Add skeleton for kilobench experiments

tools/kilobench/kilobench.cpp

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Benchmark.h"
+#include "SkCommandLineFlags.h"
+#include "SkOSFile.h"
+#include "SkStream.h"
+#include "VisualSKPBench.h"
+
+/*
+ * This is an experimental GPU only benchmarking program.  The initial implementation will only
+ * support SKPs.
+ */
+
+// To get image decoders linked in we have to do the below magic
+#include "SkForceLinking.h"
+#include "SkImageDecoder.h"
+__SK_FORCE_IMAGE_DECODER_LINKING;
+
+DEFINE_string(skps, "skps", "Directory to read skps from.");
+
+DEFINE_string2(match, m, nullptr,
+               "[~][^]substring[$] [...] of GM name to run.\n"
+               "Multiple matches may be separated by spaces.\n"
+               "~ causes a matching bench to always be skipped\n"
+               "^ requires the start of the bench to match\n"
+               "$ requires the end of the bench to match\n"
+               "^ and $ requires an exact match\n"
+               "If a bench does not match any list entry,\n"
+               "it is skipped unless some list entry starts with ~");
+
+namespace kilobench {
+class BenchmarkStream {
+public:
+    BenchmarkStream() : fCurrentSKP(0) {
+        for (int i = 0; i < FLAGS_skps.count(); i++) {
+            if (SkStrEndsWith(FLAGS_skps[i], ".skp")) {
+                fSKPs.push_back() = FLAGS_skps[i];
+            } else {
+                SkOSFile::Iter it(FLAGS_skps[i], ".skp");
+                SkString path;
+                while (it.next(&path)) {
+                    fSKPs.push_back() = SkOSPath::Join(FLAGS_skps[0], path.c_str());
+                }
+            }
+        }
+    }
+
+    Benchmark* next() {
+        Benchmark* bench = nullptr;
+        // skips non matching benches
+        while ((bench = this->innerNext()) &&
+               (SkCommandLineFlags::ShouldSkip(FLAGS_match, bench->getUniqueName()) ||
+                !bench->isSuitableFor(Benchmark::kGPU_Backend))) {
+            bench->unref();

[mtklein, 2016/01/14 16:49:43]

Might want to `delete bench;` here for consistency with the AutoTDelete below. 
This makes it seem like the ref-counting is important.

+        }
+        return bench;
+    }
+
+private:
+    static bool ReadPicture(const char* path, SkAutoTUnref<SkPicture>* pic) {
+        // Not strictly necessary, as it will be checked again later,
+        // but helps to avoid a lot of pointless work if we're going to skip it.
+        if (SkCommandLineFlags::ShouldSkip(FLAGS_match, path)) {
+            return false;
+        }
+
+        SkAutoTDelete<SkStream> stream(SkStream::NewFromFile(path));
+        if (stream.get() == nullptr) {
+            SkDebugf("Could not read %s.\n", path);
+            return false;
+        }
+
+        pic->reset(SkPicture::CreateFromStream(stream.get()));
+        if (pic->get() == nullptr) {
+            SkDebugf("Could not read %s as an SkPicture.\n", path);
+            return false;
+        }
+        return true;
+    }
+
+    Benchmark* innerNext() {
+        // Render skps
+        while (fCurrentSKP < fSKPs.count()) {
+            const SkString& path = fSKPs[fCurrentSKP++];
+            SkAutoTUnref<SkPicture> pic;
+            if (!ReadPicture(path.c_str(), &pic)) {
+                continue;
+            }
+
+            SkString name = SkOSPath::Basename(path.c_str());
+            return new VisualSKPBench(name.c_str(), pic.get());
+        }
+
+        return nullptr;
+    }
+
+    SkTArray<SkString> fSKPs;
+    int fCurrentSKP;
+};
+
+} // namespace kilobench
+
+int kilobench_main() {
+    kilobench::BenchmarkStream benchStream;
+    while (Benchmark* b = benchStream.next()) {
+        SkAutoTDelete<Benchmark> bench(b);

[bsalomon, 2016/01/14 16:45:05]

Does this work?

while (SkAutoTDelete<Benchmark> bench(benchMarkStream.next()) {

+        // TODO actual stuff
+    }
+    return 0;
+}
+
+#if !defined SK_BUILD_FOR_IOS
+int main(int argc, char** argv) {
+    SkCommandLineFlags::Parse(argc, argv);
+    return kilobench_main();
+}
+#endif