chore: fixes to lsm
This commit is contained in:
		
							parent
							
								
									36460a131e
								
							
						
					
					
						commit
						cf99e18a39
					
				@ -6,19 +6,25 @@ import (
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	"io"
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	"iter"
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	"os"
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	"path/filepath"
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	"github.com/docopt/docopt-go"
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	"go.sour.is/pkg/lsm2"
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)
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var usage = `
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Usage: lsm2 create <archive> <files>...`
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Usage: 
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  lsm2 create <archive> <files>...
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  lsm2 append <archive> <files>...
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  lsm2 read <archive> <index>`
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type args struct {
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	Create  bool
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	Append  bool
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	Read    bool
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	Archive string   `docopt:"<archive>"`
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	Files   []string `docopt:"<files>"`
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	Index   int64  `docopt:"<index>"`
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}
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func main() {
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@ -45,38 +51,67 @@ func (c console) Write(b []byte) (int, error) {
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	return c.Stdout.Write(b)
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}
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func run(console console, args args) error {
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func run(console console,a args) error {
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	fmt.Fprintln(console, "lsm")
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	switch {
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	case args.Create:
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		fmt.Fprintf(console, "creating %s from %v\n", filepath.Base(args.Archive), args.Files)
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		out, err := os.OpenFile(args.Archive, os.O_CREATE|os.O_WRONLY, 0644)
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	case a.Create:
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		f, err := os.OpenFile(a.Archive, os.O_CREATE|os.O_WRONLY, 0644)
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		if err != nil {
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			return err
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		}
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		defer out.Close()
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		defer f.Close()
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		filesWritten := 0
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		defer func() { fmt.Fprintln(console, "wrote", filesWritten, "files") }()
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		return lsm2.WriteLogFile(f, fileReaders(a.Files))
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	case a.Append:
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		f, err := os.OpenFile(a.Archive, os.O_RDWR, 0644)
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		if err != nil {
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			return err
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		}
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		defer f.Close()
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		return lsm2.WriteIter(out, iter.Seq[io.Reader](func(yield func(io.Reader) bool) {
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			for _, name := range args.Files {
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				f, err := os.Open(name)
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				if err != nil {
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					continue
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				}
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				filesWritten++
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				if !yield(f) {
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					f.Close()
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					return
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				}
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				f.Close()
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			}
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		}))
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		return lsm2.AppendLogFile(f, fileReaders(a.Files))
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	case a.Read:
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		fmt.Fprintln(console, "reading", a.Archive)
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		f, err := os.Open(a.Archive)
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		if err != nil {
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			return err
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		}
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		defer f.Close()	
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		lg, err := lsm2.ReadLogFile(f)
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		if err != nil {
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			return err
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		}
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		for i, rd := range lg.Iter() {
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			fmt.Fprintf(console, "=========================\n%d:\n", i)
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			io.Copy(console, rd)
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			fmt.Fprintln(console, "=========================")
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		}
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		if lg.Err != nil {
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			return lg.Err
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		}
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		return nil
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	default:
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		return errors.New("unknown command")
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	}
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}
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func fileReaders(names []string) iter.Seq[io.Reader] {
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	return iter.Seq[io.Reader](func(yield func(io.Reader) bool) {
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		for _, name := range names {
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			f, err := os.Open(name)
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			if err != nil {
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				continue
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			}
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			if !yield(f) {
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				f.Close()
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				return
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			}
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			f.Close()
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		}
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	})
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}
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func must[T any](v T, err error) T {
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	if err != nil {
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		panic(err)
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										288
									
								
								lsm2/sst.go
									
									
									
									
									
								
							
							
						
						
									
										288
									
								
								lsm2/sst.go
									
									
									
									
									
