mirror of https://github.com/go-gitea/gitea
380 lines
8.4 KiB
Go
380 lines
8.4 KiB
Go
// Copyright 2021 The Gitea Authors. All rights reserved.
|
|
// Use of this source code is governed by a MIT-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package gitdiff
|
|
|
|
import (
|
|
"encoding/csv"
|
|
"errors"
|
|
"io"
|
|
|
|
"code.gitea.io/gitea/modules/util"
|
|
)
|
|
|
|
const unmappedColumn = -1
|
|
const maxRowsToInspect int = 10
|
|
const minRatioToMatch float32 = 0.8
|
|
|
|
// TableDiffCellType represents the type of a TableDiffCell.
|
|
type TableDiffCellType uint8
|
|
|
|
// TableDiffCellType possible values.
|
|
const (
|
|
TableDiffCellEqual TableDiffCellType = iota + 1
|
|
TableDiffCellChanged
|
|
TableDiffCellAdd
|
|
TableDiffCellDel
|
|
)
|
|
|
|
// TableDiffCell represents a cell of a TableDiffRow
|
|
type TableDiffCell struct {
|
|
LeftCell string
|
|
RightCell string
|
|
Type TableDiffCellType
|
|
}
|
|
|
|
// TableDiffRow represents a row of a TableDiffSection.
|
|
type TableDiffRow struct {
|
|
RowIdx int
|
|
Cells []*TableDiffCell
|
|
}
|
|
|
|
// TableDiffSection represents a section of a DiffFile.
|
|
type TableDiffSection struct {
|
|
Rows []*TableDiffRow
|
|
}
|
|
|
|
// csvReader wraps a csv.Reader which buffers the first rows.
|
|
type csvReader struct {
|
|
reader *csv.Reader
|
|
buffer [][]string
|
|
line int
|
|
eof bool
|
|
}
|
|
|
|
// createCsvReader creates a csvReader and fills the buffer
|
|
func createCsvReader(reader *csv.Reader, bufferRowCount int) (*csvReader, error) {
|
|
csv := &csvReader{reader: reader}
|
|
csv.buffer = make([][]string, bufferRowCount)
|
|
for i := 0; i < bufferRowCount && !csv.eof; i++ {
|
|
row, err := csv.readNextRow()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
csv.buffer[i] = row
|
|
}
|
|
csv.line = bufferRowCount
|
|
return csv, nil
|
|
}
|
|
|
|
// GetRow gets a row from the buffer if present or advances the reader to the requested row. On the end of the file only nil gets returned.
|
|
func (csv *csvReader) GetRow(row int) ([]string, error) {
|
|
if row < len(csv.buffer) {
|
|
return csv.buffer[row], nil
|
|
}
|
|
if csv.eof {
|
|
return nil, nil
|
|
}
|
|
for {
|
|
fields, err := csv.readNextRow()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if csv.eof {
|
|
return nil, nil
|
|
}
|
|
csv.line++
|
|
if csv.line-1 == row {
|
|
return fields, nil
|
|
}
|
|
}
|
|
}
|
|
|
|
func (csv *csvReader) readNextRow() ([]string, error) {
|
|
if csv.eof {
|
|
return nil, nil
|
|
}
|
|
row, err := csv.reader.Read()
|
|
if err != nil {
|
|
if err != io.EOF {
|
|
return nil, err
|
|
}
|
|
csv.eof = true
|
|
}
|
|
return row, nil
|
|
}
|
|
|
|
// CreateCsvDiff creates a tabular diff based on two CSV readers.
|
|
func CreateCsvDiff(diffFile *DiffFile, baseReader *csv.Reader, headReader *csv.Reader) ([]*TableDiffSection, error) {
|
|
if baseReader != nil && headReader != nil {
|
|
return createCsvDiff(diffFile, baseReader, headReader)
|
|
}
|
|
|
|
if baseReader != nil {
|
|
return createCsvDiffSingle(baseReader, TableDiffCellDel)
|
|
}
|
|
return createCsvDiffSingle(headReader, TableDiffCellAdd)
|
|
}
|
|
|
|
// createCsvDiffSingle creates a tabular diff based on a single CSV reader. All cells are added or deleted.
