/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI or Corporation for National Research Initiatives or
CNRI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.

While CWI is the initial source for this software, a modified version
is made available by the Corporation for National Research Initiatives
(CNRI) at the Internet address ftp://ftp.python.org.

STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH
CENTRUM OR CNRI BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.

******************************************************************/

#include "Python.h"
#include <sys/resource.h>
#include <sys/time.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

/* don't know why this isn't defined in a header file */
#ifndef getrusage
int getrusage(int who, struct rusage *rusage);
#endif

#ifndef getpagesize
#ifdef linux
extern size_t getpagesize(void);
#else
int getpagesize(void);
#endif
#endif

#define doubletime(TV) ((double)(TV).tv_sec + (TV).tv_usec * 0.000001)

static PyObject *ResourceError;

static PyObject *
resource_getrusage(self, args)
	PyObject *self;
	PyObject *args;
{
	int who;
	struct rusage ru;

	if (!PyArg_ParseTuple(args, "i", &who))
		return NULL;

	if (getrusage(who, &ru) == -1) {
		if (errno == EINVAL) {
			PyErr_SetString(PyExc_ValueError,
					"invalid who parameter");
			return NULL;
		} 
		PyErr_SetFromErrno(ResourceError);
		return NULL;
	}

	/* Yeah, this 16-tuple is way ugly. It's probably a lot less
	   ugly than a dictionary with keys (or object attributes)
	   named things like 'ixrss'. 
	   */
	return Py_BuildValue(
		"ddiiiiiiiiiiiiii",
		doubletime(ru.ru_utime),     /* user time used */
		doubletime(ru.ru_stime),     /* system time used */
		ru.ru_maxrss,		     /* max. resident set size */
		ru.ru_ixrss,		     /* shared memory size */
		ru.ru_idrss,		     /* unshared memory size */
		ru.ru_isrss,		     /* unshared stack size */
		ru.ru_minflt,		     /* page faults not requiring I/O*/
		ru.ru_majflt,		     /* page faults requiring I/O */
		ru.ru_nswap,		     /* number of swap outs */
		ru.ru_inblock,		     /* block input operations */
		ru.ru_oublock,		     /* block output operations */
		ru.ru_msgsnd,		     /* messages sent */
		ru.ru_msgrcv,		     /* messages received */
		ru.ru_nsignals,		     /* signals received */
		ru.ru_nvcsw,		     /* voluntary context switchs */
		ru.ru_nivcsw		     /* involuntary context switchs */
		);
}


static PyObject *
resource_getrlimit(self, args)
	PyObject *self;
	PyObject *args;
{
	struct rlimit rl;
	int resource;

	if (!PyArg_ParseTuple(args, "i", &resource)) 
		return NULL;

	if (resource < 0 || resource >= RLIM_NLIMITS) {
		PyErr_SetString(PyExc_ValueError,
				"invalid resource specified");
		return NULL;
	}

	if (getrlimit(resource, &rl) == -1) {
		PyErr_SetFromErrno(ResourceError);
		return NULL;
	}
	return Py_BuildValue("ii", rl.rlim_cur, rl.rlim_max);
}

static PyObject *
resource_setrlimit(self, args)
	PyObject *self;
	PyObject *args;
{
	struct rlimit rl;
	int resource;

	if (!PyArg_ParseTuple(args, "i(ii)", &resource, &rl.rlim_cur, 
			      &rl.rlim_max)) 
		return NULL;

	if (resource < 0 || resource >= RLIM_NLIMITS) {
		PyErr_SetString(PyExc_ValueError,
				"invalid resource specified");
		return NULL;
	}

	rl.rlim_cur = rl.rlim_cur & RLIM_INFINITY;
	rl.rlim_max = rl.rlim_max & RLIM_INFINITY;
	if (setrlimit(resource, &rl) == -1) {
		if (errno == EINVAL) 
			PyErr_SetString(PyExc_ValueError,
					"current limit exceeds maximum limit");
		else if (errno == EPERM)
			PyErr_SetString(PyExc_ValueError,
					"not allowed to raise maximum limit");
		else
			PyErr_SetFromErrno(ResourceError);
		return NULL;
	}
	Py_INCREF(Py_None);
	return Py_None;
}

static PyObject *
resource_getpagesize(self, args)
	PyObject *self;
	PyObject *args;
{
	if (!PyArg_ParseTuple(args, ""))
		return NULL;
	return Py_BuildValue("i", getpagesize());
}

/* List of functions */

static struct PyMethodDef
resource_methods[] = {
	{"getrusage",    resource_getrusage,   1},
	{"getrlimit",    resource_getrlimit,   1},
	{"setrlimit",    resource_setrlimit,   1},
	{"getpagesize",  resource_getpagesize, 1},
	{NULL, NULL}			     /* sentinel */
};


/* Module initialization */

static void
ins(PyObject *dict, char *name, int value)
{
	PyObject *v = PyInt_FromLong((long) value);
	if (v) {
		PyDict_SetItemString(dict, name, v);
		Py_DECREF(v);
	}
	/* errors will be checked by initresource() */
}

void initresource()
{
	PyObject *m, *d;

	/* Create the module and add the functions */
	m = Py_InitModule("resource", resource_methods);

	/* Add some symbolic constants to the module */
	d = PyModule_GetDict(m);
	ResourceError = PyString_FromString("resource.error");
	PyDict_SetItemString(d, "error", ResourceError);

	/* insert constants */
#ifdef RLIMIT_CPU
	ins(d, "RLIMIT_CPU", RLIMIT_CPU);
#endif

#ifdef RLIMIT_FSIZE
	ins(d, "RLIMIT_FSIZE", RLIMIT_FSIZE);
#endif

#ifdef RLIMIT_DATA
	ins(d, "RLIMIT_DATA", RLIMIT_DATA);
#endif

#ifdef RLIMIT_STACK
	ins(d, "RLIMIT_STACK", RLIMIT_STACK);
#endif

#ifdef RLIMIT_CORE
	ins(d, "RLIMIT_CORE", RLIMIT_CORE);
#endif

#ifdef RLIMIT_NOFILE
	ins(d, "RLIMIT_NOFILE", RLIMIT_NOFILE);
#endif

#ifdef RLIMIT_OFILE
	ins(d, "RLIMIT_OFILE", RLIMIT_OFILE);
#endif

#ifdef RLIMIT_VMEM
	ins(d, "RLIMIT_VMEM", RLIMIT_VMEM);
#endif

#ifdef RLIMIT_AS
	ins(d, "RLIMIT_AS", RLIMIT_AS);
#endif

#ifdef RLIMIT_RSS
	ins(d, "RLIMIT_RSS", RLIMIT_RSS);
#endif

#ifdef RLIMIT_NPROC
	ins(d, "RLIMIT_NPROC", RLIMIT_NPROC);
#endif

#ifdef RLIMIT_MEMLOCK
	ins(d, "RLIMIT_MEMLOCK", RLIMIT_MEMLOCK);
#endif

#ifdef RUSAGE_SELF
	ins(d, "RUSAGE_SELF", RUSAGE_SELF);
#endif

#ifdef RUSAGE_CHILDERN
	ins(d, "RUSAGE_CHILDREN", RUSAGE_CHILDREN);
#endif

#ifdef RUSAGE_BOTH
	ins(d, "RUSAGE_BOTH", RUSAGE_BOTH);
#endif

	/* Check for errors */
	if (PyErr_Occurred())
		Py_FatalError("can't initialize module resource");
}