								
							@ -1,7 +1,5 @@
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package lsm2
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// [Sour.is|size] [size|hash][data][hash|flag|size]... [prev|count|flag|size]
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import (
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	"encoding/binary"
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	"errors"
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@ -11,6 +9,28 @@ import (
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	"iter"
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)
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// [Sour.is|size] [size|hash][data][hash|flag|size]... [prev|count|flag|size]
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// Commit1: [magic>|<end]{10} ... [<count][<size][<flag]{3..30}
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//                 +---------|--------------------------------> end = seek to end of file
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//                       <---|-------------+                    size = seek to magic header
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//                       <---|-------------+10                  size + 10 = seek to start of file
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//          <-----------------------------T+10----------------> 10 + size + trailer = full file size
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// Commit2: [magic>|<end]{10} ... [<count][<size][<flag]{3..30} ... [<prev][<count][<size][<flag]{4..40}
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//                           <---|---------+
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//                           <-------------+T----------------->
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//                  +--------|------------------------------------------------------------------------->
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//                           <-------------------------------------|----------------+
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//     prev = seek to last commit                              <---|-+
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//     prev + trailer = size of commit                         <----T+--------------------------------->
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// Block:  [hash>|<end]{10} ... [<size][<flag]{2..20}
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//               +---------|------------------------>  end = seek to end of block
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//                         <---|-+                     size = seek to end of header
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//         <-------------------|-+10                   size + 10 = seek to start of block
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//         <---------------------T+10--------------->  size + 10 + trailer = full block size
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const (
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	TypeUnknown uint64 = iota
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	TypeSegment
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@ -39,40 +59,28 @@ type header struct {
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	extra []byte
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}
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// UnmarshalBinary implements encoding.BinaryUnmarshaler.
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// It decodes the input binary data into the header struct.
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// The function expects the input data to be of a specific size (headerSize),
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// otherwise it returns an error indicating bad data.
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// It reads the 'end' field from the binary data, updates the 'extra' field,
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// and reverses the byte order of 'extra' in place.
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func (h *header) UnmarshalBinary(data []byte) error {
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	if len(data) != 10 {
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	if len(data) != headerSize {
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		return fmt.Errorf("%w: bad data", ErrDecode)
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	}
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	h.extra = append(h.extra, data...)
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	var n int
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	h.end, n = binary.Uvarint(h.extra)
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	h.extra = make([]byte, headerSize)
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	copy(h.extra, data)
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	var bytesRead int
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	h.end, bytesRead = binary.Uvarint(h.extra)
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	reverse(h.extra)
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	h.extra = h.extra[:len(h.extra)-n]
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	h.extra = h.extra[:headerSize-bytesRead]
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	return nil
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}
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// Commit1: [magic>|<end]{10} ... [<count][<size][<flag]{3..30}
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//                 +---------|--------------------------------> end = seek to end of file
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//                       <---|-------------+                    size = seek to magic header
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//                       <---|-------------+10                  size + 10 = seek to start of file
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//          <-----------------------------T+10----------------> 10 + size + trailer = full file size
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// Commit2: [magic>|<end]{10} ... [<count][<size][<flag]{3..30} ... [<prev][<count][<size][<flag]{4..40}
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//                           <---|---------+
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//                           <-------------+T----------------->
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//                  +--------|------------------------------------------------------------------------->
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//                           <-------------------------------------|----------------+
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//     prev = seek to last commit                              <---|-+
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//     prev + trailer = size of commit                         <----T+--------------------------------->
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// Block:  [hash>|<end]{10} ... [<size][<flag]{2..20}
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//               +---------|------------------------>  end = seek to end of block
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//                         <---|-+                     size = seek to end of header
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//         <-------------------|-+10                   size + 10 = seek to start of block
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//         <---------------------T+10--------------->  size + 10 + trailer = full block size
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type Commit struct {
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	flag  uint64 // flag values
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	size  uint64 // size of the trailer
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@ -85,18 +93,18 @@ type Commit struct {
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// Append marshals the trailer into binary form and appends it to data.
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// It returns the new slice.
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func (h *Commit) AppendTrailer(data []byte) []byte {
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	h.flag |= TypePrevCommit
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	if h.prev == 0 {
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		h.flag &= TypeCommit
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	}
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	h.flag |= TypeCommit
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	// if h.prev > 0 {
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	// 	h.flag |= TypePrevCommit
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	// }
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	size := len(data)
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	data = binary.AppendUvarint(data, h.size)
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	data = binary.AppendUvarint(data, h.flag)
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	data = binary.AppendUvarint(data, h.count)
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	if h.prev != 0 {
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		data = binary.AppendUvarint(data, h.prev)
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	}
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	// if h.prev > 0 {
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	// 	data = binary.AppendUvarint(data, h.prev)
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	// }
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	reverse(data[size:])
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	return data
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@ -123,7 +131,7 @@ func (h *Commit) UnmarshalBinary(data []byte) error {
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	data = data[n:]
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	h.tsize += n
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	h.prev = h.size
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	// h.prev = h.size
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	if h.flag&TypePrevCommit == TypePrevCommit {
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		h.prev, n = binary.Uvarint(data)
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		h.tsize += n
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@ -207,9 +215,6 @@ func (h *logFile) AppendMagic(data []byte) []byte {
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	return data
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}
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func (h *logFile) UnmarshalBinary(data []byte) error {
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	return h.header.UnmarshalBinary(data)
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}
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// WriteLogFile writes a log file to w, given a list of segments.
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// The caller is responsible for calling WriteAt on the correct offset.
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@ -223,7 +228,7 @@ func (h *logFile) UnmarshalBinary(data []byte) error {
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//   - A footer with the length and hash of the segment
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//   - The contents of the segment
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//   - A header with the magic, version, flag (Clean), and end offset
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func WriteLogFile(w io.WriterAt, segments ...io.Reader) error {
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func WriteLogFile(w io.WriterAt, segments iter.Seq[io.Reader]) error {
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	_, err := w.WriteAt(Magic[:], 0)
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	if err != nil {
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		return err
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@ -233,13 +238,7 @@ func WriteLogFile(w io.WriterAt, segments ...io.Reader) error {
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		WriterAt: w,
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	}
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	return lf.writeIter(w, iter.Seq[io.Reader](func(yield func(io.Reader) bool) {
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		for _, s := range segments {
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			if !yield(s) {
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				return
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			}
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		}
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	}))
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	return lf.writeIter(segments)
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}
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type rw interface {
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@ -247,7 +246,7 @@ type rw interface {
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	io.WriterAt
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}
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func AppendLogFile(rw rw, segments ...io.Reader) error {
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func AppendLogFile(rw rw, segments iter.Seq[io.Reader]) error {
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	logFile, err := ReadLogFile(rw)
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	if err != nil {
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		return err
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@ -256,35 +255,19 @@ func AppendLogFile(rw rw, segments ...io.Reader) error {
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		WriterAt: rw,
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		logFile:  logFile.logFile,
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	}
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	return lf.writeIter(rw, iter.Seq[io.Reader](func(yield func(io.Reader) bool) {
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		for _, s := range segments {
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			if !yield(s) {
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				return
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			}
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		}
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	}))
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	return lf.writeIter( segments)
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}
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func WriteIter(w io.WriterAt, segments iter.Seq[io.Reader]) error {
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	_, err := w.WriteAt(Magic[:], 0)
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	if err != nil {
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		return err
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	}
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	lf := &LogWriter{
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		WriterAt: w,
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	}
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	return lf.writeIter(w, segments)
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}
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func (lf *LogWriter) writeIter(w io.WriterAt, segments iter.Seq[io.Reader]) error {
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func (lf *LogWriter) writeIter(segments iter.Seq[io.Reader]) error {	
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	lf.size = 0
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	for s := range segments {
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		err := lf.writeSegment(s)
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		n, err := lf.writeBlock(s)
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		if err != nil {
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			return err
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		}
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		lf.end += n
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		lf.size += n
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		lf.count++
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	}
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@ -297,7 +280,7 @@ func (lf *LogWriter) writeIter(w io.WriterAt, segments iter.Seq[io.Reader]) erro
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	}
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	lf.end += uint64(n)
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	_, err = w.WriteAt(lf.AppendMagic(make([]byte, 0, 10)), 0)
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	_, err = lf.WriteAt(lf.AppendMagic(make([]byte, 0, 10)), 0)
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	return err
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}
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@ -307,24 +290,26 @@ type LogWriter struct {
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	io.WriterAt
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}
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// writeSegment writes a segment to the log file at the current end of file position.
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// writeBlock writes a segment to the log file at the current end of file position.
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// The segment is written in chunks of 1024 bytes, and the hash of the segment
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func (lf *LogWriter) writeSegment(segment io.Reader) error {
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func (lf *LogWriter) writeBlock(segment io.Reader) (uint64, error) {
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	h := hash()
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	head := Block{}
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	block := Block{}
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	start := int64(lf.end) + 10
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	end := int64(lf.end) + 10
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	end := start
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	bytesWritten := 0
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	// Write the header to the log file.
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	// The footer is written at the current end of file position.
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	n, err := lf.WriteAt(make([]byte, headerSize), start)
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	bytesWritten += n
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	end += int64(n)
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	if err != nil {
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		// If there is an error, return it.
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		return err
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		return uint64(bytesWritten), err
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	}
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	end += int64(n)
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	lf.size += uint64(n)
 | 
			
