[meta-virtualization] [PATCH][v2] docker: uprev to 1.9.0

Bruce Ashfield bruce.ashfield at gmail.com
Mon Apr 18 20:09:51 PDT 2016


On Mon, Apr 18, 2016 at 10:26 PM, Zongchun Yu <zongchun.yu at nxp.com> wrote:

> Hi Bruce.
>
> May I know if you have comments about this v2 patch? If not. Can you help
> to apply the patch?
>


I'm waiting to hear from Bogdan P: .. you said the following:

------------

Hi Bogdan P.



Can you help to provide the arm64 test and configure messages to Bruce?

-----------

And I see no other email on the subject .. so I'm not sure why I'd have
started to merge a new version.

Bruce


> Thanks.
>
> Best Regards
> Zongchun
> -----Original Message-----
> From: zongchun.yu at nxp.com [mailto:zongchun.yu at nxp.com]
> Sent: Tuesday, April 12, 2016 4:36 PM
> To: meta-virtualization at yoctoproject.org
> Cc: bruce.ashfield at gmail.com; Zongchun Yu
> Subject: [meta-virtualization][PATCH][v2] docker: uprev to 1.9.0
>
> From: Zongchun Yu <zongchun.yu at nxp.com>
>
> Uprev to 1.9.0.
> Enable build support for arm64.
> The libcontainer is removed from the source in the new version. drop the
> nsinit install lines.
>
> Signed-off-by: Zongchun Yu <zongchun.yu at nxp.com>
> ---
>  recipes-containers/docker/docker_git.bb            |   38 +-
>  .../docker/files/Bump-bolt-to-v1.1.0.patch         | 1828
> ++++++++++++++++++++
>  .../docker/files/disable_sha1sum_startup.patch     |   21 +-
>  3 files changed, 1855 insertions(+), 32 deletions(-)
>  create mode 100644
> recipes-containers/docker/files/Bump-bolt-to-v1.1.0.patch
>
> diff --git a/recipes-containers/docker/docker_git.bb
> b/recipes-containers/docker/docker_git.bb
> index 2672b22..19fdef0 100644
> --- a/recipes-containers/docker/docker_git.bb
> +++ b/recipes-containers/docker/docker_git.bb
> @@ -18,23 +18,23 @@ DESCRIPTION = "Linux container runtime \
>   subtle and/or glaring issues. \
>   "
>
> -SRCREV = "7c8fca2ddb58c8d2c4fb4df31c242886df7dd257"
> -SRCBRANCH = "v1.6.2"
> +SRCREV = "76d6bc9a9f1690e16f3721ba165364688b626de2"
>  SRC_URI = "\
> -       git://github.com/docker/docker.git;branch=${SRCBRANCH};nobranch=1
> \
> +       git://github.com/docker/docker.git;nobranch=1 \
>         file://docker.service \
>         file://docker.init \
>         file://hi.Dockerfile \
>         file://disable_sha1sum_startup.patch \
> +       file://Bump-bolt-to-v1.1.0.patch \
>         "
>
>  # Apache-2.0 for docker
>  LICENSE = "Apache-2.0"
> -LIC_FILES_CHKSUM = "file://LICENSE;md5=1cc0497778922bfd6cb48721deb80dc7"
> +LIC_FILES_CHKSUM = "file://LICENSE;md5=cc2221abf0b96ea39dd68141b70f7937"
>
>  S = "${WORKDIR}/git"
>
> -DOCKER_VERSION = "1.6.2"
> +DOCKER_VERSION = "1.9.0"
>  PV = "${DOCKER_VERSION}+git${SRCREV}"
>
>  DEPENDS = "go-cross \
> @@ -62,17 +62,17 @@ RRECOMMENDS_${PN} = "lxc docker-registry rt-tests"
>  RRECOMMENDS_${PN} += " kernel-module-dm-thin-pool kernel-module-nf-nat"
>  DOCKER_PKG="github.com/docker/docker"
>
> -do_configure() {
> -}
> +do_configure[noexec] = "1"
>
>  do_compile() {
> -       export PATH=${STAGING_BINDIR_NATIVE}/${HOST_SYS}/go-1.3:$PATH
> -
>         export GOARCH="${TARGET_ARCH}"
> -       # supported amd64, 386, arm
> +       # supported amd64, 386, arm arm64
>         if [ "${TARGET_ARCH}" = "x86_64" ]; then
>                 export GOARCH="amd64"
>         fi
> +       if [ "${TARGET_ARCH}" = "aarch64" ]; then
> +               export GOARCH="arm64"
> +       fi
>
>         # Set GOPATH. See 'PACKAGERS.md'. Don't rely on
>         # docker to download its dependencies but rather
> @@ -84,21 +84,19 @@ do_compile() {
>         export
> GOPATH="${S}/.gopath:${S}/vendor:${STAGING_DIR_TARGET}/${prefix}/local/go"
>         cd -
>
> -       export CGO_ENABLED="1"
> -
>         # Pass the needed cflags/ldflags so that cgo
>         # can find the needed headers files and libraries
> -       export CGO_CFLAGS="${BUILDSDK_CFLAGS}"
> -       export CGO_LDFLAGS="${BUILDSDK_LDFLAGS}"
> +       export CGO_ENABLED="1"
> +       export CGO_CFLAGS="${BUILDSDK_CFLAGS}
> --sysroot=${STAGING_DIR_TARGET}"
> +       export CGO_LDFLAGS="${BUILDSDK_LDFLAGS}
> --sysroot=${STAGING_DIR_TARGET}"
> +       # in order to exclude devicemapper and btrfs -
> https://github.com/docker/docker/issues/14056
> +       export DOCKER_BUILDTAGS='exclude_graphdriver_btrfs
> exclude_graphdriver_devicemapper'
>
>         # this is the unsupported built structure
>         # that doesn't rely on an existing docker
>         # to build this:
>         DOCKER_GITCOMMIT="${SRCREV}" \
>           ./hack/make.sh dynbinary
> -
> -       # make nsinit from libcontainer
> -       go install github.com/docker/libcontainer/nsinit/
>  }
>
>  inherit systemd update-rc.d
> @@ -127,12 +125,6 @@ do_install() {
>              install -m 0755 ${WORKDIR}/docker.init
> ${D}${sysconfdir}/init.d/docker.init
>         fi
>
> -       if [ -d ${S}/vendor/bin/linux_* ]; then
> -               cp ${S}/vendor/bin/linux_*/* ${D}/${bindir}
> -       else
> -               cp ${S}/vendor/bin/* ${D}/${bindir}
> -       fi
> -
>         mkdir -p ${D}/usr/share/docker/
>         cp ${WORKDIR}/hi.Dockerfile ${D}/usr/share/docker/
>  }
> diff --git a/recipes-containers/docker/files/Bump-bolt-to-v1.1.0.patch
> b/recipes-containers/docker/files/Bump-bolt-to-v1.1.0.patch
> new file mode 100644
> index 0000000..ca4ad81
> --- /dev/null
> +++ b/recipes-containers/docker/files/Bump-bolt-to-v1.1.0.patch
> @@ -0,0 +1,1828 @@
> +From a41917c2c88bd7f694d141ac67f4a194aaa16fa1 Mon Sep 17 00:00:00 2001
> +From: Qiang Huang <h.huangqiang at huawei.com>
> +Date: Wed, 28 Oct 2015 08:49:45 +0800
> +Subject: [PATCH] Bump bolt to v1.1.0
> +
> +It adds ARM64, ppc64le, s390x, solaris support, and a bunch of
> +bugfixs.
> +
> +Signed-off-by: Qiang Huang <h.huangqiang at huawei.com>
> +---
> + hack/vendor.sh                                     |   2 +-
> + vendor/src/github.com/boltdb/bolt/.gitignore       |   1 +
> + vendor/src/github.com/boltdb/bolt/README.md        | 250
> +++++++++++++++++++--
> + vendor/src/github.com/boltdb/bolt/batch.go         | 138 ++++++++++++
> + vendor/src/github.com/boltdb/bolt/bolt_386.go      |   5 +-
> + vendor/src/github.com/boltdb/bolt/bolt_amd64.go    |   3 +
> + vendor/src/github.com/boltdb/bolt/bolt_arm.go      |   5 +-
> + vendor/src/github.com/boltdb/bolt/bolt_arm64.go    |   9 +
> + vendor/src/github.com/boltdb/bolt/bolt_ppc64le.go  |   9 +
> + vendor/src/github.com/boltdb/bolt/bolt_s390x.go    |   9 +
> + vendor/src/github.com/boltdb/bolt/bolt_unix.go     |  37 ++-
> + .../github.com/boltdb/bolt/bolt_unix_solaris.go    | 101 +++++++++
> + vendor/src/github.com/boltdb/bolt/bolt_windows.go  |  10 +-
> + vendor/src/github.com/boltdb/bolt/bucket.go        |  29 ++-
> + vendor/src/github.com/boltdb/bolt/cursor.go        |  12 +-
> + vendor/src/github.com/boltdb/bolt/db.go            | 195
> ++++++++++++----
> + vendor/src/github.com/boltdb/bolt/errors.go        |   4 +
> + vendor/src/github.com/boltdb/bolt/freelist.go      |  28 ++-
> + vendor/src/github.com/boltdb/bolt/node.go          |  36 ++-
> + vendor/src/github.com/boltdb/bolt/page.go          |  45 +++-
> + vendor/src/github.com/boltdb/bolt/tx.go            |  80 +++++--
> + 21 files changed, 886 insertions(+), 122 deletions(-)
> + create mode 100644 vendor/src/github.com/boltdb/bolt/batch.go
> + create mode 100644 vendor/src/github.com/boltdb/bolt/bolt_arm64.go
> + create mode 100644 vendor/src/github.com/boltdb/bolt/bolt_ppc64le.go
> + create mode 100644 vendor/src/github.com/boltdb/bolt/bolt_s390x.go
> + create mode 100644 vendor/src/
> github.com/boltdb/bolt/bolt_unix_solaris.go
> +
> +diff --git a/hack/vendor.sh b/hack/vendor.sh
> +index d872d4a..c28e677 100755
> +--- a/hack/vendor.sh
> ++++ b/hack/vendor.sh
> +@@ -36,7 +36,7 @@ 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 v1.0
> ++clone git github.com/boltdb/bolt v1.1.0
> +
> + # get graph and distribution packages
> + clone git github.com/docker/distribution
> 20c4b7a1805a52753dfd593ee1cc35558722a0ce # docker/1.9 branch
> +diff --git a/vendor/src/github.com/boltdb/bolt/.gitignore b/vendor/src/
> github.com/boltdb/bolt/.gitignore
> +index b2bb382..c7bd2b7 100644
> +--- a/vendor/src/github.com/boltdb/bolt/.gitignore
> ++++ b/vendor/src/github.com/boltdb/bolt/.gitignore
> +@@ -1,3 +1,4 @@
> + *.prof
> + *.test
> ++*.swp
> + /bin/
> +diff --git a/vendor/src/github.com/boltdb/bolt/README.md b/vendor/src/
> github.com/boltdb/bolt/README.md
> +index 727e977..0a33ebc 100644
> +--- a/vendor/src/github.com/boltdb/bolt/README.md
> ++++ b/vendor/src/github.com/boltdb/bolt/README.md
> +@@ -16,7 +16,7 @@ and setting values. That's it.
