Added statistics reading and a command-line tool to monitor them

Makefile

@@ -60,6 +60,7 @@ $(TARGET): $(OBJECTS) $(TJS_OBJECTS) build
 	@mkdir -p $(@D)
 	$(CXX) $(CXXFLAGS) $(INCLUDE) $(LDFLAGS) -o $(APP_DIR)/$(TARGETNAME) src/$(TARGET) $(OBJECTS) $(TJS_OBJECTS)
 	$(CXX) $(CXXFLAGS) $(INCLUDE) $(LDFLAGS) -o $(APP_DIR)/test_client src/test_client.cpp 
+	$(CXX) $(CXXFLAGS) $(INCLUDE) $(LDFLAGS) -o $(APP_DIR)/db_stats src/db_stats.cpp 
 
 .PHONY: all build clean
 

include/network.hpp

@@ -7,7 +7,8 @@ enum class db_op : uint32_t {
 	version = 0,
 	read = 1,
 	write = 2,
-	remove = 3
+	remove = 3,
+	stats = 4
 };
 
 struct [[gnu::packed]] received_data {
@@ -21,4 +22,13 @@ struct [[gnu::packed]] sending_data {
 	bitops::regulated<uint64_t> rep_id = 0;
 	record_identifier identifier = record_identifier{};
 	db_page page = {0};
+};
+
+struct [[gnu::packed]] stats_data {
+	bitops::regulated<uint64_t> free;
+	bitops::regulated<uint64_t> free_deleted;
+	bitops::regulated<uint64_t> total_pages;
+	bitops::regulated<uint64_t> total_records;
+	bitops::regulated<uint64_t> total_delete;
+	bitops::regulated<uint64_t> cow_full;
 };

src/db_stats.cpp

@@ -0,0 +1,70 @@
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <variant>
+#include <chrono>
+#include <algorithm>
+#include "database.hpp"
+#include "network.hpp"
+#include <memory>
+#include <cstdlib> 
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <string.h>
+#include <stdio.h>
+#include "commander.hpp"
+
+
+int main(int argc, char** argv)
+{
+	try{
+		while(argc == 3)
+		{
+			std::stringstream ip_stream{argv[1]};
+			std::array<uint8_t, 4> ip;
+			std::string token;
+			std::getline(ip_stream, token, '.');
+			ip[0] = std::stoi(token);
+			std::getline(ip_stream, token, '.');
+			ip[1] = std::stoi(token);
+			std::getline(ip_stream, token, '.');
+			ip[2] = std::stoi(token);
+			std::getline(ip_stream, token, '.');
+			ip[3] = std::stoi(token);
+
+			uint16_t port = std::stoi(argv[2]);
+
+
+			auto soc = socket(AF_INET, SOCK_DGRAM, 0);
+			struct sockaddr_in server;
+			server.sin_family = AF_INET;
+			server.sin_addr.s_addr = *(in_addr_t*)ip.data();
+			server.sin_port = htons(port);
+
+			connect(soc, (struct sockaddr*)&server, sizeof(server));
+
+			
+			sending_data reply;
+			received_data request;
+
+			request.op = db_op::stats;
+
+			send(soc, (void*)&request, (socklen_t)sizeof(request), 0);
+			recv(soc, (void*)&reply, (socklen_t)sizeof(reply), 0);
+
+			auto stats = (stats_data*)&reply.page;
+
+			std::cout << "free_pages\t" << stats->free << std::endl;
+			std::cout << "deleted_pages\t" << stats->free_deleted << std::endl;
+			std::cout << "total_pages\t" << stats->total_pages << std::endl;
+			std::cout << "total_records\t" << stats->total_records << std::endl;
+			std::cout << "delete_cache\t" << stats->total_delete << std::endl;
+			std::cout << "inaccessible\t" << stats->cow_full << std::endl;
+
+			return 0;
+		}
+	}catch(...) {}
+	std::cerr << "Invalid command, expects ``db_stats IPV4 PORT''" << std::endl;
+	return 1;
+}

src/izaro-storage.cpp

@@ -65,6 +65,20 @@ int main(
 
 	}
 
+	size_t db_port = 20450;
+
+	if(cmd_args.isFlagSet("-port"))
+	{
+		try{
+			db_port = std::stoi(cmd_args.getFlagValue("-port"));
+			if(db_port>std::numeric_limits<uint16_t>::max()) throw std::runtime_error("invalid_port");
+		} catch (...) {
+			std::cerr << "Invalid port value" << std::endl;
+			return 1;
+		}
+
+	}
+
 #ifdef UNITTEST
 	{
 		database db(database::create(utest_str, utest_size*2));
@@ -163,7 +177,7 @@ int main(
 		auto soc = socket(AF_INET, SOCK_DGRAM, 0);
 		struct sockaddr_in addr;
 		addr.sin_family = AF_INET;
-		addr.sin_port = htons(mi">20450);
+		addr.sin_port = htons(n">db_port);
 		memset((void*)&addr.sin_addr, 0, sizeof(addr.sin_addr));
 		bind(soc,(struct sockaddr*)&addr,sizeof(addr));
 
@@ -227,6 +241,29 @@ int main(
 						reply_size = sizeof(reply.rep_id) + sizeof(reply.identifier); 
 					}
 				break;
+				case db_op::stats:
+					{
+						reply.rep_id = recv.rep_id;
+						auto stats = (stats_data*)&reply.page;
+						stats->total_pages = (*run_db.metadata).page_cnt;
+						stats->total_records = (*run_db.metadata).record_cnt;
+						stats->free_deleted = (*run_db.metadata).last_delete;
+						stats->free = 
+							(*run_db.metadata).last_delete 
+							+ (*run_db.metadata).page_cnt 
+							- (*run_db.metadata).last_page;
+						uint64_t cow_full = 0;
+						for(auto& elem : run_db.records)
+						{
+							if(elem.second.timestamp == std::numeric_limits<uint64_t>::max())
+							{
+								++cow_full;
+							}
+						}
+						stats->cow_full = cow_full;
+						reply_size = sizeof(reply);
+					}
+				break;
 				default:
 					std::cerr << "bad_request " << (uint32_t)static_cast<db_op>(recv.op)  << std::endl;
 					continue;

src/test_client.cpp

@@ -2,9 +2,14 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <random>
 
 int main(int, char** argv) {
 	{
+		std::random_device hrng{};
+
+		std::minstd_rand srng{hrng()};
+
 		auto soc = socket(AF_INET, SOCK_DGRAM, 0);
 		struct sockaddr_in server;
 		server.sin_family = AF_INET;
@@ -32,7 +37,7 @@ int main(int, char** argv) {
 
 		for(size_t idx=0;idx<tot;idx++)
 		{
-			tar.y.internal = idx;
+			tar.y.internal = srng();
 			request.op = db_op::write;
 			sendto(
 				soc,