@@ -44,7 +44,7 @@ clone git github.com/coreos/etcd v2.2.0

 fix_rewritten_imports github.com/coreos/etcd

 clone git github.com/ugorji/go 5abd4e96a45c386928ed2ca2a7ef63e2533e18ec

 clone git github.com/hashicorp/consul v0.5.2

-clone git github.com/boltdb/bolt v1.2.0

+clone git github.com/boltdb/bolt v1.2.1

 clone git github.com/miekg/dns 75e6e86cc601825c5dbcd4e0c209eab180997cd7

 # get graph and distribution packages

@@ -1,4 +1,4 @@

-Bolt [![Build Status](https://drone.io/github.com/boltdb/bolt/status.png)](https://drone.io/github.com/boltdb/bolt/latest) [![Coverage Status](https://coveralls.io/repos/boltdb/bolt/badge.svg?branch=master)](https://coveralls.io/r/boltdb/bolt?branch=master) [![GoDoc](https://godoc.org/github.com/boltdb/bolt?status.svg)](https://godoc.org/github.com/boltdb/bolt) ![Version](https://img.shields.io/badge/version-1.0-green.svg)

+Bolt [![Coverage Status](https://coveralls.io/repos/boltdb/bolt/badge.svg?branch=master)](https://coveralls.io/r/boltdb/bolt?branch=master) [![GoDoc](https://godoc.org/github.com/boltdb/bolt?status.svg)](https://godoc.org/github.com/boltdb/bolt) ![Version](https://img.shields.io/badge/version-1.0-green.svg)

 ====

 Bolt is a pure Go key/value store inspired by [Howard Chu's][hyc_symas]

