replaced idb with sqlite

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "dependencies/tlibtoml"]
 	path = dependencies/tlibtoml
 	url = https://timerix.ddns.net/git/Timerix/tlibtoml.git
+[submodule "dependencies/tsqlite"]
+	path = dependencies/tsqlite
+	url = https://timerix.ddns.net/git/Timerix/tsqlite.git

dependencies/tsqlite.config

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+# This is a dependency config.
+# You can copy it to another project to add tsqlite dependency.
+
+DEP_WORKING_DIR="$DEPENDENCIES_DIR/tsqlite"
+
+user_config_path="project.config.user"
+absolute_dep_dir=$(realpath "$DEPENDENCIES_DIR")
+
+function setup_user_config(){
+    # Set variable `DEPENDENCIES_DIR`` in `tsqlite/project.config.user`
+    # to the directory where `tlibc`` is installed
+    file_copy_default_if_not_present "$user_config_path" "$user_config_path.default"
+    replace_var_value_in_script "$user_config_path" "DEPENDENCIES_DIR" "$absolute_dep_dir"
+}
+
+if [[ "$TASK" = *_dbg ]]; then
+    dep_build_target="build_static_lib_dbg"
+else
+    dep_build_target="build_static_lib"
+fi
+DEP_PRE_BUILD_COMMAND="setup_user_config"
+DEP_BUILD_COMMAND="cbuild $dep_build_target"
+DEP_POST_BUILD_COMMAND=""
+DEP_CLEAN_COMMAND="cbuild clean"
+DEP_DYNAMIC_OUT_FILES=""
+DEP_STATIC_OUT_FILES="bin/tsqlite.a"
+DEP_OTHER_OUT_FILES=""
+PRESERVE_OUT_DIRECTORY_STRUCTURE=false

project.config

@@ -24,7 +24,7 @@ SRC_CPP="$(find src -name '*.cpp')"
 # See cbuild/example_dependency_configs
 DEPENDENCY_CONFIGS_DIR='dependencies'
 # List of dependency config files in DEPENDENCY_CONFIGS_DIR separated by space.
-ENABLED_DEPENDENCIES='bearssl tlibc tlibtoml'
+ENABLED_DEPENDENCIES='bearssl tlibc tlibtoml tsqlite'
 
 # OBJDIR structure:
 #  ├── objects/      - Compiled object files. Cleans on each call of build task
@@ -46,13 +46,13 @@ case "$OS" in
         EXEC_FILE="$PROJECT.exe"
         SHARED_LIB_FILE="$PROJECT.dll"
         INCLUDE="$INCLUDE "
-        LINKER_LIBS="-static -lpthread -lws2_32"
+        LINKER_LIBS="-static -lpthread -lws2_32 -lsqlite3"
         ;;
     LINUX)
         EXEC_FILE="$PROJECT"
         SHARED_LIB_FILE="$PROJECT.so"
         INCLUDE="$INCLUDE "
-        LINKER_LIBS=""
+        LINKER_LIBS="-lsqlite3"
         ;;
     *)
         error "operating system $OS has no configuration variants"

src/db/idb.c

@@ -1,521 +0,0 @@
-#include "idb.h"
-#include "tlibc/magic.h"
-#include "tlibc/filesystem.h"
-#include "tlibc/collections/HashMap.h"
-#include "tlibc/string/StringBuilder.h"
-#include "cryptography/AES.h"
-#include <pthread.h>
-
-static const char KEY_CHALLENGE_PLAIN[16] = "key is correct!";
-#define KEY_CHALLENGE_PLAIN_SIZE sizeof(KEY_CHALLENGE_PLAIN)
-#define KEY_CHALLENGE_CIPHER_SIZE AESBlockEncryptor_calcDstSize(KEY_CHALLENGE_PLAIN_SIZE)
-
-typedef struct TableFileHeader {
-    Magic32 magic;
-    u16 version;
-    bool _dirty_bit;
-    bool encrypted;
-    u32 row_size;
-    /* encrypted KEY_CHALLENGE_PLAIN */
-    u8 key_challenge[KEY_CHALLENGE_CIPHER_SIZE];
-} ATTRIBUTE_ALIGNED(256) TableFileHeader;
-
-typedef struct Table {
-    TableFileHeader header;
-    IncrementalDB* db;
-    str name;
-    str table_file_path;
-    str changes_file_path;
