diff options
Diffstat (limited to 'lib/btrfs/btrfssum/shortsum.go')
| -rw-r--r-- | lib/btrfs/btrfssum/shortsum.go | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/lib/btrfs/btrfssum/shortsum.go b/lib/btrfs/btrfssum/shortsum.go index e3441ae..754a79d 100644 --- a/lib/btrfs/btrfssum/shortsum.go +++ b/lib/btrfs/btrfssum/shortsum.go @@ -5,22 +5,14 @@ package btrfssum import ( - "context" "fmt" "io" "math" "strings" "git.lukeshu.com/go/lowmemjson" - - "git.lukeshu.com/btrfs-progs-ng/lib/btrfs/btrfsvol" - "git.lukeshu.com/btrfs-progs-ng/lib/diskio" ) -const BlockSize = 4 * 1024 - -// ShortSum ////////////////////////////////////////////////////////// - type ShortSum string var ( @@ -105,196 +97,3 @@ func (sum *ShortSum) DecodeJSON(r io.RuneScanner) error { *sum = ShortSum(out.String()) return nil } - -// SumRun //////////////////////////////////////////////////////////// - -type SumRun[Addr btrfsvol.IntAddr[Addr]] struct { - // How big a ShortSum is in this Run. - ChecksumSize int `json:",omitempty"` - // Base address where this run starts. - Addr Addr `json:",omitempty"` - // All of the ShortSums in this run, concatenated together. - Sums ShortSum -} - -func (run SumRun[Addr]) NumSums() int { - return len(run.Sums) / run.ChecksumSize -} - -func (run SumRun[Addr]) Size() btrfsvol.AddrDelta { - return btrfsvol.AddrDelta(run.NumSums()) * BlockSize -} - -// Get implements diskio.Sequence[int, ShortSum] -func (run SumRun[Addr]) Get(sumIdx int64) (ShortSum, error) { - if sumIdx < 0 || int(sumIdx) >= run.NumSums() { - return "", io.EOF - } - off := int(sumIdx) * run.ChecksumSize - return run.Sums[off : off+run.ChecksumSize], nil -} - -func (run SumRun[Addr]) SumForAddr(addr Addr) (ShortSum, bool) { - if addr < run.Addr || addr >= run.Addr.Add(run.Size()) { - return "", false - } - off := int((addr-run.Addr)/BlockSize) * run.ChecksumSize - return run.Sums[off : off+run.ChecksumSize], true -} - -func (run SumRun[Addr]) Walk(ctx context.Context, fn func(Addr, ShortSum) error) error { - for addr, off := run.Addr, 0; off < len(run.Sums); addr, off = addr+BlockSize, off+run.ChecksumSize { - if err := ctx.Err(); err != nil { - return err - } - if err := fn(addr, run.Sums[off:off+run.ChecksumSize]); err != nil { - return err - } - } - return nil -} - -// SumRunWithGaps //////////////////////////////////////////////////// - -type SumRunWithGaps[Addr btrfsvol.IntAddr[Addr]] struct { - // Store the start address and size, in order to facilitate - // leading and trailing gaps. - Addr Addr - Size btrfsvol.AddrDelta - - Runs []SumRun[Addr] -} - -var ( - _ lowmemjson.Encodable = SumRunWithGaps[btrfsvol.LogicalAddr]{} - _ lowmemjson.Decodable = (*SumRunWithGaps[btrfsvol.LogicalAddr])(nil) -) - -func (sg SumRunWithGaps[Addr]) NumSums() int { - return int(sg.Size / BlockSize) -} - -func (sg SumRunWithGaps[Addr]) PctFull() float64 { - total := sg.NumSums() - var full int - for _, run := range sg.Runs { - full += run.NumSums() - } - return float64(full) / float64(total) -} - -func (sg SumRunWithGaps[Addr]) RunForAddr(addr Addr) (SumRun[Addr], Addr, bool) { - for _, run := range sg.Runs { - if run.Addr > addr { - return SumRun[Addr]{}, run.Addr, false - } - if run.Addr.Add(run.Size()) <= addr { - continue - } - return run, 0, true - } - return SumRun[Addr]{}, math.MaxInt64, false -} - -func (sg SumRunWithGaps[Addr]) SumForAddr(addr Addr) (ShortSum, error) { - if addr < sg.Addr || addr >= sg.Addr.Add(sg.Size) { - return "", io.EOF - } - for _, run := range sg.Runs { - if run.Addr > addr { - return "", diskio.ErrWildcard - } - if run.Addr.Add(run.Size()) <= addr { - continue - } - off := int((addr-run.Addr)/BlockSize) * run.ChecksumSize - return run.Sums[off : off+run.ChecksumSize], nil - } - return "", diskio.ErrWildcard -} - -func (sg SumRunWithGaps[Addr]) Walk(ctx context.Context, fn func(Addr, ShortSum) error) error { - for _, run := range sg.Runs { - if err := run.Walk(ctx, fn); err != nil { - return err - } - } - return nil -} - -// Get implements diskio.Sequence[int, ShortSum] -func (sg SumRunWithGaps[Addr]) Get(sumIdx int64) (ShortSum, error) { - addr := sg.Addr.Add(btrfsvol.AddrDelta(sumIdx) * BlockSize) - return sg.SumForAddr(addr) -} - -func (sg SumRunWithGaps[Addr]) EncodeJSON(w io.Writer) error { - if _, err := fmt.Fprintf(w, `{"Addr":%d,"Size":%d,"Runs":[`, sg.Addr, sg.Size); err != nil { - return err - } - cur := sg.Addr - for i, run := range sg.Runs { - if i > 0 { - if _, err := w.Write([]byte{','}); err != nil { - return err - } - } - switch { - case run.Addr < cur: - return fmt.Errorf("invalid %T: addr went backwards: %v < %v", sg, run.Addr, cur) - case run.Addr > cur: - if _, err := fmt.Fprintf(w, `{"Gap":%d},`, run.Addr.Sub(cur)); err != nil { - return err - } - fallthrough - default: - if err := lowmemjson.NewEncoder(w).Encode(run); err != nil { - return err - } - cur = run.Addr.Add(run.Size()) - } - } - end := sg.Addr.Add(sg.Size) - switch { - case end < cur: - return fmt.Errorf("invalid %T: addr went backwards: %v < %v", sg, end, cur) - case end > cur: - if _, err := fmt.Fprintf(w, `,{"Gap":%d}`, end.Sub(cur)); err != nil { - return err - } - } - if _, err := w.Write([]byte("]}")); err != nil { - return err - } - return nil -} - -func (sg *SumRunWithGaps[Addr]) DecodeJSON(r io.RuneScanner) error { - *sg = SumRunWithGaps[Addr]{} - var name string - return lowmemjson.DecodeObject(r, - func(r io.RuneScanner) error { - return lowmemjson.NewDecoder(r).Decode(&name) - }, - func(r io.RuneScanner) error { - switch name { - case "Addr": - return lowmemjson.NewDecoder(r).Decode(&sg.Addr) - case "Size": - return lowmemjson.NewDecoder(r).Decode(&sg.Size) - case "Runs": - return lowmemjson.DecodeArray(r, func(r io.RuneScanner) error { - var run SumRun[Addr] - if err := lowmemjson.NewDecoder(r).Decode(&run); err != nil { - return err - } - if run.ChecksumSize > 0 { - sg.Runs = append(sg.Runs, run) - } - return nil - }) - default: - return fmt.Errorf("unknown key %q", name) - } - }) -} |