Reduce memory usage in testgit (#15306)

* reduce memory use in rawtest

* just use hashsum for diffs

Signed-off-by: Andrew Thornton <art27@cantab.net>

2 files changed, 69 insertions, 25 deletions

diff --git a/integrations/git_test.go b/integrations/git_test.go
index c187fc6207..26907d848a 100644
--- a/integrations/git_test.go
+++ b/integrations/git_test.go
@@ -208,13 +208,13 @@ func rawTest(t *testing.T, ctx *APITestContext, little, big, littleLFS, bigLFS s
 
 		// Request raw paths
 		req := NewRequest(t, "GET", path.Join("/", username, reponame, "/raw/branch/master/", little))
-		resp := session.MakeRequest(t, req, http.StatusOK)
-		assert.Equal(t, littleSize, resp.Body.Len())
+		resp := session.MakeRequestNilResponseRecorder(t, req, http.StatusOK)
+		assert.Equal(t, littleSize, resp.Length)
 
 		setting.CheckLFSVersion()
 		if setting.LFS.StartServer {
 			req = NewRequest(t, "GET", path.Join("/", username, reponame, "/raw/branch/master/", littleLFS))
-			resp = session.MakeRequest(t, req, http.StatusOK)
+			resp := session.MakeRequest(t, req, http.StatusOK)
 			assert.NotEqual(t, littleSize, resp.Body.Len())
 			assert.LessOrEqual(t, resp.Body.Len(), 1024)
 			if resp.Body.Len() != littleSize && resp.Body.Len() <= 1024 {
@@ -224,12 +224,12 @@ func rawTest(t *testing.T, ctx *APITestContext, little, big, littleLFS, bigLFS s
 
 		if !testing.Short() {
 			req = NewRequest(t, "GET", path.Join("/", username, reponame, "/raw/branch/master/", big))
-			resp = session.MakeRequest(t, req, http.StatusOK)
-			assert.Equal(t, bigSize, resp.Body.Len())
+			resp := session.MakeRequestNilResponseRecorder(t, req, http.StatusOK)
+			assert.Equal(t, bigSize, resp.Length)
 
 			if setting.LFS.StartServer {
 				req = NewRequest(t, "GET", path.Join("/", username, reponame, "/raw/branch/master/", bigLFS))
-				resp = session.MakeRequest(t, req, http.StatusOK)
+				resp := session.MakeRequest(t, req, http.StatusOK)
 				assert.NotEqual(t, bigSize, resp.Body.Len())
 				if resp.Body.Len() != bigSize && resp.Body.Len() <= 1024 {
 					assert.Contains(t, resp.Body.String(), models.LFSMetaFileIdentifier)
@@ -450,27 +450,27 @@ func doMergeFork(ctx, baseCtx APITestContext, baseBranch, headBranch string) fun
 		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
 
 		// Then get the diff string
-		var diffStr string
+		var diffHash string
 		t.Run("GetDiff", func(t *testing.T) {
 			req := NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d.diff", url.PathEscape(baseCtx.Username), url.PathEscape(baseCtx.Reponame), pr.Index))
-			resp := ctx.Session.MakeRequest(t, req, http.StatusOK)
-			diffStr = resp.Body.String()
+			resp := ctx.Session.MakeRequestNilResponseHashSumRecorder(t, req, http.StatusOK)
+			diffHash = string(resp.Hash.Sum(nil))
 		})
 
 		// Now: Merge the PR & make sure that doesn't break the PR page or change its diff
 		t.Run("MergePR", doAPIMergePullRequest(baseCtx, baseCtx.Username, baseCtx.Reponame, pr.Index))
 		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
-		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffStr))
+		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffHash))
 
 		// Then: Delete the head branch & make sure that doesn't break the PR page or change its diff
 		t.Run("DeleteHeadBranch", doBranchDelete(baseCtx, baseCtx.Username, baseCtx.Reponame, headBranch))
 		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
-		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffStr))
+		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffHash))
 
 		// Delete the head repository & make sure that doesn't break the PR page or change its diff
 		t.Run("DeleteHeadRepository", doAPIDeleteRepository(ctx))
 		t.Run("EnsureCanSeePull", doEnsureCanSeePull(baseCtx, pr))
-		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffStr))
+		t.Run("EnsureDiffNoChange", doEnsureDiffNoChange(baseCtx, pr, diffHash))
 	}
 }
 
@@ -514,22 +514,14 @@ func doEnsureCanSeePull(ctx APITestContext, pr api.PullRequest) func(t *testing.
 	}
 }
 