> +
> + ## Project Status
> +
> +-Bolt is stable and the API is fixed. Full unit test coverage and
> randomized
> ++Bolt is stable and the API is fixed. Full unit test coverage and
> randomized
> + black box testing are used to ensure database consistency and thread
> safety.
> + Bolt is currently in high-load production environments serving databases
> as
> + large as 1TB. Many companies such as Shopify and Heroku use Bolt-backed
> +@@ -87,6 +87,11 @@ are not thread safe. To work with data in multiple
> goroutines you must start
> + a transaction for each one or use locking to ensure only one goroutine
> accesses
> + a transaction at a time. Creating transaction from the `DB` is thread
> safe.
> +
> ++Read-only transactions and read-write transactions should not depend on
> one
> ++another and generally shouldn't be opened simultaneously in the same
> goroutine.
> ++This can cause a deadlock as the read-write transaction needs to
> periodically
> ++re-map the data file but it cannot do so while a read-only transaction
> is open.
> ++
> +
> + #### Read-write transactions
> +
> +@@ -120,12 +125,88 @@ err := db.View(func(tx *bolt.Tx) error {
> + })
> + ```
> +
> +-You also get a consistent view of the database within this closure,
> however,
> ++You also get a consistent view of the database within this closure,
> however,
> + no mutating operations are allowed within a read-only transaction. You
> can only
> + retrieve buckets, retrieve values, and copy the database within a
> read-only
> + transaction.
> +
> +
> ++#### Batch read-write transactions
> ++
> ++Each `DB.Update()` waits for disk to commit the writes. This overhead
> ++can be minimized by combining multiple updates with the `DB.Batch()`
> ++function:
> ++
> ++```go
> ++err := db.Batch(func(tx *bolt.Tx) error {
> ++      ...
> ++      return nil
> ++})
> ++```
> ++
> ++Concurrent Batch calls are opportunistically combined into larger
> ++transactions. Batch is only useful when there are multiple goroutines
> ++calling it.
> ++
> ++The trade-off is that `Batch` can call the given
> ++function multiple times, if parts of the transaction fail. The
> ++function must be idempotent and side effects must take effect only
> ++after a successful return from `DB.Batch()`.
> ++
> ++For example: don't display messages from inside the function, instead
> ++set variables in the enclosing scope:
> ++
> ++```go
> ++var id uint64
> ++err := db.Batch(func(tx *bolt.Tx) error {
> ++      // Find last key in bucket, decode as bigendian uint64, increment
> ++      // by one, encode back to []byte, and add new key.
> ++      ...
> ++      id = newValue
> ++      return nil
> ++})
> ++if err != nil {
> ++      return ...
> ++}
> ++fmt.Println("Allocated ID %d", id)
> ++```
> ++
> ++
> ++#### Managing transactions manually
> ++
> ++The `DB.View()` and `DB.Update()` functions are wrappers around the
> `DB.Begin()`
> ++function. These helper functions will start the transaction, execute a
> function,
> ++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 the
> ++transaction.
> ++
> ++```go
> ++// Start a writable transaction.
> ++tx, err := db.Begin(true)
> ++if err != nil {
> ++    return err
> ++}
> ++defer tx.Rollback()
> ++
> ++// Use the transaction...
> ++_, err := tx.CreateBucket([]byte("MyBucket"))
> ++if err != nil {
> ++    return err
> ++}
> ++
> ++// Commit the transaction and check for error.
> ++if err := tx.Commit(); err != nil {
> ++    return err
> ++}
> ++```
> ++
> ++The first argument to `DB.Begin()` is a boolean stating if the
> transaction
> ++should be writable.
> ++
> ++
> + ### Using buckets
> +
> + Buckets are collections of key/value pairs within the database. All keys
> in a
> +@@ -175,13 +256,61 @@ db.View(func(tx *bolt.Tx) error {
> + ```
> +
> + The `Get()` function does not return an error because its operation is
> +-guarenteed to work (unless there is some kind of system failure). If the
> key
> ++guaranteed to work (unless there is some kind of system failure). If the
> key
> + exists then it will return its byte slice value. If it doesn't exist
> then it
> + will return `nil`. It's important to note that you can have a
> zero-length value
> + set to a key which is different than the key not existing.
> +
> + Use the `Bucket.Delete()` function to delete a key from the bucket.
> +
> ++Please note that values returned from `Get()` are only valid while the
> ++transaction is open. If you need to use a value outside of the
> transaction
> ++then you must use `copy()` to copy it to another byte slice.
> ++
> ++
> ++### Autoincrementing integer for the bucket
> ++By using the NextSequence() function, you can let Bolt determine a
> sequence
> ++which can be used as the unique identifier for your key/value pairs. See
> the
> ++example below.
> ++
> ++```go
> ++// CreateUser saves u to the store. The new user ID is set on u once the
> data is persisted.
> ++func (s *Store) CreateUser(u *User) error {
> ++    return s.db.Update(func(tx *bolt.Tx) error {
> ++        // Retrieve the users bucket.
> ++        // This should be created when the DB is first opened.
> ++        b := tx.Bucket([]byte("users"))
> ++
> ++        // 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()
> ++        u.ID = int(id)
> ++
> ++        // Marshal user data into bytes.
> ++        buf, err := json.Marshal(u)
> ++        if err != nil {
> ++            return err
> ++        }
> ++
> ++        // Persist bytes to users bucket.
> ++        return b.Put(itob(u.ID), buf)
> ++    })
> ++}
> ++
> ++// itob returns an 8-byte big endian representation of v.
> ++func itob(v int) []byte {
> ++    b := make([]byte, 8)
> ++    binary.BigEndian.PutUint64(b, uint64(v))
> ++    return b
> ++}
> ++
> ++type User struct {
> ++    ID int
> ++    ...
> ++}
> ++
> ++```
> +
> + ### Iterating over keys
> +
> +@@ -254,7 +383,7 @@ db.View(func(tx *bolt.Tx) error {
> +       max := []byte("2000-01-01T00:00:00Z")
> +
> +       // Iterate over the 90's.
> +-      for k, v := c.Seek(min); k != nil && bytes.Compare(k, max) != -1;
> k, v = c.Next() {
> ++      for k, v := c.Seek(min); k != nil && bytes.Compare(k, max) <= 0;
> k, v = c.Next() {
> +               fmt.Printf("%s: %s\n", k, v)
> +       }
> +
> +@@ -294,7 +423,7 @@ func (*Bucket) DeleteBucket(key []byte) error
> +
> + ### Database backups
> +
> +-Bolt is a single file so it's easy to backup. You can use the `Tx.Copy()`
> ++Bolt is a single file so it's easy to backup. You can use the
> `Tx.WriteTo()`
> + function to write a consistent view of the database to a writer. If you
> call
> + this from a read-only transaction, it will perform a hot backup and not
> block
> + your other database reads and writes. It will also use `O_DIRECT` when
> available
> +@@ -305,11 +434,12 @@ do database backups:
> +
> + ```go
> + func BackupHandleFunc(w http.ResponseWriter, req *http.Request) {
> +-      err := db.View(func(tx bolt.Tx) error {
> ++      err := db.View(func(tx *bolt.Tx) error {
> +               w.Header().Set("Content-Type", "application/octet-stream")
> +               w.Header().Set("Content-Disposition", `attachment;
> filename="my.db"`)
> +               w.Header().Set("Content-Length",
> strconv.Itoa(int(tx.Size())))
> +-              return tx.Copy(w)
> ++              _, err := tx.WriteTo(w)
> ++              return err
> +       })
> +       if err != nil {
> +               http.Error(w, err.Error(), http.StatusInternalServerError)
> +@@ -351,14 +481,13 @@ go func() {
> +               // Grab the current stats and diff them.
> +               stats := db.Stats()
> +               diff := stats.Sub(&prev)
> +-
> ++
> +               // Encode stats to JSON and print to STDERR.
> +               json.NewEncoder(os.Stderr).Encode(diff)
> +
> +               // Save stats for the next loop.
> +               prev = stats
> +       }
> +-}
> + }()
> + ```
> +
> +@@ -366,25 +495,83 @@ It's also useful to pipe these stats to a service
> such as statsd for monitoring
> + or to provide an HTTP endpoint that will perform a fixed-length sample.
> +
> +
> ++### Read-Only Mode
> ++
> ++Sometimes it is useful to create a shared, read-only Bolt database. To
> this,
> ++set the `Options.ReadOnly` flag when opening your database. Read-only
> mode
> ++uses a shared lock to allow multiple processes to read from the database
> but
> ++it will block any processes from opening the database in read-write mode.
> ++
> ++```go
> ++db, err := bolt.Open("my.db", 0666, &bolt.Options{ReadOnly: true})
> ++if err != nil {
> ++      log.Fatal(err)
> ++}
> ++```
> ++
> ++
> + ## Resources
> +
> + For more information on getting started with Bolt, check out the
> following articles:
> +
> + * [Intro to BoltDB: Painless Performant Persistence](
> http://npf.io/2014/07/intro-to-boltdb-painless-performant-persistence/)
> by [Nate Finch](https://github.com/natefinch).
> ++* [Bolt -- an embedded key/value database for Go](
> https://www.progville.com/go/bolt-embedded-db-golang/) by Progville
> ++
> ++
> ++## Comparison with other databases
> ++
> ++### Postgres, MySQL, & other relational databases
> ++
> ++Relational databases structure data into rows and are only accessible
> through
> ++the use of SQL. This approach provides flexibility in how you store and
> query
> ++your data but also incurs overhead in parsing and planning SQL
> statements. Bolt
> ++accesses all data by a byte slice key. This makes Bolt fast to read and
> write
> ++data by key but provides no built-in support for joining values together.
> ++
> ++Most relational databases (with the exception of SQLite) are standalone
> servers
> ++that run separately from your application. This gives your systems
> ++flexibility to connect multiple application servers to a single database
> ++server but also adds overhead in serializing and transporting data over
> the
> ++network. Bolt runs as a library included in your application so all data
> access
> ++has to go through your application's process. This brings data closer to
> your
> ++application but limits multi-process access to the data.
> ++
> ++
> ++### LevelDB, RocksDB
> +
> ++LevelDB and its derivatives (RocksDB, HyperLevelDB) are similar to Bolt
> in that
> ++they are libraries bundled into the application, however, their
> underlying
> ++structure is a log-structured merge-tree (LSM tree). An LSM tree
> optimizes
> ++random writes by using a write ahead log and multi-tiered, sorted files
> called
> ++SSTables. Bolt uses a B+tree internally and only a single file. Both
> approaches
> ++have trade offs.
> +
> ++If you require a high random write throughput (>10,000 w/sec) or you
> need to use
> ++spinning disks then LevelDB could be a good choice. If your application
> is
> ++read-heavy or does a lot of range scans then Bolt could be a good choice.
> +
> +-## Comparing Bolt to LMDB
> ++One other important consideration is that LevelDB does not have
> transactions.
> ++It supports batch writing of key/values pairs and it supports read
> snapshots
> ++but it will not give you the ability to do a compare-and-swap operation
> safely.