		||||
	lf.end += uint64(n)
 | 
			
		||||
 | 
			
		||||
	// Write the segment to the log file.
 | 
			
		||||
	// The segment is written in chunks of 1024 bytes.
 | 
			
		||||
@ -338,7 +323,7 @@ func (lf *LogWriter) writeSegment(segment io.Reader) error {
 | 
			
		||||
				break
 | 
			
		||||
			}
 | 
			
		||||
			// If there is an error, return it.
 | 
			
		||||
			return err
 | 
			
		||||
			return uint64(bytesWritten), err
 | 
			
		||||
		}
 | 
			
		||||
 | 
			
		||||
		// Compute the hash of the chunk.
 | 
			
		||||
@ -346,42 +331,41 @@ func (lf *LogWriter) writeSegment(segment io.Reader) error {
 | 
			
		||||
 | 
			
		||||
		// Write the chunk to the log file.
 | 
			
		||||
		// The chunk is written at the current end of file position.
 | 
			
		||||
		_, err = lf.WriteAt(buf[:n], end)
 | 
			
		||||
		n, err = lf.WriteAt(buf[:n], end)
 | 
			
		||||
		bytesWritten += n
 | 
			
		||||
		if err != nil {
 | 
			
		||||
			// If there is an error, return it.
 | 
			
		||||
			return err
 | 
			
		||||
			return uint64(bytesWritten), err
 | 
			
		||||
		}
 | 
			
		||||
 | 
			
		||||
		// Update the length of the segment.
 | 
			
		||||
		end += int64(n)
 | 
			
		||||
		head.size += uint64(n)
 | 
			
		||||
		block.size += uint64(n)
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	head.extra = h.Sum(nil)
 | 
			
		||||
	head.end += head.size
 | 
			
		||||
	block.extra = h.Sum(nil)
 | 
			
		||||
	block.end += block.size
 | 
			
		||||
 | 
			
		||||
	// Write the footer to the log file.
 | 
			
		||||
	// The footer is written at the current end of file position.
 | 
			
		||||
	n, err = lf.WriteAt(head.AppendTrailer(make([]byte, 0, maxBlockSize)), end)
 | 
			
		||||
	n, err = lf.WriteAt(block.AppendTrailer(make([]byte, 0, maxBlockSize)), end)
 | 
			
