nanobench: flush after recording every Nth data point.

bench/nanobench.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <ctype.h>
 
 #include "Benchmark.h"
@@ skipping 52 matching lines @@
 DEFINE_bool(gpuCompressAlphaMasks, false, "Compress masks generated from falling back to "
                                           "software path rendering.");
 
 DEFINE_string(outResultsFile, "", "If given, write results here as JSON.");
 DEFINE_int32(maxCalibrationAttempts, 3,
              "Try up to this many times to guess loops for a bench, or skip the bench.");
 DEFINE_int32(maxLoops, 1000000, "Never run a bench more times than this.");
 DEFINE_string(clip, "0,0,1000,1000", "Clip for SKPs.");
 DEFINE_string(scales, "1.0", "Space-separated scales for SKPs.");
 DEFINE_bool(bbh, true, "Build a BBH for SKPs?");
+DEFINE_int32(flushEvery, 10, "Flush --outResultsFile every Nth run.");
 
 static SkString humanize(double ms) {
     if (FLAGS_verbose) return SkStringPrintf("%llu", (uint64_t)(ms*1e6));
     if (ms > 1e+3)     return SkStringPrintf("%.3gs",  ms/1e3);
     if (ms < 1e-3)     return SkStringPrintf("%.3gns", ms*1e6);
 #ifdef SK_BUILD_FOR_WIN
     if (ms < 1)        return SkStringPrintf("%.3gus", ms*1e3);
 #else
     if (ms < 1)        return SkStringPrintf("%.3gµs", ms*1e3);
 #endif
@@ skipping 538 matching lines @@
     } else if (FLAGS_quiet) {
         SkDebugf("median\tbench\tconfig\n");
     } else {
         SkDebugf("maxrss\tloops\tmin\tmedian\tmean\tmax\tstddev\t%-*s\tconfig\tbench\n",
                  FLAGS_samples, "samples");
     }
 
     SkTDArray<Config> configs;
     create_configs(&configs);
 
+    int runs = 0;
     BenchmarkStream benchStream;
     while (Benchmark* b = benchStream.next()) {
         SkAutoTDelete<Benchmark> bench(b);
         if (SkCommandLineFlags::ShouldSkip(FLAGS_match, bench->getUniqueName())) {
             continue;
         }
 
         SkTDArray<Target*> targets;
         create_targets(&targets, bench.get(), configs);
 
@@ skipping 32 matching lines @@
 #if SK_SUPPORT_GPU
             if (Benchmark::kGPU_Backend == targets[j]->config.backend) {
                 fill_gpu_options(log.get(), targets[j]->gl);
             }
 #endif
             log->timer("min_ms",    stats.min);
             log->timer("median_ms", stats.median);
             log->timer("mean_ms",   stats.mean);
             log->timer("max_ms",    stats.max);
             log->timer("stddev_ms", sqrt(stats.var));
+            if (runs++ % FLAGS_flushEvery == 0) {
+                log->flush();
+            }
 
             if (kAutoTuneLoops != FLAGS_loops) {
                 if (targets.count() == 1) {
                     config = ""; // Only print the config if we run the same bench on more than one.
                 }
                 SkDebugf("%4dM\t%s\t%s\n"
                          , sk_tools::getMaxResidentSetSizeMB()
                          , bench->getUniqueName()
                          , config);
             } else if (FLAGS_verbose) {
@@ skipping 36 matching lines @@
 
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char** argv) {
     SkCommandLineFlags::Parse(argc, argv);
     return nanobench_main();
 }
 #endif