1 files changed, 529 insertions, 0 deletions
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/table.go b/vendor/github.com/syndtr/goleveldb/leveldb/table.go
new file mode 100644
index 0000000..81d18a5
--- /dev/null
+++ b/vendor/github.com/syndtr/goleveldb/leveldb/table.go
@@ -0,0 +1,529 @@
+// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
+// All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package leveldb
+
+import (
+	"fmt"
+	"sort"
+	"sync/atomic"
+
+	"github.com/syndtr/goleveldb/leveldb/cache"
+	"github.com/syndtr/goleveldb/leveldb/iterator"
+	"github.com/syndtr/goleveldb/leveldb/opt"
+	"github.com/syndtr/goleveldb/leveldb/storage"
+	"github.com/syndtr/goleveldb/leveldb/table"
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+// tFile holds basic information about a table.
+type tFile struct {
+	fd         storage.FileDesc
+	seekLeft   int32
+	size       int64
+	imin, imax internalKey
+}
+
+// Returns true if given key is after largest key of this table.
+func (t *tFile) after(icmp *iComparer, ukey []byte) bool {
+	return ukey != nil && icmp.uCompare(ukey, t.imax.ukey()) > 0
+}
+
+// Returns true if given key is before smallest key of this table.
+func (t *tFile) before(icmp *iComparer, ukey []byte) bool {
+	return ukey != nil && icmp.uCompare(ukey, t.imin.ukey()) < 0
+}
+
+// Returns true if given key range overlaps with this table key range.
+func (t *tFile) overlaps(icmp *iComparer, umin, umax []byte) bool {
+	return !t.after(icmp, umin) && !t.before(icmp, umax)
+}
+
+// Cosumes one seek and return current seeks left.
+func (t *tFile) consumeSeek() int32 {
+	return atomic.AddInt32(&t.seekLeft, -1)
+}
+
+// Creates new tFile.
+func newTableFile(fd storage.FileDesc, size int64, imin, imax internalKey) *tFile {
+	f := &tFile{
+		fd:   fd,
+		size: size,
+		imin: imin,
+		imax: imax,
+	}
+
+	// We arrange to automatically compact this file after
+	// a certain number of seeks.  Let's assume:
+	//   (1) One seek costs 10ms
+	//   (2) Writing or reading 1MB costs 10ms (100MB/s)
+	//   (3) A compaction of 1MB does 25MB of IO:
+	//         1MB read from this level
+	//         10-12MB read from next level (boundaries may be misaligned)
+	//         10-12MB written to next level
+	// This implies that 25 seeks cost the same as the compaction
+	// of 1MB of data.  I.e., one seek costs approximately the
+	// same as the compaction of 40KB of data.  We are a little
+	// conservative and allow approximately one seek for every 16KB
+	// of data before triggering a compaction.
+	f.seekLeft = int32(size / 16384)
+	if f.seekLeft < 100 {
+		f.seekLeft = 100
+	}
+
+	return f
+}
+
+func tableFileFromRecord(r atRecord) *tFile {
+	return newTableFile(storage.FileDesc{storage.TypeTable, r.num}, r.size, r.imin, r.imax)
+}
+
+// tFiles hold multiple tFile.
+type tFiles []*tFile
+
+func (tf tFiles) Len() int      { return len(tf) }
+func (tf tFiles) Swap(i, j int) { tf[i], tf[j] = tf[j], tf[i] }
+
+func (tf tFiles) nums() string {
+	x := "[ "
+	for i, f := range tf {
+		if i != 0 {
+			x += ", "
+		}
+		x += fmt.Sprint(f.fd.Num)
+	}
+	x += " ]"
+	return x
+}
+
+// Returns true if i smallest key is less than j.
+// This used for sort by key in ascending order.
+func (tf tFiles) lessByKey(icmp *iComparer, i, j int) bool {
+	a, b := tf[i], tf[j]
+	n := icmp.Compare(a.imin, b.imin)
+	if n == 0 {
+		return a.fd.Num < b.fd.Num
+	}
+	return n < 0
+}
+
+// Returns true if i file number is greater than j.
+// This used for sort by file number in descending order.
+func (tf tFiles) lessByNum(i, j int) bool {
+	return tf[i].fd.Num > tf[j].fd.Num
+}
+
+// Sorts tables by key in ascending order.
