forked from Shiloh/githaven
62 lines
2.1 KiB
Go
62 lines
2.1 KiB
Go
// Package diff implements line oriented diffs, similar to the ancient
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// Unix diff command.
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//
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// The current implementation is just a wrapper around Sergi's
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// go-diff/diffmatchpatch library, which is a go port of Neil
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// Fraser's google-diff-match-patch code
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package diff
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import (
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"bytes"
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"time"
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"github.com/sergi/go-diff/diffmatchpatch"
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)
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// Do computes the (line oriented) modifications needed to turn the src
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// string into the dst string. The underlying algorithm is Meyers,
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// its complexity is O(N*d) where N is min(lines(src), lines(dst)) and d
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// is the size of the diff.
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func Do(src, dst string) (diffs []diffmatchpatch.Diff) {
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// the default timeout is time.Second which may be too small under heavy load
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return DoWithTimeout(src, dst, time.Hour)
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}
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// DoWithTimeout computes the (line oriented) modifications needed to turn the src
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// string into the dst string. The `timeout` argument specifies the maximum
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// amount of time it is allowed to spend in this function. If the timeout
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// is exceeded, the parts of the strings which were not considered are turned into
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// a bulk delete+insert and the half-baked suboptimal result is returned at once.
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// The underlying algorithm is Meyers, its complexity is O(N*d) where N is
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// min(lines(src), lines(dst)) and d is the size of the diff.
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func DoWithTimeout (src, dst string, timeout time.Duration) (diffs []diffmatchpatch.Diff) {
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dmp := diffmatchpatch.New()
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dmp.DiffTimeout = timeout
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wSrc, wDst, warray := dmp.DiffLinesToRunes(src, dst)
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diffs = dmp.DiffMainRunes(wSrc, wDst, false)
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diffs = dmp.DiffCharsToLines(diffs, warray)
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return diffs
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}
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// Dst computes and returns the destination text.
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func Dst(diffs []diffmatchpatch.Diff) string {
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var text bytes.Buffer
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for _, d := range diffs {
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if d.Type != diffmatchpatch.DiffDelete {
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text.WriteString(d.Text)
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}
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}
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return text.String()
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}
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// Src computes and returns the source text
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func Src(diffs []diffmatchpatch.Diff) string {
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var text bytes.Buffer
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for _, d := range diffs {
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if d.Type != diffmatchpatch.DiffInsert {
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text.WriteString(d.Text)
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}
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}
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return text.String()
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}
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