package chunker_test import ( "bytes" "crypto/md5" "crypto/sha256" "encoding/hex" "flag" "hash" "io" "math/rand" "os" "testing" "github.com/restic/restic/chunker" ) var benchmarkFile = flag.String("bench.file", "", "read from this file for benchmark") var testBufSize = flag.Int("test.bufsize", 256*1024, "use this buffer size for benchmark") func parseDigest(s string) []byte { d, err := hex.DecodeString(s) if err != nil { panic(err) } return d } type chunk struct { Length uint CutFP uint64 Digest []byte } // created for 32MB of random data out of math/rand's Uint32() seeded by // constant 23 // // chunking configuration: // window size 64, avg chunksize 1<<20, min chunksize 1<<19, max chunksize 1<<23 // polynom 0x3DA3358B4DC173 var chunks1 = []chunk{ chunk{2163460, 0x000b98d4cdf00000, parseDigest("4b94cb2cf293855ea43bf766731c74969b91aa6bf3c078719aabdd19860d590d")}, chunk{643703, 0x000d4e8364d00000, parseDigest("5727a63c0964f365ab8ed2ccf604912f2ea7be29759a2b53ede4d6841e397407")}, chunk{1528956, 0x0015a25c2ef00000, parseDigest("a73759636a1e7a2758767791c69e81b69fb49236c6929e5d1b654e06e37674ba")}, chunk{1955808, 0x00102a8242e00000, parseDigest("c955fb059409b25f07e5ae09defbbc2aadf117c97a3724e06ad4abd2787e6824")}, chunk{2222372, 0x00045da878000000, parseDigest("6ba5e9f7e1b310722be3627716cf469be941f7f3e39a4c3bcefea492ec31ee56")}, chunk{2538687, 0x00198a8179900000, parseDigest("8687937412f654b5cfe4a82b08f28393a0c040f77c6f95e26742c2fc4254bfde")}, chunk{609606, 0x001d4e8d17100000, parseDigest("5da820742ff5feb3369112938d3095785487456f65a8efc4b96dac4be7ebb259")}, chunk{1205738, 0x000a7204dd600000, parseDigest("cc70d8fad5472beb031b1aca356bcab86c7368f40faa24fe5f8922c6c268c299")}, chunk{959742, 0x00183e71e1400000, parseDigest("4065bdd778f95676c92b38ac265d361f81bff17d76e5d9452cf985a2ea5a4e39")}, chunk{4036109, 0x001fec043c700000, parseDigest("b9cf166e75200eb4993fc9b6e22300a6790c75e6b0fc8f3f29b68a752d42f275")}, chunk{1525894, 0x000b1574b1500000, parseDigest("2f238180e4ca1f7520a05f3d6059233926341090f9236ce677690c1823eccab3")}, chunk{1352720, 0x00018965f2e00000, parseDigest("afd12f13286a3901430de816e62b85cc62468c059295ce5888b76b3af9028d84")}, chunk{811884, 0x00155628aa100000, parseDigest("42d0cdb1ee7c48e552705d18e061abb70ae7957027db8ae8db37ec756472a70a")}, chunk{1282314, 0x001909a0a1400000, parseDigest("819721c2457426eb4f4c7565050c44c32076a56fa9b4515a1c7796441730eb58")}, chunk{1318021, 0x001cceb980000000, parseDigest("842eb53543db55bacac5e25cb91e43cc2e310fe5f9acc1aee86bdf5e91389374")}, chunk{948640, 0x0011f7a470a00000, parseDigest("b8e36bf7019bb96ac3fb7867659d2167d9d3b3148c09fe0de45850b8fe577185")}, chunk{645464, 0x00030ce2d9400000, parseDigest("5584bd27982191c3329f01ed846bfd266e96548dfa87018f745c33cfc240211d")}, chunk{533758, 0x0004435c53c00000, parseDigest("4da778a25b72a9a0d53529eccfe2e5865a789116cb1800f470d8df685a8ab05d")}, chunk{1128303, 0x0000c48517800000, parseDigest("08c6b0b38095b348d80300f0be4c5184d2744a17147c2cba5cc4315abf4c048f")}, chunk{800374, 0x000968473f900000, parseDigest("820284d2c8fd243429674c996d8eb8d3450cbc32421f43113e980f516282c7bf")}, chunk{2453512, 0x001e197c92600000, parseDigest("5fa870ed107c67704258e5e50abe67509fb73562caf77caa843b5f243425d853")}, chunk{2651975, 0x000ae6c868000000, parseDigest("181347d2bbec32bef77ad5e9001e6af80f6abcf3576549384d334ee00c1988d8")}, chunk{237392, 0x0000000000000001, parseDigest("fcd567f5d866357a8e299fd5b2359bb2c8157c30395229c4e9b0a353944a7978")}, } // test if nullbytes are correctly split, even if length is a multiple of MinSize. var chunks2 = []chunk{ chunk{chunker.MinSize, 0, parseDigest("07854d2fef297a06ba81685e660c332de36d5d18d546927d30daad6d7fda1541")}, chunk{chunker.MinSize, 0, parseDigest("07854d2fef297a06ba81685e660c332de36d5d18d546927d30daad6d7fda1541")}, chunk{chunker.MinSize, 