-    FILE* table_file;
-    FILE* changes_file;
-    pthread_mutex_t mutex;
-    u64 row_count;
-    AESBlockEncryptor enc;
-    AESBlockDecryptor dec;
-    Array(u8) enc_buf;
-} Table;
-
-typedef struct IncrementalDB {
-    str db_dir;
-    Array(u8) aes_key;
-    HashMap(Table**) tables_map;
-    pthread_mutex_t mutex;
-} IncrementalDB;
-
-static const Magic32 TABLE_FILE_MAGIC = { .bytes = { 'I', 'D', 'B', 't' } };
-
-
-static void Table_close(Table* t){
-    if(t == NULL)
-        return;
-    fclose(t->table_file);
-    fclose(t->changes_file);
-    str_destroy(t->name);
-    str_destroy(t->table_file_path);
-    str_destroy(t->changes_file_path);
-    pthread_mutex_destroy(&t->mutex);
-    Array_u8_destroy(&t->enc_buf);
-    free(t);
-}
-
-// element destructor for HashMap(Table*)
-static void TablePtr_free(void* t_ptr_ptr){
-    Table_close(*(Table**)t_ptr_ptr);
-}
-
-/// @param name must be null-terminated
-static Result(void) validateTableName(str name){
-    char forbidden_characters[] = { '/', '\\', ':', ';', '?', '"', '\'', '\n', '\r', '\t'};
-    for(u32 i = 0; i < ARRAY_LEN(forbidden_characters); i++) {
-        char c = forbidden_characters[i];
-        if(str_seekChar(name, c, 0) != -1){
-            return RESULT_ERROR_FMT(
-                "Table name '%s' contains forbidden character '%c'",
-                name.data, c);
-        }
-    }
-    
-    return RESULT_VOID;
-}
-
-static Result(void) Table_readHeader(Table* t){
-    Deferral(4);
-    // seek for start of the file
-    try_void(file_seek(t->table_file, 0, SeekOrigin_Start));
-    // read header
-    try_void(file_readStructsExactly(t->table_file, &t->header, sizeof(t->header), 1));
-    Return RESULT_VOID;
-}
-
-static Result(void) Table_writeHeader(Table* t){
-    Deferral(4);
-    // seek for start of the file
-    try_void(file_seek(t->table_file, 0, SeekOrigin_Start));
-    // write header
-    try_void(file_writeStructs(t->table_file, &t->header, sizeof(t->header), 1));
-    // TODO: add more fflush calls 
-    fflush(t->table_file);
-    fflush(t->changes_file);
-    Return RESULT_VOID;
-}
-
-static Result(void) Table_setDirtyBit(Table* t, bool val){
-    Deferral(4);
-    t->header._dirty_bit = val;
-    try_void(Table_writeHeader(t));
-    Return RESULT_VOID;
-}
-
-static Result(bool) Table_getDirtyBit(Table* t){
-    Deferral(4);
-    try_void(Table_readHeader(t));
-    Return RESULT_VALUE(i, t->header._dirty_bit);
-}
-
-static Result(void) Table_calculateRowCount(Table* t){
-    Deferral(4);
-    try(i64 file_size, i, file_getSize(t->table_file));
-    i64 data_size = file_size - sizeof(t->header);
-    i64 row_size_in_file = t->header.encrypted 
-        ? AESBlockEncryptor_calcDstSize(t->header.row_size)
-        : t->header.row_size;
-    if(data_size % row_size_in_file != 0){
-        //TODO: fix table instead of trowing error
-        Return RESULT_ERROR_FMT(
-            "Table '%s' has invalid size. Last row is incomplete.", 
-            t->name.data);
-    }
-
-    t->row_count = data_size / row_size_in_file;
-    Return RESULT_VOID;
-}
-
-static Result(void) Table_validateHeader(Table* t){
-    Deferral(4);
-    if(t->header.magic.n != TABLE_FILE_MAGIC.n
