VictoriaMetrics/lib/protoparser/firehose/parser.go

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package firehose
import (
"encoding/base64"
"fmt"
"github.com/valyala/fastjson"
)
// ProcessRequestBody converts Cloudwatch Stream protobuf metrics HTTP body delivered via Firehose into protobuf message.
func ProcessRequestBody(b *[]byte) error {
return unmarshalRequest(b)
}
var jsonParserPool fastjson.ParserPool
// unmarshalRequest extracts and decodes b64 data from Firehose HTTP destination request
//
// {
// "requestId": "<uuid-string>",
// "timestamp": <int64-value>,
// "records": [
// {
// "data": "<base64-encoded-payload>"
// }
// ]
// }
func unmarshalRequest(b *[]byte) error {
p := jsonParserPool.Get()
defer jsonParserPool.Put(p)
v, err := p.ParseBytes(*b)
if err != nil {
return err
}
o, err := v.Object()
if err != nil {
return fmt.Errorf("cannot find Firehose Request objects: %w", err)
}
index := 0
o.Visit(func(k []byte, v *fastjson.Value) {
if err != nil {
return
}
switch string(k) {
case "records":
recordObjects, errLocal := v.Array()
if errLocal != nil {
err = fmt.Errorf("cannot find Records array in Firehose Request object: %w", errLocal)
return
}
for _, fr := range recordObjects {
recordObject, errLocal := fr.Object()
if errLocal != nil {
err = fmt.Errorf("cannot find Record object: %w", errLocal)
return
}
if errLocal := unmarshalRecord(b, &index, recordObject); errLocal != nil {
err = fmt.Errorf("cannot unmarshal Record object: %w", errLocal)
return
}
}
}
})
*b = (*b)[:index]
if err != nil {
return fmt.Errorf("cannot parse Firehose Request object: %w", err)
}
return nil
}
func unmarshalRecord(b *[]byte, index *int, o *fastjson.Object) error {
var err error
var inc int
o.Visit(func(k []byte, v *fastjson.Value) {
if v.Type() != fastjson.TypeString {
err = fmt.Errorf("invalid record data type, %q", v.Type())
return
}
valueBytes := v.GetStringBytes()
if len(valueBytes) == 0 {
return
}
inc, err = base64.StdEncoding.Decode((*b)[*index:], valueBytes)
if err != nil {
err = fmt.Errorf("failed to decode and append Firehose Record data: %w", err)
return
}
*index = *index + inc
})
return err
}