diff --git a/diffmatchpatch/diff.go b/diffmatchpatch/diff.go index 4f7b424..08c36e7 100644 --- a/diffmatchpatch/diff.go +++ b/diffmatchpatch/diff.go @@ -34,8 +34,6 @@ const ( DiffInsert Operation = 1 // DiffEqual item represents an equal diff. DiffEqual Operation = 0 - //IndexSeparator is used to seperate the array indexes in an index string - IndexSeparator = "," ) // Diff represents one diff operation @@ -406,14 +404,11 @@ func (dmp *DiffMatchPatch) DiffLinesToRunes(text1, text2 string) ([]rune, []rune func (dmp *DiffMatchPatch) DiffCharsToLines(diffs []Diff, lineArray []string) []Diff { hydrated := make([]Diff, 0, len(diffs)) for _, aDiff := range diffs { - chars := strings.Split(aDiff.Text, IndexSeparator) - text := make([]string, len(chars)) + runes := []rune(aDiff.Text) + text := make([]string, len(runes)) - for i, r := range chars { - i1, err := strconv.Atoi(r) - if err == nil { - text[i] = lineArray[i1] - } + for i, r := range runes { + text[i] = lineArray[runeToInt(r)] } aDiff.Text = strings.Join(text, "") @@ -1151,13 +1146,28 @@ func (dmp *DiffMatchPatch) DiffPrettyText(diffs []Diff) string { switch diff.Type { case DiffInsert: - _, _ = buff.WriteString("\x1b[32m") - _, _ = buff.WriteString(text) - _, _ = buff.WriteString("\x1b[0m") + lines := strings.Split(text, "\n") + for i, line := range lines { + _, _ = buff.WriteString("\x1b[32m") + _, _ = buff.WriteString(line) + if i < len(lines)-1 { + _, _ = buff.WriteString("\x1b[0m\n") + } else { + _, _ = buff.WriteString("\x1b[0m") + } + } + case DiffDelete: - _, _ = buff.WriteString("\x1b[31m") - _, _ = buff.WriteString(text) - _, _ = buff.WriteString("\x1b[0m") + lines := strings.Split(text, "\n") + for i, line := range lines { + _, _ = buff.WriteString("\x1b[31m") + _, _ = buff.WriteString(line) + if i < len(lines)-1 { + _, _ = buff.WriteString("\x1b[0m\n") + } else { + _, _ = buff.WriteString("\x1b[0m") + } + } case DiffEqual: _, _ = buff.WriteString(text) } @@ -1310,7 +1320,6 @@ func (dmp *DiffMatchPatch) DiffFromDelta(text1 string, delta string) (diffs []Di // diffLinesToStrings splits two texts into a list of strings. Each string represents one line. func (dmp *DiffMatchPatch) diffLinesToStrings(text1, text2 string) (string, string, []string) { - // '\x00' is a valid character, but various debuggers don't like it. So we'll insert a junk entry to avoid generating a null character. lineArray := []string{""} // e.g. lineArray[4] == 'Hello\n' lineHash := make(map[string]int) @@ -1321,12 +1330,11 @@ func (dmp *DiffMatchPatch) diffLinesToStrings(text1, text2 string) (string, stri return intArrayToString(strIndexArray1), intArrayToString(strIndexArray2), lineArray } -// diffLinesToStringsMunge splits a text into an array of strings, and reduces the texts to a []string. -func (dmp *DiffMatchPatch) diffLinesToStringsMunge(text string, lineArray *[]string, lineHash map[string]int) []uint32 { - // Walk the text, pulling out a substring for each line. text.split('\n') would would temporarily double our memory footprint. Modifying text