reference basis

.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: ""

.github/workflows/automerge.yml

+# File managed by web3-bot. DO NOT EDIT.
+# See https://github.com/protocol/.github/ for details.
+
+# Automatically merge pull requests opened by web3-bot, as soon as (and only if) all tests pass.
+# This reduces the friction associated with updating with our workflows.
+
+on: [ pull_request ]
+name: Automerge
+
+jobs:
+  automerge-check:
+    if: github.event.pull_request.user.login == 'web3-bot'
+    runs-on: ubuntu-latest
+    outputs:
+      status: ${{ steps.should-automerge.outputs.status }}
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - name: Check if we should automerge
+      id: should-automerge
+      run: |
+        for commit in $(git rev-list --first-parent origin/${{ github.event.pull_request.base.ref }}..${{ github.event.pull_request.head.sha }}); do
+          committer=$(git show --format=$'%ce' -s $commit)
+          echo "Committer: $committer"
+          if [[ "$committer" != "web3-bot@users.noreply.github.com" ]]; then
+            echo "Commit $commit wasn't committed by web3-bot, but by $committer."
+            echo "::set-output name=status::false"
+            exit
+          fi
+        done
+        echo "::set-output name=status::true"
+  automerge:
+    needs: automerge-check
+    runs-on: ubuntu-latest
+    if: ${{ needs.automerge-check.outputs.status == 'true' }}
+    steps:
+    - name: Wait on tests
+      uses: lewagon/wait-on-check-action@bafe56a6863672c681c3cf671f5e10b20abf2eaa # v0.2
+      with:
+        ref: ${{ github.event.pull_request.head.sha }}
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        wait-interval: 10
+        running-workflow-name: 'automerge' # the name of this job
+    - name: Merge PR
+      uses: pascalgn/automerge-action@741c311a47881be9625932b0a0de1b0937aab1ae # v0.13.1
+      env:
+        GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+        MERGE_LABELS: ""
+        MERGE_METHOD: "squash"
+        MERGE_DELETE_BRANCH: true

.github/workflows/go-check.yml

+# File managed by web3-bot. DO NOT EDIT.
+# See https://github.com/protocol/.github/ for details.
+
+on: [push, pull_request]
+name: Go Checks
+
+jobs:
+  unit:
+    runs-on: ubuntu-latest
+    name: All
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - uses: actions/setup-go@v2
+        with:
+          go-version: "1.16.x"
+      - name: Install staticcheck
+        run: go install honnef.co/go/tools/cmd/staticcheck@434f5f3816b358fe468fa83dcba62d794e7fe04b # 2021.1 (v0.2.0)
+      - name: Check that go.mod is tidy
+        uses: protocol/multiple-go-modules@v1.0
+        with:
+          run: |
+            go mod tidy
+            if [[ -n $(git ls-files --other --exclude-standard --directory -- go.sum) ]]; then
+              echo "go.sum was added by go mod tidy"
+              exit 1
+            fi
+            git diff --exit-code -- go.sum go.mod
+      - name: gofmt
+        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        run: |
+          out=$(gofmt -s -l .)
+          if [[ -n "$out" ]]; then
+            echo $out | awk '{print "::error file=" $0 ",line=0,col=0::File is not gofmt-ed."}'
+            exit 1
+          fi
+      - name: go vet
+        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        uses: protocol/multiple-go-modules@v1.0
+        with:
+          run: go vet ./...
+      - name: staticcheck
+        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        uses: protocol/multiple-go-modules@v1.0
+        with:
+          run: |
+            set -o pipefail
+            staticcheck ./... | sed -e 's@\(.*\)\.go@./\1.go@g'
+

.github/workflows/go-test.yml

+# File managed by web3-bot. DO NOT EDIT.
+# See https://github.com/protocol/.github/ for details.
+
+on: [push, pull_request]
+name: Go Test
+
+jobs:
+  unit:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ "ubuntu", "windows", "macos" ]
+        go: [ "1.15.x", "1.16.x" ]
+    runs-on: ${{ matrix.os }}-latest
+    name: ${{ matrix.os}} (go ${{ matrix.go }})
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go }}
+      - name: Go information
+        run: |
+          go version
+          go env
+      - name: Run tests
+        uses: protocol/multiple-go-modules@v1.0
+        with:
+          run: go test -v -coverprofile coverage.txt ./...
+      - name: Run tests (32 bit)
+        if: ${{ matrix.os != 'macos' }} # can't run 32 bit tests on OSX.
+        uses: protocol/multiple-go-modules@v1.0
+        env:
+          GOARCH: 386
+        with:
+          run: go test -v ./...
+      - name: Run tests with race detector
+        if: ${{ matrix.os == 'ubuntu' }} # speed things up. Windows and OSX VMs are slow
+        uses: protocol/multiple-go-modules@v1.0
+        with:
+          run: go test -v -race ./...
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@a1ed4b322b4b38cb846afb5a0ebfa17086917d27 # v1.5.0
+        with:
+          file: coverage.txt
+          env_vars: OS=${{ matrix.os }}, GO=${{ matrix.go }}

