Merge remote-tracking branch 'upstream/master' into reference

.github/ISSUE_TEMPLATE/config.yml

+blank_issues_enabled: false
+contact_links:
+ - name: Getting Help on IPFS
+   url: https://ipfs.io/help
+   about: All information about how and where to get help on IPFS.
+ - name: IPFS Official Forum
+   url: https://discuss.ipfs.io
+   about: Please post general questions, support requests, and discussions here.

.github/ISSUE_TEMPLATE/open_an_issue.md

+---
+name: Open an issue
+about: Only for actionable issues relevant to this repository.
+title: ''
+labels: need/triage
+assignees: ''
+
+---
+<!--
+Hello! To ensure this issue is correctly addressed as soon as possible by the IPFS team, please try to make sure:
+
+- This issue is relevant to this repository's topic or codebase.
+
+- A clear description is provided. It should includes as much relevant information as possible and clear scope for the issue to be actionable.
+
+FOR GENERAL DISCUSSION, HELP OR QUESTIONS, please see the options at https://ipfs.io/help or head directly to https://discuss.ipfs.io.
+
+(you can delete this section after reading)
+-->

.github/config.yml

+# Configuration for welcome - https://github.com/behaviorbot/welcome
+
+# Configuration for new-issue-welcome - https://github.com/behaviorbot/new-issue-welcome
+# Comment to be posted to on first time issues
+newIssueWelcomeComment: >
+  Thank you for submitting your first issue to this repository! A maintainer
+  will be here shortly to triage and review.
+
+  In the meantime, please double-check that you have provided all the
+  necessary information to make this process easy! Any information that can
+  help save additional round trips is useful! We currently aim to give
+  initial feedback within **two business days**. If this does not happen, feel
+  free to leave a comment.
+
+  Please keep an eye on how this issue will be labeled, as labels give an
+  overview of priorities, assignments and additional actions requested by the
+  maintainers:
+
+    - "Priority" labels will show how urgent this is for the team.
+    - "Status" labels will show if this is ready to be worked on, blocked, or in progress.
+    - "Need" labels will indicate if additional input or analysis is required.
+
+  Finally, remember to use https://discuss.ipfs.io if you just need general
+  support.
+
+# Configuration for new-pr-welcome - https://github.com/behaviorbot/new-pr-welcome
+# Comment to be posted to on PRs from first time contributors in your repository
+newPRWelcomeComment: >
+  Thank you for submitting this PR!
+
+  A maintainer will be here shortly to review it.
+
+  We are super grateful, but we are also overloaded! Help us by making sure
+  that:
+
+    * The context for this PR is clear, with relevant discussion, decisions
+      and stakeholders linked/mentioned.
+
+    * Your contribution itself is clear (code comments, self-review for the
+      rest) and in its best form. Follow the [code contribution
+      guidelines](https://github.com/ipfs/community/blob/master/CONTRIBUTING.md#code-contribution-guidelines)
+      if they apply.
+
+  Getting other community members to do a review would be great help too on
+  complex PRs (you can ask in the chats/forums). If you are unsure about
+  something, just leave us a comment.
+
+  Next steps:
+
+    * A maintainer will triage and assign priority to this PR, commenting on
+      any missing things and potentially assigning a reviewer for high
+      priority items.
+
+    * The PR gets reviews, discussed and approvals as needed.
+
+    * The PR is merged by maintainers when it has been approved and comments addressed.
+
+  We currently aim to provide initial feedback/triaging within **two business
+  days**. Please keep an eye on any labelling actions, as these will indicate
+  priorities and status of your contribution.
+
+  We are very grateful for your contribution!
+
+
+# Configuration for first-pr-merge - https://github.com/behaviorbot/first-pr-merge
+# Comment to be posted to on pull requests merged by a first time user
+# Currently disabled
+#firstPRMergeComment: ""

.gitignore

+*.swp

.gx/lastpubver

+1.2.9: QmNohiVssaPw3KVLZik59DBVGTSm2dGvYT9eoXt5DQ36Yz

.travis.yml

+os:
+  - linux
+
+language: go
+
+go:
+  - 1.14.x
+
+env:
+  global:
+    - GOTFLAGS="-race"
+  matrix:
+    - BUILD_DEPTYPE=gx
+    - BUILD_DEPTYPE=gomod
+
+
+# disable travis install
+install:
+  - true
+
+script:
+  - bash <(curl -s https://raw.githubusercontent.com/ipfs/ci-helpers/master/travis-ci/run-standard-tests.sh)
+
+
+cache:
+  directories:
+    - $GOPATH/src/gx
+    - $GOPATH/pkg/mod
+    - $HOME/.cache/go-build
+
+notifications:
+  email: false

LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2016 Juan Batiz-Benet
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

README.md

-# go-dms3-util
+# go-ipfs-util
 
-dms3 go util
\ No newline at end of file
+[![](https://img.shields.io/badge/made%20by-Protocol%20Labs-blue.svg?style=flat-square)](http://ipn.io)
+[![](https://img.shields.io/badge/project-IPFS-blue.svg?style=flat-square)](http://ipfs.io/)
+[![](https://img.shields.io/badge/freenode-%23ipfs-blue.svg?style=flat-square)](http://webchat.freenode.net/?channels=%23ipfs)
+[![standard-readme compliant](https://img.shields.io/badge/standard--readme-OK-green.svg?style=flat-square)](https://github.com/RichardLitt/standard-readme)
+[![](https://img.shields.io/badge/discussion_repo-go_to_issues-brightgreen.svg?style=flat-square)](https://github.com/ipfs/NAME/issues)
+
+> Common utilities used by go-ipfs and other related go packages
+
+## Lead Maintainer
+
+[Steven Allen](https://github.com/Stebalien)
+
+## Install
+
+This is a Go module which can be installed with `go get github.com/ipfs/go-ipfs-util`. `go-ipfs-util` is however packaged with Gx, so it is recommended to use Gx to install it (see Usage section).
+
+## Usage
+
+This module is packaged with [Gx](https://github.com/whyrusleeping/gx).
+In order to use it in your own project do:
+
+```
+go get -u github.com/whyrusleeping/gx
+go get -u github.com/whyrusleeping/gx-go
+cd <your-project-repository>
+gx init
+gx import github.com/ipfs/go-ipfs-util
+gx install --global
+gx-go --rewrite
+```
+
+Please check [Gx](https://github.com/whyrusleeping/gx) and [Gx-go](https://github.com/whyrusleeping/gx-go) documentation for more information.
+
+
+## Contribute
+
+Feel free to join in. All welcome. Open an [issue](https://github.com/ipfs/go-ipfs-util/issues)!
+
+This repository falls under the IPFS [Code of Conduct](https://github.com/ipfs/community/blob/master/code-of-conduct.md).
+
+### Want to hack on IPFS?
+
+[![](https://cdn.rawgit.com/jbenet/contribute-ipfs-gif/master/img/contribute.gif)](https://github.com/ipfs/community/blob/master/contributing.md)
+
+## License
+
+MIT

file.go

+package util
+
+import "os"
+
+// FileExists check if the file with the given path exits.
+func FileExists(filename string) bool {
+	fi, err := os.Lstat(filename)
+	if fi != nil || (err != nil && !os.IsNotExist(err)) {
+		return true
+	}
+	return false
+}

file_test.go

+package util
+
+import "testing"
+
+func TestFileDoesNotExist(t *testing.T) {
+	t.Parallel()
+	if FileExists("i would be surprised to discover that this file exists") {
+		t.Fail()
+	}
+}

go.mod

+module github.com/ipfs/go-ipfs-util
+
+go 1.14
+
+require (
+	github.com/mr-tron/base58 v1.1.3
+	github.com/multiformats/go-multihash v0.0.13
+)

go.sum

+github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1 h1:lYpkrQH5ajf0OXOcUbGjvZxxijuBwbbmlSxLiuofa+g=
+github.com/minio/blake2b-simd v0.0.0-20160723061019-3f5f724cb5b1/go.mod h1:pD8RvIylQ358TN4wwqatJ8rNavkEINozVn9DtGI3dfQ=
+github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771 h1:MHkK1uRtFbVqvAgvWxafZe54+5uBxLluGylDiKgdhwo=
+github.com/minio/sha256-simd v0.1.1-0.20190913151208-6de447530771/go.mod h1:B5e1o+1/KgNmWrSQK08Y6Z1Vb5pwIktudl0J58iy0KM=
+github.com/mr-tron/base58 v1.1.3 h1:v+sk57XuaCKGXpWtVBX8YJzO7hMGx4Aajh4TQbdEFdc=
+github.com/mr-tron/base58 v1.1.3/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
+github.com/multiformats/go-multihash v0.0.13 h1:06x+mk/zj1FoMsgNejLpy6QTvJqlSt/BhLEy87zidlc=
+github.com/multiformats/go-multihash v0.0.13/go.mod h1:VdAWLKTwram9oKAatUcLxBNUjdtcVwxObEQBtRfuyjc=
+github.com/multiformats/go-varint v0.0.5 h1:XVZwSo04Cs3j/jS0uAEPpT3JY6DzMcVLLoWOSnCxOjg=
+github.com/multiformats/go-varint v0.0.5/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
+github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
+github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8 h1:1wopBVtVdWnn03fZelqdXTqk7U7zPQCb+T4rbU9ZEoU=
+golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

