diff options
| -rw-r--r-- | README.md | 14 | ||||
| -rw-r--r-- | bolt_386.go | 3 | ||||
| -rw-r--r-- | bolt_amd64.go | 3 | ||||
| -rw-r--r-- | bolt_arm.go | 21 | ||||
| -rw-r--r-- | bolt_arm64.go | 3 | ||||
| -rw-r--r-- | bolt_ppc64le.go | 3 | ||||
| -rw-r--r-- | bolt_s390x.go | 3 | ||||
| -rw-r--r-- | bucket.go | 32 | ||||
| -rw-r--r-- | bucket_test.go | 42 | ||||
| -rw-r--r-- | cmd/bolt/main.go | 208 | ||||
| -rw-r--r-- | cmd/bolt/main_test.go | 171 | ||||
| -rw-r--r-- | freelist.go | 20 | ||||
| -rw-r--r-- | node.go | 5 | ||||
| -rw-r--r-- | page.go | 6 |
14 files changed, 520 insertions, 14 deletions
@@ -1,4 +1,4 @@ -Bolt [](https://coveralls.io/r/boltdb/bolt?branch=master) [](https://godoc.org/github.com/boltdb/bolt)  +Bolt [](https://coveralls.io/r/boltdb/bolt?branch=master) [](https://godoc.org/github.com/boltdb/bolt)  ==== Bolt is a pure Go key/value store inspired by [Howard Chu's][hyc_symas] @@ -209,7 +209,7 @@ and then safely close your transaction if an error is returned. This is the recommended way to use Bolt transactions. However, sometimes you may want to manually start and end your transactions. -You can use the `Tx.Begin()` function directly but **please** be sure to close +You can use the `DB.Begin()` function directly but **please** be sure to close the transaction. ```go @@ -313,7 +313,7 @@ func (s *Store) CreateUser(u *User) error { // Generate ID for the user. // This returns an error only if the Tx is closed or not writeable. // That can't happen in an Update() call so I ignore the error check. - id, _ = b.NextSequence() + id, _ := b.NextSequence() u.ID = int(id) // Marshal user data into bytes. @@ -557,7 +557,7 @@ if err != nil { Bolt is able to run on mobile devices by leveraging the binding feature of the [gomobile](https://github.com/golang/mobile) tool. Create a struct that will contain your database logic and a reference to a `*bolt.DB` with a initializing -contstructor that takes in a filepath where the database file will be stored. +constructor that takes in a filepath where the database file will be stored. Neither Android nor iOS require extra permissions or cleanup from using this method. ```go @@ -807,6 +807,7 @@ them via pull request. Below is a list of public, open source projects that use Bolt: +* [BoltDbWeb](https://github.com/evnix/boltdbweb) - A web based GUI for BoltDB files. * [Operation Go: A Routine Mission](http://gocode.io) - An online programming game for Golang using Bolt for user accounts and a leaderboard. * [Bazil](https://bazil.org/) - A file system that lets your data reside where it is most convenient for it to reside. * [DVID](https://github.com/janelia-flyem/dvid) - Added Bolt as optional storage engine and testing it against Basho-tuned leveldb. @@ -825,7 +826,6 @@ Below is a list of public, open source projects that use Bolt: * [cayley](https://github.com/google/cayley) - Cayley is an open-source graph database using Bolt as optional backend. * [bleve](http://www.blevesearch.com/) - A pure Go search engine similar to ElasticSearch that uses Bolt as the default storage backend. * [tentacool](https://github.com/optiflows/tentacool) - REST api server to manage system stuff (IP, DNS, Gateway...) on a linux server. -* [SkyDB](https://github.com/skydb/sky) - Behavioral analytics database. * [Seaweed File System](https://github.com/chrislusf/seaweedfs) - Highly scalable distributed key~file system with O(1) disk read. * [InfluxDB](https://influxdata.com) - Scalable datastore for metrics, events, and real-time analytics. * [Freehold](http://tshannon.bitbucket.org/freehold/) - An open, secure, and lightweight platform for your files and data. @@ -842,9 +842,11 @@ Below is a list of public, open source projects that use Bolt: * [Go Report Card](https://goreportcard.com/) - Go