Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/softmotions/iowow

A C utility library and persistent key/value storage engine
https://github.com/softmotions/iowow

android-database c c11 database database-engine ejdb embedded-c freebsd key-value key-value-database key-value-store kv-store kvstore nosql osx persistent-data-structure persistent-storage skip-list skiplist

Last synced: 2 days ago
JSON representation

A C utility library and persistent key/value storage engine

Awesome Lists containing this project

README 

        
IOWOW — `C11` utility library and persistent key/value storage engine

==================================================================================================================



**NOTE: Issues tracker is disabled. You are welcome to contribute, pull requests accepted.**



[![license](https://img.shields.io/github/license/Softmotions/ejdb.svg)](https://github.com/Softmotions/iowow/blob/master/LICENSE)

![Maintained](https://img.shields.io/maintenance/yes/2024.svg)



Website https://iowow.softmotions.com



# Key components



* [utils](https://github.com/Softmotions/iowow/tree/master/src/utils) Useful data structures and various commonly used routines.

* [json](https://github.com/Softmotions/iowow/tree/master/src/json) JSON parsing and manipulation routines incluing JSON Patch/Pointers support.

* [iwkv.h](https://github.com/Softmotions/iowow/blob/master/src/kv/iwkv.h) Persistent key/value database engine.

* [iwfsmfile.h](https://github.com/Softmotions/iowow/blob/master/src/fs/iwfsmfile.h) File blocks allocation manager like `malloc()` on files.



## Used by



* EJDB2 — Embeddable JSON database engine. http://ejdb.org

* [Wirow video conferencing platform](https://github.com/wirow-io/wirow-server/)

* [Pure C Asynchronous HTTP/IO library with websockets, SSL, routing. ](https://github.com/Softmotions/iwnet)



## IWKV Features



* Support of multiple key-value databases within a single file

* Online database backups

* Native support of integer keys

* [Write Ahead Logging (WAL) support](http://iowow.io/wal)

* Ultra-fast traversal of database records

* Compound keys support

* Good performance comparing its main competitors: `lmdb`, `leveldb`, `kyoto cabinet`

* Tiny C11 library (200Kb) can be easily embedded into any software



[![IWKV Presentation](https://iowow.softmotions.com/articles/iowow-presentation-cover-small.png)](https://iowow.softmotions.com/articles/intro/)



## IWKV Limitations



* Maximum iwkv storage file size: `512 GB (0x7fffffff80)`

* Total size of a single key+value record must be not greater than `255Mb (0xfffffff)`



# Supported platforms



## Linux



#### Building debian packages



```sh

mkdir build && cd build

cmake .. -DCMAKE_BUILD_TYPE=Release -DPACKAGE_DEB=ON

make package

```



### RPM based Linux distributions

```sh

mkdir build && cd build

cmake .. -DCMAKE_BUILD_TYPE=Release -DPACKAGE_RPM=ON

make package

```



## FreeBSD



Successfully tested on FreeBSD 10/11



## OSX



Successfully tested on OSX 10.12/10.13



## Windows



[Cross-compilation for windows](http://iowow.io/iw/win)



## MIPS based systems (+big-endian)



Successfully tested on Debian 9.4, MIPS 32, gcc 6.x compiler.



# Examples



[src/kv/examples](https://github.com/Softmotions/iowow/tree/master/src/kv/examples)



## Store and retrieve records



```c

#include 

#include 

#include 



int main() {

  IWKV_OPTS opts = {

    .path = "example1.db",

    .oflags = IWKV_TRUNC // Cleanup database before open

  };

  IWKV iwkv;

  IWDB mydb;

  iwrc rc = iwkv_open(&opts, &iwkv);

  if (rc) {

    iwlog_ecode_error3(rc);

    return 1;

  }

  // Now open mydb

  // - Database id: 1

  rc = iwkv_db(iwkv, 1, 0, &mydb);

  if (rc) {

    iwlog_ecode_error2(rc, "Failed to open mydb");

    return 1;

  }

  // Work with db: put/get value

  IWKV_val key, val;

  key.data = "foo";

  key.size = strlen(key.data);

  val.data = "bar";

  val.size = strlen(val.data);



  fprintf(stdout, "put: %.*s => %.*s\n",

          (int) key.size, (char *) key.data,

          (int) val.size, (char *) val.data);



  rc = iwkv_put(mydb, &key, &val, 0);

  if (rc) {

    iwlog_ecode_error3(rc);

    return rc;

  }

  // Retrieve value associated with `foo` key

  val.data = 0;

  val.size = 0;

  rc = iwkv_get(mydb, &key, &val);

  if (rc) {

    iwlog_ecode_error3(rc);

    return rc;

  }



  fprintf(stdout, "get: %.*s => %.*s\n",

          (int) key.size, (char *) key.data,

          (int) val.size, (char *) val.data);



  iwkv_val_dispose(&val);

  iwkv_close(&iwkv);

  return 0;

}

```

**Compile and run:**



```sh

gcc -std=gnu11 -Wall -pedantic -c -o example1.o example1.c

gcc -o example1 example1.o -liowow



./example1

  put: foo => bar

  get: foo => bar