|
|
func createCsvDiffSingle(reader *csv.Reader, celltype TableDiffCellType) ([]*TableDiffSection, error) {
|
|
var rows []*TableDiffRow
|
|
i := 1
|
|
for {
|
|
row, err := reader.Read()
|
|
if err != nil {
|
|
if err == io.EOF {
|
|
break
|
|
}
|
|
return nil, err
|
|
}
|
|
cells := make([]*TableDiffCell, len(row))
|
|
for j := 0; j < len(row); j++ {
|
|
cells[j] = &TableDiffCell{LeftCell: row[j], Type: celltype}
|
|
}
|
|
rows = append(rows, &TableDiffRow{RowIdx: i, Cells: cells})
|
|
i++
|
|
}
|
|
|
|
return []*TableDiffSection{{Rows: rows}}, nil
|
|
}
|
|
|
|
func createCsvDiff(diffFile *DiffFile, baseReader *csv.Reader, headReader *csv.Reader) ([]*TableDiffSection, error) {
|
|
a, err := createCsvReader(baseReader, maxRowsToInspect)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
b, err := createCsvReader(headReader, maxRowsToInspect)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
a2b, b2a := getColumnMapping(a, b)
|
|
|
|
columns := len(a2b) + countUnmappedColumns(b2a)
|
|
if len(a2b) < len(b2a) {
|
|
columns = len(b2a) + countUnmappedColumns(a2b)
|
|
}
|
|
|
|
createDiffRow := func(aline int, bline int) (*TableDiffRow, error) {
|
|
cells := make([]*TableDiffCell, columns)
|
|
|
|
if aline == 0 || bline == 0 {
|
|
var (
|
|
row []string
|
|
celltype TableDiffCellType
|
|
err error
|
|
)
|
|
if bline == 0 {
|
|
row, err = a.GetRow(aline - 1)
|
|
celltype = TableDiffCellDel
|
|
} else {
|
|
row, err = b.GetRow(bline - 1)
|
|
celltype = TableDiffCellAdd
|
|
}
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if row == nil {
|
|
return nil, nil
|
|
}
|
|
for i := 0; i < len(row); i++ {
|
|
cells[i] = &TableDiffCell{LeftCell: row[i], Type: celltype}
|
|
}
|
|
return &TableDiffRow{RowIdx: bline, Cells: cells}, nil
|
|
}
|
|
|
|
arow, err := a.GetRow(aline - 1)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
brow, err := b.GetRow(bline - 1)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(arow) == 0 && len(brow) == 0 {
|
|
return nil, nil
|
|
}
|
|
|
|
for i := 0; i < len(a2b); i++ {
|
|
acell, _ := getCell(arow, i)
|
|
if a2b[i] == unmappedColumn {
|
|
cells[i] = &TableDiffCell{LeftCell: acell, Type: TableDiffCellDel}
|
|
} else {
|
|
bcell, _ := getCell(brow, a2b[i])
|
|
|
|
celltype := TableDiffCellChanged
|
|
if acell == bcell {
|
|
celltype = TableDiffCellEqual
|
|
}
|
|
|
|
cells[i] = &TableDiffCell{LeftCell: acell, RightCell: bcell, Type: celltype}
|
|
}
|
|
}
|
|
for i := 0; i < len(b2a); i++ {
|
|
if b2a[i] == unmappedColumn {
|
|
bcell, _ := getCell(brow, i)
|
|
cells[i] = &TableDiffCell{LeftCell: bcell, Type: TableDiffCellAdd}
|
|
}
|
|
}
|
|
|
|
return &TableDiffRow{RowIdx: bline, Cells: cells}, nil
|
|
}
|
|
|
|
var sections []*TableDiffSection
|
|
|
|
for i, section := range diffFile.Sections {
|
|
var rows []*TableDiffRow
|
|
lines := tryMergeLines(section.Lines)
|
|
for j, line := range lines {
|
|
if i == 0 && j == 0 && (line[0] != 1 || line[1] != 1) {
|
|
diffRow, err := createDiffRow(1, 1)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if diffRow != nil {
|
|
rows = append(rows, diffRow)
|
|
}
|
|
}
|
|