.gx/lastpubver

+0.0.1: QmZUbTDJ39JpvtFCSubiWeUTQRvMA1tVE5RZCJrY4oeAsC

LICENSE

+MIT License
+
+Copyright (c) 2018 IPFS
+
+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-pq
+# go-ipfs-pq
 
-dms3 priority queue
\ 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/)
+[![standard-readme compliant](https://img.shields.io/badge/standard--readme-OK-green.svg?style=flat-square)](https://github.com/RichardLitt/standard-readme)
+[![GoDoc](https://godoc.org/github.com/ipfs/go-ipfs-pq?status.svg)](https://godoc.org/github.com/ipfs/go-ipfs-pq)
+[![Build Status](https://travis-ci.org/ipfs/go-ipfs-pq.svg?branch=master)](https://travis-ci.org/ipfs/go-ipfs-pq)
+
+> go-ipfs-pq implements a priority queue.
+
+## Table of Contents
+
+- [Install](#install)
+- [Usage](#usage)
+- [Contribute](#contribute)
+- [License](#license)
+
+## Install
+
+`go-ipfs-pq` works like a regular Go module:
+
+```
+> go get github.com/ipfs/go-ipfs-pq
+```
+
+## Usage
+
+```
+import "github.com/ipfs/go-ipfs-pq"
+```
+
+Check the [GoDoc documentation](https://godoc.org/github.com/ipfs/go-ipfs-pq)
+
+## Contribute
+
+PRs accepted.
+
+Small note: If editing the README, please conform to the [standard-readme](https://github.com/RichardLitt/standard-readme) specification.
+
+## License
+
+MIT © Protocol Labs, Inc.

go.mod

+module gitlab.dms3.io/dms3/public/go-ipfs-pq
+
+go 1.15

package.json

+{
+  "author": "hsanjuan",
+  "bugs": {
+    "url": "https://github.com/ipfs/go-ipfs-pq"
+  },
+  "gx": {
+    "dvcsimport": "github.com/ipfs/go-ipfs-pq"
+  },
+  "gxVersion": "0.12.1",
+  "language": "go",
+  "license": "MIT",
+  "name": "go-ipfs-pq",
+  "releaseCmd": "git commit -a -m \"gx publish $VERSION\"",
+  "version": "0.0.1"
+}
+

pq.go

+// Package pq implements a priority queue.
+package pq
+
+import "container/heap"
+
+// PQ is a basic priority queue.
+type PQ interface {
+	// Push adds the ele
+	Push(Elem)
+	// Pop removes and returns the highest priority Elem in PQ.
+	Pop() Elem
+	// Peek returns the highest priority Elem in PQ (without removing it).
+	Peek() Elem
+	// Remove removes the item at the given index from the PQ.
+	Remove(index int) Elem
+	// Len returns the number of elements in the PQ.
+	Len() int
+	// Update `fixes` the PQ.
+	Update(index int)
+}
+
+// Elem describes elements that can be added to the PQ. Clients must implement
+// this interface.
+type Elem interface {
+	// SetIndex stores the int index.
+	SetIndex(int)
+	// Index returns the last given by SetIndex(int).
+	Index() int
+}
+
+// ElemComparator returns true if pri(a) > pri(b)
+type ElemComparator func(a, b Elem) bool
+
+// New creates a PQ with a client-supplied comparator.
+func New(cmp ElemComparator) PQ {
+	q := &wrapper{heapinterface{
+		elems: make([]Elem, 0),
+		cmp:   cmp,
+	}}
+	heap.Init(&q.heapinterface)
+	return q
+}
+
+// wrapper exists because we cannot re-define Push. We want to expose
+// Push(Elem) but heap.Interface requires Push(interface{})
+type wrapper struct {
+	heapinterface
+}
+
+var _ PQ = &wrapper{}
+
+func (w *wrapper) Push(e Elem) {
+	heap.Push(&w.heapinterface, e)
+}
+
+func (w *wrapper) Pop() Elem {
+	return heap.Pop(&w.heapinterface).(Elem)
+}
+
+func (w *wrapper) Peek() Elem {
+	if len(w.heapinterface.elems) == 0 {
+		return nil
+	}
+	return w.heapinterface.elems[0]
+}
+
+func (w *wrapper) Remove(index int) Elem {
+	return heap.Remove(&w.heapinterface, index).(Elem)
+}
+
+func (w *wrapper) Update(index int) {
+	heap.Fix(&w.heapinterface, index)
+}
+
+// heapinterface handles dirty low-level details of managing the priority queue.
+type heapinterface struct {
+	elems []Elem
+	cmp   ElemComparator
+}
+
+var _ heap.Interface = &heapinterface{}
+
+// public interface
+
+func (q *heapinterface) Len() int {
+	return len(q.elems)
+}
+
+// Less delegates the decision to the comparator
+func (q *heapinterface) Less(i, j int) bool {
+	return q.cmp(q.elems[i], q.elems[j])
+}
+
+// Swap swaps the elements with indexes i and j.
+func (q *heapinterface) Swap(i, j int) {
+	q.elems[i], q.elems[j] = q.elems[j], q.elems[i]
+	q.elems[i].SetIndex(i)
+	q.elems[j].SetIndex(j)
+}
+
+// Note that Push and Pop in this interface are for package heap's
+// implementation to call. To add and remove things from the heap, wrap with
+// the pq struct to call heap.Push and heap.Pop.
+
+func (q *heapinterface) Push(x interface{}) { // where to put the elem?
+	t := x.(Elem)
+	t.SetIndex(len(q.elems))
+	q.elems = append(q.elems, t)
+}
+
+func (q *heapinterface) Pop() interface{} {
+	old := q.elems
+	n := len(old)
+	elem := old[n-1]       // remove the last
+	elem.SetIndex(-1)      // for safety // FIXME why?
+	q.elems = old[0 : n-1] // shrink
+	return elem
+}

