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}
}
}
func (s *session) setOptions(o *opt.Options) {
no := dupOptions(o)
// Alternative filters.
if filters := o.GetAltFilters(); len(filters) > 0 {
no.AltFilters = make([]filter.Filter, len(filters))
for i, filter := range filters {
no.AltFilters[i] = &iFilter{filter}
}
}
// Block cache.
switch o.GetBlockCache() {
case nil:
no.BlockCache = cache.NewLRUCache(o.GetBlockCacheSize())
case opt.NoCache:
no.BlockCache = nil
}
// Comparer.
s.icmp = &iComparer{o.GetComparer()}
no.Comparer = s.icmp
// Filter.
if filter := o.GetFilter(); filter != nil {
no.Filter = &iFilter{filter}
}
s.o = &cachedOptions{Options: no}
s.o.cache()
}
func (s *session) setOptions(o *opt.Options) {
no := dupOptions(o)
// Alternative filters.
if filters := o.GetAltFilters(); len(filters) > 0 {
no.AltFilters = make([]filter.Filter, len(filters))
for i, filter := range filters {
no.AltFilters[i] = &iFilter{filter}
}
}
// Comparer.
s.icmp = &iComparer{o.GetComparer()}
no.Comparer = s.icmp
// Filter.
if filter := o.GetFilter(); filter != nil {
no.Filter = &iFilter{filter}
}
s.o = &cachedOptions{Options: no}
s.o.cache()
}
// NewReader creates a new initialized table reader for the file.
// The cache and bpool is optional and can be nil.
//
// The returned table reader instance is goroutine-safe.
func NewReader(f io.ReaderAt, size int64, cache cache.Namespace, bpool *util.BufferPool, o *opt.Options) *Reader {
if bpool == nil {
bpool = util.NewBufferPool(o.GetBlockSize() + blockTrailerLen)
}
r := &Reader{
reader: f,
cache: cache,
bpool: bpool,
cmp: o.GetComparer(),
checksum: o.GetStrict(opt.StrictBlockChecksum),
strictIter: o.GetStrict(opt.StrictIterator),
}
if f == nil {
r.err = errors.New("leveldb/table: Reader: nil file")
return r
}
if size < footerLen {
r.err = errors.New("leveldb/table: Reader: invalid table (file size is too small)")
return r
}
var footer [footerLen]byte
if _, err := r.reader.ReadAt(footer[:], size-footerLen); err != nil && err != io.EOF {
r.err = fmt.Errorf("leveldb/table: Reader: invalid table (could not read footer): %v", err)
}
if string(footer[footerLen-len(magic):footerLen]) != magic {
r.err = errors.New("leveldb/table: Reader: invalid table (bad magic number)")
return r
}
// Decode the metaindex block handle.
metaBH, n := decodeBlockHandle(footer[:])
if n == 0 {
r.err = errors.New("leveldb/table: Reader: invalid table (bad metaindex block handle)")
return r
}
// Decode the index block handle.
indexBH, n := decodeBlockHandle(footer[n:])
if n == 0 {
r.err = errors.New("leveldb/table: Reader: invalid table (bad index block handle)")
return r
}
// Read index block.
r.indexBlock, r.err = r.readBlock(indexBH, true)
if r.err != nil {
return r
}
// Read metaindex block.
metaBlock, err := r.readBlock(metaBH, true)
if err != nil {
r.err = err
return r
}
// Set data end.
r.dataEnd = int64(metaBH.offset)
metaIter := metaBlock.newIterator(nil, false, nil)
for metaIter.Next() {
key := string(metaIter.Key())
if !strings.HasPrefix(key, "filter.") {
continue
}
fn := key[7:]
var filter filter.Filter
if f0 := o.GetFilter(); f0 != nil && f0.Name() == fn {
filter = f0
} else {
for _, f0 := range o.GetAltFilters() {
if f0.Name() == fn {
filter = f0
break
}
}
}
if filter != nil {
filterBH, n := decodeBlockHandle(metaIter.Value())
if n == 0 {
continue
}
// Update data end.
r.dataEnd = int64(filterBH.offset)
filterBlock, err := r.readFilterBlock(filterBH, filter)
if err != nil {
continue
}
r.filterBlock = filterBlock
break
}
}
metaIter.Release()
return r
}
// NewReader creates a new initialized table reader for the file.
// The fi, cache and bpool is optional and can be nil.
//
// The returned table reader instance is goroutine-safe.
func NewReader(f io.ReaderAt, size int64, fd storage.FileDesc, cache *cache.CacheGetter, bpool *util.BufferPool, o *opt.Options) (*Reader, error) {
if f == nil {
return nil, errors.New("leveldb/table: nil file")
}
r := &Reader{
fd: fd,
reader: f,
cache: cache,
bpool: bpool,
o: o,
cmp: o.GetComparer(),
verifyChecksum: o.GetStrict(opt.StrictBlockChecksum),
}
if size < footerLen {
r.err = r.newErrCorrupted(0, size, "table", "too small")
return r, nil
}
footerPos := size - footerLen
var footer [footerLen]byte
if _, err := r.reader.ReadAt(footer[:], footerPos); err != nil && err != io.EOF {
return nil, err
}
if string(footer[footerLen-len(magic):footerLen]) != magic {
r.err = r.newErrCorrupted(footerPos, footerLen, "table-footer", "bad magic number")
return r, nil
}
var n int
// Decode the metaindex block handle.
r.metaBH, n = decodeBlockHandle(footer[:])
if n == 0 {
r.err = r.newErrCorrupted(footerPos, footerLen, "table-footer", "bad metaindex block handle")
return r, nil
}
// Decode the index block handle.
r.indexBH, n = decodeBlockHandle(footer[n:])
if n == 0 {
r.err = r.newErrCorrupted(footerPos, footerLen, "table-footer", "bad index block handle")
return r, nil
}
// Read metaindex block.
metaBlock, err := r.readBlock(r.metaBH, true)
if err != nil {
if errors.IsCorrupted(err) {
r.err = err
return r, nil
} else {
return nil, err
}
}
// Set data end.
r.dataEnd = int64(r.metaBH.offset)
// Read metaindex.
metaIter := r.newBlockIter(metaBlock, nil, nil, true)
for metaIter.Next() {
key := string(metaIter.Key())
if !strings.HasPrefix(key, "filter.") {
continue
}
fn := key[7:]
if f0 := o.GetFilter(); f0 != nil && f0.Name() == fn {
r.filter = f0
} else {
for _, f0 := range o.GetAltFilters() {
if f0.Name() == fn {
r.filter = f0
break
}
}
}
if r.filter != nil {
filterBH, n := decodeBlockHandle(metaIter.Value())
if n == 0 {
continue
}
r.filterBH = filterBH
// Update data end.
r.dataEnd = int64(filterBH.offset)
break
}
}
metaIter.Release()
metaBlock.Release()
// Cache index and filter block locally, since we don't have global cache.
if cache == nil {
r.indexBlock, err = r.readBlock(r.indexBH, true)
if err != nil {
if errors.IsCorrupted(err) {
r.err = err
return r, nil
} else {
return nil, err
}
}
if r.filter != nil {
r.filterBlock, err = r.readFilterBlock(r.filterBH)
if err != nil {
if !errors.IsCorrupted(err) {
return nil, err
}
// Don't use filter then.
r.filter = nil
}
}
}
return r, nil
}