> ++Bolt supports fully serializable ACID transactions.
> ++
> ++
> ++### LMDB
> +
> + Bolt was originally a port of LMDB so it is architecturally similar.
> Both use
> +-a B+tree, have ACID semanetics with fully serializable transactions, and
> support
> ++a B+tree, have ACID semantics with fully serializable transactions, and
> support
> + lock-free MVCC using a single writer and multiple readers.
> +
> + The two projects have somewhat diverged. LMDB heavily focuses on raw
> performance
> + while Bolt has focused on simplicity and ease of use. For example, LMDB
> allows
> +-several unsafe actions such as direct writes and append writes for the
> sake of
> +-performance. Bolt opts to disallow actions which can leave the database
> in a
> +-corrupted state. The only exception to this in Bolt is `DB.NoSync`.
> ++several unsafe actions such as direct writes for the sake of
> performance. Bolt
> ++opts to disallow actions which can leave the database in a corrupted
> state. The
> ++only exception to this in Bolt is `DB.NoSync`.
> ++
> ++There are also a few differences in API. LMDB requires a maximum mmap
> size when
> ++opening an `mdb_env` whereas Bolt will handle incremental mmap resizing
> ++automatically. LMDB overloads the getter and setter functions with
> multiple
> ++flags whereas Bolt splits these specialized cases into their own
> functions.
> +
> +
> + ## Caveats & Limitations
> +@@ -425,14 +612,33 @@ Here are a few things to note when evaluating and
> using Bolt:
> +   can in memory and will release memory as needed to other processes.
> This means
> +   that Bolt can show very high memory usage when working with large
> databases.
> +   However, this is expected and the OS will release memory as needed.
> Bolt can
> +-  handle databases much larger than the available physical RAM.
> ++  handle databases much larger than the available physical RAM, provided
> its
> ++  memory-map fits in the process virtual address space. It may be
> problematic
> ++  on 32-bits systems.
> ++
> ++* The data structures in the Bolt database are memory mapped so the data
> file
> ++  will be endian specific. This means that you cannot copy a Bolt file
> from a
> ++  little endian machine to a big endian machine and have it work. For
> most
> ++  users this is not a concern since most modern CPUs are little endian.
> ++
> ++* Because of the way pages are laid out on disk, Bolt cannot truncate
> data files
> ++  and return free pages back to the disk. Instead, Bolt maintains a free
> list
> ++  of unused pages within its data file. These free pages can be reused
> by later
> ++  transactions. This works well for many use cases as databases
> generally tend
> ++  to grow. However, it's important to note that deleting large chunks of
> data
> ++  will not allow you to reclaim that space on disk.
> ++
> ++  For more information on page allocation, [see this
> comment][page-allocation].
> ++
> ++[page-allocation]:
> https://github.com/boltdb/bolt/issues/308#issuecomment-74811638
> +
> +
> + ## Other Projects Using Bolt
> +
> + Below is a list of public, open source projects that use Bolt:
> +
> +-* [Bazil](https://github.com/bazillion/bazil) - A file system that lets
> your data reside where it is most convenient for it to reside.
> ++* [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.
> + * [Skybox Analytics](https://github.com/skybox/skybox) - A standalone
> funnel analysis tool for web analytics.
> + * [Scuttlebutt](https://github.com/benbjohnson/scuttlebutt) - Uses Bolt
> to store and process all Twitter mentions of GitHub projects.
> +@@ -450,6 +656,16 @@ Below is a list of public, open source projects that
> use Bolt:
> + * [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/weed-fs) - Highly
> scalable distributed key~file system with O(1) disk read.
> ++* [InfluxDB](http://influxdb.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.
> ++* [Prometheus Annotation Server](
> https://github.com/oliver006/prom_annotation_server) - Annotation server
> for PromDash & Prometheus service monitoring system.
> ++* [Consul](https://github.com/hashicorp/consul) - Consul is service
> discovery and configuration made easy. Distributed, highly available, and
> datacenter-aware.
> ++* [Kala](https://github.com/ajvb/kala) - Kala is a modern job scheduler
> optimized to run on a single node. It is persistent, JSON over HTTP API,
> ISO 8601 duration notation, and dependent jobs.
> ++* [drive](https://github.com/odeke-em/drive) - drive is an unofficial
> Google Drive command line client for \*NIX operating systems.
> ++* [stow](https://github.com/djherbis/stow) -  a persistence manager for
> objects
> ++  backed by boltdb.
> ++* [buckets](https://github.com/joyrexus/buckets) - a bolt wrapper
> streamlining
> ++  simple tx and key scans.
> +
> + If you are using Bolt in a project please send a pull request to add it
> to the list.
> +-
> +diff --git a/vendor/src/github.com/boltdb/bolt/batch.go b/vendor/src/
> github.com/boltdb/bolt/batch.go
> +new file mode 100644
> +index 0000000..84acae6
> +--- /dev/null
> ++++ b/vendor/src/github.com/boltdb/bolt/batch.go
> +@@ -0,0 +1,138 @@
> ++package bolt
> ++
> ++import (
> ++      "errors"
> ++      "fmt"
> ++      "sync"
> ++      "time"
> ++)
> ++
> ++// Batch calls fn as part of a batch. It behaves similar to Update,
> ++// except:
> ++//
> ++// 1. concurrent Batch calls can be combined into a single Bolt
> ++// transaction.
> ++//
> ++// 2. the function passed to Batch may be called multiple times,
> ++// regardless of whether it returns error or not.
> ++//
> ++// This means that Batch function side effects must be idempotent and
> ++// take permanent effect only after a successful return is seen in
> ++// caller.
> ++//
> ++// The maximum batch size and delay can be adjusted with DB.MaxBatchSize
> ++// and DB.MaxBatchDelay, respectively.
> ++//
> ++// Batch is only useful when there are multiple goroutines calling it.
> ++func (db *DB) Batch(fn func(*Tx) error) error {
> ++      errCh := make(chan error, 1)
> ++
> ++      db.batchMu.Lock()
> ++      if (db.batch == nil) || (db.batch != nil && len(db.batch.calls) >=
> db.MaxBatchSize) {
> ++              // There is no existing batch, or the existing batch is
> full; start a new one.
> ++              db.batch = &batch{
> ++                      db: db,
> ++              }
> ++              db.batch.timer = time.AfterFunc(db.MaxBatchDelay,
> db.batch.trigger)
> ++      }
> ++      db.batch.calls = append(db.batch.calls, call{fn: fn, err: errCh})
> ++      if len(db.batch.calls) >= db.MaxBatchSize {
> ++              // wake up batch, it's ready to run
> ++              go db.batch.trigger()
> ++      }
> ++      db.batchMu.Unlock()
> ++
> ++      err := <-errCh
> ++      if err == trySolo {
> ++              err = db.Update(fn)
> ++      }
> ++      return err
> ++}
> ++
> ++type call struct {
> ++      fn  func(*Tx) error
> ++      err chan<- error
> ++}
> ++
> ++type batch struct {
> ++      db    *DB
> ++      timer *time.Timer
> ++      start sync.Once
> ++      calls []call
> ++}
> ++
> ++// trigger runs the batch if it hasn't already been run.
> ++func (b *batch) trigger() {
> ++      b.start.Do(b.run)
> ++}
> ++
> ++// run performs the transactions in the batch and communicates results
> ++// back to DB.Batch.
> ++func (b *batch) run() {
> ++      b.db.batchMu.Lock()
> ++      b.timer.Stop()
> ++      // Make sure no new work is added to this batch, but don't break
> ++      // other batches.
> ++      if b.db.batch == b {
> ++              b.db.batch = nil
> ++      }
> ++      b.db.batchMu.Unlock()
> ++
> ++retry:
> ++      for len(b.calls) > 0 {
> ++              var failIdx = -1
> ++              err := b.db.Update(func(tx *Tx) error {
> ++                      for i, c := range b.calls {
> ++                              if err := safelyCall(c.fn, tx); err != nil
> {
> ++                                      failIdx = i
> ++                                      return err
> ++                              }
> ++                      }
> ++                      return nil
> ++              })
> ++
> ++              if failIdx >= 0 {
> ++                      // take the failing transaction out of the batch.
> it's
> ++                      // safe to shorten b.calls here because db.batch
> no longer
> ++                      // points to us, and we hold the mutex anyway.
> ++                      c := b.calls[failIdx]
> ++                      b.calls[failIdx], b.calls =
> b.calls[len(b.calls)-1], b.calls[:len(b.calls)-1]
> ++                      // tell the submitter re-run it solo, continue
> with the rest of the batch
> ++                      c.err <- trySolo
> ++                      continue retry
> ++              }
> ++
> ++              // pass success, or bolt internal errors, to all callers
> ++              for _, c := range b.calls {
> ++                      if c.err != nil {
> ++                              c.err <- err
> ++                      }
> ++              }
> ++              break retry
> ++      }
> ++}
> ++
> ++// trySolo is a special sentinel error value used for signaling that a
> ++// transaction function should be re-run. It should never be seen by
> ++// callers.
> ++var trySolo = errors.New("batch function returned an error and should be
> re-run solo")
> ++
> ++type panicked struct {
> ++      reason interface{}
> ++}
> ++
> ++func (p panicked) Error() string {
> ++      if err, ok := p.reason.(error); ok {
> ++              return err.Error()
> ++      }
> ++      return fmt.Sprintf("panic: %v", p.reason)
> ++}
> ++
> ++func safelyCall(fn func(*Tx) error, tx *Tx) (err error) {
> ++      defer func() {
> ++              if p := recover(); p != nil {
> ++                      err = panicked{p}
> ++              }
> ++      }()
> ++      return fn(tx)
> ++}
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_386.go b/vendor/src/
> github.com/boltdb/bolt/bolt_386.go
> +index 856f401..e659bfb 100644
> +--- a/vendor/src/github.com/boltdb/bolt/bolt_386.go
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_386.go
> +@@ -1,4 +1,7 @@
> + package bolt
> +
> + // maxMapSize represents the largest mmap size supported by Bolt.
> +-const maxMapSize = 0xFFFFFFF // 256MB
> ++const maxMapSize = 0x7FFFFFFF // 2GB
> ++
> ++// maxAllocSize is the size used when creating array pointers.
> ++const maxAllocSize = 0xFFFFFFF
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_amd64.go
> b/vendor/src/github.com/boltdb/bolt/bolt_amd64.go
> +index 4262932..cca6b7e 100644
> +--- a/vendor/src/github.com/boltdb/bolt/bolt_amd64.go
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_amd64.go
> +@@ -2,3 +2,6 @@ package bolt
> +
> + // maxMapSize represents the largest mmap size supported by Bolt.
> + const maxMapSize = 0xFFFFFFFFFFFF // 256TB
> ++
> ++// maxAllocSize is the size used when creating array pointers.
> ++const maxAllocSize = 0x7FFFFFFF
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_arm.go b/vendor/src/
> github.com/boltdb/bolt/bolt_arm.go
> +index 856f401..e659bfb 100644
> +--- a/vendor/src/github.com/boltdb/bolt/bolt_arm.go
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_arm.go
> +@@ -1,4 +1,7 @@
> + package bolt
> +
> + // maxMapSize represents the largest mmap size supported by Bolt.
