Function SetMaxOpenFiles

src/dbwrapper.cpp:114–137

};

static void SetMaxOpenFiles(leveldb::Options *options) {
    // On most platforms the default setting of max_open_files (which is 1000)
    // is optimal. On Windows using a large file count is OK because the handles
    // do not interfere with select() loops. On 64-bit Unix hosts this value is
    // also OK, because up to that amount LevelDB will use an mmap
    // implementation that does not use extra file descriptors (the fds are
    // closed after being mmap'ed).
    //
    // Increasing the value beyond the default is dangerous because LevelDB will
    // fall back to a non-mmap implementation when the file count is too large.
    // On 32-bit Unix host we should decrease the value because the handles use
    // up real fds, and we want to avoid fd exhaustion issues.
    //
    // See PR #12495 for further discussion.

    int default_open_files = options->max_open_files;
#ifndef WIN32
    if (sizeof(void*) < 8) {
        options->max_open_files = 64;
    }
#endif
    LogDebug(BCLog::LEVELDB, "LevelDB using max_open_files=%d (default=%d)\n",
             options->max_open_files, default_open_files);
}

static leveldb::Options GetOptions(size_t nCacheSize)
{