try to add benchmark code for CI (#548)

Author: jverzani

.github/workflows/benchmark_pr.yml

@@ -0,0 +1,22 @@
+name: Run benchmarks
+
+on:
+  pull_request:
+
+jobs:
+  Benchmark:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: julia-actions/setup-julia@latest
+        with:
+          version: 1
+      - uses: julia-actions/julia-buildpkg@latest
+      - name: Install dependencies
+        run: julia -e 'using Pkg; pkg"add PkgBenchmark [email protected]"'
+      - name: Run benchmarks
+        run: julia -e 'using BenchmarkCI; BenchmarkCI.displayjudgement()'
+      - name: Post results
+        run: julia -e 'using BenchmarkCI; BenchmarkCI.postjudge()'
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.gitignore

@@ -5,4 +5,6 @@ docs/site/
 *.jl.mem
 
 Manifest.toml
-archive/
+archive/
+/.benchmarkci
+/benchmark/*.json

src/benchmark/benchmarks.jl

@@ -0,0 +1,32 @@
+using BenchmarkTools
+using Polynomials
+
+Ps = (P=Polynomial, IP=ImmutablePolynomial, SP=SparsePolynomial,
+      LP=LaurentPolynomial)
+
+const SUITE = BenchmarkGroup()
+
+for P ∈ Ps
+    P′ = string(P)
+    SUITE[P′] = BenchmarkGroup(["Polynomials", P′])
+    SUITE[P′]["evaluation"] =
+        (@benchmarkable p(c) setup=(p=$P(rand(20)); c=rand()))
+    SUITE[P′]["scalar addition"] =
+        (@benchmarkable p + c setup=(p=$P(rand(20)); c=rand()))
+    SUITE[P′]["scalar multiplication"] =
+        (@benchmarkable p * c setup=(p=$P(rand(20)); c=rand()))
+    SUITE[P′]["scalar divistion"] =
+        (@benchmarkable p / c setup=(p=$P(rand(20)); c=rand()))
+    SUITE[P′]["poly addition"] =
+        (@benchmarkable p + q setup=(p=$P(rand(20)); q = $P(rand(25))))
+    SUITE[P′]["poly multiplication"] =
+        (@benchmarkable p * q setup=(p=$P(rand(20)); q = $P(rand(25))))
+    SUITE[P′]["mixed var add"] =
+        (@benchmarkable p + q setup=(p=$P(rand(20)); q=$P(rand(1),:y)))
+    SUITE[P′]["mixed var mul"] =
+        (@benchmarkable p * q setup=(p=$P(rand(20)); q=$P(rand(1),:y)))
+    SUITE[P′]["differentiation"] =
+        (@benchmarkable derivative(p) setup=(p=$P(rand(20))))
+    SUITE[P′]["integration"] =
+        (@benchmarkable integrate(p) setup=(p=$P(rand(20))))
+end