> +-const maxMapSize = 0xFFFFFFF // 256MB
> ++const maxMapSize = 0x7FFFFFFF // 2GB
> ++
> ++// maxAllocSize is the size used when creating array pointers.
> ++const maxAllocSize = 0xFFFFFFF
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_arm64.go
> b/vendor/src/github.com/boltdb/bolt/bolt_arm64.go
> +new file mode 100644
> +index 0000000..6d23093
> +--- /dev/null
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_arm64.go
> +@@ -0,0 +1,9 @@
> ++// +build arm64
> ++
> ++package bolt
> ++
> ++// maxMapSize represents the largest mmap size supported by Bolt.
> ++const maxMapSize = 0xFFFFFFFFFFFF // 256TB
> ++
> ++// maxAllocSize is the size used when creating array pointers.
> ++const maxAllocSize = 0x7FFFFFFF
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_ppc64le.go
> b/vendor/src/github.com/boltdb/bolt/bolt_ppc64le.go
> +new file mode 100644
> +index 0000000..8351e12
> +--- /dev/null
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_ppc64le.go
> +@@ -0,0 +1,9 @@
> ++// +build ppc64le
> ++
> ++package bolt
> ++
> ++// maxMapSize represents the largest mmap size supported by Bolt.
> ++const maxMapSize = 0xFFFFFFFFFFFF // 256TB
> ++
> ++// maxAllocSize is the size used when creating array pointers.
> ++const maxAllocSize = 0x7FFFFFFF
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_s390x.go
> b/vendor/src/github.com/boltdb/bolt/bolt_s390x.go
> +new file mode 100644
> +index 0000000..f4dd26b
> +--- /dev/null
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_s390x.go
> +@@ -0,0 +1,9 @@
> ++// +build s390x
> ++
> ++package bolt
> ++
> ++// maxMapSize represents the largest mmap size supported by Bolt.
> ++const maxMapSize = 0xFFFFFFFFFFFF // 256TB
> ++
> ++// maxAllocSize is the size used when creating array pointers.
> ++const maxAllocSize = 0x7FFFFFFF
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_unix.go b/vendor/src/
> github.com/boltdb/bolt/bolt_unix.go
> +index 95647a7..6eef6b2 100644
> +--- a/vendor/src/github.com/boltdb/bolt/bolt_unix.go
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_unix.go
> +@@ -1,8 +1,9 @@
> +-// +build !windows,!plan9
> ++// +build !windows,!plan9,!solaris
> +
> + package bolt
> +
> + import (
> ++      "fmt"
> +       "os"
> +       "syscall"
> +       "time"
> +@@ -10,7 +11,7 @@ import (
> + )
> +
> + // flock acquires an advisory lock on a file descriptor.
> +-func flock(f *os.File, timeout time.Duration) error {
> ++func flock(f *os.File, exclusive bool, timeout time.Duration) error {
> +       var t time.Time
> +       for {
> +               // If we're beyond our timeout then return an error.
> +@@ -20,9 +21,13 @@ func flock(f *os.File, timeout time.Duration) error {
> +               } else if timeout > 0 && time.Since(t) > timeout {
> +                       return ErrTimeout
> +               }
> ++              flag := syscall.LOCK_SH
> ++              if exclusive {
> ++                      flag = syscall.LOCK_EX
> ++              }
> +
> +               // Otherwise attempt to obtain an exclusive lock.
> +-              err := syscall.Flock(int(f.Fd()),
> syscall.LOCK_EX|syscall.LOCK_NB)
> ++              err := syscall.Flock(int(f.Fd()), flag|syscall.LOCK_NB)
> +               if err == nil {
> +                       return nil
> +               } else if err != syscall.EWOULDBLOCK {
> +@@ -41,11 +46,28 @@ func funlock(f *os.File) error {
> +
> + // mmap memory maps a DB's data file.
> + func mmap(db *DB, sz int) error {
> ++      // Truncate and fsync to ensure file size metadata is flushed.
> ++      // https://github.com/boltdb/bolt/issues/284
> ++      if !db.NoGrowSync && !db.readOnly {
> ++              if err := db.file.Truncate(int64(sz)); err != nil {
> ++                      return fmt.Errorf("file resize error: %s", err)
> ++              }
> ++              if err := db.file.Sync(); err != nil {
> ++                      return fmt.Errorf("file sync error: %s", err)
> ++              }
> ++      }
> ++
> ++      // Map the data file to memory.
> +       b, err := syscall.Mmap(int(db.file.Fd()), 0, sz,
> syscall.PROT_READ, syscall.MAP_SHARED)
> +       if err != nil {
> +               return err
> +       }
> +
> ++      // Advise the kernel that the mmap is accessed randomly.
> ++      if err := madvise(b, syscall.MADV_RANDOM); err != nil {
> ++              return fmt.Errorf("madvise: %s", err)
> ++      }
> ++
> +       // Save the original byte slice and convert to a byte array
> pointer.
> +       db.dataref = b
> +       db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
> +@@ -67,3 +89,12 @@ func munmap(db *DB) error {
> +       db.datasz = 0
> +       return err
> + }
> ++
> ++// NOTE: This function is copied from stdlib because it is not available
> on darwin.
> ++func madvise(b []byte, advice int) (err error) {
> ++      _, _, e1 := syscall.Syscall(syscall.SYS_MADVISE,
> uintptr(unsafe.Pointer(&b[0])), uintptr(len(b)), uintptr(advice))
> ++      if e1 != 0 {
> ++              err = e1
> ++      }
> ++      return
> ++}
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_unix_solaris.go
> b/vendor/src/github.com/boltdb/bolt/bolt_unix_solaris.go
> +new file mode 100644
> +index 0000000..f480ee7
> +--- /dev/null
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_unix_solaris.go
> +@@ -0,0 +1,101 @@
> ++
> ++package bolt
> ++
> ++import (
> ++      "fmt"
> ++      "os"
> ++      "syscall"
> ++      "time"
> ++      "unsafe"
> ++      "golang.org/x/sys/unix"
> ++)
> ++
> ++// flock acquires an advisory lock on a file descriptor.
> ++func flock(f *os.File, exclusive bool, timeout time.Duration) error {
> ++      var t time.Time
> ++      for {
> ++              // If we're beyond our timeout then return an error.
> ++              // This can only occur after we've attempted a flock once.
> ++              if t.IsZero() {
> ++                      t = time.Now()
> ++              } else if timeout > 0 && time.Since(t) > timeout {
> ++                      return ErrTimeout
> ++              }
> ++              var lock syscall.Flock_t
> ++              lock.Start = 0
> ++              lock.Len = 0
> ++              lock.Pid = 0
> ++              lock.Whence = 0
> ++              lock.Pid = 0
> ++              if exclusive {
> ++                      lock.Type = syscall.F_WRLCK
> ++              } else {
> ++                      lock.Type = syscall.F_RDLCK
> ++              }
> ++              err := syscall.FcntlFlock(f.Fd(), syscall.F_SETLK, &lock)
> ++              if err == nil {
> ++                      return nil
> ++              } else if err != syscall.EAGAIN {
> ++                      return err
> ++              }
> ++
> ++              // Wait for a bit and try again.
> ++              time.Sleep(50 * time.Millisecond)
> ++      }
> ++}
> ++
> ++// funlock releases an advisory lock on a file descriptor.
> ++func funlock(f *os.File) error {
> ++      var lock syscall.Flock_t
> ++      lock.Start = 0
> ++      lock.Len = 0
> ++      lock.Type = syscall.F_UNLCK
> ++      lock.Whence = 0
> ++      return syscall.FcntlFlock(uintptr(f.Fd()), syscall.F_SETLK, &lock)
> ++}
> ++
> ++// mmap memory maps a DB's data file.
> ++func mmap(db *DB, sz int) error {
> ++      // Truncate and fsync to ensure file size metadata is flushed.
> ++      // https://github.com/boltdb/bolt/issues/284
> ++      if !db.NoGrowSync && !db.readOnly {
> ++              if err := db.file.Truncate(int64(sz)); err != nil {
> ++                      return fmt.Errorf("file resize error: %s", err)
> ++              }
> ++              if err := db.file.Sync(); err != nil {
> ++                      return fmt.Errorf("file sync error: %s", err)
> ++              }
> ++      }
> ++
> ++      // Map the data file to memory.
> ++      b, err := unix.Mmap(int(db.file.Fd()), 0, sz, syscall.PROT_READ,
> syscall.MAP_SHARED)
> ++      if err != nil {
> ++              return err
> ++      }
> ++
> ++      // Advise the kernel that the mmap is accessed randomly.
> ++      if err := unix.Madvise(b, syscall.MADV_RANDOM); err != nil {
> ++              return fmt.Errorf("madvise: %s", err)
> ++      }
> ++
> ++      // Save the original byte slice and convert to a byte array
> pointer.
> ++      db.dataref = b
> ++      db.data = (*[maxMapSize]byte)(unsafe.Pointer(&b[0]))
> ++      db.datasz = sz
> ++      return nil
> ++}
> ++
> ++// munmap unmaps a DB's data file from memory.
> ++func munmap(db *DB) error {
> ++      // Ignore the unmap if we have no mapped data.
> ++      if db.dataref == nil {
> ++              return nil
> ++      }
> ++
> ++      // Unmap using the original byte slice.
> ++      err := unix.Munmap(db.dataref)
> ++      db.dataref = nil
> ++      db.data = nil
> ++      db.datasz = 0
> ++      return err
> ++}
> +diff --git a/vendor/src/github.com/boltdb/bolt/bolt_windows.go
> b/vendor/src/github.com/boltdb/bolt/bolt_windows.go
> +index c8539d4..8b782be 100644
> +--- a/vendor/src/github.com/boltdb/bolt/bolt_windows.go
> ++++ b/vendor/src/github.com/boltdb/bolt/bolt_windows.go
> +@@ -16,7 +16,7 @@ func fdatasync(db *DB) error {
> + }
> +
> + // flock acquires an advisory lock on a file descriptor.
> +-func flock(f *os.File, _ time.Duration) error {
> ++func flock(f *os.File, _ bool, _ time.Duration) error {
> +       return nil
> + }
> +
> +@@ -28,9 +28,11 @@ func funlock(f *os.File) error {
> + // mmap memory maps a DB's data file.
> + // Based on: https://github.com/edsrzf/mmap-go
> + func mmap(db *DB, sz int) error {
> +-      // Truncate the database to the size of the mmap.
> +-      if err := db.file.Truncate(int64(sz)); err != nil {
> +-              return fmt.Errorf("truncate: %s", err)
> ++      if !db.readOnly {
> ++              // Truncate the database to the size of the mmap.
> ++              if err := db.file.Truncate(int64(sz)); err != nil {
> ++                      return fmt.Errorf("truncate: %s", err)
> ++              }
> +       }
> +
> +       // Open a file mapping handle.
> +diff --git a/vendor/src/github.com/boltdb/bolt/bucket.go b/vendor/src/
> github.com/boltdb/bolt/bucket.go
> +index 2630800..2925288 100644
> +--- a/vendor/src/github.com/boltdb/bolt/bucket.go
> ++++ b/vendor/src/github.com/boltdb/bolt/bucket.go
> +@@ -99,6 +99,7 @@ func (b *Bucket) Cursor() *Cursor {
> +
> + // Bucket retrieves a nested bucket by name.
