| 1 | package dbdoor |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "fmt" |
| 6 | "sync" |
| 7 | ) |
| 8 | |
| 9 | const HandleHeader = "X-Carlos-DB-Handle" |
| 10 | |
| 11 | type dbHandleState struct { |
| 12 | listMu sync.Mutex |
| 13 | mu sync.Mutex |
| 14 | plan []LTXFile |
| 15 | pinned bool |
| 16 | files map[string]LTXFile |
| 17 | } |
| 18 | |
| 19 | func (c *Client) rememberFiles(level int, list ListResponse) ([]LTXFile, error) { |
| 20 | c.handles.mu.Lock() |
| 21 | defer c.handles.mu.Unlock() |
| 22 | if list.Protocol != 0 && list.Protocol != 2 { |
| 23 | return nil, errors.New("dbdoor: unsupported listing protocol") |
| 24 | } |
| 25 | if c.handles.pinned && list.Protocol != 2 { |
| 26 | return nil, errors.New("dbdoor: pinned listing protocol disappeared") |
| 27 | } |
| 28 | if list.Plan && list.Protocol != 2 { |
| 29 | return nil, errors.New("dbdoor: invalid pinned listing") |
| 30 | } |
| 31 | if list.Protocol == 0 { |
| 32 | return list.Files, nil |
| 33 | } |
| 34 | files := make(map[string]LTXFile, len(c.handles.files)+len(list.Files)) |
| 35 | for k, v := range c.handles.files { |
| 36 | files[k] = v |
| 37 | } |
| 38 | seen := map[string]bool{} |
| 39 | out := make([]LTXFile, 0, len(list.Files)) |
| 40 | for _, f := range list.Files { |
| 41 | k := GetTail(f.Level, f.MinTXID, f.MaxTXID) |
| 42 | if (!list.Plan && f.Level != level) || f.Level < 0 || f.Level > MaxLevel || f.MinTXID == 0 || f.MaxTXID < f.MinTXID || f.Handle == "" || f.Size < 0 || seen[k] { |
| 43 | return nil, errors.New("dbdoor: invalid pinned listing") |
| 44 | } |
| 45 | seen[k] = true |
| 46 | if old, ok := files[k]; ok { |
| 47 | if old.Size != f.Size { |
| 48 | return nil, errors.New("dbdoor: pinned file size changed; retry the database pull") |
| 49 | } |
| 50 | f = old // Preserve first handle and its metadata through retries/resumes. |
| 51 | } |
| 52 | files[k] = f |
| 53 | out = append(out, f) |
| 54 | } |
| 55 | if list.Plan { |
| 56 | if c.handles.plan == nil { |
| 57 | c.handles.plan = out |
| 58 | } |
| 59 | out = filesAtLevel(c.handles.plan, level) |
| 60 | } |
| 61 | c.handles.files = files |
| 62 | c.handles.pinned = true |
| 63 | return out, nil |
| 64 | } |
| 65 | |
| 66 | func (c *Client) fileHandle(level int, lo, hi uint64) (string, error) { |
| 67 | c.handles.mu.Lock() |
| 68 | defer c.handles.mu.Unlock() |
| 69 | if !c.handles.pinned { |
| 70 | return "", nil |
| 71 | } |
| 72 | if f, ok := c.handles.files[GetTail(level, lo, hi)]; ok { |
| 73 | return f.Handle, nil |
| 74 | } |
| 75 | return "", fmt.Errorf("dbdoor: coordinate has no pinned handle: %d %s", level, Span(lo, hi)) |
| 76 | } |
| 77 | |
| 78 | func filesAtLevel(files []LTXFile, level int) []LTXFile { |
| 79 | out := make([]LTXFile, 0) |
| 80 | for _, f := range files { |
| 81 | if f.Level == level { |
| 82 | out = append(out, f) |
| 83 | } |
| 84 | } |
| 85 | return out |
| 86 | } |
| 87 | |
| 88 | func (c *Client) planFiles(level int) ([]LTXFile, bool) { |
| 89 | c.handles.mu.Lock() |
| 90 | defer c.handles.mu.Unlock() |
| 91 | return filesAtLevel(c.handles.plan, level), c.handles.plan != nil |
| 92 | } |
| 93 | |
amadan