add other session providers (#5963)

vendor/github.com/syndtr/goleveldb/leveldb/options.go

@@ -0,0 +1,107 @@
+// 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 (
+	"github.com/syndtr/goleveldb/leveldb/filter"
+	"github.com/syndtr/goleveldb/leveldb/opt"
+)
+
+func dupOptions(o *opt.Options) *opt.Options {
+	newo := &opt.Options{}
+	if o != nil {
+		*newo = *o
+	}
+	if newo.Strict == 0 {
+		newo.Strict = opt.DefaultStrict
+	}
+	return newo
+}
+
+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()
+}
+
+const optCachedLevel = 7
+
+type cachedOptions struct {
+	*opt.Options
+
+	compactionExpandLimit []int
+	compactionGPOverlaps  []int
+	compactionSourceLimit []int
+	compactionTableSize   []int
+	compactionTotalSize   []int64
+}
+
+func (co *cachedOptions) cache() {
+	co.compactionExpandLimit = make([]int, optCachedLevel)
+	co.compactionGPOverlaps = make([]int, optCachedLevel)
+	co.compactionSourceLimit = make([]int, optCachedLevel)
+	co.compactionTableSize = make([]int, optCachedLevel)
+	co.compactionTotalSize = make([]int64, optCachedLevel)
+
+	for level := 0; level < optCachedLevel; level++ {
+		co.compactionExpandLimit[level] = co.Options.GetCompactionExpandLimit(level)
+		co.compactionGPOverlaps[level] = co.Options.GetCompactionGPOverlaps(level)
+		co.compactionSourceLimit[level] = co.Options.GetCompactionSourceLimit(level)
+		co.compactionTableSize[level] = co.Options.GetCompactionTableSize(level)
+		co.compactionTotalSize[level] = co.Options.GetCompactionTotalSize(level)
+	}
+}
+
+func (co *cachedOptions) GetCompactionExpandLimit(level int) int {
+	if level < optCachedLevel {
+		return co.compactionExpandLimit[level]
+	}
+	return co.Options.GetCompactionExpandLimit(level)
+}
+
+func (co *cachedOptions) GetCompactionGPOverlaps(level int) int {
+	if level < optCachedLevel {
+		return co.compactionGPOverlaps[level]
+	}
+	return co.Options.GetCompactionGPOverlaps(level)
+}
+
+func (co *cachedOptions) GetCompactionSourceLimit(level int) int {
+	if level < optCachedLevel {
+		return co.compactionSourceLimit[level]
+	}
+	return co.Options.GetCompactionSourceLimit(level)
+}
+
+func (co *cachedOptions) GetCompactionTableSize(level int) int {
+	if level < optCachedLevel {
+		return co.compactionTableSize[level]
+	}
+	return co.Options.GetCompactionTableSize(level)
+}
+
+func (co *cachedOptions) GetCompactionTotalSize(level int) int64 {
+	if level < optCachedLevel {
+		return co.compactionTotalSize[level]
+	}
+	return co.Options.GetCompactionTotalSize(level)
+}