> + // Returns nil if the bucket does not exist.
> ++// The bucket instance is only valid for the lifetime of the transaction.
> + func (b *Bucket) Bucket(name []byte) *Bucket {
> +       if b.buckets != nil {
> +               if child := b.buckets[string(name)]; child != nil {
> +@@ -148,6 +149,7 @@ func (b *Bucket) openBucket(value []byte) *Bucket {
> +
> + // CreateBucket creates a new bucket at the given key and returns the
> new bucket.
> + // Returns an error if the key already exists, if the bucket name is
> blank, or if the bucket name is too long.
> ++// The bucket instance is only valid for the lifetime of the transaction.
> + func (b *Bucket) CreateBucket(key []byte) (*Bucket, error) {
> +       if b.tx.db == nil {
> +               return nil, ErrTxClosed
> +@@ -192,6 +194,7 @@ func (b *Bucket) CreateBucket(key []byte) (*Bucket,
> error) {
> +
> + // CreateBucketIfNotExists creates a new bucket if it doesn't already
> exist and returns a reference to it.
> + // Returns an error if the bucket name is blank, or if the bucket name
> is too long.
> ++// The bucket instance is only valid for the lifetime of the transaction.
> + func (b *Bucket) CreateBucketIfNotExists(key []byte) (*Bucket, error) {
> +       child, err := b.CreateBucket(key)
> +       if err == ErrBucketExists {
> +@@ -252,6 +255,7 @@ func (b *Bucket) DeleteBucket(key []byte) error {
> +
> + // Get retrieves the value for a key in the bucket.
> + // Returns a nil value if the key does not exist or if the key is a
> nested bucket.
> ++// The returned value is only valid for the life of the transaction.
> + func (b *Bucket) Get(key []byte) []byte {
> +       k, v, flags := b.Cursor().seek(key)
> +
> +@@ -332,6 +336,12 @@ func (b *Bucket) NextSequence() (uint64, error) {
> +               return 0, 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++
> +       return b.bucket.sequence, nil
> +@@ -339,7 +349,8 @@ func (b *Bucket) NextSequence() (uint64, error) {
> +
> + // ForEach executes a function for each key/value pair in a bucket.
> + // If the provided function returns an error then the iteration is
> stopped and
> +-// the error is returned to the caller.
> ++// the error is returned to the caller. The provided function must not
> modify
> ++// the bucket; this will result in undefined behavior.
> + func (b *Bucket) ForEach(fn func(k, v []byte) error) error {
> +       if b.tx.db == nil {
> +               return ErrTxClosed
> +@@ -511,8 +522,12 @@ func (b *Bucket) spill() error {
> +               // Update parent node.
> +               var c = b.Cursor()
> +               k, _, flags := c.seek([]byte(name))
> +-              _assert(bytes.Equal([]byte(name), k), "misplaced bucket
> header: %x -> %x", []byte(name), k)
> +-              _assert(flags&bucketLeafFlag != 0, "unexpected bucket
> header flag: %x", flags)
> ++              if !bytes.Equal([]byte(name), k) {
> ++                      panic(fmt.Sprintf("misplaced bucket header: %x ->
> %x", []byte(name), k))
> ++              }
> ++              if flags&bucketLeafFlag == 0 {
> ++                      panic(fmt.Sprintf("unexpected bucket header flag:
> %x", flags))
> ++              }
> +               c.node().put([]byte(name), []byte(name), value, 0,
> bucketLeafFlag)
> +       }
> +
> +@@ -528,7 +543,9 @@ func (b *Bucket) spill() error {
> +       b.rootNode = b.rootNode.root()
> +
> +       // Update the root node for this bucket.
> +-      _assert(b.rootNode.pgid < b.tx.meta.pgid, "pgid (%d) above high
> water mark (%d)", b.rootNode.pgid, b.tx.meta.pgid)
> ++      if b.rootNode.pgid >= b.tx.meta.pgid {
> ++              panic(fmt.Sprintf("pgid (%d) above high water mark (%d)",
> b.rootNode.pgid, b.tx.meta.pgid))
> ++      }
> +       b.root = b.rootNode.pgid
> +
> +       return nil
> +@@ -659,7 +676,9 @@ func (b *Bucket) pageNode(id pgid) (*page, *node) {
> +       // Inline buckets have a fake page embedded in their value so
> treat them
> +       // differently. We'll return the rootNode (if available) or the
> fake page.
> +       if b.root == 0 {
> +-              _assert(id == 0, "inline bucket non-zero page access(2):
> %d != 0", id)
> ++              if id != 0 {
> ++                      panic(fmt.Sprintf("inline bucket non-zero page
> access(2): %d != 0", id))
> ++              }
> +               if b.rootNode != nil {
> +                       return nil, b.rootNode
> +               }
> +diff --git a/vendor/src/github.com/boltdb/bolt/cursor.go b/vendor/src/
> github.com/boltdb/bolt/cursor.go
> +index 3bfc2f1..006c548 100644
> +--- a/vendor/src/github.com/boltdb/bolt/cursor.go
> ++++ b/vendor/src/github.com/boltdb/bolt/cursor.go
> +@@ -2,6 +2,7 @@ package bolt
> +
> + import (
> +       "bytes"
> ++      "fmt"
> +       "sort"
> + )
> +
> +@@ -9,6 +10,8 @@ import (
> + // Cursors see nested buckets with value == nil.
> + // Cursors can be obtained from a transaction and are valid as long as
> the transaction is open.
> + //
> ++// Keys and values returned from the cursor are only valid for the life
> of the transaction.
> ++//
> + // Changing data while traversing with a cursor may cause it to be
> invalidated
> + // and return unexpected keys and/or values. You must reposition your
> cursor
> + // after mutating data.
> +@@ -24,6 +27,7 @@ func (c *Cursor) Bucket() *Bucket {
> +
> + // First moves the cursor to the first item in the bucket and returns
> its key and value.
> + // If the bucket is empty then a nil key and value are returned.
> ++// The returned key and value are only valid for the life of the
> transaction.
> + func (c *Cursor) First() (key []byte, value []byte) {
> +       _assert(c.bucket.tx.db != nil, "tx closed")
> +       c.stack = c.stack[:0]
> +@@ -40,6 +44,7 @@ func (c *Cursor) First() (key []byte, value []byte) {
> +
> + // Last moves the cursor to the last item in the bucket and returns its
> key and value.
> + // If the bucket is empty then a nil key and value are returned.
> ++// The returned key and value are only valid for the life of the
> transaction.
> + func (c *Cursor) Last() (key []byte, value []byte) {
> +       _assert(c.bucket.tx.db != nil, "tx closed")
> +       c.stack = c.stack[:0]
> +@@ -57,6 +62,7 @@ func (c *Cursor) Last() (key []byte, value []byte) {
> +
> + // Next moves the cursor to the next item in the bucket and returns its
> key and value.
> + // If the cursor is at the end of the bucket then a nil key and value
> are returned.
> ++// The returned key and value are only valid for the life of the
> transaction.
> + func (c *Cursor) Next() (key []byte, value []byte) {
> +       _assert(c.bucket.tx.db != nil, "tx closed")
> +       k, v, flags := c.next()
> +@@ -68,6 +74,7 @@ func (c *Cursor) Next() (key []byte, value []byte) {
> +
> + // Prev moves the cursor to the previous item in the bucket and returns
> its key and value.
> + // If the cursor is at the beginning of the bucket then a nil key and
> value are returned.
> ++// The returned key and value are only valid for the life of the
> transaction.
> + func (c *Cursor) Prev() (key []byte, value []byte) {
> +       _assert(c.bucket.tx.db != nil, "tx closed")
> +
> +@@ -99,6 +106,7 @@ func (c *Cursor) Prev() (key []byte, value []byte) {
> + // Seek moves the cursor to a given key and returns it.
> + // If the key does not exist then the next key is used. If no keys
> + // follow, a nil key is returned.
> ++// The returned key and value are only valid for the life of the
> transaction.
> + func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
> +       k, v, flags := c.seek(seek)
> +
> +@@ -228,8 +236,8 @@ func (c *Cursor) next() (key []byte, value []byte,
> flags uint32) {
> + // search recursively performs a binary search against a given page/node
> until it finds a given key.
> + func (c *Cursor) search(key []byte, pgid pgid) {
> +       p, n := c.bucket.pageNode(pgid)
> +-      if p != nil {
> +-              _assert((p.flags&(branchPageFlag|leafPageFlag)) != 0,
> "invalid page type: %d: %x", p.id, p.flags)
> ++      if p != nil && (p.flags&(branchPageFlag|leafPageFlag)) == 0 {
> ++              panic(fmt.Sprintf("invalid page type: %d: %x", p.id,
> p.flags))
> +       }
> +       e := elemRef{page: p, node: n}
> +       c.stack = append(c.stack, e)
> +diff --git a/vendor/src/github.com/boltdb/bolt/db.go b/vendor/src/
> github.com/boltdb/bolt/db.go
> +index 6c45736..d39c4aa 100644
> +--- a/vendor/src/github.com/boltdb/bolt/db.go
> ++++ b/vendor/src/github.com/boltdb/bolt/db.go
> +@@ -12,9 +12,6 @@ import (
> +       "unsafe"
> + )
> +
> +-// The smallest size that the mmap can be.
> +-const minMmapSize = 1 << 22 // 4MB
> +-
> + // The largest step that can be taken when remapping the mmap.
> + const maxMmapStep = 1 << 30 // 1GB
> +
> +@@ -30,6 +27,12 @@ const magic uint32 = 0xED0CDAED
> + // must be synchronzied using the msync(2) syscall.
> + const IgnoreNoSync = runtime.GOOS == "openbsd"
> +
> ++// Default values if not set in a DB instance.
> ++const (
> ++      DefaultMaxBatchSize  int = 1000
> ++      DefaultMaxBatchDelay     = 10 * time.Millisecond
> ++)
> ++
> + // 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.
> +@@ -52,9 +55,33 @@ type DB struct {
> +       // THIS IS UNSAFE. PLEASE USE WITH CAUTION.
> +       NoSync bool
> +
> ++      // When true, skips the truncate call when growing the database.
> ++      // Setting this to true is only safe on non-ext3/ext4 systems.
> ++      // Skipping truncation avoids preallocation of hard drive space and
> ++      // bypasses a truncate() and fsync() syscall on remapping.
> ++      //
> ++      // https://github.com/boltdb/bolt/issues/284
> ++      NoGrowSync bool
> ++
> ++      // MaxBatchSize is the maximum size of a batch. Default value is
> ++      // copied from DefaultMaxBatchSize in Open.
> ++      //
> ++      // If <=0, disables batching.
> ++      //
> ++      // Do not change concurrently with calls to Batch.
> ++      MaxBatchSize int
> ++
> ++      // MaxBatchDelay is the maximum delay before a batch starts.
> ++      // Default value is copied from DefaultMaxBatchDelay in Open.
> ++      //
> ++      // If <=0, effectively disables batching.
> ++      //
> ++      // Do not change concurrently with calls to Batch.
