func (s *session) setOptions(o *opt.Options) {
s.o = &opt.Options{}
if o != nil {
*s.o = *o
}
// Alternative filters.
if filters := o.GetAltFilters(); len(filters) > 0 {
s.o.AltFilters = make([]filter.Filter, len(filters))
for i, filter := range filters {
s.o.AltFilters[i] = &iFilter{filter}
}
}
// Block cache.
switch o.GetBlockCache() {
case nil:
s.o.BlockCache = cache.NewLRUCache(opt.DefaultBlockCacheSize)
case opt.NoCache:
s.o.BlockCache = nil
}
// Comparer.
s.cmp = &iComparer{o.GetComparer()}
s.o.Comparer = s.cmp
// Filter.
if filter := o.GetFilter(); filter != nil {
s.o.Filter = &iFilter{filter}
}
}
// NewWriter creates a new initialized table writer for the file.
//
// Table writer is not goroutine-safe.
func NewWriter(f io.Writer, o *opt.Options) *Writer {
w := &Writer{
writer: f,
cmp: o.GetComparer(),
filter: o.GetFilter(),
compression: o.GetCompression(),
blockSize: o.GetBlockSize(),
comparerScratch: make([]byte, 0),
}
// data block
w.dataBlock.restartInterval = o.GetBlockRestartInterval()
// The first 20-bytes are used for encoding block handle.
w.dataBlock.scratch = w.scratch[20:]
// index block
w.indexBlock.restartInterval = 1
w.indexBlock.scratch = w.scratch[20:]
// filter block
if w.filter != nil {
w.filterBlock.generator = w.filter.NewGenerator()
w.filterBlock.flush(0)
}
return w
}