diffRow, err := createDiffRow(line[0], line[1])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if diffRow != nil {
|
|
rows = append(rows, diffRow)
|
|
}
|
|
}
|
|
|
|
if len(rows) > 0 {
|
|
sections = append(sections, &TableDiffSection{Rows: rows})
|
|
}
|
|
}
|
|
|
|
return sections, nil
|
|
}
|
|
|
|
// getColumnMapping creates a mapping of columns between a and b
|
|
func getColumnMapping(a *csvReader, b *csvReader) ([]int, []int) {
|
|
arow, _ := a.GetRow(0)
|
|
brow, _ := b.GetRow(0)
|
|
|
|
a2b := []int{}
|
|
b2a := []int{}
|
|
|
|
if arow != nil {
|
|
a2b = make([]int, len(arow))
|
|
}
|
|
if brow != nil {
|
|
b2a = make([]int, len(brow))
|
|
}
|
|
|
|
for i := 0; i < len(b2a); i++ {
|
|
b2a[i] = unmappedColumn
|
|
}
|
|
|
|
bcol := 0
|
|
for i := 0; i < len(a2b); i++ {
|
|
a2b[i] = unmappedColumn
|
|
|
|
acell, ea := getCell(arow, i)
|
|
if ea == nil {
|
|
for j := bcol; j < len(b2a); j++ {
|
|
bcell, eb := getCell(brow, j)
|
|
if eb == nil && acell == bcell {
|
|
a2b[i] = j
|
|
b2a[j] = i
|
|
bcol = j + 1
|
|
break
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
tryMapColumnsByContent(a, a2b, b, b2a)
|
|
tryMapColumnsByContent(b, b2a, a, a2b)
|
|
|
|
return a2b, b2a
|
|
}
|
|
|
|
// tryMapColumnsByContent tries to map missing columns by the content of the first lines.
|
|
func tryMapColumnsByContent(a *csvReader, a2b []int, b *csvReader, b2a []int) {
|
|
start := 0
|
|
for i := 0; i < len(a2b); i++ {
|
|
if a2b[i] == unmappedColumn {
|
|
if b2a[start] == unmappedColumn {
|
|
rows := util.Min(maxRowsToInspect, util.Max(0, util.Min(len(a.buffer), len(b.buffer))-1))
|
|
same := 0
|
|
for j := 1; j <= rows; j++ {
|
|
acell, ea := getCell(a.buffer[j], i)
|
|
bcell, eb := getCell(b.buffer[j], start+1)
|
|
if ea == nil && eb == nil && acell == bcell {
|
|
same++
|
|
}
|
|
}
|
|
if (float32(same) / float32(rows)) > minRatioToMatch {
|
|
a2b[i] = start + 1
|
|
b2a[start+1] = i
|
|
}
|
|
}
|
|
}
|
|
start = a2b[i]
|
|
}
|
|
}
|
|
|
|
// getCell returns the specific cell or nil if not present.
|
|
func getCell(row []string, column int) (string, error) {
|
|
if column < len(row) {
|
|
return row[column], nil
|
|
}
|
|
return "", errors.New("Undefined column")
|
|
}
|
|
|
|
// countUnmappedColumns returns the count of unmapped columns.
|
|
func countUnmappedColumns(mapping []int) int {
|
|
count := 0
|
|
for i := 0; i < len(mapping); i++ {
|
|
if mapping[i] == unmappedColumn {
|
|
count++
|
|
}
|
|
}
|
|
return count
|
|
}
|
|
|
|
// tryMergeLines maps the separated line numbers of a git diff. The result is assumed to be ordered.
|
|
func tryMergeLines(lines []*DiffLine) [][2]int {
|
|
ids := make([][2]int, len(lines))
|
|
|
|
i := 0
|
|
for _, line := range lines {
|
|
if line.Type != DiffLineSection {
|
|
ids[i][0] = line.LeftIdx
|
|
ids[i][1] = line.RightIdx
|
|
i++
|
|
}
|
|
}
|
|
|
|
ids = ids[:i]
|
|
|
|
result := make([][2]int, len(ids))
|
|
|
|
j := 0
|
|
for i = 0; i < len(ids); i++ {
|
|
if ids[i][0] == 0 {
|
|
if j > 0 && result[j-1][1] == 0 {
|
|
temp := j
|
|
for temp > 0 && result[temp-1][1] == 0 {
|
|
temp--
|
|
}
|
|
result[temp][1] = ids[i][1]
|
|
continue
|
|
}
|
|
}
|
|
result[j] = ids[i]
|
|
j++
|
|
}
|
|
|
|
return result[:j]
|
|
}
|