> ++      MaxBatchDelay time.Duration
> ++
> +       path     string
> +       file     *os.File
> +-      dataref  []byte
> ++      dataref  []byte // mmap'ed readonly, write throws SEGV
> +       data     *[maxMapSize]byte
> +       datasz   int
> +       meta0    *meta
> +@@ -66,6 +93,9 @@ type DB struct {
> +       freelist *freelist
> +       stats    Stats
> +
> ++      batchMu sync.Mutex
> ++      batch   *batch
> ++
> +       rwlock   sync.Mutex   // Allows only one writer at a time.
> +       metalock sync.Mutex   // Protects meta page access.
> +       mmaplock sync.RWMutex // Protects mmap access during remapping.
> +@@ -74,6 +104,10 @@ type DB struct {
> +       ops struct {
> +               writeAt func(b []byte, off int64) (n int, err error)
> +       }
> ++
> ++      // Read only mode.
> ++      // When true, Update() and Begin(true) return ErrDatabaseReadOnly
> immediately.
> ++      readOnly bool
> + }
> +
> + // Path returns the path to currently open database file.
> +@@ -101,20 +135,34 @@ func Open(path string, mode os.FileMode, options
> *Options) (*DB, error) {
> +       if options == nil {
> +               options = DefaultOptions
> +       }
> ++      db.NoGrowSync = options.NoGrowSync
> ++
> ++      // Set default values for later DB operations.
> ++      db.MaxBatchSize = DefaultMaxBatchSize
> ++      db.MaxBatchDelay = DefaultMaxBatchDelay
> ++
> ++      flag := os.O_RDWR
> ++      if options.ReadOnly {
> ++              flag = os.O_RDONLY
> ++              db.readOnly = true
> ++      }
> +
> +       // Open data file and separate sync handler for metadata writes.
> +       db.path = path
> +-
> +       var err error
> +-      if db.file, err = os.OpenFile(db.path, os.O_RDWR|os.O_CREATE,
> mode); err != nil {
> ++      if db.file, err = os.OpenFile(db.path, flag|os.O_CREATE, mode);
> err != nil {
> +               _ = db.close()
> +               return nil, err
> +       }
> +
> +-      // Lock file so that other processes using Bolt cannot use the
> database
> +-      // at the same time. This would cause corruption since the two
> processes
> +-      // would write meta pages and free pages separately.
> +-      if err := flock(db.file, options.Timeout); err != nil {
> ++      // Lock file so that other processes using Bolt in read-write mode
> cannot
> ++      // use the database  at the same time. This would cause corruption
> since
> ++      // the two processes would write meta pages and free pages
> separately.
> ++      // The database file is locked exclusively (only one process can
> grab the lock)
> ++      // if !options.ReadOnly.
> ++      // The database file is locked using the shared lock (more than
> one process may
> ++      // hold a lock at the same time) otherwise (options.ReadOnly is
> set).
> ++      if err := flock(db.file, !db.readOnly, options.Timeout); err !=
> nil {
> +               _ = db.close()
> +               return nil, err
> +       }
> +@@ -162,16 +210,6 @@ func (db *DB) mmap(minsz int) error {
> +       db.mmaplock.Lock()
> +       defer db.mmaplock.Unlock()
> +
> +-      // Dereference all mmap references before unmapping.
> +-      if db.rwtx != nil {
> +-              db.rwtx.root.dereference()
> +-      }
> +-
> +-      // Unmap existing data before continuing.
> +-      if err := db.munmap(); err != nil {
> +-              return err
> +-      }
> +-
> +       info, err := db.file.Stat()
> +       if err != nil {
> +               return fmt.Errorf("mmap stat error: %s", err)
> +@@ -184,7 +222,20 @@ func (db *DB) mmap(minsz int) error {
> +       if size < minsz {
> +               size = minsz
> +       }
> +-      size = db.mmapSize(size)
> ++      size, err = db.mmapSize(size)
> ++      if err != nil {
> ++              return err
> ++      }
> ++
> ++      // Dereference all mmap references before unmapping.
> ++      if db.rwtx != nil {
> ++              db.rwtx.root.dereference()
> ++      }
> ++
> ++      // Unmap existing data before continuing.
> ++      if err := db.munmap(); err != nil {
> ++              return err
> ++      }
> +
> +       // Memory-map the data file as a byte slice.
> +       if err := mmap(db, size); err != nil {
> +@@ -215,22 +266,40 @@ func (db *DB) munmap() error {
> + }
> +
> + // mmapSize determines the appropriate size for the mmap given the
> current size
> +-// of the database. The minimum size is 4MB and doubles until it reaches
> 1GB.
> +-func (db *DB) mmapSize(size int) int {
> +-      if size <= minMmapSize {
> +-              return minMmapSize
> +-      } else if size < maxMmapStep {
> +-              size *= 2
> +-      } else {
> +-              size += maxMmapStep
> ++// of the database. The minimum size is 1MB and doubles until it reaches
> 1GB.
> ++// Returns an error if the new mmap size is greater than the max allowed.
> ++func (db *DB) mmapSize(size int) (int, error) {
> ++      // Double the size from 32KB until 1GB.
> ++      for i := uint(15); i <= 30; i++ {
> ++              if size <= 1<<i {
> ++                      return 1 << i, nil
> ++              }
> ++      }
> ++
> ++      // Verify the requested size is not above the maximum allowed.
> ++      if size > maxMapSize {
> ++              return 0, fmt.Errorf("mmap too large")
> ++      }
> ++
> ++      // If larger than 1GB then grow by 1GB at a time.
> ++      sz := int64(size)
> ++      if remainder := sz % int64(maxMmapStep); remainder > 0 {
> ++              sz += int64(maxMmapStep) - remainder
> +       }
> +
> +       // Ensure that the mmap size is a multiple of the page size.
> +-      if (size % db.pageSize) != 0 {
> +-              size = ((size / db.pageSize) + 1) * db.pageSize
> ++      // This should always be true since we're incrementing in MBs.
> ++      pageSize := int64(db.pageSize)
> ++      if (sz % pageSize) != 0 {
> ++              sz = ((sz / pageSize) + 1) * pageSize
> ++      }
> ++
> ++      // If we've exceeded the max size then only grow up to the max
> size.
> ++      if sz > maxMapSize {
> ++              sz = maxMapSize
> +       }
> +
> +-      return size
> ++      return int(sz), nil
> + }
> +
> + // init creates a new database file and initializes its meta pages.
> +@@ -250,7 +319,6 @@ func (db *DB) init() error {
> +               m.magic = magic
> +               m.version = version
> +               m.pageSize = uint32(db.pageSize)
> +-              m.version = version
> +               m.freelist = 2
> +               m.root = bucket{root: 3}
> +               m.pgid = 4
> +@@ -283,8 +351,15 @@ func (db *DB) init() error {
> + // Close releases all database resources.
> + // All transactions must be closed before closing the database.
> + func (db *DB) Close() error {
> ++      db.rwlock.Lock()
> ++      defer db.rwlock.Unlock()
> ++
> +       db.metalock.Lock()
> +       defer db.metalock.Unlock()
> ++
> ++      db.mmaplock.RLock()
> ++      defer db.mmaplock.RUnlock()
> ++
> +       return db.close()
> + }
> +
> +@@ -304,8 +379,11 @@ func (db *DB) close() error {
> +
> +       // Close file handles.
> +       if db.file != nil {
> +-              // Unlock the file.
> +-              _ = funlock(db.file)
> ++              // No need to unlock read-only file.
> ++              if !db.readOnly {
> ++                      // Unlock the file.
> ++                      _ = funlock(db.file)
> ++              }
> +
> +               // Close the file descriptor.
> +               if err := db.file.Close(); err != nil {
> +@@ -323,6 +401,11 @@ func (db *DB) close() error {
> + // will cause the calls to block and be serialized until the current
> write
> + // transaction finishes.
> + //
> ++// Transactions should not be depedent on one another. Opening a read
> ++// transaction and a write transaction in the same goroutine can cause
> the
> ++// writer to deadlock because the database periodically needs to re-mmap
> itself
> ++// as it grows and it cannot do that while a read transaction is open.
> ++//
> + // IMPORTANT: You must close read-only transactions after you are
> finished or
> + // else the database will not reclaim old pages.
> + func (db *DB) Begin(writable bool) (*Tx, error) {
> +@@ -371,6 +454,11 @@ func (db *DB) beginTx() (*Tx, error) {
> + }
> +
> + func (db *DB) beginRWTx() (*Tx, error) {
> ++      // If the database was opened with Options.ReadOnly, return an
> error.
> ++      if db.readOnly {
> ++              return nil, ErrDatabaseReadOnly
> ++      }
> ++
> +       // Obtain writer lock. This is released by the transaction when it
> closes.
> +       // This enforces only one writer transaction at a time.
> +       db.rwlock.Lock()
> +@@ -501,6 +589,12 @@ func (db *DB) View(fn func(*Tx) error) error {
> +       return nil
> + }
> +
> ++// Sync executes fdatasync() against the database file handle.
> ++//
> ++// This is not necessary under normal operation, however, if you use
> NoSync
> ++// then it allows you to force the database file to sync against the
> disk.
> ++func (db *DB) Sync() error { return fdatasync(db) }
> ++
> + // Stats retrieves ongoing performance stats for the database.
> + // This is only updated when a transaction closes.
> + func (db *DB) Stats() Stats {
> +@@ -561,18 +655,30 @@ func (db *DB) allocate(count int) (*page, error) {
> +       return p, nil
> + }
> +
> ++func (db *DB) IsReadOnly() bool {
> ++      return db.readOnly
> ++}
> ++
> + // Options represents the options that can be set when opening a
> database.
> + type Options struct {
> +       // Timeout is the amount of time to wait to obtain a file lock.
> +       // When set to zero it will wait indefinitely. This option is only
> +       // available on Darwin and Linux.
> +       Timeout time.Duration
> ++
> ++      // Sets the DB.NoGrowSync flag before memory mapping the file.
> ++      NoGrowSync bool
> ++
> ++      // Open database in read-only mode. Uses flock(..., LOCK_SH
> |LOCK_NB) to
> ++      // grab a shared lock (UNIX).
> ++      ReadOnly bool
> + }
> +
> + // DefaultOptions represent the options used if nil options are passed
> into Open().
> + // No timeout is used which will cause Bolt to wait indefinitely for a
> lock.
> + var DefaultOptions = &Options{
> +-      Timeout: 0,
> ++      Timeout:    0,
> ++      NoGrowSync: false,
> + }
> +
> + // Stats represents statistics about the database.
> +@@ -647,9 +753,11 @@ func (m *meta) copy(dest *meta) {
> +
> + // write writes the meta onto a page.
> + func (m *meta) write(p *page) {
> +-
> +-      _assert(m.root.root < m.pgid, "root bucket pgid (%d) above high
> water mark (%d)", m.root.root, m.pgid)
> +-      _assert(m.freelist < m.pgid, "freelist pgid (%d) above high water
> mark (%d)", m.freelist, m.pgid)
> ++      if m.root.root >= m.pgid {
> ++              panic(fmt.Sprintf("root bucket pgid (%d) above high water
> mark (%d)", m.root.root, m.pgid))
> ++      } else if m.freelist >= m.pgid {
> ++              panic(fmt.Sprintf("freelist pgid (%d) above high water
> mark (%d)", m.freelist, m.pgid))
> ++      }
> +
> +       // Page id is either going to be 0 or 1 which we can determine by
> the transaction ID.