+func (tf tFiles) sortByKey(icmp *iComparer) {
+	sort.Sort(&tFilesSortByKey{tFiles: tf, icmp: icmp})
+}
+
+// Sorts tables by file number in descending order.
+func (tf tFiles) sortByNum() {
+	sort.Sort(&tFilesSortByNum{tFiles: tf})
+}
+
+// Returns sum of all tables size.
+func (tf tFiles) size() (sum int64) {
+	for _, t := range tf {
+		sum += t.size
+	}
+	return sum
+}
+
+// Searches smallest index of tables whose its smallest
+// key is after or equal with given key.
+func (tf tFiles) searchMin(icmp *iComparer, ikey internalKey) int {
+	return sort.Search(len(tf), func(i int) bool {
+		return icmp.Compare(tf[i].imin, ikey) >= 0
+	})
+}
+
+// Searches smallest index of tables whose its largest
+// key is after or equal with given key.
+func (tf tFiles) searchMax(icmp *iComparer, ikey internalKey) int {
+	return sort.Search(len(tf), func(i int) bool {
+		return icmp.Compare(tf[i].imax, ikey) >= 0
+	})
+}
+
+// Returns true if given key range overlaps with one or more
+// tables key range. If unsorted is true then binary search will not be used.
+func (tf tFiles) overlaps(icmp *iComparer, umin, umax []byte, unsorted bool) bool {
+	if unsorted {
+		// Check against all files.
+		for _, t := range tf {
+			if t.overlaps(icmp, umin, umax) {
+				return true
+			}
+		}
+		return false
+	}
+
+	i := 0
+	if len(umin) > 0 {
+		// Find the earliest possible internal key for min.
+		i = tf.searchMax(icmp, makeInternalKey(nil, umin, keyMaxSeq, keyTypeSeek))
+	}
+	if i >= len(tf) {
+		// Beginning of range is after all files, so no overlap.
+		return false
+	}
+	return !tf[i].before(icmp, umax)
+}
+
+// Returns tables whose its key range overlaps with given key range.
+// Range will be expanded if ukey found hop across tables.
+// If overlapped is true then the search will be restarted if umax
+// expanded.
+// The dst content will be overwritten.
+func (tf tFiles) getOverlaps(dst tFiles, icmp *iComparer, umin, umax []byte, overlapped bool) tFiles {
+	dst = dst[:0]
+	for i := 0; i < len(tf); {
+		t := tf[i]
+		if t.overlaps(icmp, umin, umax) {
+			if umin != nil && icmp.uCompare(t.imin.ukey(), umin) < 0 {
+				umin = t.imin.ukey()
+				dst = dst[:0]
+				i = 0
+				continue
+			} else if umax != nil && icmp.uCompare(t.imax.ukey(), umax) > 0 {
+				umax = t.imax.ukey()
+				// Restart search if it is overlapped.
+				if overlapped {
+					dst = dst[:0]
+					i = 0
+					continue
+				}
+			}
+
+			dst = append(dst, t)
+		}
+		i++
+	}
+
+	return dst
+}
+
+// Returns tables key range.
+func (tf tFiles) getRange(icmp *iComparer) (imin, imax internalKey) {
+	for i, t := range tf {
+		if i == 0 {
+			imin, imax = t.imin, t.imax
+			continue
+		}
+		if icmp.Compare(t.imin, imin) < 0 {
+			imin = t.imin
+		}
+		if icmp.Compare(t.imax, imax) > 0 {
+			imax = t.imax
+		}
+	}
+
+	return
+}
+
+// Creates iterator index from tables.
+func (tf tFiles) newIndexIterator(tops *tOps, icmp *iComparer, slice *util.Range, ro *opt.ReadOptions) iterator.IteratorIndexer {
+	if slice != nil {
+		var start, limit int
+		if slice.Start != nil {
+			start = tf.searchMax(icmp, internalKey(slice.Start))
+		}
+		if slice.Limit != nil {
+			limit = tf.searchMin(icmp, internalKey(slice.Limit))
+		} else {
+			limit = tf.Len()
+		}
+		tf = tf[start:limit]
+	}
+	return iterator.NewArrayIndexer(&tFilesArrayIndexer{
+		tFiles: tf,
+		tops:   tops,
+		icmp:   icmp,
+		slice:  slice,
+		ro:     ro,
+	})
+}
+
+// Tables iterator index.