-            || t->header.row_size == 0)
-    {
-        Return RESULT_ERROR_FMT(
-            "Table file '%s' has invalid header", 
-            t->table_file_path.data);
-    }
-    
-    if(t->header.version != IDB_VERSION){
-        Return RESULT_ERROR_FMT(
-            "Table file '%s' was created for IDBv%u, which is incompatible with v%u", 
-            t->table_file_path.data, t->header.version, (u32)IDB_VERSION);
-    }
-    
-    try(bool dirty_bit, i, Table_getDirtyBit(t));
-    if(dirty_bit){
-        //TODO: handle dirty bit instead of throwing error
-        Return RESULT_ERROR_FMT(
-            "Table file '%s' has dirty bit set", 
-            t->table_file_path.data);
-    }
-
-    Return RESULT_VOID;
-}
-
-static Result(void) Table_validateEncryption(Table* t){
-    Deferral(1);
-
-    bool db_encrypted = t->db->aes_key.len != 0;
-    if(t->header.encrypted && !db_encrypted){
-        Return RESULT_ERROR_FMT(
-            "Table '%s' is encrypted, but encryption key is not set."
-            "Database '%s' is encrypted and must have not-null encryption key.",
-            t->name.data, t->db->db_dir.data);
-    }
-    
-    if(!t->header.encrypted && db_encrypted){
-        Return RESULT_ERROR_FMT(
-            "Table '%s' is not encrypted, but encryption key is set."
-            "Do not set encryption key for not encrypted database '%s'.",
-            t->name.data, t->db->db_dir.data);
-    }
-
-    // validate aes encryption key
-    if(t->header.encrypted){
-        try_void(
-            AESBlockDecryptor_decrypt(
-                &t->dec, 
-                Array_u8_construct(t->header.key_challenge, KEY_CHALLENGE_CIPHER_SIZE), 
-                t->enc_buf
-            )
-        );
-        if(memcmp(t->enc_buf.data, KEY_CHALLENGE_PLAIN, KEY_CHALLENGE_PLAIN_SIZE) != 0){
-            Return RESULT_ERROR_FMT(
-                "Encryption key for table '%s' is wrong", 
-                t->name.data);
-        }
-    }
-
-    Return RESULT_VOID;
-}
-
-static Result(void) Table_validateRowSize(Table* t, u32 row_size){
-    if(row_size != t->header.row_size){
-        return RESULT_ERROR_FMT(
-            "Requested row size (%u) doesn't match saved row size (%u)",
-            row_size, t->header.row_size);
-    }
-
-    return RESULT_VOID;
-}
-
-
-void idb_close(IncrementalDB* db){
-    if(db == NULL)
-        return;
-    str_destroy(db->db_dir);
-    Array_u8_destroy(&db->aes_key);
-    HashMap_destroy(&db->tables_map);
-    pthread_mutex_destroy(&db->mutex);
-    free(db);
-}
-
-Result(IncrementalDB*) idb_open(str db_dir, NULLABLE(Array(u8) aes_key)){
-    Deferral(16);
-    try_assert(db_dir.len > 0);
-    try_assert(aes_key.len == 0 || aes_key.len == 16 || aes_key.len == 24 || aes_key.len == 32);
-
-    IncrementalDB* db = (IncrementalDB*)malloc(sizeof(IncrementalDB));
-    // value of *db must be set to zero or behavior of idb_close will be undefined
-    zeroStruct(db);
-    // if object construction fails, destroy incomplete object
-    bool success = false;
-    Defer(if(!success) idb_close(db));
-    
-    if(aes_key.len != 0){
-        db->aes_key = Array_u8_copy(aes_key);
-    }
-    
-    db->db_dir = str_copy(db_dir);