> +       p.id = pgid(m.txid % 2)
> +@@ -675,13 +783,8 @@ func _assert(condition bool, msg string, v
> ...interface{}) {
> +       }
> + }
> +
> +-func warn(v ...interface{}) {
> +-      fmt.Fprintln(os.Stderr, v...)
> +-}
> +-
> +-func warnf(msg string, v ...interface{}) {
> +-      fmt.Fprintf(os.Stderr, msg+"\n", v...)
> +-}
> ++func warn(v ...interface{})              { fmt.Fprintln(os.Stderr, v...)
> }
> ++func warnf(msg string, v ...interface{}) { fmt.Fprintf(os.Stderr,
> msg+"\n", v...) }
> +
> + func printstack() {
> +       stack := strings.Join(strings.Split(string(debug.Stack()),
> "\n")[2:], "\n")
> +diff --git a/vendor/src/github.com/boltdb/bolt/errors.go b/vendor/src/
> github.com/boltdb/bolt/errors.go
> +index aa504f1..6883786 100644
> +--- a/vendor/src/github.com/boltdb/bolt/errors.go
> ++++ b/vendor/src/github.com/boltdb/bolt/errors.go
> +@@ -36,6 +36,10 @@ var (
> +       // ErrTxClosed is returned when committing or rolling back a
> transaction
> +       // that has already been committed or rolled back.
> +       ErrTxClosed = errors.New("tx closed")
> ++
> ++      // ErrDatabaseReadOnly is returned when a mutating transaction is
> started on a
> ++      // read-only database.
> ++      ErrDatabaseReadOnly = errors.New("database is in read-only mode")
> + )
> +
> + // These errors can occur when putting or deleting a value or a bucket.
> +diff --git a/vendor/src/github.com/boltdb/bolt/freelist.go b/vendor/src/
> github.com/boltdb/bolt/freelist.go
> +index 150e3e6..0161948 100644
> +--- a/vendor/src/github.com/boltdb/bolt/freelist.go
> ++++ b/vendor/src/github.com/boltdb/bolt/freelist.go
> +@@ -1,6 +1,7 @@
> + package bolt
> +
> + import (
> ++      "fmt"
> +       "sort"
> +       "unsafe"
> + )
> +@@ -47,15 +48,14 @@ func (f *freelist) pending_count() int {
> +
> + // all returns a list of all free ids and all pending ids in one sorted
> list.
> + func (f *freelist) all() []pgid {
> +-      ids := make([]pgid, len(f.ids))
> +-      copy(ids, f.ids)
> ++      m := make(pgids, 0)
> +
> +       for _, list := range f.pending {
> +-              ids = append(ids, list...)
> ++              m = append(m, list...)
> +       }
> +
> +-      sort.Sort(pgids(ids))
> +-      return ids
> ++      sort.Sort(m)
> ++      return pgids(f.ids).merge(m)
> + }
> +
> + // allocate returns the starting page id of a contiguous list of pages
> of a given size.
> +@@ -67,7 +67,9 @@ func (f *freelist) allocate(n int) pgid {
> +
> +       var initial, previd pgid
> +       for i, id := range f.ids {
> +-              _assert(id > 1, "invalid page allocation: %d", id)
> ++              if id <= 1 {
> ++                      panic(fmt.Sprintf("invalid page allocation: %d",
> id))
> ++              }
> +
> +               // Reset initial page if this is not contiguous.
> +               if previd == 0 || id-previd != 1 {
> +@@ -103,13 +105,17 @@ func (f *freelist) allocate(n int) pgid {
> + // free releases a page and its overflow for a given transaction id.
> + // If the page is already free then a panic will occur.
> + func (f *freelist) free(txid txid, p *page) {
> +-      _assert(p.id > 1, "cannot free page 0 or 1: %d", p.id)
> ++      if p.id <= 1 {
> ++              panic(fmt.Sprintf("cannot free page 0 or 1: %d", p.id))
> ++      }
> +
> +       // Free page and all its overflow pages.
> +       var ids = f.pending[txid]
> +       for id := p.id; id <= p.id+pgid(p.overflow); id++ {
> +               // Verify that page is not already free.
> +-              _assert(!f.cache[id], "page %d already freed", id)
> ++              if f.cache[id] {
> ++                      panic(fmt.Sprintf("page %d already freed", id))
> ++              }
> +
> +               // Add to the freelist and cache.
> +               ids = append(ids, id)
> +@@ -120,15 +126,17 @@ func (f *freelist) free(txid txid, p *page) {
> +
> + // release moves all page ids for a transaction id (or older) to the
> freelist.
> + func (f *freelist) release(txid txid) {
> ++      m := make(pgids, 0)
> +       for tid, ids := range f.pending {
> +               if tid <= txid {
> +                       // Move transaction's pending pages to the
> available freelist.
> +                       // Don't remove from the cache since the page is
> still free.
> +-                      f.ids = append(f.ids, ids...)
> ++                      m = append(m, ids...)
> +                       delete(f.pending, tid)
> +               }
> +       }
> +-      sort.Sort(pgids(f.ids))
> ++      sort.Sort(m)
> ++      f.ids = pgids(f.ids).merge(m)
> + }
> +
> + // rollback removes the pages from a given pending tx.
> +diff --git a/vendor/src/github.com/boltdb/bolt/node.go b/vendor/src/
> github.com/boltdb/bolt/node.go
> +index c204c39..c9fb21c 100644
> +--- a/vendor/src/github.com/boltdb/bolt/node.go
> ++++ b/vendor/src/github.com/boltdb/bolt/node.go
> +@@ -2,6 +2,7 @@ package bolt
> +
> + import (
> +       "bytes"
> ++      "fmt"
> +       "sort"
> +       "unsafe"
> + )
> +@@ -70,7 +71,9 @@ func (n *node) pageElementSize() int {
> +
> + // childAt returns the child node at a given index.
> + func (n *node) childAt(index int) *node {
> +-      _assert(!n.isLeaf, "invalid childAt(%d) on a leaf node", index)
> ++      if n.isLeaf {
> ++              panic(fmt.Sprintf("invalid childAt(%d) on a leaf node",
> index))
> ++      }
> +       return n.bucket.node(n.inodes[index].pgid, n)
> + }
> +
> +@@ -111,9 +114,13 @@ func (n *node) prevSibling() *node {
> +
> + // put inserts a key/value.
> + func (n *node) put(oldKey, newKey, value []byte, pgid pgid, flags
> uint32) {
> +-      _assert(pgid < n.bucket.tx.meta.pgid, "pgid (%d) above high water
> mark (%d)", pgid, n.bucket.tx.meta.pgid)
> +-      _assert(len(oldKey) > 0, "put: zero-length old key")
> +-      _assert(len(newKey) > 0, "put: zero-length new key")
> ++      if pgid >= n.bucket.tx.meta.pgid {
> ++              panic(fmt.Sprintf("pgid (%d) above high water mark (%d)",
> pgid, n.bucket.tx.meta.pgid))
> ++      } else if len(oldKey) <= 0 {
> ++              panic("put: zero-length old key")
> ++      } else if len(newKey) <= 0 {
> ++              panic("put: zero-length new key")
> ++      }
> +
> +       // Find insertion index.
> +       index := sort.Search(len(n.inodes), func(i int) bool { return
> bytes.Compare(n.inodes[i].key, oldKey) != -1 })
> +@@ -189,7 +196,9 @@ func (n *node) write(p *page) {
> +               p.flags |= branchPageFlag
> +       }
> +
> +-      _assert(len(n.inodes) < 0xFFFF, "inode overflow: %d (pgid=%d)",
> len(n.inodes), p.id)
> ++      if len(n.inodes) >= 0xFFFF {
> ++              panic(fmt.Sprintf("inode overflow: %d (pgid=%d)",
> len(n.inodes), p.id))
> ++      }
> +       p.count = uint16(len(n.inodes))
> +
> +       // Loop over each item and write it to the page.
> +@@ -212,11 +221,20 @@ func (n *node) write(p *page) {
> +                       _assert(elem.pgid != p.id, "write: circular
> dependency occurred")
> +               }
> +
> ++              // If the length of key+value is larger than the max
> allocation size
> ++              // then we need to reallocate the byte array pointer.
> ++              //
> ++              // See: https://github.com/boltdb/bolt/pull/335
> ++              klen, vlen := len(item.key), len(item.value)
> ++              if len(b) < klen+vlen {
> ++                      b = (*[maxAllocSize]byte)(unsafe.Pointer(&b[0]))[:]
> ++              }
> ++
> +               // Write data for the element to the end of the page.
> +               copy(b[0:], item.key)
> +-              b = b[len(item.key):]
> ++              b = b[klen:]
> +               copy(b[0:], item.value)
> +-              b = b[len(item.value):]
> ++              b = b[vlen:]
> +       }
> +
> +       // DEBUG ONLY: n.dump()
> +@@ -348,7 +366,9 @@ func (n *node) spill() error {
> +               }
> +
> +               // Write the node.
> +-              _assert(p.id < tx.meta.pgid, "pgid (%d) above high water
> mark (%d)", p.id, tx.meta.pgid)
> ++              if p.id >= tx.meta.pgid {
> ++                      panic(fmt.Sprintf("pgid (%d) above high water mark
> (%d)", p.id, tx.meta.pgid))
> ++              }
> +               node.pgid = p.id
> +               node.write(p)
> +               node.spilled = true
> +diff --git a/vendor/src/github.com/boltdb/bolt/page.go b/vendor/src/
> github.com/boltdb/bolt/page.go
> +index b3dc473..818aa1b 100644
> +--- a/vendor/src/github.com/boltdb/bolt/page.go
> ++++ b/vendor/src/github.com/boltdb/bolt/page.go
> +@@ -3,12 +3,12 @@ package bolt
> + import (
> +       "fmt"
> +       "os"
> ++      "sort"
> +       "unsafe"
> + )
> +
> + const pageHeaderSize = int(unsafe.Offsetof(((*page)(nil)).ptr))
> +
> +-const maxAllocSize = 0xFFFFFFF
> + const minKeysPerPage = 2
> +
> + const branchPageElementSize = int(unsafe.Sizeof(branchPageElement{}))
> +@@ -97,7 +97,7 @@ type branchPageElement struct {
> + // key returns a byte slice of the node key.
> + func (n *branchPageElement) key() []byte {
> +       buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
> +-      return buf[n.pos : n.pos+n.ksize]
> ++      return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize]
> + }
> +
> + // leafPageElement represents a node on a leaf page.
> +@@ -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 buf[n.pos : n.pos+n.ksize]
> ++      return (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos]))[:n.ksize]
> + }
> +
> + // value returns a byte slice of the node value.
> + func (n *leafPageElement) value() []byte {
> +       buf := (*[maxAllocSize]byte)(unsafe.Pointer(n))
> +-      return buf[n.pos+n.ksize : n.pos+n.ksize+n.vsize]
> ++      return
> (*[maxAllocSize]byte)(unsafe.Pointer(&buf[n.pos+n.ksize]))[:n.vsize]
> + }
> +
> + // PageInfo represents human readable information about a page.
