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chore: fixes to lsm

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This commit is contained in:
xuu 2024-11-03 14:19:09 -07:00
parent 36460a131e
commit cf99e18a39
Signed by: xuu
GPG Key ID: 8B3B0604F164E04F
3 changed files with 299 additions and 240 deletions
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81
lsm2/cli/main.go
View File

@ -6,19 +6,25 @@ import (
"io" "io"
"iter" "iter"
"os" "os"
"path/filepath"
"github.com/docopt/docopt-go" "github.com/docopt/docopt-go"
"go.sour.is/pkg/lsm2" "go.sour.is/pkg/lsm2"
) )
var usage = ` var usage = `
Usage: lsm2 create <archive> <files>...` Usage:
lsm2 create <archive> <files>...
lsm2 append <archive> <files>...
lsm2 read <archive> <index>`
type args struct { type args struct {
Create bool Create bool
Append bool
Read bool
Archive string `docopt:"<archive>"` Archive string `docopt:"<archive>"`
Files []string `docopt:"<files>"` Files []string `docopt:"<files>"`
Index int64 `docopt:"<index>"`
} }
func main() { func main() {
@ -45,38 +51,67 @@ func (c console) Write(b []byte) (int, error) {
return c.Stdout.Write(b) return c.Stdout.Write(b)
} }
func run(console console, args args) error { func run(console console,a args) error {
fmt.Fprintln(console, "lsm")
switch { switch {
case args.Create: case a.Create:
fmt.Fprintf(console, "creating %s from %v\n", filepath.Base(args.Archive), args.Files) f, err := os.OpenFile(a.Archive, os.O_CREATE|os.O_WRONLY, 0644)
out, err := os.OpenFile(args.Archive, os.O_CREATE|os.O_WRONLY, 0644)
if err != nil { if err != nil {
return err return err
} }
defer out.Close() defer f.Close()
filesWritten := 0 return lsm2.WriteLogFile(f, fileReaders(a.Files))
defer func() { fmt.Fprintln(console, "wrote", filesWritten, "files") }() case a.Append:
f, err := os.OpenFile(a.Archive, os.O_RDWR, 0644)
if err != nil {
return err
}
defer f.Close()
return lsm2.WriteIter(out, iter.Seq[io.Reader](func(yield func(io.Reader) bool) { return lsm2.AppendLogFile(f, fileReaders(a.Files))
for _, name := range args.Files { case a.Read:
f, err := os.Open(name) fmt.Fprintln(console, "reading", a.Archive)
if err != nil {
continue f, err := os.Open(a.Archive)
} if err != nil {
filesWritten++ return err
if !yield(f) { }
f.Close() defer f.Close()
return lg, err := lsm2.ReadLogFile(f)
} if err != nil {
f.Close() return err
} }
})) for i, rd := range lg.Iter() {
fmt.Fprintf(console, "=========================\n%d:\n", i)
io.Copy(console, rd)
fmt.Fprintln(console, "=========================")
}
if lg.Err != nil {
return lg.Err
}
return nil
default: default:
return errors.New("unknown command") return errors.New("unknown command")
} }
} }
func fileReaders(names []string) iter.Seq[io.Reader] {
return iter.Seq[io.Reader](func(yield func(io.Reader) bool) {
for _, name := range names {
f, err := os.Open(name)
if err != nil {
continue
}
if !yield(f) {
f.Close()
return
}
f.Close()
}
})
}
func must[T any](v T, err error) T { func must[T any](v T, err error) T {
if err != nil { if err != nil {
panic(err) panic(err)

288
lsm2/sst.go
View File

@ -1,7 +1,5 @@
package lsm2 package lsm2
// [Sour.is|size] [size|hash][data][hash|flag|size]... [prev|count|flag|size]
import ( import (
"encoding/binary" "encoding/binary"
"errors" "errors"
@ -11,6 +9,28 @@ import (
"iter" "iter"
) )
// [Sour.is|size] [size|hash][data][hash|flag|size]... [prev|count|flag|size]
// Commit1: [magic>|<end]{10} ... [<count][<size][<flag]{3..30}
// +---------|--------------------------------> end = seek to end of file
// <---|-------------+ size = seek to magic header
// <---|-------------+10 size + 10 = seek to start of file
// <-----------------------------T+10----------------> 10 + size + trailer = full file size
// Commit2: [magic>|<end]{10} ... [<count][<size][<flag]{3..30} ... [<prev][<count][<size][<flag]{4..40}
// <---|---------+
// <-------------+T----------------->
// +--------|------------------------------------------------------------------------->
// <-------------------------------------|----------------+
// prev = seek to last commit <---|-+
// prev + trailer = size of commit <----T+--------------------------------->
// Block: [hash>|<end]{10} ... [<size][<flag]{2..20}
// +---------|------------------------> end = seek to end of block
// <---|-+ size = seek to end of header
// <-------------------|-+10 size + 10 = seek to start of block
// <---------------------T+10---------------> size + 10 + trailer = full block size
const ( const (
TypeUnknown uint64 = iota TypeUnknown uint64 = iota
TypeSegment TypeSegment
@ -39,40 +59,28 @@ type header struct {
extra []byte extra []byte
} }
// UnmarshalBinary implements encoding.BinaryUnmarshaler.