		||||
	bytesWritten += n
 | 
			
		||||
	if err != nil {
 | 
			
		||||
		// If there is an error, return it.
 | 
			
		||||
		return err
 | 
			
		||||
		return uint64(bytesWritten), err
 | 
			
		||||
	}
 | 
			
		||||
	end += int64(n)
 | 
			
		||||
	head.end += uint64(n)
 | 
			
		||||
	block.end += uint64(n)
 | 
			
		||||
 | 
			
		||||
	// Update header to the log file.
 | 
			
		||||
	// The footer is written at the current end of file position.
 | 
			
		||||
	_, err = lf.WriteAt(head.AppendHeader(make([]byte, 0, headerSize)), start)
 | 
			
		||||
	_, err = lf.WriteAt(block.AppendHeader(make([]byte, 0, headerSize)), start)
 | 
			
		||||
	if err != nil {
 | 
			
		||||
		// If there is an error, return it.
 | 
			
		||||
		return err
 | 
			
		||||
		return uint64(bytesWritten), err
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	// Update the end of file position.
 | 
			
		||||
	lf.size += head.end
 | 
			
		||||
	lf.end += head.end
 | 
			
		||||
	return nil
 | 
			
		||||
	return uint64(bytesWritten), nil
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// reverse reverses a slice in-place.
 | 
			
		||||
@ -446,16 +430,18 @@ func (lf *LogReader) Iter() iter.Seq2[uint64, io.Reader] {
 | 
			
		||||
 | 
			
		||||
	return func(yield func(uint64, io.Reader) bool) {
 | 
			
		||||
		start := int64(10)
 | 
			
		||||
		var adj uint64
 | 
			
		||||
		for _, commit := range commits {
 | 
			
		||||
			size := int64(commit.prev)
 | 
			
		||||
			size := int64(commit.size)
 | 
			
		||||
			it := iterBlocks(io.NewSectionReader(lf, start, size), size)
 | 
			
		||||
			for i, block := range it {
 | 
			
		||||
				if !yield(i, block) {
 | 
			
		||||
				if !yield(adj+i, block) {
 | 
			
		||||
					return
 | 
			
		||||
				}
 | 
			
		||||
			}
 | 
			
		||||
 | 
			
		||||
			start += size + int64(commit.tsize)
 | 
			
		||||
			adj = commit.count
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
@ -464,9 +450,10 @@ func iterBlocks(r io.ReaderAt, end int64) iter.Seq2[uint64, io.Reader] {
 | 
			
		||||
	var start int64
 | 
			
		||||
	var i uint64
 | 
			
		||||
	return func(yield func(uint64, io.Reader) bool) {
 | 
			
		||||
		buf := make([]byte, maxBlockSize)
 | 
			
		||||
		for start < end {
 | 
			
		||||
			block := &Block{}
 | 
			
		||||
			buf := make([]byte, 10)
 | 
			
		||||
			buf = buf[:10]
 | 
			
		||||
			n, err := rsr(r, int64(start), 10).ReadAt(buf, 0)
 | 
			
		||||
			if n == 0 && err != nil {
 | 
			
		||||
				return
 | 
			
		||||
@ -476,8 +463,7 @@ func iterBlocks(r io.ReaderAt, end int64) iter.Seq2[uint64, io.Reader] {
 | 
			
		||||
			if err := block.header.UnmarshalBinary(buf); err != nil {
 | 
			
		||||
				return
 | 
			
		||||
			}
 | 
			
		||||
 | 
			
		||||
			buf = make([]byte, maxBlockSize)
 | 
			
		||||
			buf = buf[:maxBlockSize]
 | 
			
		||||
			n, err = rsr(r, int64(start), int64(block.end)).ReadAt(buf, 0)
 | 
			
		||||
			if n == 0 && err != nil {
 | 
			
		||||
				return
 | 
			
		||||
@ -498,15 +484,12 @@ func iterBlocks(r io.ReaderAt, end int64) iter.Seq2[uint64, io.Reader] {
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
 | 
			
		||||
func (lf *LogReader) iterCommits() iter.Seq[Commit] {
 | 
			
		||||
	eof := lf.end + 10
 | 
			
		||||
 | 
			
		||||
	if eof <= 10 {
 | 
			
		||||
	if lf.end == 0 {
 | 
			
		||||
		return func(yield func(Commit) bool) {}
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	offset := eof - 10 - lf.prev - uint64(lf.tsize)
 | 
			
		||||
	offset := lf.end - lf.size - uint64(lf.tsize)
 | 
			
		||||
	return func(yield func(Commit) bool) {
 | 
			
		||||
		if !yield(lf.Commit) {
 | 
			
		||||
			return
 | 
			
		||||
@ -529,50 +512,40 @@ func (lf *LogReader) iterCommits() iter.Seq[Commit] {
 | 
			
		||||
			if !yield(commit) {
 | 
			
		||||
				return
 | 
			
		||||
			}
 | 
			
		||||
			offset -= commit.prev + uint64(commit.tsize)
 | 
			
		||||
			offset -= commit.size + uint64(commit.tsize)
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// func (lf *LogReader) Rev() iter.Seq2[uint64, io.Reader] {
 | 
			