> +@@ -133,3 +133,40 @@ type pgids []pgid
> + func (s pgids) Len() int           { return len(s) }
> + func (s pgids) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
> + func (s pgids) Less(i, j int) bool { return s[i] < s[j] }
> ++
> ++// merge returns the sorted union of a and b.
> ++func (a pgids) merge(b pgids) pgids {
> ++      // Return the opposite slice if one is nil.
> ++      if len(a) == 0 {
> ++              return b
> ++      } else if len(b) == 0 {
> ++              return a
> ++      }
> ++
> ++      // Create a list to hold all elements from both lists.
> ++      merged := make(pgids, 0, len(a)+len(b))
> ++
> ++      // Assign lead to the slice with a lower starting value, follow to
> the higher value.
> ++      lead, follow := a, b
> ++      if b[0] < a[0] {
> ++              lead, follow = b, a
> ++      }
> ++
> ++      // Continue while there are elements in the lead.
> ++      for len(lead) > 0 {
> ++              // Merge largest prefix of lead that is ahead of follow[0].
> ++              n := sort.Search(len(lead), func(i int) bool { return
> lead[i] > follow[0] })
> ++              merged = append(merged, lead[:n]...)
> ++              if n >= len(lead) {
> ++                      break
> ++              }
> ++
> ++              // Swap lead and follow.
> ++              lead, follow = follow, lead[n:]
> ++      }
> ++
> ++      // Append what's left in follow.
> ++      merged = append(merged, follow...)
> ++
> ++      return merged
> ++}
> +diff --git a/vendor/src/github.com/boltdb/bolt/tx.go b/vendor/src/
> github.com/boltdb/bolt/tx.go
> +index c041d73..fe6c287 100644
> +--- a/vendor/src/github.com/boltdb/bolt/tx.go
> ++++ b/vendor/src/github.com/boltdb/bolt/tx.go
> +@@ -87,18 +87,21 @@ func (tx *Tx) Stats() TxStats {
> +
> + // Bucket retrieves a bucket by name.
> + // Returns nil if the bucket does not exist.
> ++// The bucket instance is only valid for the lifetime of the transaction.
> + func (tx *Tx) Bucket(name []byte) *Bucket {
> +       return tx.root.Bucket(name)
> + }
> +
> + // CreateBucket creates a new bucket.
> + // Returns an error if the bucket already exists, if the bucket name is
> blank, or if the bucket name is too long.
> ++// The bucket instance is only valid for the lifetime of the transaction.
> + func (tx *Tx) CreateBucket(name []byte) (*Bucket, error) {
> +       return tx.root.CreateBucket(name)
> + }
> +
> + // CreateBucketIfNotExists creates a new bucket if it doesn't already
> exist.
> + // Returns an error if the bucket name is blank, or if the bucket name
> is too long.
> ++// The bucket instance is only valid for the lifetime of the transaction.
> + func (tx *Tx) CreateBucketIfNotExists(name []byte) (*Bucket, error) {
> +       return tx.root.CreateBucketIfNotExists(name)
> + }
> +@@ -127,7 +130,8 @@ func (tx *Tx) OnCommit(fn func()) {
> + }
> +
> + // Commit writes all changes to disk and updates the meta page.
> +-// Returns an error if a disk write error occurs.
> ++// Returns an error if a disk write error occurs, or if Commit is
> ++// called on a read-only transaction.
> + func (tx *Tx) Commit() error {
> +       _assert(!tx.managed, "managed tx commit not allowed")
> +       if tx.db == nil {
> +@@ -203,7 +207,8 @@ func (tx *Tx) Commit() error {
> +       return nil
> + }
> +
> +-// Rollback closes the transaction and ignores all previous updates.
> ++// Rollback closes the transaction and ignores all previous updates.
> Read-only
> ++// transactions must be rolled back and not committed.
> + func (tx *Tx) Rollback() error {
> +       _assert(!tx.managed, "managed tx rollback not allowed")
> +       if tx.db == nil {
> +@@ -234,7 +239,8 @@ func (tx *Tx) close() {
> +               var freelistPendingN = tx.db.freelist.pending_count()
> +               var freelistAlloc = tx.db.freelist.size()
> +
> +-              // Remove writer lock.
> ++              // Remove transaction ref & writer lock.
> ++              tx.db.rwtx = nil
> +               tx.db.rwlock.Unlock()
> +
> +               // Merge statistics.
> +@@ -248,41 +254,51 @@ func (tx *Tx) close() {
> +       } else {
> +               tx.db.removeTx(tx)
> +       }
> ++
> ++      // Clear all references.
> +       tx.db = nil
> ++      tx.meta = nil
> ++      tx.root = Bucket{tx: tx}
> ++      tx.pages = nil
> + }
> +
> + // Copy writes the entire database to a writer.
> +-// A reader transaction is maintained during the copy so it is safe to
> continue
> +-// using the database while a copy is in progress.
> +-// Copy will write exactly tx.Size() bytes into the writer.
> ++// This function exists for backwards compatibility. Use WriteTo() in
> + func (tx *Tx) Copy(w io.Writer) error {
> +-      var f *os.File
> +-      var err error
> ++      _, err := tx.WriteTo(w)
> ++      return err
> ++}
> +
> ++// WriteTo writes the entire database to a writer.
> ++// If err == nil then exactly tx.Size() bytes will be written into the
> writer.
> ++func (tx *Tx) WriteTo(w io.Writer) (n int64, err error) {
> +       // Attempt to open reader directly.
> ++      var f *os.File
> +       if f, err = os.OpenFile(tx.db.path, os.O_RDONLY|odirect, 0); err
> != nil {
> +               // Fallback to a regular open if that doesn't work.
> +               if f, err = os.OpenFile(tx.db.path, os.O_RDONLY, 0); err
> != nil {
> +-                      return err
> ++                      return 0, err
> +               }
> +       }
> +
> +       // Copy the meta pages.
> +       tx.db.metalock.Lock()
> +-      _, err = io.CopyN(w, f, int64(tx.db.pageSize*2))
> ++      n, err = io.CopyN(w, f, int64(tx.db.pageSize*2))
> +       tx.db.metalock.Unlock()
> +       if err != nil {
> +               _ = f.Close()
> +-              return fmt.Errorf("meta copy: %s", err)
> ++              return n, fmt.Errorf("meta copy: %s", err)
> +       }
> +
> +       // Copy data pages.
> +-      if _, err := io.CopyN(w, f, tx.Size()-int64(tx.db.pageSize*2));
> err != nil {
> ++      wn, err := io.CopyN(w, f, tx.Size()-int64(tx.db.pageSize*2))
> ++      n += wn
> ++      if err != nil {
> +               _ = f.Close()
> +-              return err
> ++              return n, err
> +       }
> +
> +-      return f.Close()
> ++      return n, f.Close()
> + }
> +
> + // CopyFile copies the entire database to file at the given path.
> +@@ -416,15 +432,39 @@ func (tx *Tx) write() error {
> +       // Write pages to disk in order.
> +       for _, p := range pages {
> +               size := (int(p.overflow) + 1) * tx.db.pageSize
> +-              buf := (*[maxAllocSize]byte)(unsafe.Pointer(p))[:size]
> +               offset := int64(p.id) * int64(tx.db.pageSize)
> +-              if _, err := tx.db.ops.writeAt(buf, offset); err != nil {
> +-                      return err
> +-              }
> +
> +-              // Update statistics.
> +-              tx.stats.Write++
> ++              // Write out page in "max allocation" sized chunks.
> ++              ptr := (*[maxAllocSize]byte)(unsafe.Pointer(p))
> ++              for {
> ++                      // Limit our write to our max allocation size.
> ++                      sz := size
> ++                      if sz > maxAllocSize-1 {
> ++                              sz = maxAllocSize - 1
> ++                      }
> ++
> ++                      // Write chunk to disk.
> ++                      buf := ptr[:sz]
> ++                      if _, err := tx.db.ops.writeAt(buf, offset); err
> != nil {
> ++                              return err
> ++                      }
> ++
> ++                      // Update statistics.
> ++                      tx.stats.Write++
> ++
> ++                      // Exit inner for loop if we've written all the
> chunks.
> ++                      size -= sz
> ++                      if size == 0 {
> ++                              break
> ++                      }
> ++
> ++                      // Otherwise move offset forward and move pointer
> to next chunk.
> ++                      offset += int64(sz)
> ++                      ptr =
> (*[maxAllocSize]byte)(unsafe.Pointer(&ptr[sz]))
> ++              }
> +       }
> ++
> ++      // Ignore file sync if flag is set on DB.
> +       if !tx.db.NoSync || IgnoreNoSync {
> +               if err := fdatasync(tx.db); err != nil {
> +                       return err
> +--
> +1.9.1
> +
> diff --git a/recipes-containers/docker/files/disable_sha1sum_startup.patch
> b/recipes-containers/docker/files/disable_sha1sum_startup.patch
> index 580ca23..cafd83d 100644
> --- a/recipes-containers/docker/files/disable_sha1sum_startup.patch
> +++ b/recipes-containers/docker/files/disable_sha1sum_startup.patch
> @@ -12,20 +12,23 @@ of the binary instead.
>
>  Signed-off-by: Amy Fong <amy.fong at windriver.com>
>  ---
> - utils/utils.go |   17 +----------------
> - 1 file changed, 1 insertion(+), 16 deletions(-)
> + utils/utils.go | 18 +-----------------
> + 1 file changed, 1 insertion(+), 17 deletions(-)
>
> +diff --git a/utils/utils.go b/utils/utils.go
> +index a17ab9d..3fc514a 100644
>  --- a/utils/utils.go
>  +++ b/utils/utils.go
> -@@ -3,7 +3,6 @@
> +@@ -2,8 +2,6 @@ package utils
> +
>   import (
>         "bufio"
> -       "bytes"
>  -      "crypto/sha1"
> -       "crypto/sha256"
> -       "encoding/hex"
> +-      "encoding/hex"
>         "fmt"
> -@@ -75,20 +74,6 @@
> +       "io"
> +       "io/ioutil"
> +@@ -42,20 +40,6 @@ func SelfPath() string {
>         return path
>   }
>
> @@ -46,7 +49,7 @@ Signed-off-by: Amy Fong <amy.fong at windriver.com>
>   func isValidDockerInitPath(target string, selfPath string) bool { //
> target and selfPath should be absolute (InitPath and SelfPath already do
> this)
>         if target == "" {
>                 return false
> -@@ -110,7 +95,7 @@
> +@@ -77,7 +61,7 @@ func isValidDockerInitPath(target string, selfPath
> string) bool { // target and
>                 }
>                 return os.SameFile(targetFileInfo, selfPathFileInfo)
>         }
> @@ -54,4 +57,4 @@ Signed-off-by: Amy Fong <amy.fong at windriver.com>
>  +      return true
>   }
>
> - // Figure out the path of our dockerinit (which may be SelfPath())
> + // DockerInitPath figures out the path of our dockerinit (which may be
> SelfPath())
> --
> 1.8.3.2
>
>


-- 
"Thou shalt not follow the NULL pointer, for chaos and madness await thee
at its end"
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