feat(logging): add DIRECT I/O to file

perf(logging): reduce system calls for file
feat(utils): add generate_date_string and number_pad methods
feat(utils): add open_file method
feat(server): add error checking when initializing logs
feat(commands): better getting connected at data for CLIENT INFO command

Makefile

@@ -1,7 +1,7 @@
 CC := gcc
 LIBRARIES := -lm -lpthread $(shell pkg-config --cflags --libs openssl) -lcrypt
 CFLAGS := -O3 -Wall -Wextra \
--D_GNU_SOURCE \
+-D_GNU_SOURCE -D_LARGEFILE64_SOURCE \
 -DGIT_HASH=\"$(shell git rev-parse HEAD)\" -DVERSION=\"$(shell git describe --abbrev=0 --tags)\"
 
 compile:

README.md

@@ -14,7 +14,8 @@ A key-value database project for educational purposes.
 > Look at:  
 > [docs/SPECS.md](./docs/SPECS.md) for more technical information,  
 > [docs/FILE.md](./docs/FILE.md) for information about provided files by tellydb,  
-> [docs/COMMANDS.md](./docs/COMMANDS.md) for information about commands
+> [docs/COMMANDS.md](./docs/COMMANDS.md) for information about commands,  
+> [docs/AUTH.md](./docs/AUTH.md) for information about authorization
 
 ## Quick Start
 * Install a client that allows to connect tellydb or redis server

headers/config.h

@@ -8,7 +8,6 @@ struct Configuration {
   uint16_t port;
   uint16_t max_clients;
   uint8_t allowed_log_levels;
-  uint32_t max_log_len;
   int32_t max_log_lines;
   char data_file[49];
   char log_file[49];

headers/utils.h

@@ -5,6 +5,7 @@
 #include <string.h> // IWYU pragma: keep
 #include <stdint.h>
 #include <stdbool.h>
+#include <time.h>
 
 #define streq(s1, s2) (strcmp((s1), (s2)) == 0)
 
@@ -30,14 +31,18 @@ enum LogLevel {
   LOG_ERR  = 0b100,
 };
 
-void initialize_logs(struct Configuration *config);
+bool initialize_logs(struct Configuration *config);
 void write_log(enum LogLevel level, const char *fmt, ...);
-void close_logs();
+void save_and_close_logs();
 
 bool is_integer(const char *value);
 uint32_t get_digit_count(int64_t number);
+void number_pad(char *res, const uint32_t value);
 
 void read_string_from_file(const int fd, string_t *string, const bool unallocated, const bool terminator);
 void generate_random_string(char *dest, size_t length);
+void generate_date_string(char *text, const time_t value);
+
+int open_file(const char *file, int flags);
 
 uint64_t hash(char *key);

src/commands/generic/client.c

@@ -58,16 +58,20 @@ static void run(struct Client *client, commanddata_t *command, __attribute__((un
         }
 
         char buf[512];
+
+        char connected_at[21];
+        generate_date_string(connected_at, client->connected_at);
+
         const size_t buf_len = sprintf(buf, (
           "ID: %d\r\n"
           "Socket file descriptor: %d\r\n"
-          "Connected at: %.24s\r\n"
+          "Connected at: %.20s\r\n"
           "Last used command: %s\r\n"
           "Library name: %s\r\n"
           "Library version: %s\r\n"
           "Protocol: %s\r\n"
           "Permissions: %s\r\n"
-        ), client->id, client->connfd, ctime(&client->connected_at), client->command->name, lib_name, lib_ver, protocol, permissions);
+        ), client->id, client->connfd, connected_at, client->command->name, lib_name, lib_ver, protocol, permissions);
 
         char res[1024];
         const size_t nbytes = sprintf(res, "$%ld\r\n%s\r\n", buf_len, buf);

src/server/server.c

@@ -97,7 +97,7 @@ static void close_server() {
   write_log(LOG_INFO, "Free'd all memory blocks and closed the server.");
 
   write_log(LOG_INFO, "Closing log file, free'ing configuration and exiting the process...");
-  close_logs();
+  save_and_close_logs();
   free_configuration(conf);
 
   unlink(".tellylock");
@@ -110,16 +110,22 @@ static void sigint_signal(__attribute__((unused)) int arg) {
 }
 
 void start_server(struct Configuration *config) {
+  conf = config;
   struct stat lock;
 
   if (stat(".tellylock", &lock) != -1) {
-    fputs("tellydb is already opened in this directory.\n", stderr);
+    write_log(LOG_ERR, "tellydb is already opened in this directory.");
+    free_configuration(config);
     exit(EXIT_FAILURE);
   } else creat(".tellylock", 0);
 
