Eet

Eet Data Handling Library Public API Calls.

These routines are used for Eet Library interaction.

Date
  2000 (created)

# Table of Contents

- Introduction
- How to compile
- Next Steps
- Introductory Examples

# Introduction

It is a tiny library designed to write an arbitrary set of chunks of data to a file and optionally compress each chunk (very much like a zip file) and allow fast random-access reading of the file later on. It does not do zip as a zip itself has more complexity than is needed, and it was much simpler to implement this once here.

Eet is extremely fast, small and simple. Eet files can be very small and highly compressed, making them very optimal for just sending across the internet without having to archive, compress or decompress and install them. They allow for lightning-fast random-access reads once created, making them perfect for storing data that is written once (or rarely) and read many times, but the program does not want to have to read it all in at once.

It also can encode and decode data structures in memory, as well as image data for saving to Eet files or sending across the network to other machines, or just writing to arbitrary files on the system. All data is encoded in a platform independent way and can be written and read by any architecture.

# How to compile

Eet is a library your application links to. The procedure for this is very simple. You simply have to compile your application with the appropriate compiler flags that the `pkg-config` script outputs. For example:

Compiling C or C++ files into object files:

    gcc -c -o main.o main.c `pkg-config --cflags eet`

Linking object files into a binary executable:

    gcc -o my_application main.o `pkg-config --libs eet`

See pkgconfig

# Next Steps

After you understood what Eet is and installed it in your system you should proceed understanding the programming interface. We'd recommend you to take a while to learn Eina as it is very convenient and optimized, and Eet provides integration with it.

Recommended reading:

- Eet File Main Functions to know the basics to open and save files.
- Eet Data Serialization to know the convenient way to serialize and parse your data structures automatically. Just create your descriptors and let Eet do the work for you.

# Introductory Examples

Here is a simple example on how to use Eet to save a series of strings to a file and load them again. The advantage of using Eet over just fprintf() and fscanf() is that not only can these entries be strings, they need no special parsing to handle delimiter characters or escaping, they can be binary data, image data, data structures containing integers, strings, other data structures, linked lists and much more, without the programmer having to worry about parsing, and best of all, Eet is very fast.

This is just a very simple example that doesn't show all of the capabilities of Eet, but it serves to illustrate its simplicity.

//Compile with:
// gcc -o eet-basic eet-basic.c `pkg-config --cflags --libs eet`
#include <Eet.h>
int
main(void)
{
Eet_File *ef;
char *ret;
int size;
char *entries[] =
{
"Entry 1",
"Big text string here compared to others",
"Eet is cool"
};
eet_init();
// blindly open an file for output and write strings with their NUL char
ef = eet_open("test.eet", EET_FILE_MODE_WRITE);
eet_write(ef, "Entry 1", entries[0], strlen(entries[0]) + 1, 0);
eet_write(ef, "Entry 2", entries[1], strlen(entries[1]) + 1, 1);
eet_write(ef, "Entry 3", entries[2], strlen(entries[2]) + 1, 0);
eet_close(ef);
// open the file again and blindly get the entries we wrote
ef = eet_open("test.eet", EET_FILE_MODE_READ);
ret = eet_read(ef, "Entry 1", &size);
printf("%s\n", ret);
free(ret);
ret = eet_read(ef, "Entry 2", &size);
printf("%s\n", ret);
free(ret);
ret = eet_read(ef, "Entry 3", &size);
printf("%s\n", ret);
free(ret);
eet_close(ef);
eet_shutdown();
}
Eet.h
The file that provides the eet functions.
eet_close
EAPI Eet_Error eet_close(Eet_File *ef)
Closes an eet file handle and flush pending writes.
Definition eet_lib.c:1934
Eet_File
struct _Eet_File Eet_File
Opaque handle that defines an Eet file (or memory).
Definition Eet.h:527
eet_open
EAPI Eet_File * eet_open(const char *file, Eet_File_Mode mode)
Opens an eet file on disk, and returns a handle to it.
Definition eet_lib.c:1525
eet_write
EAPI int eet_write(Eet_File *ef, const char *name, const void *data, int size, int compress)
Write a specified entry to an eet file handle.
Definition eet_lib.c:2527
eet_read
EAPI void * eet_read(Eet_File *ef, const char *name, int *size_ret)
Reads a specified entry from an eet file and return data.
Definition eet_lib.c:2041
EET_FILE_MODE_READ
@ EET_FILE_MODE_READ
File is read-only.
Definition Eet.h:479
EET_FILE_MODE_WRITE
@ EET_FILE_MODE_WRITE
File is write-only.
Definition Eet.h:480
eet_init
EAPI int eet_init(void)
Initializes the EET library.
Definition eet_lib.c:543
eet_shutdown
EAPI int eet_shutdown(void)
Shuts down the EET library.
Definition eet_lib.c:597

More examples can be found at EET Examples.