// It decodes the input binary data into the header struct.
// The function expects the input data to be of a specific size (headerSize),
// otherwise it returns an error indicating bad data.
// It reads the 'end' field from the binary data, updates the 'extra' field,
// and reverses the byte order of 'extra' in place.
func (h *header) UnmarshalBinary(data []byte) error { func (h *header) UnmarshalBinary(data []byte) error {
if len(data) != 10 { if len(data) != headerSize {
return fmt.Errorf("%w: bad data", ErrDecode) return fmt.Errorf("%w: bad data", ErrDecode)
} }
h.extra = append(h.extra, data...)
var n int h.extra = make([]byte, headerSize)
h.end, n = binary.Uvarint(h.extra) copy(h.extra, data)
var bytesRead int
h.end, bytesRead = binary.Uvarint(h.extra)
reverse(h.extra) reverse(h.extra)
h.extra = h.extra[:len(h.extra)-n] h.extra = h.extra[:headerSize-bytesRead]
return nil return nil
} }
// Commit1: [magic>|<end]{10} ... [<count][<size][<flag]{3..30}
// +---------|--------------------------------> end = seek to end of file
// <---|-------------+ size = seek to magic header
// <---|-------------+10 size + 10 = seek to start of file
// <-----------------------------T+10----------------> 10 + size + trailer = full file size
// Commit2: [magic>|<end]{10} ... [<count][<size][<flag]{3..30} ... [<prev][<count][<size][<flag]{4..40}
// <---|---------+
// <-------------+T----------------->
// +--------|------------------------------------------------------------------------->
// <-------------------------------------|----------------+
// prev = seek to last commit <---|-+
// prev + trailer = size of commit <----T+--------------------------------->
// Block: [hash>|<end]{10} ... [<size][<flag]{2..20}
// +---------|------------------------> end = seek to end of block
// <---|-+ size = seek to end of header
// <-------------------|-+10 size + 10 = seek to start of block
// <---------------------T+10---------------> size + 10 + trailer = full block size
type Commit struct { type Commit struct {
flag uint64 // flag values flag uint64 // flag values
size uint64 // size of the trailer size uint64 // size of the trailer
@ -85,18 +93,18 @@ type Commit struct {
// Append marshals the trailer into binary form and appends it to data. // Append marshals the trailer into binary form and appends it to data.
// It returns the new slice. // It returns the new slice.
func (h *Commit) AppendTrailer(data []byte) []byte { func (h *Commit) AppendTrailer(data []byte) []byte {
h.flag |= TypePrevCommit h.flag |= TypeCommit
if h.prev == 0 { // if h.prev > 0 {
h.flag &= TypeCommit // h.flag |= TypePrevCommit
} // }
size := len(data) size := len(data)
data = binary.AppendUvarint(data, h.size) data = binary.AppendUvarint(data, h.size)
data = binary.AppendUvarint(data, h.flag) data = binary.AppendUvarint(data, h.flag)
data = binary.AppendUvarint(data, h.count) data = binary.AppendUvarint(data, h.count)
if h.prev != 0 { // if h.prev > 0 {
data = binary.AppendUvarint(data, h.prev) // data = binary.AppendUvarint(data, h.prev)
} // }
reverse(data[size:]) reverse(data[size:])
return data return data
@ -123,7 +131,7 @@ func (h *Commit) UnmarshalBinary(data []byte) error {
data = data[n:] data = data[n:]
h.tsize += n h.tsize += n
h.prev = h.size // h.prev = h.size
if h.flag&TypePrevCommit == TypePrevCommit { if h.flag&TypePrevCommit == TypePrevCommit {
h.prev, n = binary.Uvarint(data) h.prev, n = binary.Uvarint(data)
h.tsize += n h.tsize += n
@ -207,9 +215,6 @@ func (h *logFile) AppendMagic(data []byte) []byte {
return data return data
} }
func (h *logFile) UnmarshalBinary(data []byte) error {
return h.header.UnmarshalBinary(data)
}
// WriteLogFile writes a log file to w, given a list of segments. // WriteLogFile writes a log file to w, given a list of segments.