-  conf = config;
-  initialize_logs(conf);
-  write_log(LOG_INFO, "Initialized logs and configuration.");
+  if (!initialize_logs(conf)) {
+    write_log(LOG_ERR, "Cannot initialized logs.");
+    write_log(LOG_INFO, "Initialized configuration.");
+  } else {
+    write_log(LOG_INFO, "Initialized logs and configuration.");
+  }
+
   write_log(LOG_INFO, "version=" VERSION ", commit hash=" GIT_HASH);
 
   if (conf->default_conf) {
@@ -242,7 +248,7 @@ void start_server(struct Configuration *config) {
       write_log(LOG_INFO, "Read authorization part of database file. Loaded password count: %d", get_password_count());
 
       get_all_keys(authorization_end_at);
-      write_log(LOG_INFO, "Read all database file to created keyspace. Loaded key count: %d", cache->size);
+      write_log(LOG_INFO, "Read all database file to create keyspace. Loaded key count: %d", cache->size);
     } else {
       write_log(LOG_INFO, "Database file is empty. Loaded key and password count: 0");
     }

src/utils/config.c

@@ -10,7 +10,6 @@ static struct Configuration default_conf = {
   .port = 6379,
   .max_clients = 128,
   .allowed_log_levels = LOG_INFO | LOG_ERR | LOG_WARN,
-  .max_log_len = 8192,
   .max_log_lines = 128,
   .data_file = ".tellydb",
   .log_file = ".tellylog",
@@ -81,10 +80,6 @@ struct Configuration parse_configuration(FILE *file) {
                 break;
             }
           }
-        } else if (streq(buf, "MAX_LOG_LEN")) {
-          buf[0] = '\0';
-          parse_value(file, buf);
-          conf.max_log_len = atoi(buf);
         } else if (streq(buf, "MAX_LOG_LINES")) {
           buf[0] = '\0';
           parse_value(file, buf);
@@ -160,21 +155,20 @@ size_t get_configuration_string(char *buf, struct Configuration conf) {
     "# e = error\n\n"
     "# Order of keys does not matter\n"
     "ALLOWED_LOG_LEVELS=%s\n\n"
-    "# Specifies maximum writeable log length to STDOUT\n"
-    "MAX_LOG_LEN=%u\n\n"
     "# Specifies maximum line count of logs will be saved to log file, to make undetermined, change it to -1\n"
+    "# MAX_LOG_LINES * (FILE BLOCK SIZE [512, 4096 or a power of 2] + 1) bytes will be allocated, so be careful\n"
     "MAX_LOG_LINES=%d\n\n"
     "# Specifies database file where data will be saved\n"
     "DATA_FILE=%s\n\n"
-    "# Specifies log file where logs will be appended\n"
+    "# Specifies log file where logs will be saved\n"
     "LOG_FILE=%s\n\n"
     "# Enables/disables creating TLS server\n"
     "# If it is enabled, CERT specifies certificate file path of TLS server and PRIVATE_KEY specifies private key file path of TLS server\n"
     "# TLS value must be true or false\n"
     "TLS=%s\n"
     "CERT=%s\n"
     "PRIVATE_KEY=%s\n"
-  ), conf.port, conf.max_clients, allowed_log_levels, conf.max_log_len, conf.max_log_lines, conf.data_file, conf.log_file,
+  ), conf.port, conf.max_clients, allowed_log_levels, conf.max_log_lines, conf.data_file, conf.log_file,
      conf.tls ? "true" : "false", conf.cert, conf.private_key
   );
 }

src/utils/file.c

@@ -0,0 +1,37 @@
+#include "../../headers/utils.h"
+
+#include <errno.h>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+int open_file(const char *file, int flags) {
+  int fd;
+
+  if ((fd = open(file, (O_RDWR | O_CREAT | O_DIRECT | flags), (S_IRUSR | S_IWUSR))) == -1) {
+    switch (errno) {
+      case EINVAL:
+        write_log(LOG_ERR, "Direct I/O does not be supported by your file system, cannot open file.");
+        break;
+
+      case EISDIR:
+        write_log(LOG_ERR, "Specified file is a directory, cannot open file.");
+        break;
+
+      case ENOMEM:
+        write_log(LOG_ERR, "No available memory to create/open file.");
+        break;
+
+      case EROFS:
+        write_log(LOG_ERR, "Your file system is read-only, cannot open file for writing.");
+        break;
+
+      default:
+        write_log(LOG_ERR, "File cannot be opened or created.");
+    }
+
+    return -1;
+  }
+
+  return fd;
+}

src/utils/integer.c

@@ -1,5 +1,6 @@
 #include "../../headers/utils.h"
 
+#include <stdio.h>
 #include <stdbool.h>
 #include <ctype.h>
 #include <stdint.h>
@@ -30,3 +31,11 @@ uint32_t get_digit_count(int64_t number) {
     return 1 + log10(number);
   }
 }
+
+void number_pad(char *res, const uint32_t value) {
+  if (value < 10) {
+    sprintf(res, "0%u", value);
+  } else if (value < 100) {
+    sprintf(res, "%u", value);
+  }
+}