diff options
Diffstat (limited to 'libgo/go/patch/textdiff.go')
-rw-r--r-- | libgo/go/patch/textdiff.go | 179 |
1 files changed, 0 insertions, 179 deletions
diff --git a/libgo/go/patch/textdiff.go b/libgo/go/patch/textdiff.go deleted file mode 100644 index c9cffee..0000000 --- a/libgo/go/patch/textdiff.go +++ /dev/null @@ -1,179 +0,0 @@ -// Copyright 2009 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package patch - -import ( - "bytes" - "errors" -) - -type TextDiff []TextChunk - -// A TextChunk specifies an edit to a section of a file: -// the text beginning at Line, which should be exactly Old, -// is to be replaced with New. -type TextChunk struct { - Line int - Old []byte - New []byte -} - -func ParseTextDiff(raw []byte) (TextDiff, error) { - var chunkHeader []byte - - // Copy raw so it is safe to keep references to slices. - _, chunks := sections(raw, "@@ -") - delta := 0 - diff := make(TextDiff, len(chunks)) - for i, raw := range chunks { - c := &diff[i] - - // Parse start line: @@ -oldLine,oldCount +newLine,newCount @@ junk - chunk := splitLines(raw) - chunkHeader = chunk[0] - var ok bool - var oldLine, oldCount, newLine, newCount int - s := chunkHeader - if oldLine, s, ok = atoi(s, "@@ -", 10); !ok { - goto ErrChunkHdr - } - if len(s) == 0 || s[0] != ',' { - oldCount = 1 - } else if oldCount, s, ok = atoi(s, ",", 10); !ok { - goto ErrChunkHdr - } - if newLine, s, ok = atoi(s, " +", 10); !ok { - goto ErrChunkHdr - } - if len(s) == 0 || s[0] != ',' { - newCount = 1 - } else if newCount, s, ok = atoi(s, ",", 10); !ok { - goto ErrChunkHdr - } - if !hasPrefix(s, " @@") { - goto ErrChunkHdr - } - - // Special case: for created or deleted files, the empty half - // is given as starting at line 0. Translate to line 1. - if oldCount == 0 && oldLine == 0 { - oldLine = 1 - } - if newCount == 0 && newLine == 0 { - newLine = 1 - } - - // Count lines in text - var dropOldNL, dropNewNL bool - var nold, nnew int - var lastch byte - chunk = chunk[1:] - for _, l := range chunk { - if nold == oldCount && nnew == newCount && (len(l) == 0 || l[0] != '\\') { - if len(bytes.TrimSpace(l)) != 0 { - return nil, SyntaxError("too many chunk lines") - } - continue - } - if len(l) == 0 { - return nil, SyntaxError("empty chunk line") - } - switch l[0] { - case '+': - nnew++ - case '-': - nold++ - case ' ': - nnew++ - nold++ - case '\\': - if _, ok := skip(l, "\\ No newline at end of file"); ok { - switch lastch { - case '-': - dropOldNL = true - case '+': - dropNewNL = true - case ' ': - dropOldNL = true - dropNewNL = true - default: - return nil, SyntaxError("message `\\ No newline at end of file' out of context") - } - break - } - fallthrough - default: - return nil, SyntaxError("unexpected chunk line: " + string(l)) - } - lastch = l[0] - } - - // Does it match the header? - if nold != oldCount || nnew != newCount { - return nil, SyntaxError("chunk header does not match line count: " + string(chunkHeader)) - } - if oldLine+delta != newLine { - return nil, SyntaxError("chunk delta is out of sync with previous chunks") - } - delta += nnew - nold - c.Line = oldLine - - var old, new bytes.Buffer - nold = 0 - nnew = 0 - for _, l := range chunk { - if nold == oldCount && nnew == newCount { - break - } - ch, l := l[0], l[1:] - if ch == '\\' { - continue - } - if ch != '+' { - old.Write(l) - nold++ - } - if ch != '-' { - new.Write(l) - nnew++ - } - } - c.Old = old.Bytes() - c.New = new.Bytes() - if dropOldNL { - c.Old = c.Old[0 : len(c.Old)-1] - } - if dropNewNL { - c.New = c.New[0 : len(c.New)-1] - } - } - return diff, nil - -ErrChunkHdr: - return nil, SyntaxError("unexpected chunk header line: " + string(chunkHeader)) -} - -var ErrPatchFailure = errors.New("patch did not apply cleanly") - -// Apply applies the changes listed in the diff -// to the data, returning the new version. -func (d TextDiff) Apply(data []byte) ([]byte, error) { - var buf bytes.Buffer - line := 1 - for _, c := range d { - var ok bool - var prefix []byte - prefix, data, ok = getLine(data, c.Line-line) - if !ok || !bytes.HasPrefix(data, c.Old) { - return nil, ErrPatchFailure - } - buf.Write(prefix) - data = data[len(c.Old):] - buf.Write(c.New) - line = c.Line + bytes.Count(c.Old, newline) - } - buf.Write(data) - return buf.Bytes(), nil -} |