File size: 2,759 Bytes
d7a5f2f | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 | // Copyright 2024 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package pgo
import (
"bufio"
"fmt"
"io"
"strconv"
"strings"
)
// IsSerialized returns true if r is a serialized Profile.
//
// IsSerialized only peeks at r, so seeking back after calling is not
// necessary.
func IsSerialized(r *bufio.Reader) (bool, error) {
hdr, err := r.Peek(len(serializationHeader))
if err == io.EOF {
// Empty file.
return false, nil
} else if err != nil {
return false, fmt.Errorf("error reading profile header: %w", err)
}
return string(hdr) == serializationHeader, nil
}
// FromSerialized parses a profile from serialization output of Profile.WriteTo.
func FromSerialized(r io.Reader) (*Profile, error) {
d := emptyProfile()
scanner := bufio.NewScanner(r)
scanner.Split(bufio.ScanLines)
if !scanner.Scan() {
if err := scanner.Err(); err != nil {
return nil, fmt.Errorf("error reading preprocessed profile: %w", err)
}
return nil, fmt.Errorf("preprocessed profile missing header")
}
if gotHdr := scanner.Text() + "\n"; gotHdr != serializationHeader {
return nil, fmt.Errorf("preprocessed profile malformed header; got %q want %q", gotHdr, serializationHeader)
}
for scanner.Scan() {
readStr := scanner.Text()
callerName := readStr
if !scanner.Scan() {
if err := scanner.Err(); err != nil {
return nil, fmt.Errorf("error reading preprocessed profile: %w", err)
}
return nil, fmt.Errorf("preprocessed profile entry missing callee")
}
calleeName := scanner.Text()
if !scanner.Scan() {
if err := scanner.Err(); err != nil {
return nil, fmt.Errorf("error reading preprocessed profile: %w", err)
}
return nil, fmt.Errorf("preprocessed profile entry missing weight")
}
readStr = scanner.Text()
split := strings.Split(readStr, " ")
if len(split) != 2 {
return nil, fmt.Errorf("preprocessed profile entry got %v want 2 fields", split)
}
co, err := strconv.Atoi(split[0])
if err != nil {
return nil, fmt.Errorf("preprocessed profile error processing call line: %w", err)
}
edge := NamedCallEdge{
CallerName: callerName,
CalleeName: calleeName,
CallSiteOffset: co,
}
weight, err := strconv.ParseInt(split[1], 10, 64)
if err != nil {
return nil, fmt.Errorf("preprocessed profile error processing call weight: %w", err)
}
if _, ok := d.NamedEdgeMap.Weight[edge]; ok {
return nil, fmt.Errorf("preprocessed profile contains duplicate edge %+v", edge)
}
d.NamedEdgeMap.ByWeight = append(d.NamedEdgeMap.ByWeight, edge) // N.B. serialization is ordered.
d.NamedEdgeMap.Weight[edge] += weight
d.TotalWeight += weight
}
return d, nil
}
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