-func doEnsureDiffNoChange(ctx APITestContext, pr api.PullRequest, diffStr string) func(t *testing.T) {
+func doEnsureDiffNoChange(ctx APITestContext, pr api.PullRequest, diffHash string) func(t *testing.T) {
 	return func(t *testing.T) {
 		req := NewRequest(t, "GET", fmt.Sprintf("/%s/%s/pulls/%d.diff", url.PathEscape(ctx.Username), url.PathEscape(ctx.Reponame), pr.Index))
-		resp := ctx.Session.MakeRequest(t, req, http.StatusOK)
-		expectedMaxLen := len(diffStr)
-		if expectedMaxLen > 800 {
-			expectedMaxLen = 800
-		}
-		actual := resp.Body.String()
-		actualMaxLen := len(actual)
-		if actualMaxLen > 800 {
-			actualMaxLen = 800
-		}
+		resp := ctx.Session.MakeRequestNilResponseHashSumRecorder(t, req, http.StatusOK)
+		actual := string(resp.Hash.Sum(nil))
 
-		equal := diffStr == actual
-		assert.True(t, equal, "Unexpected change in the diff string: expected: %s but was actually: %s", diffStr[:expectedMaxLen], actual[:actualMaxLen])
+		equal := diffHash == actual
+		assert.True(t, equal, "Unexpected change in the diff string: expected hash: %s but was actually: %s", diffHash, actual)
 	}
 }
 
diff --git a/integrations/integration_test.go b/integrations/integration_test.go
index 10331a1560..74227416c4 100644
--- a/integrations/integration_test.go
+++ b/integrations/integration_test.go
@@ -9,6 +9,8 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"hash"
+	"hash/fnv"
 	"io"
 	"net/http"
 	"net/http/cookiejar"
@@ -58,6 +60,26 @@ func NewNilResponseRecorder() *NilResponseRecorder {
 	}
 }
 
+type NilResponseHashSumRecorder struct {
+	httptest.ResponseRecorder
+	Hash   hash.Hash
+	Length int
+}
+
+func (n *NilResponseHashSumRecorder) Write(b []byte) (int, error) {
+	_, _ = n.Hash.Write(b)
+	n.Length += len(b)
+	return len(b), nil
+}
+
+// NewRecorder returns an initialized ResponseRecorder.
+func NewNilResponseHashSumRecorder() *NilResponseHashSumRecorder {
+	return &NilResponseHashSumRecorder{
+		Hash:             fnv.New32(),
+		ResponseRecorder: *httptest.NewRecorder(),
+	}
+}
+
 func TestMain(m *testing.M) {
 	defer log.Close()
 
@@ -284,6 +306,23 @@ func (s *TestSession) MakeRequestNilResponseRecorder(t testing.TB, req *http.Req
 	return resp
 }
 
+func (s *TestSession) MakeRequestNilResponseHashSumRecorder(t testing.TB, req *http.Request, expectedStatus int) *NilResponseHashSumRecorder {
+	t.Helper()
+	baseURL, err := url.Parse(setting.AppURL)
+	assert.NoError(t, err)
+	for _, c := range s.jar.Cookies(baseURL) {
+		req.AddCookie(c)
+	}
+	resp := MakeRequestNilResponseHashSumRecorder(t, req, expectedStatus)
+
+	ch := http.Header{}
+	ch.Add("Cookie", strings.Join(resp.Header()["Set-Cookie"], ";"))
+	cr := http.Request{Header: ch}
+	s.jar.SetCookies(baseURL, cr.Cookies())
+
+	return resp
+}
+
 const userPassword = "password"
 
 var loginSessionCache = make(map[string]*TestSession, 10)
@@ -429,6 +468,19 @@ func MakeRequestNilResponseRecorder(t testing.TB, req *http.Request, expectedSta
 	return recorder
 }
 
+func MakeRequestNilResponseHashSumRecorder(t testing.TB, req *http.Request, expectedStatus int) *NilResponseHashSumRecorder {
+	t.Helper()
+	recorder := NewNilResponseHashSumRecorder()
+	c.ServeHTTP(recorder, req)
+	if expectedStatus != NoExpectedStatus {
+		if !assert.EqualValues(t, expectedStatus, recorder.Code,
+			"Request: %s %s", req.Method, req.URL.String()) {
+			logUnexpectedResponse(t, &recorder.ResponseRecorder)
+		}
+	}
+	return recorder
+}
+
 // logUnexpectedResponse logs the contents of an unexpected response.
 func logUnexpectedResponse(t testing.TB, recorder *httptest.ResponseRecorder) {
 	t.Helper()