DownloadToCache retrieves resources while using a content based cache.
(ref, version string)
| 215 | |
| 216 | // DownloadToCache retrieves resources while using a content based cache. |
| 217 | func (c *ChartDownloader) DownloadToCache(ref, version string) (string, *provenance.Verification, error) { |
| 218 | if c.Cache == nil { |
| 219 | if c.ContentCache == "" { |
| 220 | return "", nil, errors.New("content cache must be set") |
| 221 | } |
| 222 | c.Cache = &DiskCache{Root: c.ContentCache} |
| 223 | slog.Debug("set up default downloader cache") |
| 224 | } |
| 225 | |
| 226 | digestString, u, err := c.ResolveChartVersion(ref, version) |
| 227 | if err != nil { |
| 228 | return "", nil, err |
| 229 | } |
| 230 | |
| 231 | g, err := c.Getters.ByScheme(u.Scheme) |
| 232 | if err != nil { |
| 233 | return "", nil, err |
| 234 | } |
| 235 | |
| 236 | c.Options = append(c.Options, getter.WithAcceptHeader("application/gzip,application/octet-stream")) |
| 237 | |
| 238 | // Check the cache for the file |
| 239 | // Strip the algorithm prefix (e.g., "sha256:") if present |
| 240 | digest, err := hex.DecodeString(stripDigestAlgorithm(digestString)) |
| 241 | if err != nil { |
| 242 | return "", nil, fmt.Errorf("unable to decode digest: %w", err) |
| 243 | } |
| 244 | if digestString != "" && len(digest) != 32 { |
| 245 | return "", nil, fmt.Errorf("invalid digest length: %d", len(digest)) |
| 246 | } |
| 247 | var digest32 [32]byte |
| 248 | copy(digest32[:], digest) |
| 249 | |
| 250 | var pth string |
| 251 | // only fetch from the cache if we have a digest |
| 252 | if len(digest) > 0 { |
| 253 | pth, err = c.Cache.Get(digest32, CacheChart) |
| 254 | if err == nil { |
| 255 | slog.Debug("found chart in cache", "id", digestString) |
| 256 | } |
| 257 | } |
| 258 | if len(digest) == 0 || err != nil { |
| 259 | slog.Debug("attempting to download chart", "ref", ref, "version", version) |
| 260 | if err != nil && !os.IsNotExist(err) { |
| 261 | return "", nil, err |
| 262 | } |
| 263 | |
| 264 | // Get file not in the cache |
| 265 | data, gerr := g.Get(u.String(), c.Options...) |
| 266 | if gerr != nil { |
| 267 | return "", nil, gerr |
| 268 | } |
| 269 | |
| 270 | // Generate the digest |
| 271 | if len(digest) == 0 { |
| 272 | digest32 = sha256.Sum256(data.Bytes()) |
| 273 | } |
| 274 |