<std::vector<const char*>()> G_TEST_COMMAND_LINE_ARGUMENTS = []() {
+    return g_bench_command_line_args();
+};
 
 /**
  * Retrieve the name of the currently in-use benchmark.
@@ -103,6 +112,13 @@ void BenchRunner::RunAll(const Args& args)
         std::cout << "Running with -sanity-check option, output is being suppressed as benchmark results will be useless." << std::endl;
     }
 
+    // Load inner test setup args
+    g_bench_command_line_args = [&args]() {
+        std::vector<const char*> ret;
+        for (const auto& arg : args.setup_args) ret.emplace_back(arg.c_str());
+        return ret;
+    };
+
     std::vector<ankerl::nanobench::Result> benchmarkResults;
     for (const auto& [name, bench_func] : benchmarks()) {
         const auto& [func, priority_level] = bench_func;

src/bench/bench.h

@@ -61,6 +61,7 @@ struct Args {
     fs::path output_json;
     std::string regex_filter;
     uint8_t priority;
+    std::vector<std::string> setup_args;
 };
 
 class BenchRunner

src/bench/bench_bitcoin.cpp

@@ -37,6 +37,7 @@ static void SetupBenchArgs(ArgsManager& argsman)
     argsman.AddArg("-sanity-check", "Run benchmarks for only one iteration with no output", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
     argsman.AddArg("-priority-level=<l1,l2,l3>", strprintf("Run benchmarks of one or multiple priority level(s) (%s), default: '%s'",
                                                            benchmark::ListPriorities(), DEFAULT_PRIORITY), ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
+    argsman.AddArg("-testdatadir", "Run benchmarks on a custom directory (default: </tmp/>)", ArgsManager::ALLOW_ANY, OptionsCategory::DEBUG_TEST);
 }
 
 // parses a comma separated list like "10,20,30,50"
@@ -60,6 +61,17 @@ static uint8_t parsePriorityLevel(const std::string& str) {
     return levels;
 }
 
+// Parses test setup related arguments
+static std::vector<std::string> parseTestSetupArgs(const ArgsManager& argsman) {
+    std::vector<std::string> args;
+
+    // Test data directory
+    fs::path test_datadir = argsman.GetPathArg("-testdatadir");
+    if (!test_datadir.empty()) args.emplace_back(strprintf("-testdatadir=%s", PathToString(test_datadir)));
+
+    return args;
+}
+
 int main(int argc, char** argv)
 {
     ArgsManager argsman;
@@ -131,6 +143,7 @@ int main(int argc, char** argv)
         args.regex_filter = argsman.GetArg("-filter", DEFAULT_BENCH_FILTER);
         args.sanity_check = argsman.GetBoolArg("-sanity-check", false);
         args.priority = parsePriorityLevel(argsman.GetArg("-priority-level", DEFAULT_PRIORITY));
+        args.setup_args = parseTestSetupArgs(argsman);
 
         benchmark::BenchRunner::RunAll(args);