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/*
* Copyright (c) 2015 Kurt Jung (Gmail: kurt.w.jung)
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package gofpdf
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"regexp"
)
var (
// 00000230 44 46 20 31 2e 37 29 0a 2f 43 72 65 61 74 69 6f |DF 1.7)./Creatio|
// 00000240 6e 44 61 74 65 20 28 44 3a 32 30 31 35 31 30 30 |nDate (D:2015100|
// 00000250 38 31 32 33 30 34 35 29 0a 3e 3e 0a 65 6e 64 6f |8123045).>>.endo|
creationDateRe = regexp.MustCompile("/CreationDate \\(D:\\d{14}\\)")
fixDate = []byte("/CreationDate (D:20000101000000)")
)
func writeBytes(leadStr string, startPos int, sl []byte) {
var pos, max int
var b byte
fmt.Printf("%s %07x", leadStr, startPos)
max = len(sl)
for pos < max {
fmt.Printf(" ")
for k := 0; k < 8; k++ {
if pos < max {
fmt.Printf(" %02x", sl[pos])
} else {
fmt.Printf(" ")
}
pos++
}
}
fmt.Printf(" |")
pos = 0
for pos < max {
b = sl[pos]
if b < 32 || b >= 128 {
b = '.'
}
fmt.Printf("%c", b)
pos++
}
fmt.Printf("|\n")
}
func checkBytes(pos int, sl1, sl2 []byte) (eq bool) {
eq = bytes.Equal(sl1, sl2)
if !eq {
writeBytes("<", pos, sl1)
writeBytes(">", pos, sl2)
}
return
}
// compareBytes compares the bytes referred to by sl1 with those referred to by
// sl2. The comparison is done byte-for-byte with the exception of the
// CreationDate fields which are effectively ignored. Nil is returned if the
// buffers are equal, otherwise an error.
func compareBytes(sl1, sl2 []byte) (err error) {
var posStart, posEnd, len1, len2, length int
var diffs bool
sl1 = creationDateRe.ReplaceAll(sl1, fixDate)
sl2 = creationDateRe.ReplaceAll(sl2, fixDate)
len1 = len(sl1)
len2 = len(sl2)
length = len1
if length > len2 {
length = len2
}
for posStart < length-1 {
posEnd = posStart + 16
if posEnd > length {
posEnd = length
}
if !checkBytes(posStart, sl1[posStart:posEnd], sl2[posStart:posEnd]) {
diffs = true
}
posStart = posEnd
}
if diffs {
err = fmt.Errorf("documents are different")
}
return
}
// ComparePDFs reads and compares the full contents of the two specified
// readers. The comparison is done byte-for-byte with the exception of the
// CreationDate fields which are effectively ignored. Nil is returned if the
// buffers are equal, otherwise an error.
func ComparePDFs(rdr1, rdr2 io.Reader) (err error) {
var b1, b2 *bytes.Buffer
_, err = b1.ReadFrom(rdr1)
if err == nil {
_, err = b2.ReadFrom(rdr2)
if err == nil {
err = compareBytes(b1.Bytes(), b2.Bytes())
}
}
return
}
// ComparePDFFiles reads and compares the full contents of the two specified
// files. The comparison is done byte-for-byte with the exception of the
// CreationDate fields which are effectively ignored. Nil is returned if the
// file contents are equal, or if the second file is missing, otherwise an
// error.
func ComparePDFFiles(file1Str, file2Str string) (err error) {
var sl1, sl2 []byte
sl1, err = ioutil.ReadFile(file1Str)
if err == nil {
sl2, err = ioutil.ReadFile(file2Str)
if err == nil {
err = compareBytes(sl1, sl2)
} else {
// Second file is missing; treat this as success
err = nil
}
}
return
}
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