// The caller is responsible for calling WriteAt on the correct offset. // The caller is responsible for calling WriteAt on the correct offset.
@ -223,7 +228,7 @@ func (h *logFile) UnmarshalBinary(data []byte) error {
// - A footer with the length and hash of the segment // - A footer with the length and hash of the segment
// - The contents of the segment // - The contents of the segment
// - A header with the magic, version, flag (Clean), and end offset // - A header with the magic, version, flag (Clean), and end offset
func WriteLogFile(w io.WriterAt, segments ...io.Reader) error { func WriteLogFile(w io.WriterAt, segments iter.Seq[io.Reader]) error {
_, err := w.WriteAt(Magic[:], 0) _, err := w.WriteAt(Magic[:], 0)
if err != nil { if err != nil {
return err return err
@ -233,13 +238,7 @@ func WriteLogFile(w io.WriterAt, segments ...io.Reader) error {
WriterAt: w, WriterAt: w,
} }
return lf.writeIter(w, iter.Seq[io.Reader](func(yield func(io.Reader) bool) { return lf.writeIter(segments)
for _, s := range segments {
if !yield(s) {
return
}
}
}))
} }
type rw interface { type rw interface {
@ -247,7 +246,7 @@ type rw interface {
io.WriterAt io.WriterAt
} }
func AppendLogFile(rw rw, segments ...io.Reader) error { func AppendLogFile(rw rw, segments iter.Seq[io.Reader]) error {
logFile, err := ReadLogFile(rw) logFile, err := ReadLogFile(rw)
if err != nil { if err != nil {
return err return err
@ -256,35 +255,19 @@ func AppendLogFile(rw rw, segments ...io.Reader) error {
WriterAt: rw, WriterAt: rw,
logFile: logFile.logFile, logFile: logFile.logFile,
} }
return lf.writeIter(rw, iter.Seq[io.Reader](func(yield func(io.Reader) bool) { return lf.writeIter( segments)
for _, s := range segments {
if !yield(s) {
return
}
}
}))
} }
func WriteIter(w io.WriterAt, segments iter.Seq[io.Reader]) error {
_, err := w.WriteAt(Magic[:], 0)
if err != nil {
return err
}
lf := &LogWriter{ func (lf *LogWriter) writeIter(segments iter.Seq[io.Reader]) error {
WriterAt: w, lf.size = 0
}
return lf.writeIter(w, segments)
}
func (lf *LogWriter) writeIter(w io.WriterAt, segments iter.Seq[io.Reader]) error {
for s := range segments { for s := range segments {
err := lf.writeSegment(s) n, err := lf.writeBlock(s)
if err != nil { if err != nil {
return err return err
} }
lf.end += n
lf.size += n
lf.count++ lf.count++
} }
@ -297,7 +280,7 @@ func (lf *LogWriter) writeIter(w io.WriterAt, segments iter.Seq[io.Reader]) erro
} }
lf.end += uint64(n) lf.end += uint64(n)
_, err = w.WriteAt(lf.AppendMagic(make([]byte, 0, 10)), 0) _, err = lf.WriteAt(lf.AppendMagic(make([]byte, 0, 10)), 0)
return err return err
} }
@ -307,24 +290,26 @@ type LogWriter struct {
io.WriterAt io.WriterAt
} }
// writeSegment writes a segment to the log file at the current end of file position. // writeBlock writes a segment to the log file at the current end of file position.
