Merge pull request #906 from src-d/perf/packfile-reads

Improve packfile reading performance

1 files changed, 154 insertions, 0 deletions

diff --git a/plumbing/format/idxfile/idxfile_test.go b/plumbing/format/idxfile/idxfile_test.go
new file mode 100644
index 0000000..d15accf
--- /dev/null
+++ b/plumbing/format/idxfile/idxfile_test.go
@@ -0,0 +1,154 @@
+package idxfile_test
+
+import (
+	"bytes"
+	"encoding/base64"
+	"fmt"
+	"io"
+	"testing"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/format/idxfile"
+
+	. "gopkg.in/check.v1"
+	"gopkg.in/src-d/go-git-fixtures.v3"
+)
+
+func BenchmarkFindOffset(b *testing.B) {
+	idx, err := fixtureIndex()
+	if err != nil {
+		b.Fatalf(err.Error())
+	}
+
+	for i := 0; i < b.N; i++ {
+		for _, h := range fixtureHashes {
+			_, err := idx.FindOffset(h)
+			if err != nil {
+				b.Fatalf("error getting offset: %s", err)
+			}
+		}
+	}
+}
+
+func BenchmarkFindCRC32(b *testing.B) {
+	idx, err := fixtureIndex()
+	if err != nil {
+		b.Fatalf(err.Error())
+	}
+
+	for i := 0; i < b.N; i++ {
+		for _, h := range fixtureHashes {
+			_, err := idx.FindCRC32(h)
+			if err != nil {
+				b.Fatalf("error getting crc32: %s", err)
+			}
+		}
+	}
+}
+
+func BenchmarkContains(b *testing.B) {
+	idx, err := fixtureIndex()
+	if err != nil {
+		b.Fatalf(err.Error())
+	}
+
+	for i := 0; i < b.N; i++ {
+		for _, h := range fixtureHashes {
+			ok, err := idx.Contains(h)
+			if err != nil {
+				b.Fatalf("error checking if hash is in index: %s", err)
+			}
+
+			if !ok {
+				b.Error("expected hash to be in index")
+			}
+		}
+	}
+}
+
+func BenchmarkEntries(b *testing.B) {
+	idx, err := fixtureIndex()
+	if err != nil {
+		b.Fatalf(err.Error())
+	}
+
+	for i := 0; i < b.N; i++ {
+		iter, err := idx.Entries()
+		if err != nil {
+			b.Fatalf("unexpected error getting entries: %s", err)
+		}
+
+		var entries int
+		for {
+			_, err := iter.Next()
+			if err != nil {
+				if err == io.EOF {
+					break
+				}
+
+				b.Errorf("unexpected error getting entry: %s", err)
+			}
+
+			entries++
+		}
+
+		if entries != len(fixtureHashes) {
+			b.Errorf("expecting entries to be %d, got %d", len(fixtureHashes), entries)
+		}
+	}
+}
+
+type IndexSuite struct {
+	fixtures.Suite
+}
+
+var _ = Suite(&IndexSuite{})
+
+func (s *IndexSuite) TestFindHash(c *C) {
+	idx, err := fixtureIndex()
+	c.Assert(err, IsNil)
+
+	for i, pos := range fixtureOffsets {
+		hash, err := idx.FindHash(pos)
+		c.Assert(err, IsNil)
+		c.Assert(hash, Equals, fixtureHashes[i])
+	}
+}
+
+var fixtureHashes = []plumbing.Hash{
+	plumbing.NewHash("303953e5aa461c203a324821bc1717f9b4fff895"),
+	plumbing.NewHash("5296768e3d9f661387ccbff18c4dea6c997fd78c"),
+	plumbing.NewHash("03fc8d58d44267274edef4585eaeeb445879d33f"),
+	plumbing.NewHash("8f3ceb4ea4cb9e4a0f751795eb41c9a4f07be772"),
+	plumbing.NewHash("e0d1d625010087f79c9e01ad9d8f95e1628dda02"),
+	plumbing.NewHash("90eba326cdc4d1d61c5ad25224ccbf08731dd041"),
+	plumbing.NewHash("bab53055add7bc35882758a922c54a874d6b1272"),
+	plumbing.NewHash("1b8995f51987d8a449ca5ea4356595102dc2fbd4"),
+	plumbing.NewHash("35858be9c6f5914cbe6768489c41eb6809a2bceb"),
+}
+
+var fixtureOffsets = []int64{
+	12,
+	142,
+	1601322837,
+	2646996529,
+	3452385606,
+	3707047470,
+	5323223332,
+	5894072943,
+	5924278919,
+}
+
+func fixtureIndex() (*idxfile.MemoryIndex, error) {
+	f := bytes.NewBufferString(fixtureLarge4GB)
+
+	idx := new(idxfile.MemoryIndex)
+
+	d := idxfile.NewDecoder(base64.NewDecoder(base64.StdEncoding, f))
+	err := d.Decode(idx)
+	if err != nil {
+		return nil, fmt.Errorf("unexpected error decoding index: %s", err)
+	}
+
+	return idx, nil
+}