```



## Cursor iteration example



```c

///

/// Fills database with a set of football table records

/// then traverse records according to club name in ascending and descending orders.

///



#include "iwkv.h"

#include 

#include 

#include 



static struct data_s {

  const char *club;

  uint8_t     points;

} _points[] = {



  { "Aston Villa",              25  },

  { "Manchester City",          57  },

  { "Arsenal",                  40  },

  { "Everton",                  37  },

  { "West Ham United",          27  },

  { "Tottenham Hotspur",        41  },

  { "Wolverhampton Wanderers",  43  },

  { "Norwich City",             21  },

  { "Leicester City",           53  },

  { "Manchester United",        45  },

  { "Newcastle United",         35  },

  { "Brighton & Hove Albion",   29  },

  { "AFC Bournemouth",          27  },

  { "Crystal Palace",           39  },

  { "Sheffield United",         43  },

  { "Burnley",                  39  },

  { "Southampton",              34  },

  { "Watford",                  27  },

  { "Chelsea",                  48  },

  { "Liverpool",                82  },

};



static iwrc run(void) {

  IWKV_OPTS opts = {

    .path = "cursor1.db",

    .oflags = IWKV_TRUNC // Cleanup database before open

  };

  IWKV iwkv;

  IWDB db;

  IWKV_cursor cur = 0;

  iwrc rc = iwkv_open(&opts, &iwkv);

  RCRET(rc);



  rc = iwkv_db(iwkv, 1, 0, &db);

  RCGO(rc, finish);



  for (int i = 0; i < sizeof(_points) / sizeof(_points[0]); ++i) {

    struct data_s *n = &_points[i];

    IWKV_val key = { .data = (void *) n->club, .size = strlen(n->club) };

    IWKV_val val = { .data = &n->points, .size = sizeof(n->points) };

    RCC(rc, finish, iwkv_put(db, &key, &val, 0));

  }



  fprintf(stdout, ">>>> Traverse in descending order\n");

  RCC(rc, finish, iwkv_cursor_open(db, &cur, IWKV_CURSOR_BEFORE_FIRST, 0));

  while ((rc = iwkv_cursor_to(cur, IWKV_CURSOR_NEXT)) == 0) {

    IWKV_val key, val;

    RCC(rc, finish, iwkv_cursor_get(cur, &key, &val));

    fprintf(stdout, "%.*s: %u\n",

            (int) key.size, (char *) key.data,

            *(uint8_t *) val.data);

    iwkv_kv_dispose(&key, &val);

  }

  rc = 0;

  iwkv_cursor_close(&cur);



  fprintf(stdout, "\n>>>> Traverse in ascending order\n");

  RCC(rc, finish, iwkv_cursor_open(db, &cur, IWKV_CURSOR_AFTER_LAST, 0));

  while ((rc = iwkv_cursor_to(cur, IWKV_CURSOR_PREV)) == 0) {

    IWKV_val key, val;

    RCC(rc, finish, iwkv_cursor_get(cur, &key, &val));

    fprintf(stdout, "%.*s: %u\n",

            (int) key.size, (char *) key.data,

            *(uint8_t *) val.data);

    iwkv_kv_dispose(&key, &val);

  }

  rc = 0;

  iwkv_cursor_close(&cur);



  // Select all keys greater or equal than: Manchester United

  {

    fprintf(stdout, "\n>>>> Records GE: %s\n", _points[9].club);

    IWKV_val key = { .data = (void *) _points[9].club, .size = strlen(_points[9].club) }, val;

    RCC(rc, finish, iwkv_cursor_open(db, &cur, IWKV_CURSOR_GE, &key));

    do {

      RCC(rc, finish, iwkv_cursor_get(cur, &key, &val));

      fprintf(stdout, "%.*s: %u\n",

              (int) key.size, (char *) key.data,

              *(uint8_t *) val.data);

      iwkv_kv_dispose(&key, &val);

    } while ((rc = iwkv_cursor_to(cur, IWKV_CURSOR_NEXT)) == 0);

    rc = 0;

  }

  iwkv_cursor_close(&cur);



finish:

  if (cur) {

    iwkv_cursor_close(&cur);

  }

  iwkv_close(&iwkv);

  return rc;

}



int main() {

  iwrc rc = run();

  if (rc) {

    iwlog_ecode_error3(rc);

    return 1;

  }

  return 0;

}

```



Output:

```

>>>> Traverse in descending order

Wolverhampton Wanderers: 43

West Ham United: 27

Watford: 27

Tottenham Hotspur: 41

Southampton: 34

Sheffield United: 43

Norwich City: 21

Newcastle United: 35

Manchester United: 45

Manchester City: 57

Liverpool: 82

Leicester City: 53

Everton: 37

Crystal Palace: 39

Chelsea: 48

Burnley: 39

Brighton & Hove Albion: 29

Aston Villa: 25

Arsenal: 40

AFC Bournemouth: 27



>>>> Traverse in ascending order

AFC Bournemouth: 27

Arsenal: 40

Aston Villa: 25

Brighton & Hove Albion: 29

Burnley: 39

Chelsea: 48

Crystal Palace: 39

Everton: 37

Leicester City: 53

Liverpool: 82

Manchester City: 57

Manchester United: 45

Newcastle United: 35

Norwich City: 21

Sheffield United: 43

Southampton: 34

Tottenham Hotspur: 41

Watford: 27

West Ham United: 27

Wolverhampton Wanderers: 43



>>>> Records GE: Manchester United

Manchester United: 45

Manchester City: 57

Liverpool: 82

Leicester City: 53

Everton: 37

Crystal Palace: 39

Chelsea: 48

Burnley: 39

Brighton & Hove Albion: 29

Aston Villa: 25

Arsenal: 40

AFC Bournemouth: 27

```



## IWSTART



[IWSTART](https://github.com/Softmotions/iwstart) is an automatic CMake initial project generator for C projects based on iowow / [iwnet](https://github.com/Softmotions/iwnet) / [ejdb2](https://github.com/Softmotions/ejdb) libs.



https://github.com/Softmotions/iwstart



# License

```



MIT License



Copyright (c) 2012-2024 Softmotions Ltd 



Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:



The above copyright notice and this permission notice shall be included in all

copies or substantial portions of the Software.



THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

SOFTWARE.



```