== [Proposal] Coding Style ==

In general, the [http://kerneltrap.org/files/Jeremy/CodingStyle.txt coding standards] used in the Linux kernel are versatile, comprehensive and quite good looking. They are boiling down to the following guide lines:

 Indentation:: Hardtabs
 Spaces:: Spaces around keywords but not in inner parenthesis.
 Brace placement:: '{' at end of line except for function definition and '}' on its own line except in do-while-loops.
 Naming:: Descriptive for global functions and usually lower case with underscores.
 Macros:: Upper case for constants, lower case with underscores for macros resembling functions.
 Structures:: No typedefs, although this is debatable. For shared data structures reference counting should be implemented.

I would add the following:

 Position of C-pointer star:: At variable name not type.
 const:: Wherever possible.
 White space:: Avoid at all costs.
 C99:: Enable it and declare variables only when needed.

There are still some open questions:

* Number of white lines to separate functions?
* Comments: C vs. C++ style, usage of '*'?
* Alignment of multiple assignments?
* Breaking of long lines, especially argument lists?
* #define indentation? Commenting each #endif with the corresponding #define name makes the code hard to read in my opinion.
* Documentation tools? ([http://www.stack.nl/~dimitri/doxygen/ Doxygen], [http://sphinx.pocoo.org/ Sphinx], [http://www.naturaldocs.org/ Natural Docs])
* Name prefixes? (e.g. 'g_' for global)

In essence, a bit of code would look like that:

{{{
#!c
#define PI 3.14159265
#define min(a,b) ((a) < (b) ? (a) : (b))

struct string {
    char *content;
    size_t length;
    int refcount;
};

struct string* clone_string(const char *s)
{
    if (s == NULL)
        return NULL;

    struct string *clone = (struct string *) malloc(sizeof(struct string));
    const int len = strlen(s);
    clone->content = (char *) malloc(len);
    clone->length = len;
    clone->refcount = 1;
    strncpy(clone->content, s, len);

    return clone;
}
}}}

== PyHST and OpenCL ==

To a certain degree, PyHST has been ported to OpenCL. Check-out the code via

* git clone ssh://<user>@ipefser1.fzk.de/home/ipefser1/vogelgesang/repos/oclfft.git
* git clone ssh://<user>@ipefser1.fzk.de/home/ipefser1/vogelgesang/repos/pyHST.git

Build and install the OpenCL FFT library

* cd $OCLFFT_DIR && cmake . && make && sudo make install

as well as PyHST. Make sure to enable OpenCL support and copy the OpenCL kernel file wherever you intend to run PyHST. Please note: This has only been tested with a limited set of data and does not yet cover all features from the pure CPU version (such as FAI360 support).