llvm-6502/utils/json-bench/JSONBench.cpp

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//===- 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));
static llvm::cl::opt<unsigned>
MemoryLimitMB("memory-limit", llvm::cl::desc(
"Do not use more megabytes of memory"),
llvm::cl::init(1000));
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::SourceMgr SM;
llvm::JSONParser Parser(JSONText, &SM);
if (!Parser.validate()) {
llvm::errs() << "Parsing error in JSON parser benchmark.\n";
exit(1);
}
Parsing.stopTimer();
}
std::string createJSONText(size_t MemoryMB, unsigned ValueSize) {
std::string JSONText;
llvm::raw_string_ostream Stream(JSONText);
Stream << "[\n";
size_t MemoryBytes = MemoryMB * 1024 * 1024;
while (JSONText.size() < MemoryBytes) {
Stream << " {\n"
<< " \"key1\": \"" << std::string(ValueSize, '*') << "\",\n"
<< " \"key2\": \"" << std::string(ValueSize, '*') << "\",\n"
<< " \"key3\": \"" << std::string(ValueSize, '*') << "\"\n"
<< " }";
Stream.flush();
if (JSONText.size() < MemoryBytes) 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(10, 500));
} else {
benchmark(Group, "Small Values", createJSONText(MemoryLimitMB, 5));
benchmark(Group, "Medium Values", createJSONText(MemoryLimitMB, 500));
benchmark(Group, "Large Values", createJSONText(MemoryLimitMB, 50000));
}
return 0;
}