would create many large strings to garbage collect. +// diffLinesToStringsMunge splits a text into an array of strings, and reduces the texts to a []index. +func (dmp *DiffMatchPatch) diffLinesToStringsMunge(text string, lineArray *[]string, lineHash map[string]int) []index { lineStart := 0 lineEnd := -1 - strs := []uint32{} + strs := []index{} for lineEnd < len(text)-1 { lineEnd = indexOf(text, "\n", lineStart) @@ -1340,11 +1348,11 @@ func (dmp *DiffMatchPatch) diffLinesToStringsMunge(text string, lineArray *[]str lineValue, ok := lineHash[line] if ok { - strs = append(strs, uint32(lineValue)) + strs = append(strs, index(lineValue)) } else { *lineArray = append(*lineArray, line) lineHash[line] = len(*lineArray) - 1 - strs = append(strs, uint32(len(*lineArray)-1)) + strs = append(strs, index(len(*lineArray)-1)) } } diff --git a/diffmatchpatch/diff_test.go b/diffmatchpatch/diff_test.go index d6fed50..2c43864 100644 --- a/diffmatchpatch/diff_test.go +++ b/diffmatchpatch/diff_test.go @@ -314,12 +314,12 @@ func TestDiffLinesToChars(t *testing.T) { dmp := New() for i, tc := range []TestCase{ - {"", "alpha\r\nbeta\r\n\r\n\r\n", "", "1,2,3,3", []string{"", "alpha\r\n", "beta\r\n", "\r\n"}}, - {"a", "b", "1", "2", []string{"", "a", "b"}}, + {"", "alpha\r\nbeta\r\n\r\n\r\n", "", "\x01\x02\x03\x03", []string{"", "alpha\r\n", "beta\r\n", "\r\n"}}, + {"a", "b", "\x01", "\x02", []string{"", "a", "b"}}, // Omit final newline. - {"alpha\nbeta\nalpha", "", "1,2,3", "", []string{"", "alpha\n", "beta\n", "alpha"}}, + {"alpha\nbeta\nalpha", "", "\x01\x02\x03", "", []string{"", "alpha\n", "beta\n", "alpha"}}, // Same lines in Text1 and Text2 - {"abc\ndefg\n12345\n", "abc\ndef\n12345\n678", "1,2,3", "1,4,3,5", []string{"", "abc\n", "defg\n", "12345\n", "def\n", "678"}}, + {"abc\ndefg\n12345\n", "abc\ndef\n12345\n678", "\x01\x02\x03", "\x01\x04\x03\x05", []string{"", "abc\n", "defg\n", "12345\n", "def\n", "678"}}, } { actualChars1, actualChars2, actualLines := dmp.DiffLinesToChars(tc.Text1, tc.Text2) assert.Equal(t, tc.ExpectedChars1, actualChars1, fmt.Sprintf("Test case #%d, %#v", i, tc)) @@ -332,14 +332,14 @@ func TestDiffLinesToChars(t *testing.T) { lineList := []string{ "", // Account for the initial empty element of the lines array. } - var charList []string + var charList []index for x := 1; x < n+1; x++ { lineList = append(lineList, strconv.Itoa(x)+"\n") - charList = append(charList, strconv.Itoa(x)) + charList = append(charList, index(x)) } lines := strings.Join(lineList, "") - chars := strings.Join(charList[:], ",") - assert.Equal(t, n, len(strings.Split(chars, ","))) + chars := indexesToString(charList) + assert.Equal(t, n, len(charList)) actualChars1, actualChars2, actualLines := dmp.DiffLinesToChars(lines, "") assert.Equal(t, chars, actualChars1) @@ -360,8 +360,8 @@ func TestDiffCharsToLines(t *testing.T) { for i, tc := range []TestCase{ { Diffs: []Diff{ - {DiffEqual, "1,2,1"}, - {DiffInsert, "2,1,2"}, + {DiffEqual, "\x01\x02\x01"}, + {DiffInsert, "\x02\x01\x02"}, }, Lines: []string{"", "alpha\n", "beta\n"}, @@ -380,13 +380,13 @@ func TestDiffCharsToLines(t *testing.T) { lineList := []string{ "", // Account for the initial empty element of the lines array. } - charList := []string{} + charList := []index{} for x := 1; x <= n; x++ { lineList = append(lineList, strconv.Itoa(x)+"\n") - charList = append(charList, strconv.Itoa(x)) + charList = append(charList, index(x)) } assert.Equal(t, n, len(charList)) - chars := strings.Join(charList[:], ",") + chars := indexesToString(charList) actual := dmp.DiffCharsToLines([]Diff{Diff{DiffDelete, chars}}, lineList) assert.Equal(t, []Diff{Diff{DiffDelete, strings.Join(lineList, "")}}, actual) @@ -1033,6 +1033,17 @@ func TestDiffPrettyText(t *testing.T) { Expected: "a\n\x1b[31mb\x1b[0m\x1b[32mc&d\x1b[0m", }, + { + Diffs: []Diff{ + {Type: DiffEqual, Text: "a\n"}, + {Type: DiffDelete, Text: "b\nc\n"}, + {Type: DiffEqual, Text: "def"}, + {Type: DiffInsert, Text: "\ng\nh"}, + {Type: DiffEqual, Text: "\ni"}, + }, + + Expected: "a\n\x1b[31mb\x1b[0m\n\x1b[31mc\x1b[0m\n\x1b[31m\x1b[0mdef\x1b[32m\x1b[0m\n\x1b[32mg\x1b[0m\n\x1b[32mh\x1b[0m\ni", + }, } { actual := dmp.DiffPrettyText(tc.Diffs) assert.Equal(t, tc.Expected, actual, fmt.Sprintf("Test case #%d, %#v", i, tc)) @@ -1468,6 +1479,38 @@ func TestMassiveRuneDiffConversion(t *testing.T) { assert.NotEmpty(t, diffs) } +func TestDiffPartialLineIndex(t *testing.T) { + dmp := New() + t1, t2, tt := dmp.DiffLinesToChars( + `line 1 +line 2 +line 3 +line 4 +line 5 +line 6 +line 7 +line 8 +line 9 +line 10 text1`, + `line 1 +line 2 +line 3 +line 4 +line 5 +line 6 +line 7 +line 8 +line 9 +line 10 text2`) + diffs := dmp.DiffMain(t1, t2, false) + diffs = dmp.DiffCharsToLines(diffs, tt) + assert.Equal(t, []Diff{ + Diff{DiffEqual, "line 1\nline 2\nline 3\nline 4\nline 5\nline 6\nline 7\nline 8\nline 9\n"}, + Diff{DiffDelete, "line 10 text1"}, + Diff{DiffInsert, "line 10 text2"}, + }, diffs) +} + func BenchmarkDiffMain(bench *testing.B) { s1 := "`Twas brillig, and the slithy toves\nDid gyre and gimble in the wabe:\nAll mimsy were the borogoves,\nAnd the mome raths outgrabe.\n" s2 := "I am the very model of a modern major general,\nI've information vegetable, animal, and mineral,\nI know the kings of England, and I quote the fights historical,\nFrom Marathon to Waterloo, in order categorical.\n" diff --git a/diffmatchpatch/index.go b/diffmatchpatch/index.go new file mode 100644 index 0000000..965a1c6 --- /dev/null +++ b/diffmatchpatch/index.go @@ -0,0 +1,32 @@ +package diffmatchpatch + +type index uint32 + +const runeSkipStart = 0xd800 +const runeSkipEnd = 0xdfff + 1 +const runeMax = 0x110000 // next invalid code point + +func stringToIndex(text string) []index { + runes := []rune(text) + indexes := make([]index, len(runes)) + for i, r := range runes { + if r < runeSkipEnd { + indexes[i] = index(r) + } else { + indexes[i] = index(r) - (runeSkipEnd - runeSkipStart) + } + } + return indexes +} + +func indexesToString(indexes []index) string { + runes := make([]rune, len(indexes)) + for i, index := range indexes { + if index < runeSkipStart { + runes[i] = rune(index) + } else { + runes[i] = rune(index + (runeSkipEnd - runeSkipStart)) + } + } + return string(runes) +} diff --git a/diffmatchpatch/index_test.go b/diffmatchpatch/index_test.go new file mode 100644 index 0000000..6f1d982 --- /dev/null +++ b/diffmatchpatch/index_test.go @@ -0,0 +1,16 @@ +package diffmatchpatch + +import ( + "github.com/stretchr/testify/assert" + "testing" +) + +func TestIndexConversion(t *testing.T) { + n := runeMax - (runeSkipEnd - runeSkipStart) + indexes := make([]index, n) + for i := 0; i < n; i++ { + indexes[i] = index(i) + } + indexes2 := stringToIndex(indexesToString(indexes)) + assert.EqualValues(t, indexes, indexes2) +} diff --git a/diffmatchpatch/patch_test.go b/diffmatchpatch/patch_test.go index b019f88..c564f8c 100644 --- a/diffmatchpatch/patch_test.go +++ b/diffmatchpatch/patch_test.go @@ -337,3 +337,28 @@ func TestPatchApply(t *testing.T) { assert.Equal(t, tc.ExpectedApplies, actualApplies, fmt.Sprintf("Test case #%d, %s", i, tc.Name)) } } + +func TestPatchMakeOutOfRangePanic(t *testing.T) { + text1 := ` + 1111111111111 000000 + ------------- ------ + xxxxxxxxxxxxx ------ + xxxxxxxxxxxxx ------ + xxxxxxxxxxxxx xxxxxx + xxxxxxxxxxxxx ...... + xxxxxxxxxxxxx 111111 + xxxxxxxxxxxxx ?????? + xxxxxxxxxxxxx 333333 + xxxxxxxxxxxxx 555555 + xxxxxxxxxx xxxxx + xxxxxxxxxx xxxxx + xxxxxxxxxx xxxxx + xxxxxxxxxx xxxxx +` + text2 := ` + 2222222222222 000000 + xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx` + dmp := New() + patches := dmp.PatchMake(text1, text2) + assert.Equal(t, 6, len(patches), "TestPatchMakeOutOfRangePanic") +} diff --git a/diffmatchpatch/stringutil.go b/diffmatchpatch/stringutil.go index 44c4359..573b6bf 100644 --- a/diffmatchpatch/stringutil.go +++ b/diffmatchpatch/stringutil.go @@ -9,11 +9,16 @@ package diffmatchpatch import ( - "strconv" + "fmt" "strings" "unicode/utf8" ) +const UNICODE_INVALID_RANGE_START = 0xD800 +const UNICODE_INVALID_RANGE_END = 0xDFFF +const UNICODE_INVALID_RANGE_DELTA = UNICODE_INVALID_RANGE_END - UNICODE_INVALID_RANGE_START + 1 +const UNICODE_RANGE_MAX = 0x10FFFF + // unescaper unescapes selected chars for compatibility with JavaScript's encodeURI. // In speed critical applications this could be dropped since the receiving application will certainly decode these fine. Note that this function is case-sensitive. Thus "%3F" would not be unescaped. But this is ok because it is only called with the output of HttpUtility.UrlEncode which returns lowercase hex. Example: "%3f" -> "?", "%24" -> "$", etc. var unescaper = strings.NewReplacer( @@ -88,19 +93,98 @@ func runesIndex(r1, r2 []rune) int { return -1 } -func intArrayToString(ns []uint32) string { +func intArrayToString(ns []index) string { if len(ns) == 0 { return "" } - indexSeparator := IndexSeparator[0] - - // Appr. 3 chars per num plus the comma. - b := []byte{} + b := []rune{} for _, n := range ns { - b = strconv.AppendInt(b, int64(n), 10) - b = append(b, indexSeparator) + b = append(b, intToRune(uint32(n))) } - b = b[:len(b)-1] return string(b) } + +// These constants define the number of bits representable +// in 1,2,3,4 byte utf8 sequences, respectively. +const ONE_BYTE_BITS = 7 +const TWO_BYTE_BITS = 11 +const THREE_BYTE_BITS = 16 +const FOUR_BYTE_BITS = 21 + +// Helper for getting a sequence of bits from an integer. +func getBits(i uint32, cnt byte, from byte) byte { + return byte((i >> from) & ((1 << cnt) - 1)) +} + +// Converts an integer in the range 0~1112060 into a rune. +// Based on the ranges table in https://en.wikipedia.org/wiki/UTF-8 +func intToRune(i uint32) rune { + if i < (1 << ONE_BYTE_BITS) { + return rune(i) + } + + if i < (1 << TWO_BYTE_BITS) { + r, size := utf8.DecodeRune([]byte{0b11000000 | getBits(i, 5, 6), 0b10000000 | getBits(i, 6, 0)}) + if size != 2 || r == utf8.RuneError { + panic(fmt.Sprintf("Error encoding an int %d with size 2, got rune %v and size %d", size, r, i)) + } + return r + } + + // Last -3 here needed because for some reason 3rd to last codepoint 65533 in this range + // was returning utf8.RuneError during encoding. + if i < ((1 << THREE_BYTE_BITS) - UNICODE_INVALID_RANGE_DELTA - 3) { + if i >= UNICODE_INVALID_RANGE_START { + i += UNICODE_INVALID_RANGE_DELTA + } + + r, size := utf8.DecodeRune([]byte{0b11100000 | getBits(i, 4, 12), 0b10000000 | getBits(i, 6, 6), 0b10000000 | getBits(i, 6, 0)}) + if size != 3 || r == utf8.RuneError { + panic(fmt.Sprintf("Error encoding an int %d with size 3, got rune %v and size %d", size, r, i)) + } + return r + } + + if i < (1<= UNICODE_INVALID_RANGE_END { + return result - UNICODE_INVALID_RANGE_DELTA + } + + return result + } + + if size == 4 { + result := uint32(bytes[0]&0b111)<<18 | uint32(bytes[1]&0b111111)<<12 | uint32(bytes[2]&0b111111)<<6 | uint32(bytes[3]&0b111111) + return result - UNICODE_INVALID_RANGE_DELTA - 3 + } + + panic(fmt.Sprintf("Unexpected state decoding rune=%v size=%d", r, size)) +} diff --git a/diffmatchpatch/stringutil_test.go b/diffmatchpatch/stringutil_test.go index ab2bc10..73ab6ca 100644 --- a/diffmatchpatch/stringutil_test.go +++ b/diffmatchpatch/stringutil_test.go @@ -114,3 +114,21 @@ func TestLastIndexOf(t *testing.T) { assert.Equal(t, tc.Expected, actual, fmt.Sprintf("Test case #%d, %#v", i, tc)) } } + +// Exhaustive check for all ints from 0 to 1112060 for correctness of implementation +// of `intToRune() -> runeToInt()`. +// This test is slow and runs longer than 5 seconds but it does provide a safety +// guarantee that these 2 functions are correct for the ranges we support. +func TestRuneToInt(t *testing.T) { + + for i := uint32(0); i <= UNICODE_RANGE_MAX-UNICODE_INVALID_RANGE_DELTA-3; i += 1 { + r := intToRune(i) + ic := runeToInt(r) + + assert.Equal(t, i, ic, fmt.Sprintf("intToRune(%d)=%d and runeToInt(%d)=%d", i, r, r, ic)) + } + + assert.Panics(t, func() { + intToRune(UNICODE_RANGE_MAX - UNICODE_INVALID_RANGE_DELTA - 2) + }) +} diff --git a/go.mod b/go.mod index c731033..c7886ce 100644 --- a/go.mod +++ b/go.mod @@ -8,4 +8,4 @@ require ( gopkg.in/yaml.v2 v2.4.0 // indirect ) -go 1.12 +go 1.13