code quality report cards as a (free and open source) service. * [Boltdb Boilerplate](https://github.com/bobintornado/boltdb-boilerplate) - Boilerplate wrapper around bolt aiming to make simple calls one-liners. * [lru](https://github.com/crowdriff/lru) - Easy to use Bolt-backed Least-Recently-Used (LRU) read-through cache with chainable remote stores. -* [Storm](https://github.com/asdine/storm) - A simple ORM around BoltDB. +* [Storm](https://github.com/asdine/storm) - Simple and powerful ORM for BoltDB. * [GoWebApp](https://github.com/josephspurrier/gowebapp) - A basic MVC web application in Go using BoltDB. * [SimpleBolt](https://github.com/xyproto/simplebolt) - A simple way to use BoltDB. Deals mainly with strings. * [Algernon](https://github.com/xyproto/algernon) - A HTTP/2 web server with built-in support for Lua. Uses BoltDB as the default database backend. +* [MuLiFS](https://github.com/dankomiocevic/mulifs) - Music Library Filesystem creates a filesystem to organise your music files. +* [GoShort](https://github.com/pankajkhairnar/goShort) - GoShort is a URL shortener written in Golang and BoltDB for persistent key/value storage and for routing it's using high performent HTTPRouter. If you are using Bolt in a project please send a pull request to add it to the list. diff --git a/bolt_386.go b/bolt_386.go index e659bfb..820d533 100644 --- a/bolt_386.go +++ b/bolt_386.go @@ -5,3 +5,6 @@ const maxMapSize = 0x7FFFFFFF // 2GB // maxAllocSize is the size used when creating array pointers. const maxAllocSize = 0xFFFFFFF + +// Are unaligned load/stores broken on this arch? +var brokenUnaligned = false diff --git a/bolt_amd64.go b/bolt_amd64.go index cca6b7e..98fafdb 100644 --- a/bolt_amd64.go +++ b/bolt_amd64.go @@ -5,3 +5,6 @@ const maxMapSize = 0xFFFFFFFFFFFF // 256TB // maxAllocSize is the size used when creating array pointers. const maxAllocSize = 0x7FFFFFFF + +// Are unaligned load/stores broken on this arch? +var brokenUnaligned = false diff --git a/bolt_arm.go b/bolt_arm.go index e659bfb..7e5cb4b 100644 --- a/bolt_arm.go +++ b/bolt_arm.go @@ -1,7 +1,28 @@ package bolt +import "unsafe" + // maxMapSize represents the largest mmap size supported by Bolt. const maxMapSize = 0x7FFFFFFF // 2GB // maxAllocSize is the size used when creating array pointers. const maxAllocSize = 0xFFFFFFF + +// Are unaligned load/stores broken on this arch? +var brokenUnaligned bool + +func init() { + // Simple check to see whether this arch handles unaligned load/stores + // correctly. + + // ARM9 and older devices require load/stores to be from/to aligned + // addresses. If not, the lower 2 bits are cleared and that address is + // read in a jumbled up order. + + // See http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka15414.html + + raw := [6]byte{0xfe, 0xef, 0x11, 0x22, 0x22, 0x11} + val := *(*uint32)(unsafe.Pointer(uintptr(unsafe.Pointer(&raw)) + 2)) + + brokenUnaligned = val != 0x11222211 +} diff --git a/bolt_arm64.go b/bolt_arm64.go index 6d23093..b26d84f 100644 --- a/bolt_arm64.go +++ b/bolt_arm64.go @@ -7,3 +7,6 @@ const maxMapSize = 0xFFFFFFFFFFFF // 256TB // maxAllocSize is the size used when creating array pointers. const maxAllocSize = 0x7FFFFFFF + +// Are unaligned load/stores broken on this arch? +var brokenUnaligned = false diff --git a/bolt_ppc64le.go b/bolt_ppc64le.go index 8351e12..8c143bc 100644 --- a/bolt_ppc64le.go +++ b/bolt_ppc64le.go @@ -7,3 +7,6 @@ const maxMapSize = 0xFFFFFFFFFFFF // 256TB // maxAllocSize is the size used when creating array pointers. const maxAllocSize = 0x7FFFFFFF + +// Are unaligned load/stores broken on this arch? +var brokenUnaligned = false diff --git a/bolt_s390x.go b/bolt_s390x.go index f4dd26b..d7c39af 100644 --- a/bolt_s390x.go +++ b/bolt_s390x.go @@ -7,3 +7,6 @@ const