mirror of
https://github.com/moses-smt/mosesdecoder.git
synced 2024-09-11 11:25:40 +03:00
70 lines
1.5 KiB
C++
70 lines
1.5 KiB
C++
#include "util/parallel_read.hh"
|
|
|
|
#include "util/file.hh"
|
|
|
|
#ifdef WITH_THREADS
|
|
#include "util/thread_pool.hh"
|
|
|
|
namespace util {
|
|
namespace {
|
|
|
|
class Reader {
|
|
public:
|
|
explicit Reader(int fd) : fd_(fd) {}
|
|
|
|
struct Request {
|
|
void *to;
|
|
std::size_t size;
|
|
uint64_t offset;
|
|
|
|
bool operator==(const Request &other) const {
|
|
return (to == other.to) && (size == other.size) && (offset == other.offset);
|
|
}
|
|
};
|
|
|
|
void operator()(const Request &request) {
|
|
util::ErsatzPRead(fd_, request.to, request.size, request.offset);
|
|
}
|
|
|
|
private:
|
|
int fd_;
|
|
};
|
|
|
|
} // namespace
|
|
|
|
void ParallelRead(int fd, void *to, std::size_t amount, uint64_t offset) {
|
|
Reader::Request poison;
|
|
poison.to = NULL;
|
|
poison.size = 0;
|
|
poison.offset = 0;
|
|
unsigned threads = boost::thread::hardware_concurrency();
|
|
if (!threads) threads = 2;
|
|
ThreadPool<Reader> pool(2 /* don't need much of a queue */, threads, fd, poison);
|
|
const std::size_t kBatch = 1ULL << 25; // 32 MB
|
|
Reader::Request request;
|
|
request.to = to;
|
|
request.size = kBatch;
|
|
request.offset = offset;
|
|
for (; amount > kBatch; amount -= kBatch) {
|
|
pool.Produce(request);
|
|
request.to = reinterpret_cast<uint8_t*>(request.to) + kBatch;
|
|
request.offset += kBatch;
|
|
}
|
|
request.size = amount;
|
|
if (request.size) {
|
|
pool.Produce(request);
|
|
}
|
|
}
|
|
|
|
} // namespace util
|
|
|
|
#else // WITH_THREADS
|
|
|
|
namespace util {
|
|
void ParallelRead(int fd, void *to, std::size_t amount, uint64_t offset) {
|
|
util::ErsatzPRead(fd, to, amount, offset);
|
|
}
|
|
} // namespace util
|
|
|
|
#endif
|