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Merge "[benchmark] Refactor io read measurement with pread"

This commit is contained in:
Alice Wang 2022-11-14 11:42:02 +00:00 committed by Gerrit Code Review
parent 012c1ef8e6 3e963dc5a0
commit e5b221d93c
1 changed files with 5 additions and 9 deletions
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14
tests/benchmark/src/native/benchmarkbinary.cpp
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@ -94,11 +94,12 @@ private:
Result<double> measure_read_rate(const std::string& filename, int64_t fileSizeBytes, Result<double> measure_read_rate(const std::string& filename, int64_t fileSizeBytes,
bool is_rand) { bool is_rand) {
const int64_t block_count = fileSizeBytes / kBlockSizeBytes; const int64_t block_count = fileSizeBytes / kBlockSizeBytes;
std::vector<uint64_t> offsets; std::vector<uint64_t> offsets(block_count);
for (auto i = 0; i < block_count; ++i) {
offsets.push_back(i * kBlockSizeBytes);
}
if (is_rand) { if (is_rand) {
std::mt19937 rd{std::random_device{}()}; std::mt19937 rd{std::random_device{}()};
offsets.reserve(block_count);
for (auto i = 0; i < block_count; ++i) offsets.push_back(i * kBlockSizeBytes);
std::shuffle(offsets.begin(), offsets.end(), rd); std::shuffle(offsets.begin(), offsets.end(), rd);
} }
char buf[kBlockSizeBytes]; char buf[kBlockSizeBytes];
@ -109,12 +110,7 @@ private:
return ErrnoError() << "Read: opening " << filename << " failed"; return ErrnoError() << "Read: opening " << filename << " failed";
} }
for (auto i = 0; i < block_count; ++i) { for (auto i = 0; i < block_count; ++i) {
if (is_rand) { auto bytes = pread(fd, buf, kBlockSizeBytes, offsets[i]);
if (lseek(fd.get(), offsets[i], SEEK_SET) == -1) {
return ErrnoError() << "failed to lseek";
}
}
auto bytes = read(fd.get(), buf, kBlockSizeBytes);
if (bytes == 0) { if (bytes == 0) {
return Error() << "unexpected end of file"; return Error() << "unexpected end of file";
} else if (bytes == -1) { } else if (bytes == -1) {