maxMapSize = 0xFFFFFFFFFFFF // 256TB // maxAllocSize is the size used when creating array pointers. const maxAllocSize = 0x7FFFFFFF + +// Are unaligned load/stores broken on this arch? +var brokenUnaligned = false @@ -130,9 +130,17 @@ func (b *Bucket) Bucket(name []byte) *Bucket { func (b *Bucket) openBucket(value []byte) *Bucket { var child = newBucket(b.tx) + // If unaligned load/stores are broken on this arch and value is + // unaligned simply clone to an aligned byte array. + unaligned := brokenUnaligned && uintptr(unsafe.Pointer(&value[0]))&3 != 0 + + if unaligned { + value = cloneBytes(value) + } + // If this is a writable transaction then we need to copy the bucket entry. // Read-only transactions can point directly at the mmap entry. - if b.tx.writable { + if b.tx.writable && !unaligned { child.bucket = &bucket{} *child.bucket = *(*bucket)(unsafe.Pointer(&value[0])) } else { @@ -329,6 +337,28 @@ func (b *Bucket) Delete(key []byte) error { return nil } +// Sequence returns the current integer for the bucket without incrementing it. +func (b *Bucket) Sequence() uint64 { return b.bucket.sequence } + +// SetSequence updates the sequence number for the bucket. +func (b *Bucket) SetSequence(v uint64) error { + if b.tx.db == nil { + return ErrTxClosed + } else if !b.Writable() { + return ErrTxNotWritable + } + + // Materialize the root node if it hasn't been already so that the + // bucket will be saved during commit. + if b.rootNode == nil { + _ = b.node(b.root, nil) + } + + // Increment and return the sequence. + b.bucket.sequence = v + return nil +} + // NextSequence returns an autoincrementing integer for the bucket. func (b *Bucket) NextSequence() (uint64, error) { if b.tx.db == nil { diff --git a/bucket_test.go b/bucket_test.go index 528fec2..cddbe27 100644 --- a/bucket_test.go +++ b/bucket_test.go @@ -782,6 +782,48 @@ func TestBucket_DeleteBucket_IncompatibleValue(t *testing.T) { } } +// Ensure bucket can set and update its sequence number. +func TestBucket_Sequence(t *testing.T) { + db := MustOpenDB() + defer db.MustClose() + + if err := db.Update(func(tx *bolt.Tx) error { + bkt, err := tx.CreateBucket([]byte("0")) + if err != nil { + t.Fatal(err) + } + + // Retrieve sequence. + if v := bkt.Sequence(); v != 0 { + t.Fatalf("unexpected sequence: %d", v) + } + + // Update sequence. + if err := bkt.SetSequence(1000); err != nil { + t.Fatal(err) + } + + // Read sequence again. + if v := bkt.Sequence(); v != 1000 { + t.Fatalf("unexpected sequence: %d", v) + } + + return nil + }); err != nil { + t.Fatal(err) + } + + // Verify sequence in separate transaction. + if err := db.View(func(tx *bolt.Tx) error { + if v := tx.Bucket([]byte("0")).Sequence(); v != 1000 { + t.Fatalf("unexpected sequence: %d", v) + } + return nil + }); err != nil { + t.Fatal(err) + } +} + // Ensure that a bucket can return an autoincrementing sequence. func TestBucket_NextSequence(t *testing.T) { db := MustOpenDB() diff --git a/cmd/bolt/main.go b/cmd/bolt/main.go index 9d599f1..29e393f 100644 --- a/cmd/bolt/main.go +++ b/cmd/bolt/main.go @@ -102,6 +102,8 @@ func (m *Main) Run(args ...string) error { return newBenchCommand(m).Run(args[1:]...) case "check": return newCheckCommand(m).Run(args[1:]...) + case "compact": + return newCompactCommand(m).Run(args[1:]...) case "dump": return newDumpCommand(m).Run(args[1:]...) case "info": @@ -130,6 +132,7 @@ The commands are: bench run synthetic benchmark against bolt check verifies integrity of bolt database + compact copies a bolt database, compacting it in the process info print basic info help print this screen pages print list of pages with their types @@ -1530,3 +1533,208 @@ func (n *leafPageElement) value() []byte { buf := (*[maxAllocSize]byte)(unsafe.Pointer(n)) return buf[n.pos+n.ksize : n.pos+n.ksize+n.vsize] } + +// CompactCommand represents the "compact" command execution. +type CompactCommand struct { + Stdin io.Reader + Stdout io.Writer + Stderr io.Writer + + SrcPath string + DstPath string + TxMaxSize int64 +} + +// newCompactCommand returns a CompactCommand. +func newCompactCommand(m *Main) *CompactCommand { + return &CompactCommand{ + Stdin: m.Stdin, + Stdout: m.Stdout, + Stderr: m.Stderr, + } +} + +// Run executes the command. +func (cmd *CompactCommand) Run(args ...string) (err error) { + // Parse flags. + fs := flag.NewFlagSet("", flag.ContinueOnError) + fs.SetOutput(ioutil.Discard) + fs.StringVar(&cmd.DstPath, "o", "", "") + fs.Int64Var(&cmd.TxMaxSize, "tx-max-size", 65536, "") + if err := fs.Parse(args); err == flag.ErrHelp { + fmt.Fprintln(cmd.Stderr, cmd.Usage()) + return ErrUsage + } else if err != nil { + return err + } else if cmd.DstPath == "" { + return fmt.Errorf("output file required") + } + + // Require database paths. + cmd.SrcPath = fs.Arg(0) + if cmd.SrcPath == "" { + return ErrPathRequired + } + + // Ensure source file exists. + fi, err := os.Stat(cmd.SrcPath) + if os.IsNotExist(err) { + return ErrFileNotFound + } else if err != nil { + return err + } + initialSize := fi.Size() + + // Open source database. + src, err := bolt.Open(cmd.SrcPath, 0444, nil) + if err != nil { + return err + } + defer src.Close() + + // Open destination database. + dst, err := bolt.Open(cmd.DstPath, fi.Mode(), nil) + if err != nil { + return err + } + defer dst.Close() + + // Run compaction. + if err := cmd.compact(dst, src); err != nil { + return err + } + + // Report stats on new size. + fi, err = os.Stat(cmd.DstPath) + if err != nil { + return err + } else if fi.Size() == 0 { + return fmt.Errorf("zero db size") + } + fmt.Fprintf(cmd.Stdout, "%d -> %d bytes (gain=%.2fx)\n", initialSize, fi.Size(), float64(initialSize)/float64(fi.Size())) + + return nil +} + +func (cmd *CompactCommand) compact(dst, src *bolt.DB) error { + // commit regularly, or we'll run out of memory for large datasets if using one transaction. + var size int64 + tx, err := dst.Begin(true) + if err != nil { + return err + } + defer tx.Rollback() + + if err := cmd.walk(src, func(keys [][]byte, k, v []byte, seq uint64) error { + // On each key/value, check if we have exceeded tx size. + sz := int64(len(k) + len(v)) + if size+sz > cmd.TxMaxSize && cmd.TxMaxSize != 0 { + // Commit previous transaction. + if err := tx.Commit(); err != nil { + return err + } + + // Start new transaction. + tx, err = dst.Begin(true) + if err != nil { + return err + } + size = 0 + } + size += sz + + // Create bucket on the root transaction if this is the first level. + nk := len(keys) + if nk == 0 { + bkt, err := tx.CreateBucket(k) + if err != nil { + return err + } + if err := bkt.SetSequence(seq); err != nil { + return err + } + return nil + } + + // Create buckets on subsequent levels, if necessary. + b := tx.Bucket(keys[0]) + if nk > 1 { + for _, k := range keys[1:] { + b = b.Bucket(k) + } + } + + // If there is no value then this is a bucket call. + if v == nil { + bkt, err := b.CreateBucket(k) + if err != nil { + return err + } + if err := bkt.SetSequence(seq); err != nil { + return err + } + return nil + } + + // Otherwise treat it as a key/value pair. + return b.Put(k, v) + }); err != nil { + return err + } + + return tx.Commit() +} + +// walkFunc is the type of the function called for keys (buckets and "normal" +// values) discovered by Walk. keys is the list of keys to descend to the bucket +// owning the discovered key/value pair k/v. +type walkFunc func(keys [][]byte, k, v []byte, seq uint64) error + +// walk walks recursively the bolt database db, calling walkFn for each key it finds. +func (cmd *CompactCommand) walk(db *bolt.DB, walkFn walkFunc) error { + return db.View(func(tx *bolt.Tx) error { + return tx.ForEach(func(name []byte, b *bolt.Bucket) error { + return cmd.walkBucket(b, nil, name, nil, b.Sequence(), walkFn) + }) + }) +} + +func (cmd *CompactCommand) walkBucket(b *bolt.Bucket, keypath [][]byte, k, v []byte, seq uint64, fn walkFunc) error { + // Execute callback. + if err := fn(keypath, k, v, seq); err != nil { + return err + } + + // If this is not a bucket then stop. + if v != nil { + return nil + } + + // Iterate over each child key/value. + keypath = append(keypath, k) + return b.ForEach(func(k, v []byte) error { + if v == nil { + bkt := b.Bucket(k) + return cmd.walkBucket(bkt, keypath, k, nil, bkt.Sequence(), fn) + } + return cmd.walkBucket(b, keypath, k, v, b.Sequence(), fn) + }) +} + +// Usage returns the help message. +func (cmd *CompactCommand) Usage() string { + return strings.TrimLeft(` +usage: bolt compact [options] -o DST SRC + +Compact opens a database at SRC path and walks it recursively, copying keys +as they are found from all buckets, to a newly created database at DST path. + +The original database is left untouched. + +Additional options include: + + -tx-max-size NUM + Specifies the maximum size of individual transactions. + Defaults to 64KB. +`, "\n") +} diff --git a/cmd/bolt/main_test.go b/cmd/bolt/main_test.go index c378b79..0a11ff3 100644 --- a/cmd/bolt/main_test.go +++ b/cmd/bolt/main_test.go @@ -2,7 +2,12 @@ package main_test import ( "bytes" + crypto "crypto/rand" + "encoding/binary" + "fmt" + "io" "io/ioutil" + "math/rand" "os" "strconv" "testing" @@ -183,3 +188,169 @@ func (db *DB) Close() error { defer os.Remove(db.Path) return db.DB.Close() } + +func TestCompactCommand_Run(t *testing.T) { + var s int64 + if err := binary.Read(crypto.Reader, binary.BigEndian, &s); err != nil { + t.Fatal(err) + } + rand.Seed(s) + + dstdb := MustOpen(0666, nil) + dstdb.Close() + + // fill the db + db := MustOpen(0666, nil) + if err := db.Update(func(tx *bolt.Tx) error { + n := 2 + rand.Intn(5) + for i := 0; i < n; i++ { + k := []byte(fmt.Sprintf("b%d", i)) + b, err := tx.CreateBucketIfNotExists(k) + if err != nil { + return err + } + if err := b.SetSequence(uint64(i)); err != nil { + return err + } + if err := fillBucket(b, append(k, '.')); err != nil { + return err + } + } + return nil + }); err != nil { + db.Close() + t.Fatal(err) + } + + // make the db grow by adding large values, and delete them. + if err := db.Update(func(tx *bolt.Tx) error { + b, err := tx.CreateBucketIfNotExists([]byte("large_vals")) + if err != nil { + return err + } + n := 5 + rand.Intn(5) + for i := 0; i < n; i++ { + v := make([]byte, 1000*1000*(1+rand.Intn(5))) + _, err := crypto.Read(v) + if err != nil { + return err + } + if err := b.Put([]byte(fmt.Sprintf("l%d", i)), v); err != nil { + return err + } + } + return nil + }); err != nil { + db.Close() + t.Fatal(err) + } + if err := db.Update(func(tx *bolt.Tx) error { + c := tx.Bucket([]byte("large_vals")).Cursor() + for k, _ := c.First(); k != nil; k, _ = c.Next() { + if err := c.Delete(); err != nil { + return err + } + } + return tx.DeleteBucket([]byte("large_vals")) + }); err != nil { + db.Close() + t.Fatal(err) + } + db.DB.Close() + defer db.Close() + defer dstdb.Close() + + dbChk, err := chkdb(db.Path) + if err != nil { + t.Fatal(err) + } + + m := NewMain() + if err := m.Run("compact", "-o", dstdb.Path, db.Path); err != nil { + t.Fatal(err) + } + + dbChkAfterCompact, err := chkdb(db.Path) + if err != nil { + t.Fatal(err) + } + + dstdbChk, err := chkdb(dstdb.Path) + if err != nil { + t.Fatal(err) + } + + if !bytes.Equal(dbChk, dbChkAfterCompact) { + t.Error("the original db has been touched") + } + if !bytes.Equal(dbChk, dstdbChk) { + t.Error("the compacted db data isn't the same than the original db") + } +} + +func