package.json

+{
+  "author": "whyrusleeping",
+  "bugs": {},
+  "gx": {
+    "dvcsimport": "github.com/ipfs/go-ipfs-util"
+  },
+  "gxDependencies": [
+    {
+      "author": "multiformats",
+      "hash": "QmerPMzPk1mJVowm8KgmoknWa4yCYvvugMPsgWmDNUvDLW",
+      "name": "go-multihash",
+      "version": "1.0.9"
+    },
+    {
+      "author": "mr-tron",
+      "hash": "QmWFAMPqsEyUX7gDUsRVmMWz59FxSpJ1b2v6bJ1yYzo7jY",
+      "name": "go-base58-fast",
+      "version": "0.1.1"
+    }
+  ],
+  "gxVersion": "0.9.1",
+  "language": "go",
+  "license": "",
+  "name": "go-ipfs-util",
+  "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
+  "version": "1.2.9"
+}
+

time.go

+package util
+
+import "time"
+
+// TimeFormatIpfs is the format ipfs uses to represent time in string form.
+var TimeFormatIpfs = time.RFC3339Nano
+
+// ParseRFC3339 parses an RFC3339Nano-formatted time stamp and
+// returns the UTC time.
+func ParseRFC3339(s string) (time.Time, error) {
+	t, err := time.Parse(TimeFormatIpfs, s)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return t.UTC(), nil
+}
+
+// FormatRFC3339 returns the string representation of the
+// UTC value of the given time in RFC3339Nano format.
+func FormatRFC3339(t time.Time) string {
+	return t.UTC().Format(TimeFormatIpfs)
+}

time_test.go

+package util
+
+import (
+	"testing"
+	"time"
+)
+
+func TestTimeFormatParseInversion(t *testing.T) {
+	v, err := ParseRFC3339(FormatRFC3339(time.Now()))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if v.Location() != time.UTC {
+		t.Fatal("Time should be UTC")
+	}
+}