-    try_void(dir_create(db->db_dir.data));
-    HashMap_construct(&db->tables_map, Table*, TablePtr_free);
-    try_stderrcode(pthread_mutex_init(&db->mutex, NULL));
-
-    success = true;
-    Return RESULT_VALUE(p, db);
-}
-
-void idb_lockDB(IncrementalDB* db){
-    try_fatal_stderrcode(pthread_mutex_lock(&db->mutex));
-}
-
-void idb_unlockDB(IncrementalDB* db){
-    try_fatal_stderrcode(pthread_mutex_unlock(&db->mutex));
-}
-
-void idb_lockTable(Table* t){
-    try_fatal_stderrcode(pthread_mutex_lock(&t->mutex));
-}
-
-void idb_unlockTable(Table* t){
-    try_fatal_stderrcode(pthread_mutex_unlock(&t->mutex));
-}
-
-
-Result(Table*) idb_getOrCreateTable(IncrementalDB* db, str subdir, str table_name, u32 row_size, bool lock_db){
-    Deferral(16);
-
-    if(lock_db){
-        idb_lockDB(db);
-        Defer(idb_unlockDB(db));
-    }
-
-    Table** tpp = HashMap_tryGetPtr(&db->tables_map, table_name);
-    if(tpp != NULL){
-        Table* existing_table = *tpp;
-        try_void(Table_validateRowSize(existing_table, row_size));
-        Return RESULT_VALUE(p, existing_table);
-    }
-
-    try_void(validateTableName(table_name));
-
-    Table* t = (Table*)malloc(sizeof(Table));
-    // value of *t must be set to zero or behavior of Table_close will be undefined
-    zeroStruct(t);
-    // if object construction fails, destroy incomplete object
-    bool success = false;
-    Defer(if(!success) Table_close(t));
-
-    t->db = db;
-    try_stderrcode(pthread_mutex_init(&t->mutex, NULL));
-    t->name = str_copy(table_name);
-
-    // set file paths
-    StringBuilder sb = StringBuilder_alloc(256);
-    Defer(StringBuilder_destroy(&sb));
-    StringBuilder_append_str(&sb, db->db_dir);
-    StringBuilder_append_char(&sb, path_sep);
-    if(subdir.len != 0){
-        StringBuilder_append_str(&sb, subdir);
-        try_void(dir_create(StringBuilder_getStr(&sb).data));
-        StringBuilder_append_char(&sb, path_sep);
-    }
-    StringBuilder_append_str(&sb, t->name);
-    // table file
-    str table_file_ext = STR(".idb-table");
-    StringBuilder_append_str(&sb, table_file_ext);
-    t->table_file_path = str_copy(StringBuilder_getStr(&sb));
-    // changes file
-    str changes_file_ext = STR(".idb-changes");
-    StringBuilder_removeFromEnd(&sb, table_file_ext.len);
-    StringBuilder_append_str(&sb, changes_file_ext);
-    t->changes_file_path = str_copy(StringBuilder_getStr(&sb));
-
-    bool table_file_exists = file_exists(t->table_file_path.data);
-
-    // open or create file with table data
-    try(t->table_file, p, file_openOrCreateReadWrite(t->table_file_path.data));
-    // open or create file with backups of updated rows
-    try(t->changes_file, p, file_openOrCreateReadWrite(t->changes_file_path.data));
-
-    // init encryptor and decryptor now to use them in table header validation/creation
-    if(db->aes_key.len != 0) {
-        AESBlockEncryptor_construct(&t->enc, db->aes_key, AESBlockEncryptor_DEFAULT_CLASS);
-        AESBlockDecryptor_construct(&t->dec, db->aes_key, AESBlockDecryptor_DEFAULT_CLASS);
-        u32 row_size_in_file = AESBlockEncryptor_calcDstSize(row_size);
-        t->enc_buf = Array_u8_alloc(row_size_in_file);