// The segment is written in chunks of 1024 bytes, and the hash of the segment // The segment is written in chunks of 1024 bytes, and the hash of the segment
func (lf *LogWriter) writeSegment(segment io.Reader) error { func (lf *LogWriter) writeBlock(segment io.Reader) (uint64, error) {
h := hash() h := hash()
head := Block{} block := Block{}
start := int64(lf.end) + 10 start := int64(lf.end) + 10
end := int64(lf.end) + 10 end := start
bytesWritten := 0
// Write the header to the log file. // Write the header to the log file.
// The footer is written at the current end of file position. // The footer is written at the current end of file position.
n, err := lf.WriteAt(make([]byte, headerSize), start) n, err := lf.WriteAt(make([]byte, headerSize), start)
bytesWritten += n
end += int64(n)
if err != nil { if err != nil {
// If there is an error, return it. // If there is an error, return it.
return err return uint64(bytesWritten), err
} }
end += int64(n)
lf.size += uint64(n)
lf.end += uint64(n)
// Write the segment to the log file. // Write the segment to the log file.
// The segment is written in chunks of 1024 bytes. // The segment is written in chunks of 1024 bytes.
@ -338,7 +323,7 @@ func (lf *LogWriter) writeSegment(segment io.Reader) error {
break break
} }
// If there is an error, return it. // If there is an error, return it.
return err return uint64(bytesWritten), err
} }
// Compute the hash of the chunk. // 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. // Write the chunk to the log file.
// The chunk is written at the current end of file position. // 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 err != nil {
// If there is an error, return it. // If there is an error, return it.
return err return uint64(bytesWritten), err
} }
// Update the length of the segment. // Update the length of the segment.
end += int64(n) end += int64(n)
head.size += uint64(n) block.size += uint64(n)
} }
head.extra = h.Sum(nil) block.extra = h.Sum(nil)
head.end += head.size block.end += block.size
// Write the footer to the log file. // Write the footer to the log file.
// The footer is written at the current end of file position. // 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 err != nil {
// If there is an error, return it. // If there is an error, return it.
return err return uint64(bytesWritten), err
} }
end += int64(n) end += int64(n)
head.end += uint64(n) block.end += uint64(n)
// Update header to the log file. // Update header to the log file.
// The footer is written at the current end of file position. // 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 err != nil {
// If there is an error, return it. // If there is an error, return it.
return err return uint64(bytesWritten), err
} }
// Update the end of file position. return uint64(bytesWritten), nil
lf.size += head.end
lf.end += head.end
return nil
} }
// reverse reverses a slice in-place. // 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) { return func(yield func(uint64, io.Reader) bool) {
start := int64(10) start := int64(10)
var adj uint64
for _, commit := range commits { for _, commit := range commits {
size := int64(commit.prev) size := int64(commit.size)
it := iterBlocks(io.NewSectionReader(lf, start, size), size) it := iterBlocks(io.NewSectionReader(lf, start, size), size)
for i, block := range it { for i, block := range it {
if !yield(i, block) { if !yield(adj+i, block) {
return return
} }
} }
start += size + int64(commit.tsize) 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 start int64
var i uint64 var i uint64
return func(yield func(uint64, io.Reader) bool) { return func(yield func(uint64, io.Reader) bool) {
buf := make([]byte, maxBlockSize)
for start < end { for start < end {
block := &Block{} block := &Block{}
buf := make([]byte, 10) buf = buf[:10]
n, err := rsr(r, int64(start), 10).ReadAt(buf, 0) n, err := rsr(r, int64(start), 10).ReadAt(buf, 0)
if n == 0 && err != nil { if n == 0 && err != nil {