		||||
// 	end := lf.end + 10
 | 
			
		||||
// 	i := lf.count
 | 
			
		||||
// 	return func(yield func(uint64, io.Reader) bool) {
 | 
			
		||||
func (lf *LogReader) Rev() iter.Seq2[uint64, io.Reader] {
 | 
			
		||||
	end := lf.end + 10
 | 
			
		||||
	i := lf.count
 | 
			
		||||
	return func(yield func(uint64, io.Reader) bool) {
 | 
			
		||||
 | 
			
		||||
// 		for commit := range lf.iterCommits() {
 | 
			
		||||
// 			end -= uint64(commit.tsize)
 | 
			
		||||
// 			start := end - commit.prev - uint64(commit.tsize)
 | 
			
		||||
// 			for start > end{
 | 
			
		||||
// 				block := &Block{}
 | 
			
		||||
// 				buf := make([]byte, min(maxBlockSize, commit.size))
 | 
			
		||||
// 				n, err := lf.ReaderAt.ReadAt(buf, max(0, int64(end)-int64(len(buf))))
 | 
			
		||||
// 				if n == 0 && err != nil {
 | 
			
		||||
// 					lf.Err = err
 | 
			
		||||
// 					return
 | 
			
		||||
// 				}
 | 
			
		||||
// 				buf = buf[:n]
 | 
			
		||||
// 				err = block.UnmarshalBinary(buf)
 | 
			
		||||
// 				if err != nil {
 | 
			
		||||
// 					lf.Err = err
 | 
			
		||||
// 					return
 | 
			
		||||
// 				}
 | 
			
		||||
// 				if !yield(i, io.NewSectionReader(lf, int64(end-block.size)-int64(block.tsize), int64(block.size))) {
 | 
			
		||||
// 					return
 | 
			
		||||
// 				}
 | 
			
		||||
// 				end -= block.size + 10 + uint64(block.tsize)
 | 
			
		||||
// 				i--
 | 
			
		||||
// 			}
 | 
			
		||||
 | 
			
		||||
// 		}
 | 
			
		||||
// 	}
 | 
			
		||||
// }
 | 
			
		||||
 | 
			
		||||
func iterOne[I, T any](it iter.Seq2[I, T]) iter.Seq[T] {
 | 
			
		||||
	return func(yield func(T) bool) {
 | 
			
		||||
		for _, v := range it {
 | 
			
		||||
			if !yield(v) {
 | 
			
		||||
				return
 | 
			
		||||
		for commit := range lf.iterCommits() {
 | 
			
		||||
			end -= uint64(commit.tsize)
 | 
			
		||||
			start := end - commit.size
 | 
			
		||||
			for start < end {
 | 
			
		||||
				block := &Block{}
 | 
			
		||||
				buf := make([]byte, maxBlockSize)
 | 
			
		||||
				n, err := rsr(lf, int64(start), int64(commit.size)).ReadAt(buf, 0)
 | 
			
		||||
				if n == 0 && err != nil {
 | 
			
		||||
					lf.Err = err
 | 
			
		||||
					return
 | 
			
		||||
				}
 | 
			
		||||
				buf = buf[:n]
 | 
			
		||||
				err = block.UnmarshalBinary(buf)
 | 
			
		||||
				if err != nil {
 | 
			
		||||
					lf.Err = err
 | 
			
		||||
					return
 | 
			
		||||
				}
 | 
			
		||||
				if !yield(i-1, io.NewSectionReader(lf, int64(end-block.size)-int64(block.tsize), int64(block.size))) {
 | 
			
		||||
					return
 | 
			
		||||
				}
 | 
			
		||||
				end -= block.size + 10 + uint64(block.tsize)
 | 
			
		||||
				i--
 | 
			
		||||
			}
 | 
			
		||||
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
@ -606,36 +579,3 @@ func (r *revSegmentReader) ReadAt(data []byte, offset int64) (int, error) {
 | 
			
		||||
	reverse(data[:i])
 | 
			
		||||
	return i, err
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// rdr    : 0 1 2|3 4 5 6|7 8 9 10
 | 
			
		||||
// rsr 6,4:       3 2 1 0
 | 
			
		||||
//                      6
 | 
			
		||||
//                ------- -4
 | 
			
		||||
//                0 1 2 3
 | 
			
		||||
// offset - size
 | 
			
		||||
// rdr    : 0 1 2|3 4 5 6|7 8 9 10
 | 
			
		||||
//                0 1 2 3
 | 
			
		||||
// offset=0      |-------|        d[:4], o=3  3-0=3
 | 
			
		||||
// offset=1     _|-----  |        d[:3], o=3  3-1=2
 | 
			
		||||
// offset=2   ___|---    |        d[:2], o=3  3-2=1
 | 
			
		||||
// offset=3 _____|-      |  	  d[:1], o=3  3-3=0
 | 
			
		||||
// offset=4+_____|       |  	  d[:0], o=3  3-4=0
 | 
			
		||||
 | 
			
		||||
// rdr    : 0 1 2|3 4 5 6|7 8 9 10
 | 
			
		||||
// offset=0      |-------|        d[:4], o=0 -> 3
 | 
			
		||||
// offset=0      |  -----|        d[:3], o=1 -> 4
 | 
			
		||||
// offset=0      |    ---|        d[:2], o=2 -> 5
 | 
			
		||||
// offset=0      |      -|        d[:1], o=3 -> 6
 | 
			
		||||
// offset=0      |       |        d[:0], o=4+-> 7
 | 
			
		||||
 | 
			
		||||
// rdr    : 0 1 2|3 4 5 6|7 8 9 10
 | 
			
		||||
// offset=4   ___|       |        d[:0], o=0
 | 
			
		||||
// offset=3     _|-      |        d[:1], o=0
 | 
			
		||||
// offset=2      |---    |        d[:2], o=0
 | 
			
		||||
// offset=1      |  ---  |        d[:2], o=1
 | 
			
		||||
// offset=0      |    ---|        d[:2], o=2
 | 
			
		||||
// offset=-1     |      -|_       d[:2], o=3
 | 
			
		||||
// offset=-2     |       |___     d[:2], o=4+
 | 
			
		||||
 | 
			
		||||
// o = max(0, offset - len)
 | 
			
		||||
// d =
 | 
			
		||||
 | 
			
		||||
							
								
								