fillBucket(b *bolt.Bucket, prefix []byte) error { + n := 10 + rand.Intn(50) + for i := 0; i < n; i++ { + v := make([]byte, 10*(1+rand.Intn(4))) + _, err := crypto.Read(v) + if err != nil { + return err + } + k := append(prefix, []byte(fmt.Sprintf("k%d", i))...) + if err := b.Put(k, v); err != nil { + return err + } + } + // limit depth of subbuckets + s := 2 + rand.Intn(4) + if len(prefix) > (2*s + 1) { + return nil + } + n = 1 + rand.Intn(3) + for i := 0; i < n; i++ { + k := append(prefix, []byte(fmt.Sprintf("b%d", i))...) + sb, err := b.CreateBucket(k) + if err != nil { + return err + } + if err := fillBucket(sb, append(k, '.')); err != nil { + return err + } + } + return nil +} + +func chkdb(path string) ([]byte, error) { + db, err := bolt.Open(path, 0666, nil) + if err != nil { + return nil, err + } + defer db.Close() + var buf bytes.Buffer + err = db.View(func(tx *bolt.Tx) error { + return tx.ForEach(func(name []byte, b *bolt.Bucket) error { + return walkBucket(b, name, nil, &buf) + }) + }) + if err != nil { + return nil, err + } + return buf.Bytes(), nil +} + +func walkBucket(parent *bolt.Bucket, k []byte, v []byte, w io.Writer) error { + if _, err := fmt.Fprintf(w, "%d:%x=%x\n", parent.Sequence(), k, v); err != nil { + return err + } + + // not a bucket, exit. + if v != nil { + return nil + } + return parent.ForEach(func(k, v []byte) error { + if v == nil { + return walkBucket(parent.Bucket(k), k, nil, w) + } + return walkBucket(parent, k, v, w) + }) +} diff --git a/freelist.go b/freelist.go index 0161948..d32f6cd 100644 --- a/freelist.go +++ b/freelist.go @@ -166,12 +166,16 @@ func (f *freelist) read(p *page) { } // Copy the list of page ids from the freelist. - ids := ((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[idx:count] - f.ids = make([]pgid, len(ids)) - copy(f.ids, ids) + if count == 0 { + f.ids = nil + } else { + ids := ((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[idx:count] + f.ids = make([]pgid, len(ids)) + copy(f.ids, ids) - // Make sure they're sorted. - sort.Sort(pgids(f.ids)) + // Make sure they're sorted. + sort.Sort(pgids(f.ids)) + } // Rebuild the page cache. f.reindex() @@ -189,7 +193,9 @@ func (f *freelist) write(p *page) error { // The page.count can only hold up to 64k elements so if we overflow that // number then we handle it by putting the size in the first element. - if len(ids) < 0xFFFF { + if len(ids) == 0 { + p.count = uint16(len(ids)) + } else if len(ids) < 0xFFFF { p.count = uint16(len(ids)) copy(((*[maxAllocSize]pgid)(unsafe.Pointer(&p.ptr)))[:], ids) } else { @@ -230,7 +236,7 @@ func (f *freelist) reload(p *page) { // reindex rebuilds the free cache based on available and pending free lists. func (f *freelist) reindex() { - f.cache = make(map[pgid]bool) + f.cache = make(map[pgid]bool, len(f.ids)) for _, id := range f.ids { f.cache[id] = true } @@ -201,6 +201,11 @@ func (n *node) write(p *page) { } p.count = uint16(len(n.inodes)) + // Stop here if there are no items to write. + if p.count == 0 { + return + } + // Loop over each item and write it to the page. b := (*[maxAllocSize]byte)(unsafe.Pointer(&p.ptr))[n.pageElementSize()*len(n.inodes):] for i, item := range n.inodes { @@ -62,6 +62,9 @@ func (p *page) leafPageElement(index uint16) *leafPageElement { // leafPageElements retrieves a list of leaf nodes. func (p *page) leafPageElements() []leafPageElement { + if p.count == 0 { + return nil + } return ((*[0x7FFFFFF]leafPageElement)(unsafe.Pointer(&p.ptr)))[:] } @@ -72,6 +75,9 @@ func (p *page) branchPageElement(index uint16) *branchPageElement { // branchPageElements retrieves a list of branch nodes. func (p *page) branchPageElements() []branchPageElement { + if p.count == 0 { + return nil + } return ((*[0x7FFFFFF]branchPageElement)(unsafe.Pointer(&p.ptr)))[:] } |