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authorDavid Symonds <dsymonds@golang.org>2018-05-30 11:06:44 +1000
committerDavid Symonds <dsymonds@golang.org>2018-05-30 11:34:26 +1000
commitcf532f99e3e7632bc1d813245a4c79ae38b4d320 (patch)
tree702b13e6e462ca39fcfff119c1be949963f32705 /plumbing/format/packfile/index_test.go
parent57570e84f8c5739f0f4a59387493e590e709dde9 (diff)
downloadgo-git-cf532f99e3e7632bc1d813245a4c79ae38b4d320.tar.gz
packfile: improve Index memory representation to be more compact
Instead of using a map for offset indexing, use a sorted slice. Binary searching is fast, and a slice is much more compact. This has a negligible hit on speed, but has a significant impact on memory usage, especially for larger repos. benchmark old ns/op new ns/op delta BenchmarkIndexConstruction-12 15506506 14056098 -9.35% benchmark old allocs new allocs delta BenchmarkIndexConstruction-12 60764 60385 -0.62% benchmark old bytes new bytes delta BenchmarkIndexConstruction-12 4318145 3913169 -9.38% Signed-off-by: David Symonds <dsymonds@golang.org>
Diffstat (limited to 'plumbing/format/packfile/index_test.go')
-rw-r--r--plumbing/format/packfile/index_test.go37
1 files changed, 24 insertions, 13 deletions
diff --git a/plumbing/format/packfile/index_test.go b/plumbing/format/packfile/index_test.go
index 6714704..8de886d 100644
--- a/plumbing/format/packfile/index_test.go
+++ b/plumbing/format/packfile/index_test.go
@@ -3,6 +3,7 @@ package packfile
import (
"strconv"
"strings"
+ "testing"
"gopkg.in/src-d/go-git.v4/plumbing"
@@ -26,12 +27,12 @@ func (s *IndexSuite) TestLookupOffset(c *C) {
e, ok := idx.LookupOffset(uint64(o2))
c.Assert(ok, Equals, true)
c.Assert(e, NotNil)
- c.Assert(e.Hash, Equals, s.toHash(o2))
+ c.Assert(e.Hash, Equals, toHash(o2))
c.Assert(e.Offset, Equals, uint64(o2))
}
}
- h1 := s.toHash(o1)
+ h1 := toHash(o1)
idx.Add(h1, uint64(o1), 0)
for o2 := 0; o2 < 10000; o2 += 100 {
@@ -43,7 +44,7 @@ func (s *IndexSuite) TestLookupOffset(c *C) {
e, ok := idx.LookupOffset(uint64(o2))
c.Assert(ok, Equals, true)
c.Assert(e, NotNil)
- c.Assert(e.Hash, Equals, s.toHash(o2))
+ c.Assert(e.Hash, Equals, toHash(o2))
c.Assert(e.Offset, Equals, uint64(o2))
}
}
@@ -56,31 +57,31 @@ func (s *IndexSuite) TestLookupHash(c *C) {
for o1 := 0; o1 < 10000; o1 += 100 {
for o2 := 0; o2 < 10000; o2 += 100 {
if o2 >= o1 {
- e, ok := idx.LookupHash(s.toHash(o2))
+ e, ok := idx.LookupHash(toHash(o2))
c.Assert(ok, Equals, false)
c.Assert(e, IsNil)
} else {
- e, ok := idx.LookupHash(s.toHash(o2))
+ e, ok := idx.LookupHash(toHash(o2))
c.Assert(ok, Equals, true)
c.Assert(e, NotNil)
- c.Assert(e.Hash, Equals, s.toHash(o2))
+ c.Assert(e.Hash, Equals, toHash(o2))
c.Assert(e.Offset, Equals, uint64(o2))
}
}
- h1 := s.toHash(o1)
+ h1 := toHash(o1)
idx.Add(h1, uint64(o1), 0)
for o2 := 0; o2 < 10000; o2 += 100 {
if o2 > o1 {
- e, ok := idx.LookupHash(s.toHash(o2))
+ e, ok := idx.LookupHash(toHash(o2))
c.Assert(ok, Equals, false)
c.Assert(e, IsNil)
} else {
- e, ok := idx.LookupHash(s.toHash(o2))
+ e, ok := idx.LookupHash(toHash(o2))
c.Assert(ok, Equals, true)
c.Assert(e, NotNil)
- c.Assert(e.Hash, Equals, s.toHash(o2))
+ c.Assert(e.Hash, Equals, toHash(o2))
c.Assert(e.Offset, Equals, uint64(o2))
}
}
@@ -92,7 +93,7 @@ func (s *IndexSuite) TestSize(c *C) {
for o1 := 0; o1 < 1000; o1++ {
c.Assert(idx.Size(), Equals, o1)
- h1 := s.toHash(o1)
+ h1 := toHash(o1)
idx.Add(h1, uint64(o1), 0)
}
}
@@ -107,7 +108,7 @@ func (s *IndexSuite) TestIdxFileEmpty(c *C) {
func (s *IndexSuite) TestIdxFile(c *C) {
idx := NewIndex(0)
for o1 := 0; o1 < 1000; o1++ {
- h1 := s.toHash(o1)
+ h1 := toHash(o1)
idx.Add(h1, uint64(o1), 0)
}
@@ -115,8 +116,18 @@ func (s *IndexSuite) TestIdxFile(c *C) {
c.Assert(idx, DeepEquals, idx2)
}
-func (s *IndexSuite) toHash(i int) plumbing.Hash {
+func toHash(i int) plumbing.Hash {
is := strconv.Itoa(i)
padding := strings.Repeat("a", 40-len(is))
return plumbing.NewHash(padding + is)
}
+
+func BenchmarkIndexConstruction(b *testing.B) {
+ b.ReportAllocs()
+
+ idx := NewIndex(0)
+ for o := 0; o < 1e6*b.N; o += 100 {
+ h1 := toHash(o)
+ idx.Add(h1, uint64(o), 0)
+ }
+}