0, parseDigest("07854d2fef297a06ba81685e660c332de36d5d18d546927d30daad6d7fda1541")}, chunk{chunker.MinSize, 0, parseDigest("07854d2fef297a06ba81685e660c332de36d5d18d546927d30daad6d7fda1541")}, } func test_with_data(t *testing.T, chnker *chunker.Chunker, testChunks []chunk) []*chunker.Chunk { chunks := []*chunker.Chunk{} pos := uint(0) for i, chunk := range testChunks { c, err := chnker.Next() if err != nil { t.Fatalf("Error returned with chunk %d: %v", i, err) } if c == nil { t.Fatalf("Nil chunk returned") } if c != nil { if c.Start != pos { t.Fatalf("Start for chunk %d does not match: expected %d, got %d", i, pos, c.Start) } if c.Length != chunk.Length { t.Fatalf("Length for chunk %d does not match: expected %d, got %d", i, chunk.Length, c.Length) } if c.Cut != chunk.CutFP { t.Fatalf("Cut fingerprint for chunk %d/%d does not match: expected %016x, got %016x", i, len(chunks)-1, chunk.CutFP, c.Cut) } if !bytes.Equal(c.Digest, chunk.Digest) { t.Fatalf("Digest fingerprint for chunk %d/%d does not match: expected %02x, got %02x", i, len(chunks)-1, chunk.Digest, c.Digest) } pos += c.Length chunks = append(chunks, c) } } c, err := chnker.Next() if c != nil { t.Fatal("additional non-nil chunk returned") } if err != io.EOF { t.Fatal("wrong error returned after last chunk") } return chunks } func get_random(seed, count int) []byte { buf := make([]byte, count) rnd := rand.New(rand.NewSource(23)) for i := 0; i < count; i += 4 { r := rnd.Uint32() buf[i] = byte(r) buf[i+1] = byte(r >> 8) buf[i+2] = byte(r >> 16) buf[i+3] = byte(r >> 24) } return buf } func TestChunker(t *testing.T) { // setup data source buf := get_random(23, 32*1024*1024) ch := chunker.New(bytes.NewReader(buf), *testBufSize, sha256.New) chunks := test_with_data(t, ch, chunks1) // test reader for i, c := range chunks { rd := c.Reader(bytes.NewReader(buf)) h := sha256.New() n, err := io.Copy(h, rd) if err != nil { t.Fatalf("io.Copy(): %v", err) } if uint(n) != chunks1[i].Length { t.Fatalf("reader returned wrong number of bytes: expected %d, got %d", chunks1[i].Length, n) } d := h.Sum(nil) if !bytes.Equal(d, chunks1[i].Digest) { t.Fatalf("wrong hash returned: expected %02x, got %02x", chunks1[i].Digest, d) } } // setup nullbyte data source buf = bytes.Repeat([]byte{0}, len(chunks2)*chunker.MinSize) ch = chunker.New(bytes.NewReader(buf), *testBufSize, sha256.New) test_with_data(t, ch, chunks2) } func TestChunkerReuse(t *testing.T) { // test multiple uses of the same chunker ch := chunker.New(nil, *testBufSize, sha256.New) buf := get_random(23, 32*1024*1024) for i := 0; i < 4; i++ { ch.Reset(bytes.NewReader(buf)) test_with_data(t, ch, chunks1) } } func benchmarkChunker(b *testing.B, hash func() hash.Hash) { var ( rd io.ReadSeeker size int ) b.Logf("using bufsize %v", *testBufSize) if *benchmarkFile != "" { b.Logf("using file %q for benchmark", *benchmarkFile) f, err := os.Open(*benchmarkFile) if err != nil { b.Fatalf("open(%q): %v", *benchmarkFile, err) } fi, err := f.Stat() if err != nil { b.Fatalf("lstat(%q): %v", *benchmarkFile, err) } size = int(fi.Size()) rd = f } else { size = 10 * 1024 * 1024 rd = bytes.NewReader(get_random(23, size)) } b.ResetTimer() b.SetBytes(int64(size)) var chunks int for i := 0; i < b.N; i++ { chunks = 0 rd.Seek(0, 0) ch := chunker.New(rd, *testBufSize, hash) for { _, err := ch.Next() if err == io.EOF { break } if err != nil { b.Fatalf("Unexpected error occurred: %v", err) } chunks++ } } b.Logf("%d chunks, average chunk size: %d bytes", chunks, size/chunks) } func BenchmarkChunkerWithSHA256(b *testing.B) { benchmarkChunker(b, sha256.New) } func BenchmarkChunkerWithMD5(b *testing.B) { benchmarkChunker(b, md5.New) } func BenchmarkChunker(b *testing.B) { benchmarkChunker(b, nil) }