Merge branch 'Workiva:master' into basic_heaps

Author: Florimond

.github/CODEOWNERS

@@ -0,0 +1 @@
+@Workiva/skreams

.github/workflows/tests.yaml

@@ -0,0 +1,64 @@
+name: "Tests"
+
+on:
+  pull_request:
+  push:
+    branches:
+      - 'master'
+    tags:
+      - '*'
+
+permissions:
+  pull-requests: write
+  contents: write
+  id-token: write
+
+jobs:
+  Tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go: [ '1.15', 'stable' ]
+    name: Tests on Go ${{ matrix.go }}
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v4
+        with:
+          path: go/src/github.com/Workiva/go-datastructures
+
+      - name: Setup Go
+        uses: actions/[email protected]
+        with:
+          go-version: ${{ matrix.go }}
+
+      # go install does not work because it needs credentials
+      - name: install go2xunit
+        run: |
+          git clone https://github.com/tebeka/go2xunit.git
+          cd go2xunit
+          git checkout v1.4.10
+          go install 
+          cd ..
+
+      - name: Run Tests
+        timeout-minutes: 10
+        run: |
+          cd go/src/github.com/Workiva/go-datastructures
+          go test ./... | tee ${{github.workspace}}/go-test.txt 
+
+      - name: XML output
+        run: |
+          mkdir artifacts
+          go2xunit -input ./go-test.txt -output ./artifacts/tests_go_version-${{ matrix.go }}.xml
+
+      - name: Upload Test Results
+        uses: actions/upload-artifact@v4
+        with:
+          name: go-datastructures test go ${{ matrix.go }}
+          path: ./artifacts/tests_go_version-${{ matrix.go }}.xml
+          retention-days: 7
+
+      - uses: anchore/sbom-action@v0
+        with:
+          path: ./  
+          format: cyclonedx-json

.travis.yml

@@ -1,4 +1,3 @@
-
 go-datastructures
 =================
 
@@ -150,7 +149,7 @@ interface and the most expensive operation in CPU profiling is the interface
 method which in turn calls into runtime.assertI2T.  We need generics.
 
 #### Immutable B Tree
-A btree based on two principals, immutablability and concurrency. 
+A btree based on two principles, immutability and concurrency. 
 Somewhat slow for single value lookups and puts, it is very fast for bulk operations.
 A persister can be injected to make this index persistent.
 
@@ -229,6 +228,6 @@ Requirements to commit here:
 
 
 ### Maintainers
-
- - Dustin Hiatt <[[email protected]](mailto:[email protected])>
  - Alexander Campbell <[[email protected]](mailto:[email protected])>
+ - Dustin Hiatt <[[email protected]](mailto:[email protected])>
+ - Ryan Jackson <[[email protected]](mailto:[email protected])>

README.md

@@ -27,8 +27,11 @@ func MultithreadedSortComparators(comparators Comparators) Comparators {
 	var wg sync.WaitGroup
 
 	numCPU := int64(runtime.NumCPU())
-	if numCPU%2 == 1 { // single core machine
-		numCPU++
+	if numCPU == 1 { // single core machine
+		numCPU = 2
+	} else {
+		// otherwise this algo only works with a power of two
+		numCPU = int64(prevPowerOfTwo(uint64(numCPU)))
 	}
 
 	chunks := chunk(toBeSorted, numCPU)
@@ -70,3 +73,13 @@ func chunk(comparators Comparators, numParts int64) []Comparators {
 	}
 	return parts
 }
+
+func prevPowerOfTwo(x uint64) uint64 {
+	x = x | (x >> 1)
+	x = x | (x >> 2)
+	x = x | (x >> 4)
+	x = x | (x >> 8)
+	x = x | (x >> 16)
+	x = x | (x >> 32)
+	return x - (x >> 1)
+}