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bluekeyesbluekeyes
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Move formatting functions to formatter
This cleans up the code a bit and allows writing everything to a single buffer when formatting a full file.
1 parent 7cec3fe commit 3eb61e6

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5 files changed

+284
-248
lines changed

5 files changed

+284
-248
lines changed

‎gitdiff/format.go

Lines changed: 277 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,277 @@
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package gitdiff
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import (
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"bytes"
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"compress/zlib"
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"fmt"
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"io"
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"strconv"
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)
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type formatter struct {
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w io.Writer
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err error
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}
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func newFormatter(w io.Writer) *formatter {
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return &formatter{w: w}
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}
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func (fm *formatter) Write(p []byte) (int, error) {
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if fm.err != nil {
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return len(p), nil
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}
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if _, err := fm.w.Write(p); err != nil {
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fm.err = err
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}
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return len(p), nil
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}
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func (fm *formatter) WriteString(s string) (int, error) {
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fm.Write([]byte(s))
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return len(s), nil
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}
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func (fm *formatter) WriteByte(c byte) error {
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fm.Write([]byte{c})
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return nil
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}
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func (fm *formatter) WriteQuotedName(s string) {
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qpos := 0
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for i := 0; i < len(s); i++ {
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ch := s[i]
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if q, quoted := quoteByte(ch); quoted {
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if qpos == 0 {
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fm.WriteByte('"')
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}
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fm.WriteString(s[qpos:i])
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fm.Write(q)
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qpos = i + 1
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}
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}
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fm.WriteString(s[qpos:])
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if qpos > 0 {
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fm.WriteByte('"')
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}
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}
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var quoteEscapeTable = map[byte]byte{
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'\a': 'a',
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'\b': 'b',
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'\t': 't',
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'\n': 'n',
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'\v': 'v',
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'\f': 'f',
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'\r': 'r',
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'"': '"',
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'\\': '\\',
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}
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func quoteByte(b byte) ([]byte, bool) {
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if q, ok := quoteEscapeTable[b]; ok {
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return []byte{'\\', q}, true
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}
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if b < 0x20 || b >= 0x7F {
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return []byte{
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'\\',
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'0' + (b>>6)&0o3,
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'0' + (b>>3)&0o7,
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'0' + (b>>0)&0o7,
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}, true
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}
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return nil, false
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}
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func (fm *formatter) FormatFile(f *File) {
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fm.WriteString("diff --git ")
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var aName, bName string
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switch {
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case f.OldName == "":
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aName = f.NewName
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bName = f.NewName
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case f.NewName == "":
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aName = f.OldName
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bName = f.OldName
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default:
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aName = f.OldName
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bName = f.NewName
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}
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fm.WriteQuotedName("a/" + aName)
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fm.WriteByte(' ')
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fm.WriteQuotedName("b/" + bName)
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fm.WriteByte('\n')
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if f.OldMode != 0 {
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if f.IsDelete {
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fmt.Fprintf(fm, "deleted file mode %o\n", f.OldMode)
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} else if f.NewMode != 0 {
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fmt.Fprintf(fm, "old mode %o\n", f.OldMode)
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}
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}
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if f.NewMode != 0 {
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if f.IsNew {
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fmt.Fprintf(fm, "new file mode %o\n", f.NewMode)
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} else if f.OldMode != 0 {
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fmt.Fprintf(fm, "new mode %o\n", f.NewMode)
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}
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}
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if f.Score > 0 {
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if f.IsCopy || f.IsRename {
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fmt.Fprintf(fm, "similarity index %d%%\n", f.Score)
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} else {
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fmt.Fprintf(fm, "dissimilarity index %d%%\n", f.Score)
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}
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}
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if f.IsCopy {
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if f.OldName != "" {
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fm.WriteString("copy from ")
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fm.WriteQuotedName(f.OldName)
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fm.WriteByte('\n')
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}
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if f.NewName != "" {
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fm.WriteString("copy to ")
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fm.WriteQuotedName(f.NewName)