									
										170
									
								
								lsm2/sst_test.go
									
									
									
									
									
								
							
							
						
						
									
										170
									
								
								lsm2/sst_test.go
									
									
									
									
									
								
							@ -4,14 +4,38 @@ import (
 | 
			
		||||
	"bytes"
 | 
			
		||||
	"encoding/base64"
 | 
			
		||||
	"errors"
 | 
			
		||||
	"fmt"
 | 
			
		||||
	"io"
 | 
			
		||||
	"iter"
 | 
			
		||||
	"slices"
 | 
			
		||||
	"testing"
 | 
			
		||||
 | 
			
		||||
	"github.com/docopt/docopt-go"
 | 
			
		||||
	"github.com/matryer/is"
 | 
			
		||||
)
 | 
			
		||||
 | 
			
		||||
// TestAppend tests AppendLogFile and WriteLogFile against a set of test cases.
 | 
			
		||||
//
 | 
			
		||||
// Each test case contains a slice of slices of io.Readers, which are passed to
 | 
			
		||||
// AppendLogFile and WriteLogFile in order. The test case also contains the
 | 
			
		||||
// expected encoded output as a base64 string, as well as the expected output
 | 
			
		||||
// when the file is read back using ReadLogFile.
 | 
			
		||||
//
 | 
			
		||||
// The test case also contains the expected output when the file is read back in
 | 
			
		||||
// reverse order using ReadLogFile.Rev().
 | 
			
		||||
//
 | 
			
		||||
// The test cases are as follows:
 | 
			
		||||
//
 | 
			
		||||
// - nil reader: Passes a nil slice of io.Readers to WriteLogFile.
 | 
			
		||||
// - err reader: Passes a slice of io.Readers to WriteLogFile which returns an
 | 
			
		||||
//   error when read.
 | 
			
		||||
// - single reader: Passes a single io.Reader to WriteLogFile.
 | 
			
		||||
// - multiple readers: Passes a slice of multiple io.Readers to WriteLogFile.
 | 
			
		||||
// - multiple commit: Passes multiple slices of io.Readers to AppendLogFile.
 | 
			
		||||
// - multiple commit 3x: Passes multiple slices of io.Readers to AppendLogFile
 | 
			
		||||
//   three times.
 | 
			
		||||
//
 | 
			
		||||
// The test uses the is package from github.com/matryer/is to check that the
 | 
			
		||||
// output matches the expected output.
 | 
			
		||||
func TestAppend(t *testing.T) {
 | 
			
		||||
	type test struct {
 | 
			
		||||
		name string
 | 
			
		||||
@ -22,40 +46,77 @@ func TestAppend(t *testing.T) {
 | 
			
		||||
	}
 | 
			
		||||
	tests := []test{
 | 
			
		||||
		{
 | 
			
		||||
			"nil reader",
 | 
			
		||||
			nil,
 | 
			
		||||
			"U291ci5pcwAAAwACAA",
 | 
			
		||||
			[][]byte{},
 | 
			
		||||
			[][]byte{},
 | 
			
		||||
			name: "nil reader",
 | 
			
		||||
			in:   nil,
 | 
			
		||||
			enc:  "U291ci5pcwAAAwACAA",
 | 
			
		||||
			out:  [][]byte{},
 | 
			
		||||
			rev:  [][]byte{},
 | 
			
		||||
		},
 | 
			
		||||
		{
 | 
			
		||||
			"single reader",
 | 
			
		||||
			[][]io.Reader{
 | 
			
		||||
			name: "err reader",
 | 
			
		||||
			in:   nil,
 | 
			
		||||
			enc:  "U291ci5pcwAAAwACAA",
 | 
			
		||||
			out:  [][]byte{},
 | 
			
		||||
			rev:  [][]byte{},
 | 
			
		||||
		},
 | 
			
		||||
		{
 | 
			
		||||
			name: "single reader",
 | 
			
		||||
			in: [][]io.Reader{
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{1, 2, 3, 4})}},
 | 
			
		||||
			"U291ci5pcwAAE756XndRZXhdAAYBAgMEAQQBAhA",
 | 
			
		||||
			[][]byte{{1, 2, 3, 4}},
 | 
			
		||||
			[][]byte{{1, 2, 3, 4}}},
 | 
			
		||||
			enc: "U291ci5pcwAAE756XndRZXhdAAYBAgMEAQQBAhA",
 | 
			
		||||
			out: [][]byte{{1, 2, 3, 4}},
 | 
			
		||||
			rev: [][]byte{{1, 2, 3, 4}}},
 | 
			
		||||
		{
 | 
			
		||||
			"multiple readers",
 | 
			
		||||
			[][]io.Reader{
 | 
			
		||||
			name: "multiple readers",
 | 
			
		||||
			in: [][]io.Reader{
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{1, 2, 3, 4}),
 | 
			