+type tFilesArrayIndexer struct {
+	tFiles
+	tops  *tOps
+	icmp  *iComparer
+	slice *util.Range
+	ro    *opt.ReadOptions
+}
+
+func (a *tFilesArrayIndexer) Search(key []byte) int {
+	return a.searchMax(a.icmp, internalKey(key))
+}
+
+func (a *tFilesArrayIndexer) Get(i int) iterator.Iterator {
+	if i == 0 || i == a.Len()-1 {
+		return a.tops.newIterator(a.tFiles[i], a.slice, a.ro)
+	}
+	return a.tops.newIterator(a.tFiles[i], nil, a.ro)
+}
+
+// Helper type for sortByKey.
+type tFilesSortByKey struct {
+	tFiles
+	icmp *iComparer
+}
+
+func (x *tFilesSortByKey) Less(i, j int) bool {
+	return x.lessByKey(x.icmp, i, j)
+}
+
+// Helper type for sortByNum.
+type tFilesSortByNum struct {
+	tFiles
+}
+
+func (x *tFilesSortByNum) Less(i, j int) bool {
+	return x.lessByNum(i, j)
+}
+
+// Table operations.
+type tOps struct {
+	s      *session
+	noSync bool
+	cache  *cache.Cache
+	bcache *cache.Cache
+	bpool  *util.BufferPool
+}
+
+// Creates an empty table and returns table writer.
+func (t *tOps) create() (*tWriter, error) {
+	fd := storage.FileDesc{storage.TypeTable, t.s.allocFileNum()}
+	fw, err := t.s.stor.Create(fd)
+	if err != nil {
+		return nil, err
+	}
+	return &tWriter{
+		t:  t,
+		fd: fd,
+		w:  fw,
+		tw: table.NewWriter(fw, t.s.o.Options),
+	}, nil
+}
+
+// Builds table from src iterator.
+func (t *tOps) createFrom(src iterator.Iterator) (f *tFile, n int, err error) {
+	w, err := t.create()
+	if err != nil {
+		return
+	}
+
+	defer func() {
+		if err != nil {
+			w.drop()
+		}
+	}()
+
+	for src.Next() {
+		err = w.append(src.Key(), src.Value())
+		if err != nil {
+			return
+		}
+	}
+	err = src.Error()
+	if err != nil {
+		return
+	}
+
+	n = w.tw.EntriesLen()
+	f, err = w.finish()
+	return
+}
+
+// Opens table. It returns a cache handle, which should
+// be released after use.
+func (t *tOps) open(f *tFile) (ch *cache.Handle, err error) {
+	ch = t.cache.Get(0, uint64(f.fd.Num), func() (size int, value cache.Value) {
+		var r storage.Reader
+		r, err = t.s.stor.Open(f.fd)
+		if err != nil {
+			return 0, nil
+		}
+
+		var bcache *cache.NamespaceGetter
+		if t.bcache != nil {
+			bcache = &cache.NamespaceGetter{Cache: t.bcache, NS: uint64(f.fd.Num)}
+		}
+
+		var tr *table.Reader
+		tr, err = table.NewReader(r, f.size, f.fd, bcache, t.bpool, t.s.o.Options)
+		if err != nil {
+			r.Close()
+			return 0, nil
+		}
+		return 1, tr
+
+	})
+	if ch == nil && err == nil {
+		err = ErrClosed
+	}
+	return
+}
+
+// Finds key/value pair whose key is greater than or equal to the
+// given key.
+func (t *tOps) find(f *tFile, key []byte, ro *opt.ReadOptions) (rkey, rvalue []byte, err error) {
+	ch, err := t.open(f)
+	if err != nil {
+		return nil, nil, err
+	}
+	defer ch.Release()
+	return ch.Value().(*table.Reader).Find(key, true, ro)
+}
+
+// Finds key that is greater than or equal to the given key.
+func (t *tOps) findKey(f *tFile, key []byte, ro *opt.ReadOptions) (rkey []byte, err error) {
+	ch, err := t.open(f)
+	if err != nil {
+		return nil, err
+	}
+	defer ch.Release()
+	return ch.Value().(*table.Reader).FindKey(key, true, ro)
+}
+
+// Returns approximate offset of the given key.
