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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "prio.h"
#include "prinrval.h"
#include "prmem.h"
#include <stdio.h>
#include <math.h>
void
NS_MeanAndStdDev(double n, double sumOfValues, double sumOfSquaredValues,
double *meanResult, double *stdDevResult)
{
double mean = 0.0, var = 0.0, stdDev = 0.0;
if (n > 0.0 && sumOfValues >= 0) {
mean = sumOfValues / n;
double temp = (n * sumOfSquaredValues) - (sumOfValues * sumOfValues);
if (temp < 0.0 || n <= 1)
var = 0.0;
else
var = temp / (n * (n - 1));
// for some reason, Windows says sqrt(0.0) is "-1.#J" (?!) so do this:
stdDev = var != 0.0 ? sqrt(var) : 0.0;
}
*meanResult = mean;
*stdDevResult = stdDev;
}
int
Test(const char* filename, int32_t minSize, int32_t maxSize,
int32_t sizeIncrement, int32_t iterations)
{
fprintf(stdout, " size write: mean stddev iters total: mean stddev iters\n");
for (int32_t size = minSize; size <= maxSize; size += sizeIncrement) {
// create a buffer of stuff to write
char* buf = (char*)PR_Malloc(size);
if (buf == nullptr)
return -1;
// initialize it with a pattern
int32_t i;
char hex[] = "0123456789ABCDEF";
for (i = 0; i < size; i++) {
buf[i] = hex[i & 0xF];
}
double writeCount = 0, writeRate = 0, writeRateSquared = 0;
double totalCount = 0, totalRate = 0, totalRateSquared = 0;
for (i = 0; i < iterations; i++) {
PRIntervalTime start = PR_IntervalNow();
char name[1024];
sprintf(name, "%s_%d", filename, i);
PRFileDesc* fd = PR_Open(name, PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE, 0664);
if (fd == nullptr)
return -1;
PRIntervalTime writeStart = PR_IntervalNow();
int32_t rv = PR_Write(fd, buf, size);
if (rv < 0) return rv;
if (rv != size) return -1;
PRIntervalTime writeStop = PR_IntervalNow();
PRStatus st = PR_Close(fd);
if (st == PR_FAILURE) return -1;
PRIntervalTime stop = PR_IntervalNow();
PRIntervalTime writeTime = PR_IntervalToMilliseconds(writeStop - writeStart);
if (writeTime > 0) {
double wr = size / writeTime;
writeRate += wr;
writeRateSquared += wr * wr;
writeCount++;
}
PRIntervalTime totalTime = PR_IntervalToMilliseconds(stop - start);
if (totalTime > 0) {
double t = size / totalTime;
totalRate += t;
totalRateSquared += t * t;
totalCount++;
}
}
PR_Free(buf);
double writeMean, writeStddev;
double totalMean, totalStddev;
NS_MeanAndStdDev(writeCount, writeRate, writeRateSquared,
&writeMean, &writeStddev);
NS_MeanAndStdDev(totalCount, totalRate, totalRateSquared,
&totalMean, &totalStddev);
fprintf(stdout, "%10d %10.2f %10.2f %10d %10.2f %10.2f %10d\n",
size, writeMean, writeStddev, (int32_t)writeCount,
totalMean, totalStddev, (int32_t)totalCount);
}
return 0;
}
int
main(int argc, char* argv[])
{
if (argc != 5) {
printf("usage: %s <min buf size (K)> <max buf size (K)> <size increment (K)> <iterations>\n", argv[0]);
return -1;
}
Test("y:\\foo",
atoi(argv[1]) * 1024,
atoi(argv[2]) * 1024,
atoi(argv[3]) * 1024,
atoi(argv[4]));
return 0;
}
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