func (t *Reader) getDataIter(bi *bInfo, ro opt.ReadOptionsGetter) (it *block.Iterator, cache cache.Object, err error) {
var b *block.Reader
if t.cache != nil {
cache, _ = t.cache.Get(bi.offset, func() (ok bool, value interface{}, charge int, fin func()) {
var buf []byte
buf, err = bi.readAll(t.r, ro.HasFlag(opt.RFVerifyChecksums))
if err != nil {
return
}
b, err = block.NewReader(buf, t.o.GetComparer())
if err != nil {
return
}
ok = true
value = b
charge = int(bi.size)
return
})
if err != nil {
return
}
if b == nil {
b = cache.Value().(*block.Reader)
}
} else {
var buf []byte
buf, err = bi.readAll(t.r, ro.HasFlag(opt.RFVerifyChecksums))
if err != nil {
return
}
b, err = block.NewReader(buf, t.o.GetComparer())
if err != nil {
return
}
}
it = b.NewIterator()
return
}
func (t *Reader) getDataIter(bi *bInfo, ro opt.ReadOptionsGetter) (it *block.Iterator, cache cache.Object, err error) {
var b *block.Reader
if t.cache != nil {
var ok bool
cache, ok = t.cache.Get(bi.offset, func() (ok bool, value interface{}, charge int, fin func()) {
if ro.HasFlag(opt.RFDontFillCache) {
return
}
b, err = t.getBlock(bi, ro)
if err == nil {
ok = true
value = b
charge = int(bi.size)
}
return
})
if err != nil {
return
}
if !ok {
b, err = t.getBlock(bi, ro)
if err != nil {
return
}
} else if b == nil {
b = cache.Value().(*block.Reader)
}
} else {
b, err = t.getBlock(bi, ro)
if err != nil {
return
}
}
it = b.NewIterator()
return
}
// NewReader create new initialized table reader.
func NewReader(r desc.Reader, size uint64, o opt.OptionsGetter, cache cache.Namespace) (p *Reader, err error) {
mb, ib, err := readFooter(r, size)
if err != nil {
return
}
t := &Reader{r: r, o: o, dataEnd: mb.offset, cache: cache}
// index block
buf, err := ib.readAll(r, true)
if err != nil {
return
}
t.index, err = block.NewReader(buf, o.GetComparer())
if err != nil {
return
}
// filter block
filter := o.GetFilter()
if filter != nil {
// we will ignore any errors at meta/filter block
// since it is not essential for operation
// meta block
buf, err = mb.readAll(r, true)
if err != nil {
goto out
}
var meta *block.Reader
meta, err = block.NewReader(buf, comparer.BytesComparer{})
if err != nil {
goto out
}
// check for filter name
iter := meta.NewIterator()
key := "filter." + filter.Name()
if iter.Seek([]byte(key)) && string(iter.Key()) == key {
fb := new(bInfo)
_, err = fb.decodeFrom(iter.Value())
if err != nil {
return
}
// now the data end before filter block start offset
t.dataEnd = fb.offset
// filter block
buf, err = fb.readAll(r, true)
if err != nil {
goto out
}
t.filter, err = block.NewFilterReader(buf, filter)
if err != nil {
goto out
}
}
}
out:
return t, nil
}