|
| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "context" |
| 6 | + "encoding/json" |
| 7 | + "fmt" |
| 8 | + "io" |
| 9 | + "log" |
| 10 | + "os" |
| 11 | + "os/exec" |
| 12 | + "slices" |
| 13 | + "strings" |
| 14 | + "sync" |
| 15 | + |
| 16 | + "golang.org/x/mod/modfile" |
| 17 | + "golang.org/x/mod/module" |
| 18 | + "golang.org/x/mod/semver" |
| 19 | + "golang.org/x/sync/errgroup" |
| 20 | +) |
| 21 | + |
| 22 | +type goModDownload struct { |
| 23 | + Path string |
| 24 | + Version string |
| 25 | + Info string |
| 26 | + GoMod string |
| 27 | + Zip string |
| 28 | + Dir string |
| 29 | + Sum string |
| 30 | + GoModSum string |
| 31 | +} |
| 32 | + |
| 33 | +func downloadModules(directory string, packages []string) ([]*goModDownload, error) { |
| 34 | + var downloads []*goModDownload |
| 35 | + |
| 36 | + cmd := exec.Command("go", append([]string{"mod", "download", "--json"}, packages...)...) |
| 37 | + cmd.Dir = directory |
| 38 | + stdout, err := cmd.Output() |
| 39 | + if err != nil { |
| 40 | + if exiterr, ok := err.(*exec.ExitError); ok { |
| 41 | + return nil, fmt.Errorf("failed to run 'go mod download --json: %s\n%s", exiterr, exiterr.Stderr) |
| 42 | + } else { |
| 43 | + return nil, fmt.Errorf("failed to run 'go mod download --json': %s", err) |
| 44 | + } |
| 45 | + } |
| 46 | + |
| 47 | + dec := json.NewDecoder(bytes.NewReader(stdout)) |
| 48 | + for { |
| 49 | + var dl *goModDownload |
| 50 | + err := dec.Decode(&dl) |
| 51 | + if err == io.EOF { |
| 52 | + break |
| 53 | + } else { |
| 54 | + downloads = append(downloads, dl) |
| 55 | + } |
| 56 | + } |
| 57 | + |
| 58 | + return downloads, nil |
| 59 | +} |
| 60 | + |
| 61 | +func downloadModule(directory string, packagePath string, version string) (*goModDownload, error) { |
| 62 | + log.Printf("Downloading %s@%s", packagePath, version) |
| 63 | + |
| 64 | + cmd := exec.Command("go", "mod", "download", "--json", fmt.Sprintf("%s@%s", packagePath, version)) |
| 65 | + cmd.Dir = directory |
| 66 | + stdout, err := cmd.Output() |
| 67 | + if err != nil { |
| 68 | + if exiterr, ok := err.(*exec.ExitError); ok { |
| 69 | + return nil, fmt.Errorf("failed to run 'go mod download --json: %s\n%s", exiterr, exiterr.Stderr) |
| 70 | + } else { |
| 71 | + return nil, fmt.Errorf("failed to run 'go mod download --json': %s", err) |
| 72 | + } |
| 73 | + } |
| 74 | + |
| 75 | + dec := json.NewDecoder(bytes.NewReader(stdout)) |
| 76 | + for { |
| 77 | + var dl *goModDownload |
| 78 | + err := dec.Decode(&dl) |
| 79 | + if err == io.EOF { |
| 80 | + break |
| 81 | + } else { |
| 82 | + return dl, err |
| 83 | + } |
| 84 | + } |
| 85 | + |
| 86 | + return nil, fmt.Errorf("error downloading %s@%s: no module download returned", packagePath, version) |
| 87 | +} |
| 88 | + |
| 89 | +func discoverDependencies(directory string, workers int, sumVersions map[string]string) ([]*goModDownload, error) { |
| 90 | + var downloadMod func(context.Context, module.Version) error |
| 91 | + var discoverMod func(module.Version) |
| 92 | + var wg sync.WaitGroup |
| 93 | + |
| 94 | + downloads := map[string]*goModDownload{} |
| 95 | + var downloadsMu sync.RWMutex |
| 96 | + |
| 97 | + eg := errgroup.Group{} |
| 98 | + eg.SetLimit(workers) |
| 99 | + |
| 100 | + discoveredVersions := map[string]string{} |
| 101 | + var discoveredMu sync.RWMutex |
| 102 | + discoverSem := make(chan struct{}, workers) |
| 103 | + errChan := make(chan error, workers) |
| 104 | + |
| 105 | + ctx, cancel := context.WithCancel(context.Background()) |
| 106 | + defer cancel() |
| 107 | + |
| 108 | + discoverMod = func(mod module.Version) { |
| 109 | + if mod.Path[0] == '.' { // Disregard local replacements |
| 110 | + return |
| 111 | + } |
| 112 | + |
| 113 | + wg.Add(1) |
| 114 | + |
| 115 | + doWork := func() error { |
| 116 | + select { |
| 117 | + case <-ctx.Done(): |
| 118 | + return ctx.Err() |
| 119 | + case discoverSem <- struct{}{}: |
| 120 | + } |
| 121 | + |
| 122 | + defer func() { |
| 123 | + <-discoverSem |
| 124 | + wg.Done() |
| 125 | + }() |
| 126 | + |
| 127 | + // If package was found through go.sum it's always a fixed version |
| 128 | + if prevVersion, ok := sumVersions[mod.Path]; ok { |
| 129 | + discoveredMu.Lock() |
| 130 | + discoveredVersions[mod.Path] = prevVersion |
| 131 | + discoveredMu.Unlock() |
| 132 | + |
| 133 | + return downloadMod(ctx, module.Version{ |
| 134 | + Path: mod.Path, |
| 135 | + Version: prevVersion, |
| 136 | + }) |
| 137 | + } |
