зеркало из https://github.com/mozilla/gecko-dev.git
117 строки
3.8 KiB
C++
117 строки
3.8 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "prio.h"
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#include "prinrval.h"
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#include "prmem.h"
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#include <stdio.h>
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#include <math.h>
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void
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NS_MeanAndStdDev(double n, double sumOfValues, double sumOfSquaredValues,
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double *meanResult, double *stdDevResult)
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{
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double mean = 0.0, var = 0.0, stdDev = 0.0;
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if (n > 0.0 && sumOfValues >= 0) {
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mean = sumOfValues / n;
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double temp = (n * sumOfSquaredValues) - (sumOfValues * sumOfValues);
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if (temp < 0.0 || n <= 1)
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var = 0.0;
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else
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var = temp / (n * (n - 1));
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// for some reason, Windows says sqrt(0.0) is "-1.#J" (?!) so do this:
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stdDev = var != 0.0 ? sqrt(var) : 0.0;
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}
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*meanResult = mean;
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*stdDevResult = stdDev;
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}
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int
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Test(const char* filename, PRInt32 minSize, PRInt32 maxSize,
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PRInt32 sizeIncrement, PRInt32 iterations)
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{
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fprintf(stdout, " size write: mean stddev iters total: mean stddev iters\n");
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for (PRInt32 size = minSize; size <= maxSize; size += sizeIncrement) {
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// create a buffer of stuff to write
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char* buf = (char*)PR_Malloc(size);
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if (buf == NULL)
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return -1;
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// initialize it with a pattern
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PRInt32 i;
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char hex[] = "0123456789ABCDEF";
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for (i = 0; i < size; i++) {
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buf[i] = hex[i & 0xF];
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}
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double writeCount = 0, writeRate = 0, writeRateSquared = 0;
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double totalCount = 0, totalRate = 0, totalRateSquared = 0;
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for (i = 0; i < iterations; i++) {
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PRIntervalTime start = PR_IntervalNow();
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char name[1024];
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sprintf(name, "%s_%d", filename, i);
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PRFileDesc* fd = PR_Open(name, PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE, 0664);
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if (fd == NULL)
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return -1;
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PRIntervalTime writeStart = PR_IntervalNow();
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PRInt32 rv = PR_Write(fd, buf, size);
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if (rv < 0) return rv;
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if (rv != size) return -1;
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PRIntervalTime writeStop = PR_IntervalNow();
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PRStatus st = PR_Close(fd);
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if (st == PR_FAILURE) return -1;
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PRIntervalTime stop = PR_IntervalNow();
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PRIntervalTime writeTime = PR_IntervalToMilliseconds(writeStop - writeStart);
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if (writeTime > 0) {
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double wr = size / writeTime;
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writeRate += wr;
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writeRateSquared += wr * wr;
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writeCount++;
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}
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PRIntervalTime totalTime = PR_IntervalToMilliseconds(stop - start);
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if (totalTime > 0) {
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double t = size / totalTime;
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totalRate += t;
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totalRateSquared += t * t;
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totalCount++;
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}
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}
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PR_Free(buf);
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double writeMean, writeStddev;
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double totalMean, totalStddev;
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NS_MeanAndStdDev(writeCount, writeRate, writeRateSquared,
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&writeMean, &writeStddev);
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NS_MeanAndStdDev(totalCount, totalRate, totalRateSquared,
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&totalMean, &totalStddev);
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fprintf(stdout, "%10d %10.2f %10.2f %10d %10.2f %10.2f %10d\n",
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size, writeMean, writeStddev, (PRInt32)writeCount,
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totalMean, totalStddev, (PRInt32)totalCount);
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}
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return 0;
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}
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int
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main(int argc, char* argv[])
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{
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if (argc != 5) {
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printf("usage: %s <min buf size (K)> <max buf size (K)> <size increment (K)> <iterations>\n", argv[0]);
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return -1;
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}
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Test("y:\\foo",
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atoi(argv[1]) * 1024,
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atoi(argv[2]) * 1024,
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atoi(argv[3]) * 1024,
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atoi(argv[4]));
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return 0;
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}
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