		||||
					bytes.NewBuffer([]byte{5, 6, 7, 8})}},
 | 
			
		||||
			"U291ci5pcwAAI756XndRZXhdAAYBAgMEAQRhQyZWDDn5BQAGBQYHCAEEAgIg",
 | 
			
		||||
			[][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}},
 | 
			
		||||
			[][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}},
 | 
			
		||||
			enc: "U291ci5pcwAAI756XndRZXhdAAYBAgMEAQRhQyZWDDn5BQAGBQYHCAEEAgIg",
 | 
			
		||||
			out: [][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}},
 | 
			
		||||
			rev: [][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}},
 | 
			
		||||
		{
 | 
			
		||||
			"multiple commit",
 | 
			
		||||
			[][]io.Reader{
 | 
			
		||||
			name: "multiple commit",
 | 
			
		||||
			in: [][]io.Reader{
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{1, 2, 3, 4})},
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{5, 6, 7, 8})}},
 | 
			
		||||
			"U291ci5pcwAAJ756XndRZXhdAAYBAgMEAQQBAhBhQyZWDDn5BQAGBQYHCAEEEAIDIA",
 | 
			
		||||
			[][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}},
 | 
			
		||||
			[][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}},
 | 
			
		||||
	}
 | 
			
		||||
			enc: "U291ci5pcwAAJr56XndRZXhdAAYBAgMEAQQBAhBhQyZWDDn5BQAGBQYHCAEEAgIQ",
 | 
			
		||||
			out: [][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}},
 | 
			
		||||
			rev: [][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}},
 | 
			
		||||
		{
 | 
			
		||||
			name: "multiple commit",
 | 
			
		||||
			in: [][]io.Reader{
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{1, 2, 3, 4}),
 | 
			
		||||
					bytes.NewBuffer([]byte{5, 6, 7, 8})},
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{9, 10, 11, 12})},
 | 
			
		||||
			},
 | 
			
		||||
			enc: "U291ci5pcwAANr56XndRZXhdAAYBAgMEAQRhQyZWDDn5BQAGBQYHCAEEAgIgA4Buuio8Ro0ABgkKCwwBBAMCEA",
 | 
			
		||||
			out: [][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}},
 | 
			
		||||
			rev: [][]byte{{9, 10, 11, 12}, {5, 6, 7, 8}, {1, 2, 3, 4}}},
 | 
			
		||||
		{
 | 
			
		||||
			name: "multiple commit 3x",
 | 
			
		||||
			in: [][]io.Reader{
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{1, 2, 3}),
 | 
			
		||||
					bytes.NewBuffer([]byte{4, 5, 6}),
 | 
			
		||||
				},
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{7, 8, 9}),
 | 
			
		||||
				},
 | 
			
		||||
				{
 | 
			
		||||
					bytes.NewBuffer([]byte{10, 11, 12}),
 | 
			
		||||
					bytes.NewBuffer([]byte{13, 14, 15}),
 | 
			
		||||
				},
 | 
			
		||||
			},
 | 
			
		||||
			enc: "U291ci5pcwAAVNCqYhhnLPWrAAUBAgMBA7axWhhYd+HsAAUEBQYBAwICHr9ryhhdbkEZAAUHCAkBAwMCDy/UIhidCwCqAAUKCwwBA/NCwhh6wXgXAAUNDg8BAwUCHg",
 | 
			
		||||
			out: [][]byte{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}, {10, 11, 12}, {13, 14, 15}},
 | 
			
		||||
			rev: [][]byte{{13, 14, 15}, {10, 11, 12}, {7, 8, 9}, {4, 5, 6}, {1, 2, 3}}},
 | 
			