pq_test.go

+package pq
+
+import (
+	"sort"
+	"testing"
+)
+
+type TestElem struct {
+	Key      string
+	Priority int
+	index    int
+}
+
+func (e *TestElem) Index() int {
+	return e.index
+}
+
+func (e *TestElem) SetIndex(i int) {
+	e.index = i
+}
+
+var PriorityComparator = func(i, j Elem) bool {
+	return i.(*TestElem).Priority > j.(*TestElem).Priority
+}
+
+func TestQueuesReturnTypeIsSameAsParameterToPush(t *testing.T) {
+	q := New(PriorityComparator)
+	expectedKey := "foo"
+	elem := &TestElem{Key: expectedKey}
+	q.Push(elem)
+	switch v := q.Pop().(type) {
+	case *TestElem:
+		if v.Key != expectedKey {
+			t.Fatal("the key doesn't match the pushed value")
+		}
+	default:
+		t.Fatal("the queue is not casting values appropriately")
+	}
+}
+
+func TestCorrectnessOfPop(t *testing.T) {
+	q := New(PriorityComparator)
+	tasks := []TestElem{
+		{Key: "a", Priority: 9},
+		{Key: "b", Priority: 4},
+		{Key: "c", Priority: 3},
+		{Key: "d", Priority: 0},
+		{Key: "e", Priority: 6},
+	}
+	for _, e := range tasks {
+		q.Push(&e)
+	}
+	var priorities []int
+	var peekPriorities []int
+	for q.Len() > 0 {
+		i := q.Peek().(*TestElem).Priority
+		peekPriorities = append(peekPriorities, i)
+		j := q.Pop().(*TestElem).Priority
+		t.Logf("popped %v", j)
+		priorities = append(priorities, j)
+	}
+	if !sort.IntsAreSorted(peekPriorities) {
+		t.Fatal("the values were not returned in sorted order")
+	}
+	if !sort.IntsAreSorted(priorities) {
+		t.Fatal("the popped values were not returned in sorted order")
+	}
+}
+
+func TestRemove(t *testing.T) {
+	q := New(PriorityComparator)
+	tasks := []TestElem{
+		{Key: "a", Priority: 9},
+		{Key: "b", Priority: 4},
+		{Key: "c", Priority: 3},
+	}
+	for i := range tasks {
+		q.Push(&tasks[i])
+	}
+	removed := q.Remove(1).(*TestElem)
+	if q.Len() != 2 {
+		t.Fatal("expected item to have been removed")
+	}
+	if q.Pop().(*TestElem).Key == removed.Key {
+		t.Fatal("Remove() returned wrong element")
+	}
+	if q.Pop().(*TestElem).Key == removed.Key {
+		t.Fatal("Remove() returned wrong element")
+	}
+}
+
+func TestUpdate(t *testing.T) {
+	t.Log(`
+	Add 3 elements.
+	Update the highest priority element to have the lowest priority and fix the queue.
+	It should come out last.`)
+	q := New(PriorityComparator)
+	lowest := &TestElem{Key: "originallyLowest", Priority: 1}
+	middle := &TestElem{Key: "originallyMiddle", Priority: 2}
+	highest := &TestElem{Key: "toBeUpdated", Priority: 3}
+	q.Push(middle)
+	q.Push(highest)
+	q.Push(lowest)
+	if q.Peek().(*TestElem).Key != highest.Key {
+		t.Fatal("head element doesn't have the highest priority")
+	}
+	if q.Pop().(*TestElem).Key != highest.Key {
+		t.Fatal("popped element doesn't have the highest priority")
+	}
+	q.Push(highest)           // re-add the popped element
+	highest.Priority = 0      // update the PQ
+	q.Update(highest.Index()) // fix the PQ
+	if q.Peek().(*TestElem).Key != middle.Key {
+		t.Fatal("middle element should now have the highest priority")
+	}
+	if q.Pop().(*TestElem).Key != middle.Key {
+		t.Fatal("middle element should now have the highest priority")
+	}
+}