-    }
-
-    // init header
-    if(table_file_exists){
-        // read table file
-        try_void(Table_readHeader(t));
-        try_void(Table_validateHeader(t));
-        try_void(Table_validateEncryption(t));
-        try_void(Table_validateRowSize(t, row_size));
-        try_void(Table_calculateRowCount(t));
-    }
-    else {
-        // create table file
-        t->header.magic.n = TABLE_FILE_MAGIC.n;
-        t->header.version = IDB_VERSION;
-        t->header.encrypted = db->aes_key.len != 0;
-        t->header._dirty_bit = false;
-        t->header.row_size = row_size;
-        memset(t->header.key_challenge, 0, KEY_CHALLENGE_CIPHER_SIZE);
-        try_void(
-            AESBlockEncryptor_encrypt(
-                &t->enc,
-                Array_u8_construct((void*)KEY_CHALLENGE_PLAIN, KEY_CHALLENGE_PLAIN_SIZE),
-                Array_u8_construct(t->header.key_challenge, KEY_CHALLENGE_CIPHER_SIZE)
-            )
-        );
-        try_void(Table_writeHeader(t));
-    }
-
-    if(!HashMap_tryPush(&db->tables_map, t->name, &t)){
-        Return RESULT_ERROR_FMT(
-            "Table '%s' is already open", 
-            t->name.data);
-    }
-
-    success = true;
-    Return RESULT_VALUE(p, t);
-}
-
-Result(void) idb_getRows(Table* t, u64 id, void* dst, u64 count, bool lock_table){
-    Deferral(8);
-
-    if(lock_table){
-        idb_lockTable(t);
-        Defer(idb_unlockTable(t));
-    }
-
-    if(id + count > t->row_count){
-        Return RESULT_ERROR_FMT(
-            "Can't read "FMT_u64" rows at index "FMT_u64
-            " because table '%s' has only "FMT_u64" rows",
-            count, id, t->name.data, t->row_count);
-    }
-
-    u32 row_size = t->header.row_size;
-    u32 row_size_in_file = t->header.encrypted ? t->enc_buf.len : row_size;
-    i64 file_pos = sizeof(t->header) + id * row_size_in_file;
-
-    // seek for the row position in file
-    try_void(file_seek(t->table_file, file_pos, SeekOrigin_Start));
-    
-    // read rows from file
-    for(u64 i = 0; i < count; i++){
-        void* row_ptr = (u8*)dst + row_size * i;
-        void* read_dst = t->header.encrypted 
-            ? t->enc_buf.data 
-            : row_ptr;
-        try_void(file_readStructsExactly(t->table_file, read_dst, row_size_in_file, 1));
-        if(t->header.encrypted) {
-            try_void(
-                AESBlockDecryptor_decrypt(
-                    &t->dec,
-                    t->enc_buf,
-                    Array_u8_construct(row_ptr, row_size)
-                )
-            );
-        }
-    }
-
-    Return RESULT_VOID;
-}
-
-Result(void) idb_updateRows(Table* t, u64 id, const void* src, u64 count, bool lock_table){
-    Deferral(8);
-
-    if(lock_table){
-        idb_lockTable(t);
-        Defer(idb_unlockTable(t));
-    }
-
-    if(id + count > t->row_count){
-        Return RESULT_ERROR_FMT(
-            "Can't update "FMT_u64" rows at index "FMT_u64
-            " because table '%s' has only "FMT_u64" rows",
-            count, id, t->name.data, t->row_count);
-    }
-
-    try_void(Table_setDirtyBit(t, true));
-    Defer(IGNORE_RESULT Table_setDirtyBit(t, false));
-
-    u32 row_size = t->header.row_size;