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fm.WriteByte('\n')
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}
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}
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if f.IsRename {
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if f.OldName != "" {
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fm.WriteString("rename from ")
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fm.WriteQuotedName(f.OldName)
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fm.WriteByte('\n')
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}
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if f.NewName != "" {
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fm.WriteString("rename to ")
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fm.WriteQuotedName(f.NewName)
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fm.WriteByte('\n')
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}
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}
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if f.OldOIDPrefix != "" && f.NewOIDPrefix != "" {
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fmt.Fprintf(fm, "index %s..%s", f.OldOIDPrefix, f.NewOIDPrefix)
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// Mode is only included on the index line when it is not changing
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if f.OldMode != 0 && ((f.NewMode == 0 && !f.IsDelete) || f.OldMode == f.NewMode) {
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fmt.Fprintf(fm, " %o", f.OldMode)
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}
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fm.WriteByte('\n')
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}
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if f.IsBinary {
171+
if f.BinaryFragment == nil {
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fm.WriteString("Binary files fmer\n")
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} else {
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fm.WriteString("GIT binary patch\n")
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fm.FormatBinaryFragment(f.BinaryFragment)
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if f.ReverseBinaryFragment != nil {
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fm.FormatBinaryFragment(f.ReverseBinaryFragment)
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}
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}
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}
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// The "---" and "+++" lines only appear for text patches with fragments
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if len(f.TextFragments) > 0 {
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fm.WriteString("--- ")
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if f.OldName == "" {
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fm.WriteString("/dev/null")
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} else {
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fm.WriteQuotedName("a/" + f.OldName)
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}
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fm.WriteByte('\n')
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fm.WriteString("+++ ")
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if f.NewName == "" {
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fm.WriteString("/dev/null")
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} else {
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fm.WriteQuotedName("b/" + f.NewName)
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}
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fm.WriteByte('\n')
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for _, frag := range f.TextFragments {
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fm.FormatTextFragment(frag)
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}
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}
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}
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func (fm *formatter) FormatTextFragment(f *TextFragment) {
207+
fm.FormatTextFragmentHeader(f)
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fm.WriteByte('\n')
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for _, line := range f.Lines {
211+
fm.WriteString(line.Op.String())
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fm.WriteString(line.Line)
213+
if line.NoEOL() {
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fm.WriteString("\n\\ No newline at end of file\n")
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}
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}
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}
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func (fm *formatter) FormatTextFragmentHeader(f *TextFragment) {
220+
fmt.Fprintf(fm, "@@ -%d,%d +%d,%d @@", f.OldPosition, f.OldLines, f.NewPosition, f.NewLines)
221+
if f.Comment != "" {
222+
fm.WriteByte(' ')
223+
fm.WriteString(f.Comment)
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}
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}
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227+
func (fm *formatter) FormatBinaryFragment(f *BinaryFragment) {
228+
const (
229+
maxBytesPerLine = 52
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)
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232+
switch f.Method {
233+
case BinaryPatchDelta:
234+
fm.WriteString("delta ")
235+
case BinaryPatchLiteral:
236+
fm.WriteString("literal ")
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}
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fm.Write(strconv.AppendInt(nil, f.Size, 10))
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fm.WriteByte('\n')
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data := deflateBinaryChunk(f.Data)
242+
n := (len(data) / maxBytesPerLine) * maxBytesPerLine
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buf := make([]byte, base85Len(maxBytesPerLine))
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for i := 0; i < n; i += maxBytesPerLine {
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base85Encode(buf, data[i:i+maxBytesPerLine])
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fm.WriteByte('z')
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fm.Write(buf)
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fm.WriteByte('\n')
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}
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if remainder := len(data) - n; remainder > 0 {
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buf = buf[0:base85Len(remainder)]
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sizeChar := byte(remainder)
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if remainder <= 26 {
256+
sizeChar = 'A' + sizeChar - 1
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} else {
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sizeChar = 'a' + sizeChar - 27
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}
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base85Encode(buf, data[n:])
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fm.WriteByte(sizeChar)
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fm.Write(buf)
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fm.WriteByte('\n')
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}
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fm.WriteByte('\n')
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}
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func deflateBinaryChunk(data []byte) []byte {
270+
var b bytes.Buffer
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zw := zlib.NewWriter(&b)
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_, _ = zw.Write(data)
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_ = zw.Close()
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return b.Bytes()
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}

‎gitdiff/gitdiff_string_test.go renamed to ‎gitdiff/format_roundtrip_test.go

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,7 @@ import (
99
"testing"
1010
)
1111

12-
func TestParseRoundtrip(t *testing.T) {
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func TestFormatRoundtrip(t *testing.T) {
1313
patches := []struct {
1414
File string
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SkipTextCompare bool

‎gitdiff/quote_test.go renamed to ‎gitdiff/format_test.go

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -5,7 +5,7 @@ import (
55
"testing"
66
)
77

8-
func TestWriteQuotedName(t *testing.T) {
8+
func TestFormatter_WriteQuotedName(t *testing.T) {
99
tests := []struct {
1010
Input string
1111
Expected string
@@ -20,7 +20,7 @@ func TestWriteQuotedName(t *testing.T) {
2020

2121
for _, test := range tests {
2222
var b strings.Builder
23-
writeQuotedName(&b, test.Input)
23+
newFormatter(&b).WriteQuotedName(test.Input)
2424
if b.String() != test.Expected {
2525
t.Errorf("expected %q, got %q", test.Expected, b.String())
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}

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