// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.

#include <vespa/searchlib/docstore/logdatastore.h>
#include <vespa/searchlib/index/dummyfileheadercontext.h>
#include <vespa/vespalib/util/closure.h>
#include <vespa/vespalib/util/closuretask.h>
#include <vespa/searchlib/transactionlog/nosyncproxy.h>
#include <vespa/vespalib/util/threadstackexecutor.h>
#include <vespa/vespalib/data/databuffer.h>
#include <vespa/fastos/app.h>

#include <vespa/log/log.h>
LOG_SETUP("documentstore.benchmark");

using namespace search;

class BenchmarkDataStoreApp : public FastOS_Application
{
    void usage();
    int benchmark(const vespalib::string & directory, size_t numReads, size_t numThreads, size_t perChunk, const vespalib::string & readType);
    int Main() override;
    void read(size_t numReads, size_t perChunk, const IDataStore * dataStore);
};



void
BenchmarkDataStoreApp::usage()
{
    printf("Usage: %s <direcory> <numreads> <numthreads> <objects per read> <normal,directio,mmap,mlock>\n", _argv[0]);
    fflush(stdout);
}

int
BenchmarkDataStoreApp::Main()
{
    if (_argc >= 2) {
        size_t numThreads(16);
        size_t numReads(1000000);
        size_t perChunk(1);
        vespalib::string readType("directio");
        vespalib::string directory(_argv[1]);
        if (_argc >= 3) {
            numReads = strtoul(_argv[2], NULL, 0);
            if (_argc >= 4) {
                numThreads = strtoul(_argv[3], NULL, 0);
                if (_argc >= 5) {
                    perChunk = strtoul(_argv[4], NULL, 0);
                    if (_argc >= 5) {
                        readType = _argv[5];
                    }
                }
            }
        }
        return benchmark(directory, numReads, numThreads, perChunk, readType);
    } else {
        fprintf(stderr, "Too few arguments\n");
        usage();
        return 1;
    }
    return 0;
}

void BenchmarkDataStoreApp::read(size_t numReads, size_t perChunk, const IDataStore * dataStore)
{
    vespalib::DataBuffer buf;
    struct random_data rstate;
    char state[8];
    memset(state, 0, sizeof(state));
    memset(&rstate, 0, sizeof(rstate));
    const size_t docIdLimit(dataStore->getDocIdLimit());
    assert(docIdLimit > 0);
    initstate_r(getpid(), state, sizeof(state), &rstate);
    assert(srandom_r(getpid(), &rstate) == 0);
    int32_t rnd(0);
    for ( size_t i(0); i < numReads; i++) {
        random_r(&rstate, &rnd);
        uint32_t lid(rnd%docIdLimit);
        for (uint32_t j(lid); j < std::min(docIdLimit, lid+perChunk); j++) {
            dataStore->read(j, buf);
            buf.clear();
        }
    }
}

int
BenchmarkDataStoreApp::benchmark(const vespalib::string & dir, size_t numReads, size_t numThreads, size_t perChunk, const vespalib::string & readType)
{
    int retval(0);
    LogDataStore::Config config;
    GrowStrategy growStrategy;
    TuneFileSummary tuning;
    if (readType == "directio") {
        tuning._randRead.setWantDirectIO();
    } else if (readType == "normal") {
        tuning._randRead.setWantNormal();
    } else if (readType == "mmap") {
        tuning._randRead.setWantMemoryMap();
    }
    search::index::DummyFileHeaderContext fileHeaderContext;
    vespalib::ThreadStackExecutor executor(config.getNumThreads(), 128*1024);
    transactionlog::NoSyncProxy noTlSyncer;
    LogDataStore store(executor, dir, config, growStrategy, tuning,
                       fileHeaderContext,
                       noTlSyncer, NULL, true);
    vespalib::ThreadStackExecutor bmPool(numThreads, 128*1024);
    LOG(info, "Start read benchmark with %lu threads doing %lu reads in chunks of %lu reads. Totally %lu objects", numThreads, numReads, perChunk, numThreads * numReads * perChunk);
    for (size_t i(0); i < numThreads; i++) {
        bmPool.execute(vespalib::makeTask(vespalib::makeClosure(this, &BenchmarkDataStoreApp::read, numReads, perChunk, static_cast<const IDataStore *>(&store))));
    }
    bmPool.sync();
    LOG(info, "Benchmark done.");
    return retval;
}

FASTOS_MAIN(BenchmarkDataStoreApp);