+func (t *tOps) offsetOf(f *tFile, key []byte) (offset int64, err error) {
+	ch, err := t.open(f)
+	if err != nil {
+		return
+	}
+	defer ch.Release()
+	return ch.Value().(*table.Reader).OffsetOf(key)
+}
+
+// Creates an iterator from the given table.
+func (t *tOps) newIterator(f *tFile, slice *util.Range, ro *opt.ReadOptions) iterator.Iterator {
+	ch, err := t.open(f)
+	if err != nil {
+		return iterator.NewEmptyIterator(err)
+	}
+	iter := ch.Value().(*table.Reader).NewIterator(slice, ro)
+	iter.SetReleaser(ch)
+	return iter
+}
+
+// Removes table from persistent storage. It waits until
+// no one use the the table.
+func (t *tOps) remove(f *tFile) {
+	t.cache.Delete(0, uint64(f.fd.Num), func() {
+		if err := t.s.stor.Remove(f.fd); err != nil {
+			t.s.logf("table@remove removing @%d %q", f.fd.Num, err)
+		} else {
+			t.s.logf("table@remove removed @%d", f.fd.Num)
+		}
+		if t.bcache != nil {
+			t.bcache.EvictNS(uint64(f.fd.Num))
+		}
+	})
+}
+
+// Closes the table ops instance. It will close all tables,
+// regadless still used or not.
+func (t *tOps) close() {
+	t.bpool.Close()
+	t.cache.Close()
+	if t.bcache != nil {
+		t.bcache.CloseWeak()
+	}
+}
+
+// Creates new initialized table ops instance.
+func newTableOps(s *session) *tOps {
+	var (
+		cacher cache.Cacher
+		bcache *cache.Cache
+		bpool  *util.BufferPool
+	)
+	if s.o.GetOpenFilesCacheCapacity() > 0 {
+		cacher = cache.NewLRU(s.o.GetOpenFilesCacheCapacity())
+	}
+	if !s.o.GetDisableBlockCache() {
+		var bcacher cache.Cacher
+		if s.o.GetBlockCacheCapacity() > 0 {
+			bcacher = cache.NewLRU(s.o.GetBlockCacheCapacity())
+		}
+		bcache = cache.NewCache(bcacher)
+	}
+	if !s.o.GetDisableBufferPool() {
+		bpool = util.NewBufferPool(s.o.GetBlockSize() + 5)
+	}
+	return &tOps{
+		s:      s,
+		noSync: s.o.GetNoSync(),
+		cache:  cache.NewCache(cacher),
+		bcache: bcache,
+		bpool:  bpool,
+	}
+}
+
+// tWriter wraps the table writer. It keep track of file descriptor
+// and added key range.
+type tWriter struct {
+	t *tOps
+
+	fd storage.FileDesc
+	w  storage.Writer
+	tw *table.Writer
+
+	first, last []byte
+}
+
+// Append key/value pair to the table.
+func (w *tWriter) append(key, value []byte) error {
+	if w.first == nil {
+		w.first = append([]byte{}, key...)
+	}
+	w.last = append(w.last[:0], key...)
+	return w.tw.Append(key, value)
+}
+
+// Returns true if the table is empty.
+func (w *tWriter) empty() bool {
+	return w.first == nil
+}
+
+// Closes the storage.Writer.
+func (w *tWriter) close() {
+	if w.w != nil {
+		w.w.Close()
+		w.w = nil
+	}
+}
+
+// Finalizes the table and returns table file.
+func (w *tWriter) finish() (f *tFile, err error) {
+	defer w.close()
+	err = w.tw.Close()
+	if err != nil {
+		return
+	}
+	if !w.t.noSync {
+		err = w.w.Sync()
+		if err != nil {
+			return
+		}
+	}
+	f = newTableFile(w.fd, int64(w.tw.BytesLen()), internalKey(w.first), internalKey(w.last))
+	return
+}
+
+// Drops the table.
+func (w *tWriter) drop() {
+	w.close()
+	w.t.s.stor.Remove(w.fd)
+	w.t.s.reuseFileNum(w.fd.Num)
+	w.tw = nil
+	w.first = nil
+	w.last = nil
+}