Adds a JSON parser and a benchmark (json-bench) to catch performance regressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146735 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/json-bench/JSONBench.cpp b/utils/json-bench/JSONBench.cpp
new file mode 100644
index 0000000..b9f4af6
--- /dev/null
+++ b/utils/json-bench/JSONBench.cpp
@@ -0,0 +1,77 @@
+//===- JSONBench - Benchmark the JSONParser implementation ----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This program executes the JSONParser on differntly sized JSON texts and
+// outputs the run time.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/JSONParser.h"
+#include "llvm/Support/Timer.h"
+#include "llvm/Support/raw_ostream.h"
+
+static llvm::cl::opt<bool>
+Verify("verify", llvm::cl::desc(
+ "Run a quick verification useful for regression testing"),
+ llvm::cl::init(false));
+
+void benchmark(llvm::TimerGroup &Group, llvm::StringRef Name,
+ llvm::StringRef JSONText) {
+ llvm::Timer BaseLine((Name + ": Loop").str(), Group);
+ BaseLine.startTimer();
+ char C = 0;
+ for (llvm::StringRef::iterator I = JSONText.begin(),
+ E = JSONText.end();
+ I != E; ++I) { C += *I; }
+ BaseLine.stopTimer();
+ volatile char DontOptimizeOut = C; (void)DontOptimizeOut;
+
+ llvm::Timer Parsing((Name + ": Parsing").str(), Group);
+ Parsing.startTimer();
+ llvm::JSONParser Parser(JSONText);
+ if (!Parser.validate()) {
+ llvm::errs() << "Parsing error in JSON parser benchmark.\n";
+ exit(1);
+ }
+ Parsing.stopTimer();
+}
+
+std::string createJSONText(int N, int ValueSize) {
+ std::string JSONText;
+ llvm::raw_string_ostream Stream(JSONText);
+ Stream << "[\n";
+ for (int I = 0; I < N; ++I) {
+ Stream << " {\n"
+ << " \"key1\": \"" << std::string(ValueSize, '*') << "\",\n"
+ << " \"key2\": \"" << std::string(ValueSize, '*') << "\",\n"
+ << " \"key3\": \"" << std::string(ValueSize, '*') << "\"\n"
+ << " }";
+ if (I + 1 < N) Stream << ",";
+ Stream << "\n";
+ }
+ Stream << "]\n";
+ Stream.flush();
+ return JSONText;
+}
+
+int main(int argc, char **argv) {
+ llvm::cl::ParseCommandLineOptions(argc, argv);
+ llvm::TimerGroup Group("JSON parser benchmark");
+ if (Verify) {
+ benchmark(Group, "Fast", createJSONText(1000, 500));
+ } else {
+ benchmark(Group, "Small Values", createJSONText(1000000, 5));
+ benchmark(Group, "Medium Values", createJSONText(1000000, 500));
+ benchmark(Group, "Large Values", createJSONText(10000, 50000));
+ }
+ return 0;
+}
+