-    u32 row_size_in_file = t->header.encrypted ? t->enc_buf.len : row_size;
-    i64 file_pos = sizeof(t->header) + id * row_size_in_file;
-
-    // TODO: set dirty bit in backup file too
-    // TODO: save old values to the backup file 
-    
-    // seek for the row position in file
-    try_void(file_seek(t->table_file, file_pos, SeekOrigin_Start));
-
-    // replace rows in file
-    for(u64 i = 0; i < count; i++){
-        void* row_ptr = (u8*)src + row_size * i;
-        if(t->header.encrypted){
-            try_void(
-                AESBlockEncryptor_encrypt(
-                    &t->enc, 
-                    Array_u8_construct(row_ptr, row_size), 
-                    t->enc_buf
-                )
-            );
-            row_ptr = t->enc_buf.data;
-        }
-        try_void(file_writeStructs(t->table_file, row_ptr, row_size_in_file, 1));
-    }
-    
-    Return RESULT_VOID;
-}
-
-Result(u64) idb_pushRows(Table* t, const void* src, u64 count, bool lock_table){
-    Deferral(8);
-    
-    if(lock_table){
-        idb_lockTable(t);
-        Defer(idb_unlockTable(t));
-    }
-
-    try_void(Table_setDirtyBit(t, true));
-    Defer(IGNORE_RESULT Table_setDirtyBit(t, false));
-
-    u32 row_size = t->header.row_size;
-    u32 row_size_in_file = t->header.encrypted ? t->enc_buf.len : row_size;
-    const u64 new_row_index = t->row_count;
-
-    // seek for end of the file
-    try_void(file_seek(t->table_file, 0, SeekOrigin_End));
-
-    // write new rows to the file
-    for(u64 i = 0; i < count; i++){
-        void* row_ptr = (u8*)src + row_size * i;
-        if(t->header.encrypted){
-            try_void(
-                AESBlockEncryptor_encrypt(
-                    &t->enc, 
-                    Array_u8_construct(row_ptr, row_size), 
-                    t->enc_buf
-                )
-            );
-            row_ptr = t->enc_buf.data;
-        }
-        try_void(file_writeStructs(t->table_file, row_ptr, row_size_in_file, 1));
-        t->row_count++;
-    }
-
-    Return RESULT_VALUE(u, new_row_index);
-}
-
-Result(u64) idb_getRowCount(Table* t, bool lock_table){
-    Deferral(4);
-    
-    if(lock_table){
-        idb_lockTable(t);
-        Defer(idb_unlockTable(t));
-    }
-
-    u64 count = t->row_count;
-    Return RESULT_VALUE(u, count);
-}
-
-Result(void) idb_createListFromTable(Table* t, List_* l, bool lock_table){
-    Deferral(1);
-
-    if(lock_table){
-        idb_lockTable(t);
-        Defer(idb_unlockTable(t));
-    }
-
-    u64 row_count = t->row_count;
-    u64 row_size = t->header.row_size;
-    u64 total_size = row_count * row_size;
-    *l = _List_alloc(total_size, row_size);
-    l->len = row_count;
-    bool success = false;
-    Defer(if(!success) _List_destroy(l));
-
-    try_void(idb_getRows(t, 0, l->data, row_count, false));
-
-    success = true;
-    Return RESULT_VOID;
-}

src/db/idb.h

@@ -1,47 +0,0 @@
-#pragma once
-
-#include "tlibc/errors.h"
-#include "tlibc/collections/List.h"
-
-#define IDB_VERSION 2
-#define IDB_AES_KEY_SIZE 32
-
-typedef struct IncrementalDB IncrementalDB;
-typedef struct Table Table;
-
-
-Result(IncrementalDB*) idb_open(str db_dir, NULLABLE(Array(u8) aes_key));
