# libtuberia

libtuberia: a library to implement a pipeline

A pipeline would be:

*[Source] -> [queue_1] -> [Stage_1] -> [Queue_2] -> [Stage_2] -> [...] -> [Sink]*

Each source, stage, and sink runs in a thread, reads from its imput queue and
write to the output queue

You can ommit the source and sink, and inject or retrive elements from the
pipeline

## Building, Compiling, Installing

If you don't have a ./configure file, run:

- `autoreconf -fi`

When you have the ./configure file, run:

- `./configure`
- `make`
- `make install`

You can see some configuration options with:

- `./configure --help`

## Using this library

Include tuberia.h, and link libtuberia.a and pthread: `-ltuberia -lpthread`

You can also use: `pkg-config --cflags --libs --static tuberia`

## Quick Guide

See the files `example/simple.c` and `example/decode_resize_encode.c`
(function `do_tuberia()` in particular)

Create a source with `tube_source_alloc()`.
If you set fetch to something, there will be a thread running fetch to inject
elements into the pipeline.
If you set fetch to NULL, you have to inject the elements with `tube_inject()`.

Create as many stages as you need with `tube_stage_alloc()`, and append them
to the source with `tube_stage_append()`.

Build the pipeline with `tube_alloc()`. If you set sink to something,
there will be a thread running sink to get the elements from the pipeline.
If you set sink to NULL, you have to retrieve the elements with
`tube_retrieve()`.

The `tube_alloc()` function copies the source and all the appended stages,
so you can free the source and stages with `tube_source_and_stages_free()`.
Or, you can reutilize the same `tube_source` to build more pipelines.

Start the pipeline with `tube_start()`.

Free the pipeline with `tube_free()`.


### Quick example

See `examples/simple.c`

Compile with: `gcc -o simple simple.c -ltuberia -lpthread`

Or with: ``gcc -o simple simple.c `pkg-config --cflags --libs --static tuberia```

```C
#include <stdio.h>
#include <stdlib.h>
#include <tuberia.h>

void *stage_one(void *element, void *opaque)
{
    int *i = element;
    *i += 5;
    return i;
}

void *stage_two(void *element, void *opaque)
{
    int *i = element;
    *i *= 10;
    return i;
}

void sink(void *element, void *opaque)
{
    int *i = element;
    printf("sink: %d\n", *i);
    free(i);
}

int main(void)
{
    tube *ctx;
    tube_source *source;
    int *element, n;

    source = tube_source_alloc(2, NULL, NULL, free);
    tube_stage_append(source, tube_stage_alloc(2, stage_one, NULL, free));
    tube_stage_append(source, tube_stage_alloc(2, stage_two, NULL, free));
    ctx = tube_alloc(source, sink, NULL);
    tube_source_and_stages_free(&source);
    tube_start(ctx);
    while (scanf("%d", &n) == 1) {
        element = malloc(sizeof(*element));
        *element = n;
        tube_inject(ctx, 1000, element);
    }
    tube_free(&ctx);

    return 0;
}
```