| 138 | + |
| 139 | + discoveredMu.RLock() |
| 140 | + prevVersion, ok := discoveredVersions[mod.Path] |
| 141 | + discoveredMu.RUnlock() |
| 142 | + |
| 143 | + if ok { |
| 144 | + if semver.Compare(mod.Version, prevVersion) == 1 { |
| 145 | + discoveredMu.Lock() |
| 146 | + discoveredVersions[mod.Path] = mod.Version |
| 147 | + discoveredMu.Unlock() |
| 148 | + return downloadMod(ctx, mod) |
| 149 | + } else { |
| 150 | + return nil |
| 151 | + } |
| 152 | + } else { |
| 153 | + discoveredMu.Lock() |
| 154 | + discoveredVersions[mod.Path] = mod.Version |
| 155 | + discoveredMu.Unlock() |
| 156 | + return downloadMod(ctx, mod) |
| 157 | + } |
| 158 | + } |
| 159 | + |
| 160 | + go func() { |
| 161 | + if err := doWork(); err != nil { |
| 162 | + select { |
| 163 | + case errChan <- err: |
| 164 | + default: |
| 165 | + // Channel full, error already reported |
| 166 | + } |
| 167 | + } |
| 168 | + }() |
| 169 | + } |
| 170 | + |
| 171 | + downloadMod = func(ctx context.Context, goModule module.Version) error { |
| 172 | + // Check for cancellation |
| 173 | + select { |
| 174 | + case <-ctx.Done(): |
| 175 | + return ctx.Err() |
| 176 | + default: |
| 177 | + } |
| 178 | + |
| 179 | + key := fmt.Sprintf("%s@%s", goModule.Path, goModule.Version) |
| 180 | + |
| 181 | + // Check if already being handled |
| 182 | + downloadsMu.Lock() |
| 183 | + _, ok := downloads[key] |
| 184 | + |
| 185 | + if ok { |
| 186 | + downloadsMu.Unlock() |
| 187 | + return nil |
| 188 | + } |
| 189 | + |
| 190 | + // Set a nil value to indicate it is _being_ handled, but not handled yet |
| 191 | + _, exists := downloads[key] |
| 192 | + if exists { |
| 193 | + downloadsMu.Unlock() |
| 194 | + return nil |
| 195 | + } |
| 196 | + downloads[key] = nil |
| 197 | + downloadsMu.Unlock() |
| 198 | + |
| 199 | + download, err := downloadModule(directory, goModule.Path, goModule.Version) |
| 200 | + if err != nil { |
| 201 | + return fmt.Errorf("error downloading module %s@%s: %w", goModule.Path, goModule.Version, err) |
| 202 | + } |
| 203 | + |
| 204 | + contents, err := os.ReadFile(download.GoMod) |
| 205 | + if err != nil { |
| 206 | + return fmt.Errorf("error reading %s: %v", download.GoMod, err) |
| 207 | + } |
| 208 | + |
| 209 | + mod, err := modfile.Parse(download.GoMod, contents, nil) |
| 210 | + if err != nil { |
| 211 | + return fmt.Errorf("error parsing %s: %v", download.GoMod, err) |
| 212 | + } |
| 213 | + |
| 214 | + requireLoop: |
| 215 | + for _, require := range mod.Require { |
| 216 | + // Check for cancellation in loop |
| 217 | + select { |
| 218 | + case <-ctx.Done(): |
| 219 | + return ctx.Err() |
| 220 | + default: |
| 221 | + } |
| 222 | + |
| 223 | + for _, replacement := range mod.Replace { |
| 224 | + if require.Mod.Path == replacement.Old.Path { |
| 225 | + discoverMod(replacement.New) |
| 226 | + continue requireLoop |
| 227 | + } |
| 228 | + } |
| 229 | + |
| 230 | + discoverMod(require.Mod) |
| 231 | + } |
| 232 | + |
| 233 | + downloadsMu.Lock() |
| 234 | + downloads[key] = download |
| 235 | + downloadsMu.Unlock() |
| 236 | + |
| 237 | + return nil |
| 238 | + } |
| 239 | + |
| 240 | + // Start a goroutine to monitor for errors and cancel on first error |
| 241 | + done := make(chan struct{}) |
| 242 | + var firstErr error |
| 243 | + go func() { |
| 244 | + for err := range errChan { |
| 245 | + if firstErr == nil { |
| 246 | + firstErr = err |
| 247 | + cancel() // Cancel all ongoing work on first error |
| 248 | + } |
| 249 | + } |
| 250 | + close(done) |
| 251 | + }() |
| 252 | + |
| 253 | + for packagePath, version := range sumVersions { |
| 254 | + discoverMod(module.Version{ |
| 255 | + Path: packagePath, |
| 256 | + Version: version, |
| 257 | + }) |
| 258 | + } |
| 259 | + |
| 260 | + wg.Wait() |
| 261 | + close(errChan) |
| 262 | + <-done |
| 263 | + |
| 264 | + if firstErr != nil { |
| 265 | + return nil, firstErr |
| 266 | + } |
| 267 | + |
| 268 | + modDownloads := make([]*goModDownload, len(discoveredVersions)) |
| 269 | + i := 0 |
| 270 | + for packagePath, version := range discoveredVersions { |
| 271 | + modDownloads[i] = downloads[fmt.Sprintf("%s@%s", packagePath, version)] |
| 272 | + i++ |
| 273 | + } |
| 274 | + |
| 275 | + slices.SortFunc(modDownloads, func(a, b *goModDownload) int { |
| 276 | + return strings.Compare(a.Path, b.Path) |
| 277 | + }) |
| 278 | + |
| 279 | + return modDownloads, nil |
| 280 | +} |
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