/
manifest.go
99 lines (87 loc) · 2.17 KB
/
manifest.go
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package main
import (
"crypto/sha1"
"encoding/hex"
"golang.org/x/text/unicode/norm"
"os"
"path/filepath"
"time"
)
// ChecksumRecord stores checksum and metadata for a file.
type ChecksumRecord struct {
Checksum string `json:"checksum"`
ModTime time.Time `json:"mod_time"`
}
// Manifest of all files under a path.
type Manifest struct {
Path string `json:"path"`
CreatedAt time.Time `json:"created_at"`
Entries map[string]ChecksumRecord `json:"entries"`
}
// NewManifest generates a Manifest from a directory path.
func NewManifest(path string, config *Config) (*Manifest, error) {
entries, err := directoryChecksums(path, config)
if err != nil {
return nil, err
}
return &Manifest{
Path: path,
CreatedAt: time.Now().UTC(),
Entries: entries,
}, nil
}
// Private functions
func generateChecksum(file string) (string, error) {
// TODO: experiment with varying buffer to determine optimal size
bufferSize := 10 * 1024 * 1024 // 10MiB buffer
reader, err := newSha1Reader(file, bufferSize)
if err != nil {
return "", err
}
sum, err := reader.SHA1Sum()
if err != nil {
return "", err
}
return hex.EncodeToString(sum), nil
}
func checksumHexString(data *[]byte) string {
sum := sha1.Sum(*data)
return hex.EncodeToString(sum[:])
}
func directoryChecksums(path string, config *Config) (map[string]ChecksumRecord, error) {
records := map[string]ChecksumRecord{}
err := filepath.Walk(path, func(entryPath string, info os.FileInfo, err error) error {
if err != nil {
return err
}
if config.isIgnoredPath(entryPath) {
if info.IsDir() {
// Skip walking this directory
return filepath.SkipDir
}
return nil
}
if info.Mode().IsRegular() {
var relPath string
relPath, err = filepath.Rel(path, entryPath)
if err != nil {
return err
}
// Normalize Unicode combining characters
relPath = norm.NFC.String(relPath)
checksum, err := generateChecksum(entryPath)
if err != nil {
return err
}
records[relPath] = ChecksumRecord{
Checksum: checksum,
ModTime: info.ModTime().UTC(),
}
}
return nil
})
if err != nil {
return nil, err
}
return records, nil
}