util.go

+// Package util implements various utility functions used within ipfs
+// that do not currently have a better place to live.
+package util
+
+import (
+	"errors"
+	"io"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"runtime/debug"
+	"strings"
+	"time"
+
+	b58 "github.com/mr-tron/base58/base58"
+	mh "github.com/multiformats/go-multihash"
+)
+
+// DefaultIpfsHash is the current default hash function used by IPFS.
+const DefaultIpfsHash = mh.SHA2_256
+
+// Debug is a global flag for debugging.
+var Debug bool
+
+// ErrNotImplemented signifies a function has not been implemented yet.
+var ErrNotImplemented = errors.New("Error: not implemented yet.")
+
+// ErrTimeout implies that a timeout has been triggered
+var ErrTimeout = errors.New("Error: Call timed out.")
+
+// ErrSearchIncomplete implies that a search type operation didnt
+// find the expected node, but did find 'a' node.
+var ErrSearchIncomplete = errors.New("Error: Search Incomplete.")
+
+// ErrCast is returned when a cast fails AND the program should not panic.
+func ErrCast() error {
+	debug.PrintStack()
+	return errCast
+}
+
+var errCast = errors.New("cast error")
+
+// ExpandPathnames takes a set of paths and turns them into absolute paths
+func ExpandPathnames(paths []string) ([]string, error) {
+	var out []string
+	for _, p := range paths {
+		abspath, err := filepath.Abs(p)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, abspath)
+	}
+	return out, nil
+}
+
+type randGen struct {
+	rand.Rand
+}
+
+// NewTimeSeededRand returns a random bytes reader
+// which has been initialized with the current time.
+func NewTimeSeededRand() io.Reader {
+	src := rand.NewSource(time.Now().UnixNano())
+	return &randGen{
+		Rand: *rand.New(src),
+	}
+}
+
+// NewSeededRand returns a random bytes reader
+// initialized with the given seed.
+func NewSeededRand(seed int64) io.Reader {
+	src := rand.NewSource(seed)
+	return &randGen{
+		Rand: *rand.New(src),
+	}
+}
+
+func (r *randGen) Read(p []byte) (n int, err error) {
+	for i := 0; i < len(p); i++ {
+		p[i] = byte(r.Rand.Intn(255))
+	}
+	return len(p), nil
+}
+
+// GetenvBool is the way to check an env var as a boolean
+func GetenvBool(name string) bool {
+	v := strings.ToLower(os.Getenv(name))
+	return v == "true" || v == "t" || v == "1"
+}
+
+// MultiErr is a util to return multiple errors
+type MultiErr []error
+
+func (m MultiErr) Error() string {
+	if len(m) == 0 {
+		return "no errors"
+	}
+
+	s := "Multiple errors: "
+	for i, e := range m {
+		if i != 0 {
+			s += ", "
+		}
+		s += e.Error()
+	}
+	return s
+}
+
+// Partition splits a subject 3 parts: prefix, separator, suffix.
+// The first occurrence of the separator will be matched.
+// ie. Partition("Ready, steady, go!", ", ") -> ["Ready", ", ", "steady, go!"]
+func Partition(subject string, sep string) (string, string, string) {
+	if i := strings.Index(subject, sep); i != -1 {
+		return subject[:i], subject[i : i+len(sep)], subject[i+len(sep):]
+	}
+	return subject, "", ""
+}
+
+// RPartition splits a subject 3 parts: prefix, separator, suffix.
+// The last occurrence of the separator will be matched.
+// ie. RPartition("Ready, steady, go!", ", ") -> ["Ready, steady", ", ", "go!"]
+func RPartition(subject string, sep string) (string, string, string) {
+	if i := strings.LastIndex(subject, sep); i != -1 {
+		return subject[:i], subject[i : i+len(sep)], subject[i+len(sep):]
+	}
+	return subject, "", ""
+}
+
+// Hash is the global IPFS hash function. uses multihash SHA2_256, 256 bits
+func Hash(data []byte) mh.Multihash {
+	h, err := mh.Sum(data, DefaultIpfsHash, -1)
+	if err != nil {
+		// this error can be safely ignored (panic) because multihash only fails
+		// from the selection of hash function. If the fn + length are valid, it
+		// won't error.
+		panic("multihash failed to hash using SHA2_256.")
+	}
+	return h
+}
+
+// IsValidHash checks whether a given hash is valid (b58 decodable, len > 0)
+func IsValidHash(s string) bool {
+	out, err := b58.Decode(s)
+	if err != nil {
+		return false
+	}
+	_, err = mh.Cast(out)
+	return err == nil
+}
+
+// XOR takes two byte slices, XORs them together, returns the resulting slice.
+func XOR(a, b []byte) []byte {
+	c := make([]byte, len(a))
+	for i := 0; i < len(a); i++ {
+		c[i] = a[i] ^ b[i]
+	}
+	return c
+}

util_test.go

+package util
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestXOR(t *testing.T) {
+	cases := [][3][]byte{
+		{
+			{0xFF, 0xFF, 0xFF},
+			{0xFF, 0xFF, 0xFF},
+			{0x00, 0x00, 0x00},
+		},
+		{
+			{0x00, 0xFF, 0x00},
+			{0xFF, 0xFF, 0xFF},
+			{0xFF, 0x00, 0xFF},
+		},
+		{
+			{0x55, 0x55, 0x55},
+			{0x55, 0xFF, 0xAA},
+			{0x00, 0xAA, 0xFF},
+		},
+	}
+
+	for _, c := range cases {
+		r := XOR(c[0], c[1])
+		if !bytes.Equal(r, c[2]) {
+			t.Error("XOR failed")
+		}
+	}
+}
+
+func BenchmarkHash256K(b *testing.B) {
+	buf := make([]byte, 256*1024)
+	NewTimeSeededRand().Read(buf)
+	b.SetBytes(int64(256 * 1024))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Hash(buf)
+	}
+}
+
+func BenchmarkHash512K(b *testing.B) {
+	buf := make([]byte, 512*1024)
+	NewTimeSeededRand().Read(buf)
+	b.SetBytes(int64(512 * 1024))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Hash(buf)
+	}
+}
+
+func BenchmarkHash1M(b *testing.B) {
+	buf := make([]byte, 1024*1024)
+	NewTimeSeededRand().Read(buf)
+	b.SetBytes(int64(1024 * 1024))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Hash(buf)
+	}
+}