diff options
Diffstat (limited to 'vendor/github.com/google/gopacket/bytediff/bytediff.go')
| -rw-r--r-- | vendor/github.com/google/gopacket/bytediff/bytediff.go | 217 |
1 files changed, 0 insertions, 217 deletions
diff --git a/vendor/github.com/google/gopacket/bytediff/bytediff.go b/vendor/github.com/google/gopacket/bytediff/bytediff.go deleted file mode 100644 index 63addd9..0000000 --- a/vendor/github.com/google/gopacket/bytediff/bytediff.go +++ /dev/null @@ -1,217 +0,0 @@ -// Copyright 2012 Google, Inc. All rights reserved. -// -// Use of this source code is governed by a BSD-style license -// that can be found in the LICENSE file in the root of the source -// tree. - -// Package bytediff provides a simple diff utility for looking at differences in byte -// slices. It's slow, clunky, and not particularly good by any measure, but -// it does provide very useful visualizations for diffs between small byte -// slices. -// -// Our diff algorithm uses a dynamic programming implementation of longest common -// substring to find matching parts of slices, then recursively calls itself on -// the prefix/suffix of that matching part for each packet. This is a Bad Idea -// (tm) for normal (especially large) input, but for packets where large portions -// repeat frequently and we expect minor changes between results, it's actually -// quite useful. -package bytediff - -import ( - "bytes" - "fmt" -) - -// OutputFormat tells a Differences.String call how to format the set of -// differences into a human-readable string. Its internals are currently -// unexported because we may want to change them drastically in the future. For -// the moment, please just use one of the provided OutputFormats that comes with -// this library. -type OutputFormat struct { - start, finish, add, remove, change, reset string -} - -var ( - // BashOutput uses bash escape sequences to color output. - BashOutput = &OutputFormat{ - reset: "\033[0m", - remove: "\033[32m", - add: "\033[31m", - change: "\033[33m", - } - // HTMLOutput uses a <pre> to wrap output, and <span>s to color it. - // HTMLOutput is pretty experimental, so use at your own risk ;) - HTMLOutput = &OutputFormat{ - start: "<pre>", - finish: "</pre>", - reset: "</span>", - remove: "<span style='color:red'>", - add: "<span style='color:green'>", - change: "<span style='color:yellow'>", - } -) - -// longestCommonSubstring uses a O(MN) dynamic programming approach to find the -// longest common substring in a set of slices. It returns the index in each -// slice at which the substring begins, plus the length of the commonality. -func longestCommonSubstring(strA, strB []byte) (indexA, indexB, length int) { - lenA, lenB := len(strA), len(strB) - if lenA == 0 || lenB == 0 { - return 0, 0, 0 - } - arr := make([][]int, lenA) - for i := 0; i < lenA; i++ { - arr[i] = make([]int, lenB) - } - var maxLength int - var maxA, maxB int - for a := 0; a < lenA; a++ { - for b := 0; b < lenB; b++ { - if strA[a] == strB[b] { - length := 1 - if a > 0 && b > 0 { - length = arr[a-1][b-1] + 1 - } - arr[a][b] = length - if length > maxLength { - maxLength = length - maxA = a - maxB = b - } - } - } - } - a, b := maxA, maxB - for a >= 0 && b >= 0 && strA[a] == strB[b] { - indexA = a - indexB = b - a-- - b-- - length++ - } - return -} - -func intMax(a, b int) int { - if a > b { - return a - } - return b -} - -// Difference represents a single part of the data being diffed, containing -// information about both the original and new values. -// From and To are the sets of bytes in the original and the new byte slice. -// !Replace implies From == To (no change) -// len(To) == 0 implies From is being deleted -// len(From) == 0 implies To is being inserted -// else implies From is being replaced by To -type Difference struct { - Replace bool - From, To []byte -} - -// color returns the bash color for a given difference. -func (c *OutputFormat) color(d Difference) string { - switch { - case !d.Replace: - return "" - case len(d.From) == 0: - return c.remove - case len(d.To) == 0: - return c.add - default: - return c.change - } -} - -// Diff diffs strA and strB, returning a list of differences which -// can be used to construct either the original or new string. -// -// Diff is optimized for comparing VERY SHORT slices. It's meant for comparing -// things like packets off the wire, not large files or the like. -// As such, its runtime can be catastrophic if large inputs are passed in. -// You've been warned. -func Diff(strA, strB []byte) Differences { - if len(strA) == 0 && len(strB) == 0 { - return nil - } - ia, ib, l := longestCommonSubstring(strA, strB) - if l == 0 { - return Differences{ - Difference{true, strA, strB}, - } - } - beforeA, match, afterA := strA[:ia], strA[ia:ia+l], strA[ia+l:] - beforeB, afterB := strB[:ib], strB[ib+l:] - var diffs Differences - diffs = append(diffs, Diff(beforeA, beforeB)...) - diffs = append(diffs, Difference{false, match, match}) - diffs = append(diffs, Diff(afterA, afterB)...) - return diffs -} - -// Differences is a set of differences for a given diff'd pair of byte slices. -type Differences []Difference - -// String outputs a previously diff'd set of strings, showing differences -// between them, highlighted by colors. -// -// The output format of this function is NOT guaranteed consistent, and may be -// changed at any time by the library authors. It's meant solely for human -// consumption. -func (c *OutputFormat) String(diffs Differences) string { - var buf bytes.Buffer - count := 0 - fmt.Fprintf(&buf, "%s", c.start) - fmt.Fprintf(&buf, "00000000 ") - for i := 0; i < len(diffs); i++ { - diff := diffs[i] - color := c.color(diff) - reset := "" - if color != "" { - reset = c.reset - } - fmt.Fprint(&buf, color) - for _, b := range diff.From { - fmt.Fprintf(&buf, " %02x", b) - count++ - switch count % 16 { - case 0: - fmt.Fprintf(&buf, "%v\n%08x%v ", reset, count, color) - case 8: - fmt.Fprintf(&buf, " ") - } - } - fmt.Fprint(&buf, reset) - } - fmt.Fprintf(&buf, "\n\n00000000 ") - count = 0 - for i := 0; i < len(diffs); i++ { - diff := diffs[i] - str := diff.From - if diff.Replace { - str = diff.To - } - color := c.color(diff) - reset := "" - if color != "" { - reset = c.reset - } - fmt.Fprint(&buf, color) - for _, b := range str { - fmt.Fprintf(&buf, " %02x", b) - count++ - switch count % 16 { - case 0: - fmt.Fprintf(&buf, "%v\n%08x%v ", reset, count, color) - case 8: - fmt.Fprintf(&buf, " ") - } - } - fmt.Fprint(&buf, reset) - } - fmt.Fprint(&buf, "\n") - fmt.Fprintf(&buf, "%s", c.finish) - return string(buf.Bytes()) -} |