		||||
	}	
 | 
			
		||||
 | 
			
		||||
	for _, test := range tests {
 | 
			
		||||
		t.Run(test.name, func(t *testing.T) {
 | 
			
		||||
@ -65,17 +126,17 @@ func TestAppend(t *testing.T) {
 | 
			
		||||
			buffers := 0
 | 
			
		||||
 | 
			
		||||
			if len(test.in) == 0 {
 | 
			
		||||
				err := WriteLogFile(buf)
 | 
			
		||||
				err := WriteLogFile(buf, slices.Values([]io.Reader{}))
 | 
			
		||||
				is.NoErr(err)
 | 
			
		||||
			}
 | 
			
		||||
			for i, in := range test.in {
 | 
			
		||||
				buffers += len(in)
 | 
			
		||||
 | 
			
		||||
				if i == 0 {
 | 
			
		||||
					err := WriteLogFile(buf, in...)
 | 
			
		||||
					err := WriteLogFile(buf, slices.Values(in))
 | 
			
		||||
					is.NoErr(err)
 | 
			
		||||
				} else {
 | 
			
		||||
					err := AppendLogFile(buf, in...)
 | 
			
		||||
					err := AppendLogFile(buf, slices.Values(in))
 | 
			
		||||
					is.NoErr(err)
 | 
			
		||||
				}
 | 
			
		||||
			}
 | 
			
		||||
@ -86,47 +147,52 @@ func TestAppend(t *testing.T) {
 | 
			
		||||
			is.NoErr(err)
 | 
			
		||||
 | 
			
		||||
			i := 0
 | 
			
		||||
			for fp := range iterOne(files.Iter()) {
 | 
			
		||||
			for j, fp := range files.Iter() {
 | 
			
		||||
				buf, err := io.ReadAll(fp)
 | 
			
		||||
				is.NoErr(err)
 | 
			
		||||
 | 
			
		||||
				is.Equal(buf, test.out[i])
 | 
			
		||||
				is.True(len(test.out) > int(j))
 | 
			
		||||
				is.Equal(buf, test.out[j])
 | 
			
		||||
				i++
 | 
			
		||||
			}
 | 
			
		||||
			is.NoErr(files.Err)
 | 
			
		||||
			is.Equal(i, buffers)
 | 
			
		||||
 | 
			
		||||
			// i = 0
 | 
			
		||||
			// for fp := range iterOne(files.Rev()) {
 | 
			
		||||
			// 	buf, err := io.ReadAll(fp)
 | 
			
		||||
			// 	is.NoErr(err)
 | 
			
		||||
			i = 0
 | 
			
		||||
			for j, fp := range files.Rev() {
 | 
			
		||||
				buf, err := io.ReadAll(fp)
 | 
			
		||||
				is.NoErr(err)
 | 
			
		||||
 | 
			
		||||
			// 	is.Equal(buf, test.rev[i])
 | 
			
		||||
			// 	i++
 | 
			
		||||
			// }
 | 
			
		||||
			// is.NoErr(files.Err)
 | 
			
		||||
			// is.Equal(i, buffers)
 | 
			
		||||
				is.Equal(buf, test.rev[i])
 | 
			
		||||
				is.Equal(buf, test.out[j])
 | 
			
		||||
				i++
 | 
			
		||||
			}
 | 
			
		||||
			is.NoErr(files.Err)
 | 
			
		||||
			is.Equal(i, buffers)
 | 
			
		||||
 | 
			
		||||
		})
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// TestArgs tests that the CLI arguments are correctly parsed.
 | 
			
		||||
func TestArgs(t *testing.T) {
 | 
			
		||||
	is := is.New(t)
 | 
			
		||||
	usage := `Usage: lsm2 create <archive> <files>...
 | 
			
		||||
	`
 | 
			
		||||
	opts, err := docopt.ParseArgs(usage, []string{"create", "archive", "file1", "file2"}, "1.0")
 | 
			
		||||
	usage := `Usage: lsm2 create <archive> <files>...`
 | 
			
		||||
 | 
			
		||||
	arguments, err := docopt.ParseArgs(usage, []string{"create", "archive", "file1", "file2"}, "1.0")
 | 
			
		||||
	is.NoErr(err)
 | 
			
		||||
 | 
			
		||||
	args := struct {
 | 
			
		||||
	var params struct {
 | 
			
		||||
		Create  bool     `docopt:"create"`
 | 
			
		||||
		Archive string   `docopt:"<archive>"`
 | 
			
		||||
		Files   []string `docopt:"<files>"`
 | 
			
		||||
	}{}
 | 
			
		||||
	err = opts.Bind(&args)
 | 
			
		||||
	}
 | 
			
		||||
	err = arguments.Bind(¶ms)
 | 
			
		||||
	is.NoErr(err)
 | 
			
		||||
	fmt.Println(args)
 | 
			
		||||
 | 
			
		||||
	is.Equal(params.Create, true)
 | 
			
		||||
	is.Equal(params.Archive, "archive")
 | 
			
		||||
	is.Equal(params.Files, []string{"file1", "file2"})
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
type buffer struct {
 | 
			
		||||
@ -155,6 +221,10 @@ func (b *buffer) WriteAt(data []byte, offset int64) (written int, err error) {
 | 
			
		||||
	return
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// ReadAt implements io.ReaderAt. It reads data from the internal buffer starting
 | 
			
		||||
// from the specified offset and writes it into the provided data slice. If the
 | 
			
		||||
// offset is negative, it returns an error. If the requested read extends beyond
 | 
			
		||||
// the buffer's length, it returns the data read so far along with an io.EOF error.
 | 
			
		||||
func (b *buffer) ReadAt(data []byte, offset int64) (int, error) {
 | 
			
		||||
	if offset < 0 {
 | 
			
		||||
		return 0, errors.New("negative offset")
 | 
			
		||||
@ -166,3 +236,17 @@ func (b *buffer) ReadAt(data []byte, offset int64) (int, error) {
 | 
			
		||||
 | 
			
		||||
	return copy(data, b.buf[offset:]), nil
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
// IterOne takes an iterator that yields values of type T along with a value of
 | 
			
		||||
// type I, and returns an iterator that yields only the values of type T. It
 | 
			
		||||
// discards the values of type I.
 | 
			
		||||
func IterOne[I, T any](it iter.Seq2[I, T]) iter.Seq[T] {
 | 
			
		||||
	return func(yield func(T) bool) {
 | 
			
		||||
		for i, v := range it {
 | 
			
		||||
			_ = i
 | 
			
		||||
			if !yield(v) {
 | 
			
		||||
				return
 | 
			
		||||
			}
 | 
			
		||||
		}
 | 
			
		||||
	}
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
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		Reference in New Issue
	
	Block a user