-void idb_close(IncrementalDB* db);
-
-/// before performing atransaction on DB lock it manually or call functions with parameter lock_db=true
-void idb_lockDB(IncrementalDB* db);
-
-/// USAGE:
-/// idb_lockDB(db);
-/// Defer(idb_unlockDB(db));
-void idb_unlockDB(IncrementalDB* db);
-
-/// before performing a transaction on Table lock it manually or call function with parameter lock_db=true
-void idb_lockTable(Table* t);
-
-/// USAGE:
-/// idb_lockTable(t);
-/// Defer(idb_unlockTable(t));
-void idb_unlockTable(Table* t);
-
-
-Result(Table*) idb_getOrCreateTable(IncrementalDB* db, NULLABLE(str) subdir, str table_name, u32 row_size, bool lock_db);
-
-Result(void) idb_getRows(Table* t, u64 start_from_id, void* dst, u64 count, bool lock_table);
-#define idb_getRow(T, ID, DST, LOCK) idb_getRows(T, ID, DST, 1, LOCK)
-
-Result(u64) idb_pushRows(Table* t, const void* src, u64 count, bool lock_table);
-#define idb_pushRow(T, SRC, LOCK) idb_pushRows(T, SRC, 1, LOCK)
-
-Result(void) idb_updateRows(Table* t, u64 start_from_id, const void* src, u64 count, bool lock_table);
-#define idb_updateRow(T, ID, SRC, LOCK) idb_updateRows(T, ID, SRC, 1, LOCK)
-
-Result(u64) idb_getRowCount(Table* t, bool lock_table);
-
-/// construct new list and load whole table into it
-Result(void) idb_createListFromTable(Table* t, List_* l, bool lock_table);

src/db/tables.h

@@ -1,63 +0,0 @@
-#pragma once
-#include "tcp-chat/common_constants.h"
-#include "tlibc/time.h"
-#include "tlibc/magic.h"
-
-// TODO: add table versions
-
-typedef struct UserInfo {
-    u16 name_len;
-    char name[USERNAME_SIZE_MAX + 1];  // null-terminated
-    u8 token[PASSWORD_HASH_SIZE]; // token is hashed again on server side
-    DateTime registration_time_utc;
-} ATTRIBUTE_ALIGNED(256) UserInfo;
-
-
-typedef struct ServerInfo {
-    u16 address_len;
-    char address[HOSTADDR_SIZE_MAX + 1];
-    u32 pk_base64_len;
-    char pk_base64[PUBLIC_KEY_BASE64_SIZE_MAX + 1];
-    u16 name_len;
-    char name[SERVER_NAME_SIZE_MAX + 1];
-    u16 desc_len;
-    char desc[SERVER_DESC_SIZE_MAX + 1];
-} ATTRIBUTE_ALIGNED(16*1024) ServerInfo;
-
-
-typedef struct ChannelInfo {
-    u16 name_len;
-    char name[CHANNEL_NAME_SIZE_MAX + 1];
-    u16 desc_len;
-    char desc[CHANNEL_DESC_SIZE_MAX + 1];
-} ATTRIBUTE_ALIGNED(4*1024) ChannelInfo;
-
-
-// not a table
-typedef struct MessageMeta {
-    /* 
-    In block messages can be stored with some padding (zero bytes) between them.
-    To distinguish message from padding, each message starts with MESSAGE_MAGIC.
-    */
-    Magic32 magic;
-    u16 data_size;
-    u64 id;
-    u64 sender_id;
-    DateTime receiving_time_utc;
-} ATTRIBUTE_ALIGNED(64) MessageMeta;
-
-#define MESSAGE_MAGIC ((Magic32){ .bytes = { 'M', 's', 'g', 'S' } })
-
-// Stores some number of messages. Look in MessageBlockMeta to see how much.
-typedef struct MessageBlock {
-    /* ((sequence MessageMeta), (sequence binary-data)) */
-    u8 data[MESSAGE_BLOCK_SIZE];
-} ATTRIBUTE_ALIGNED(64) MessageBlock;
-
-// is used to find in which MessageBlock a message is stored
-typedef struct MessageBlockMeta {
-    u64 first_message_id;
-    u32 messages_count;
-    u32 data_size;
-} ATTRIBUTE_ALIGNED(16) MessageBlockMeta;
-