/
file.go
77 lines (60 loc) · 1.57 KB
/
file.go
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// Unless explicitly stated otherwise all files in this repository are licensed
// under the Apache License Version 2.0.
// This product includes software developed at Datadog (https://www.datadoghq.com/).
// Copyright 2016-2021 Datadog, Inc.
//go:build !serverless
package replay
import (
"fmt"
"io"
"github.com/h2non/filetype"
"github.com/h2non/filetype/matchers"
)
var (
datadogType = filetype.NewType("dog", "datadog/capture")
)
func init() {
// Register the new matcher and its type
filetype.AddMatcher(datadogType, datadogMatcher)
filetype.AddMatcher(matchers.TypeZstd, matchers.Zst)
}
func datadogMatcher(buf []byte) bool {
if len(buf) < len(datadogHeader) {
return false
}
for i := 0; i < len(datadogHeader); i++ {
if i == versionIndex {
if buf[i]&datadogHeader[i] != datadogHeader[i] {
return false
}
} else if buf[i] != datadogHeader[i] {
return false
}
}
return true
}
func fileVersion(buf []byte) (int, error) {
if !datadogMatcher(buf) {
return -1, fmt.Errorf("Cannot verify file version bad buffer or invalid file")
}
ver := int(0xF0 ^ buf[4])
if ver > int(datadogFileVersion) {
return -1, fmt.Errorf("Unsupported file version")
}
return ver, nil
}
// WriteHeader writes the datadog header to the Writer argument to conform to the .dog file format.
func WriteHeader(w io.Writer) error {
hdr := make([]byte, len(datadogHeader))
copy(hdr, datadogHeader)
hdr[versionIndex] |= datadogFileVersion
//Write header
n, err := w.Write(hdr)
if err != nil {
return err
}
if n < len(datadogHeader) {
return ErrHeaderWrite
}
return nil
}