| 1 | package main |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "os" |
| 6 | "path/filepath" |
| 7 | "reasonix/internal/identitylock" |
| 8 | ) |
| 9 | |
| 10 | func acquireHistoricalSource(ctx context.Context, id string, source historicalSource) (func(), error) { |
| 11 | if err := ctx.Err(); err != nil { |
| 12 | return nil, err |
| 13 | } |
| 14 | lockDir := filepath.Join(desktopConfigDir(), "desktop", "historical-import-locks") |
| 15 | if err := os.MkdirAll(lockDir, 0700); err != nil { |
| 16 | return nil, err |
| 17 | } |
| 18 | lockKey := desktopSourceKey(source.path, source.head) |
| 19 | release, err := identitylock.TryAcquire(filepath.Join(lockDir, lockKey+".lock")) |
| 20 | if err != nil { |
| 21 | return nil, err |
| 22 | } |
| 23 | if source.format != "canonical" { |
| 24 | return release, nil |
| 25 | } |
| 26 | ownership, err := acquireHistoricalCanonicalRead(source.path) |
| 27 | if err != nil { |
| 28 | release() |
| 29 | return nil, err |
| 30 | } |
| 31 | return func() { ownership(); release() }, nil |
| 32 | } |
| 33 | |
| 34 | func acquireHistoricalCanonicalRead(path string) (func(), error) { |
| 35 | ownership, err := identitylock.TryAcquireMode(filepath.Join(filepath.Dir(path), "."+filepath.Base(path)+".ownership.lock"), identitylock.ModeShared) |
| 36 | if err != nil { |
| 37 | return nil, err |
| 38 | } |
| 39 | writer, err := identitylock.TryAcquireMode(filepath.Join(path, "writer.lock"), identitylock.ModeShared) |
| 40 | if err != nil { |
| 41 | ownership() |
| 42 | return nil, err |
| 43 | } |
| 44 | return func() { writer(); ownership() }, nil |
| 45 | } |
| 46 |