@@ -427,6 +427,8 @@ db.View(func(tx *bolt.Tx) error {

 })

 ```

+Note that, while RFC3339 is sortable, the Golang implementation of RFC3339Nano does not use a fixed number of digits after the decimal point and is therefore not sortable.

+

 #### ForEach()

@@ -437,7 +439,7 @@ all the keys in a bucket:

 db.View(func(tx *bolt.Tx) error {

 	// Assume bucket exists and has keys

 	b := tx.Bucket([]byte("MyBucket"))

-	

+

 	b.ForEach(func(k, v []byte) error {

 		fmt.Printf("key=%s, value=%s\n", k, v)

 		return nil

@@ -617,7 +619,7 @@ Boltmobiledemo.BoltDB boltDB = Boltmobiledemo.NewBoltDB(path)

 {

     NSURL* URL= [NSURL fileURLWithPath: filePathString];

     assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);

-    

+

     NSError *error = nil;

     BOOL success = [URL setResourceValue: [NSNumber numberWithBool: YES]

                                   forKey: NSURLIsExcludedFromBackupKey error: &error];

@@ -840,5 +842,9 @@ 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.

+* [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.

 If you are using Bolt in a project please send a pull request to add it to the list.

@@ -36,6 +36,9 @@ const (

 	DefaultAllocSize         = 16 * 1024 * 1024

 )

+// default page size for db is set to the OS page size.

+var defaultPageSize = os.Getpagesize()

+

 // DB represents a collection of buckets persisted to a file on disk.

 // All data access is performed through transactions which can be obtained through the DB.

 // All the functions on DB will return a ErrDatabaseNotOpen if accessed before Open() is called.

@@ -94,7 +97,7 @@ type DB struct {

 	path     string

 	file     *os.File

 	lockfile *os.File // windows only

-	dataref  []byte // mmap'ed readonly, write throws SEGV

+	dataref  []byte   // mmap'ed readonly, write throws SEGV

 	data     *[maxMapSize]byte

 	datasz   int

 	filesz   int // current on disk file size

@@ -107,6 +110,8 @@ type DB struct {

 	freelist *freelist

 	stats    Stats

+	pagePool sync.Pool

+

 	batchMu sync.Mutex

 	batch   *batch

@@ -200,12 +205,27 @@ func Open(path string, mode os.FileMode, options *Options) (*DB, error) {

 		if _, err := db.file.ReadAt(buf[:], 0); err == nil {

 			m := db.pageInBuffer(buf[:], 0).meta()

 			if err := m.validate(); err != nil {

-				return nil, err

+				// If we can't read the page size, we can assume it's the same

+				// as the OS -- since that's how the page size was chosen in the

+				// first place.

+				//

+				// If the first page is invalid and this OS uses a different

+				// page size than what the database was created with then we

+				// are out of luck and cannot access the database.

+				db.pageSize = os.Getpagesize()

+			} else {

+				db.pageSize = int(m.pageSize)

 			}

-			db.pageSize = int(m.pageSize)

 		}

 	}

+	// Initialize page pool.

+	db.pagePool = sync.Pool{

+		New: func() interface{} {

+			return make([]byte, db.pageSize)

+		},

+	}

+

 	// Memory map the data file.

 	if err := db.mmap(options.InitialMmapSize); err != nil {

 		_ = db.close()

@@ -262,12 +282,13 @@ func (db *DB) mmap(minsz int) error {

 	db.meta0 = db.page(0).meta()

 	db.meta1 = db.page(1).meta()

-	// Validate the meta pages.

-	if err := db.meta0.validate(); err != nil {

-		return err

-	}

-	if err := db.meta1.validate(); err != nil {

-		return err

+	// Validate the meta pages. We only return an error if both meta pages fail

+	// validation, since meta0 failing validation means that it wasn't saved

+	// properly -- but we can recover using meta1. And vice-versa.

+	err0 := db.meta0.validate()

+	err1 := db.meta1.validate()

+	if err0 != nil && err1 != nil {

+		return err0

 	}

 	return nil

@@ -339,6 +360,7 @@ func (db *DB) init() error {

 		m.root = bucket{root: 3}

 		m.pgid = 4

 		m.txid = txid(i)

+		m.checksum = m.sum64()

 	}

 	// Write an empty freelist at page 3.

@@ -383,11 +405,10 @@ func (db *DB) close() error {

 	if !db.opened {

 		return nil

 	}

-	

+

 	db.opened = false

 	db.freelist = nil

-	db.path = ""

 	// Clear ops.

 	db.ops.writeAt = nil

@@ -414,6 +435,7 @@ func (db *DB) close() error {

 		db.file = nil

 	}

+	db.path = ""

 	return nil

 }

@@ -778,16 +800,37 @@ func (db *DB) pageInBuffer(b []byte, id pgid) *page {

 // meta retrieves the current meta page reference.

 func (db *DB) meta() *meta {

-	if db.meta0.txid > db.meta1.txid {

-		return db.meta0

+	// We have to return the meta with the highest txid which doesn't fail

+	// validation. Otherwise, we can cause errors when in fact the database is

+	// in a consistent state. metaA is the one with the higher txid.

+	metaA := db.meta0

+	metaB := db.meta1

+	if db.meta1.txid > db.meta0.txid {

+		metaA = db.meta1

+		metaB = db.meta0

+	}

+

+	// Use higher meta page if valid. Otherwise fallback to previous, if valid.

+	if err := metaA.validate(); err == nil {

+		return metaA

+	} else if err := metaB.validate(); err == nil {

+		return metaB

 	}

-	return db.meta1

+

+	// This should never be reached, because both meta1 and meta0 were validated

+	// on mmap() and we do fsync() on every write.

+	panic("bolt.DB.meta(): invalid meta pages")

 }

 // allocate returns a contiguous block of memory starting at a given page.

 func (db *DB) allocate(count int) (*page, error) {

 	// Allocate a temporary buffer for the page.

-	buf := make([]byte, count*db.pageSize)

+	var buf []byte

+	if count == 1 {

+		buf = db.pagePool.Get().([]byte)

+	} else {

+		buf = make([]byte, count*db.pageSize)

+	}

 	p := (*page)(unsafe.Pointer(&buf[0]))

 	p.overflow = uint32(count - 1)

@@ -937,12 +980,12 @@ type meta struct {

 // validate checks the marker bytes and version of the meta page to ensure it matches this binary.

 func (m *meta) validate() error {

-	if m.checksum != 0 && m.checksum != m.sum64() {

-		return ErrChecksum

-	} else if m.magic != magic {

+	if m.magic != magic {

 		return ErrInvalid

 	} else if m.version != version {

 		return ErrVersionMismatch

+	} else if m.checksum != 0 && m.checksum != m.sum64() {

+		return ErrChecksum

 	}

 	return nil

 }

@@ -12,7 +12,8 @@ var (

 	// already open.

 	ErrDatabaseOpen = errors.New("database already open")

-	// ErrInvalid is returned when a data file is not a Bolt-formatted database.

+	// ErrInvalid is returned when both meta pages on a database are invalid.

+	// This typically occurs when a file is not a bolt database.

 	ErrInvalid = errors.New("invalid database")

 	// ErrVersionMismatch is returned when the data file was created with a

@@ -111,13 +111,13 @@ type leafPageElement struct {

 // key returns a byte slice of the node key.

 func (n *leafPageElement) key() []byte {

 	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))

-	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize]

+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize:n.ksize]

 }

 // value returns a byte slice of the node value.

 func (n *leafPageElement) value() []byte {

 	buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))

-	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize]

+	return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize:n.vsize]

 }

 // PageInfo represents human readable information about a page.

@@ -473,6 +473,8 @@ func (tx *Tx) write() error {

 	for _, p := range tx.pages {

 		pages = append(pages, p)

 	}

+	// Clear out page cache early.

+	tx.pages = make(map[pgid]*page)

 	sort.Sort(pages)

 	// Write pages to disk in order.

@@ -517,8 +519,22 @@ func (tx *Tx) write() error {

 		}

 	}

-	// Clear out page cache.

-	tx.pages = make(map[pgid]*page)

+	// Put small pages back to page pool.

+	for _, p := range pages {

+		// Ignore page sizes over 1 page.

+		// These are allocated using make() instead of the page pool.

+		if int(p.overflow) != 0 {

+			continue

+		}

+

+		buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:tx.db.pageSize]

+

+		// See https://go.googlesource.com/go/+/f03c9202c43e0abb130669852082117ca50aa9b1

+		for i := range buf {

+			buf[i] = 0

+		}

+		tx.db.pagePool.Put(buf)

+	}

 	return nil

 }