return 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 { if err := block.header.UnmarshalBinary(buf); err != nil {
return return
} }
buf = buf[:maxBlockSize]
buf = make([]byte, maxBlockSize)
n, err = rsr(r, int64(start), int64(block.end)).ReadAt(buf, 0) n, err = rsr(r, int64(start), int64(block.end)).ReadAt(buf, 0)
if n == 0 && err != nil { if n == 0 && err != nil {
return return
@ -498,15 +484,12 @@ func iterBlocks(r io.ReaderAt, end int64) iter.Seq2[uint64, io.Reader] {
} }
} }
func (lf *LogReader) iterCommits() iter.Seq[Commit] { func (lf *LogReader) iterCommits() iter.Seq[Commit] {
eof := lf.end + 10 if lf.end == 0 {
if eof <= 10 {
return func(yield func(Commit) bool) {} 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) { return func(yield func(Commit) bool) {
if !yield(lf.Commit) { if !yield(lf.Commit) {
return return
@ -529,50 +512,40 @@ func (lf *LogReader) iterCommits() iter.Seq[Commit] {
if !yield(commit) { if !yield(commit) {
return return
} }
offset -= commit.prev + uint64(commit.tsize) offset -= commit.size + uint64(commit.tsize)
} }
} }
} }
// func (lf *LogReader) Rev() iter.Seq2[uint64, io.Reader] { func (lf *LogReader) Rev() iter.Seq2[uint64, io.Reader] {
// end := lf.end + 10 end := lf.end + 10
// i := lf.count i := lf.count
// return func(yield func(uint64, io.Reader) bool) { return func(yield func(uint64, io.Reader) bool) {
// for commit := range lf.iterCommits() { for commit := range lf.iterCommits() {
// end -= uint64(commit.tsize) end -= uint64(commit.tsize)
// start := end - commit.prev - uint64(commit.tsize) start := end - commit.size
// for start > end{ for start < end {
// block := &Block{} block := &Block{}
// buf := make([]byte, min(maxBlockSize, commit.size)) buf := make([]byte, maxBlockSize)
// n, err := lf.ReaderAt.ReadAt(buf, max(0, int64(end)-int64(len(buf)))) n, err := rsr(lf, int64(start), int64(commit.size)).ReadAt(buf, 0)
// if n == 0 && err != nil { if n == 0 && err != nil {
// lf.Err = err lf.Err = err
// return return
// } }
// buf = buf[:n] buf = buf[:n]
// err = block.UnmarshalBinary(buf) err = block.UnmarshalBinary(buf)
// if err != nil { if err != nil {
// lf.Err = err lf.Err = err
// return return
// } }
// if !yield(i, io.NewSectionReader(lf, int64(end-block.size)-int64(block.tsize), int64(block.size))) { if !yield(i-1, io.NewSectionReader(lf, int64(end-block.size)-int64(block.tsize), int64(block.size))) {
// return return
// } }
// end -= block.size + 10 + uint64(block.tsize) end -= block.size + 10 + uint64(block.tsize)
// i-- 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
} }
} }
} }
} }
@ -606,36 +579,3 @@ func (r *revSegmentReader) ReadAt(data []byte, offset int64) (int, error) {
reverse(data[:i]) reverse(data[:i])
return i, err 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 =

168
lsm2/sst_test.go
View File

@ -4,14 +4,38 @@ import (
"bytes" "bytes"
"encoding/base64" "encoding/base64"
"errors" "errors"
"fmt"
"io" "io"
"iter"
"slices"
"testing" "testing"
"github.com/docopt/docopt-go" "github.com/docopt/docopt-go"
"github.com/matryer/is" "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) { func TestAppend(t *testing.T) {
type test struct { type test struct {
name string name string
@ -22,39 +46,76 @@ func TestAppend(t *testing.T) {
} }
tests := []test{ tests := []test{
{ {
"nil reader", name: "nil reader",
nil, in: nil,
"U291ci5pcwAAAwACAA", enc: "U291ci5pcwAAAwACAA",
[][]byte{}, out: [][]byte{},
[][]byte{}, rev: [][]byte{},
}, },
{ {
"single reader", name: "err reader",
[][]io.Reader{ in: nil,
enc: "U291ci5pcwAAAwACAA",
out: [][]byte{},
rev: [][]byte{},
},
{
name: "single reader",
in: [][]io.Reader{
{ {
bytes.NewBuffer([]byte{1, 2, 3, 4})}}, bytes.NewBuffer([]byte{1, 2, 3, 4})}},
"U291ci5pcwAAE756XndRZXhdAAYBAgMEAQQBAhA", enc: "U291ci5pcwAAE756XndRZXhdAAYBAgMEAQQBAhA",
[][]byte{{1, 2, 3, 4}}, out: [][]byte{{1, 2, 3, 4}},
[][]byte{{1, 2, 3, 4}}}, rev: [][]byte{{1, 2, 3, 4}}},
{ {
"multiple readers", name: "multiple readers",
[][]io.Reader{ in: [][]io.Reader{
{ {
bytes.NewBuffer([]byte{1, 2, 3, 4}), bytes.NewBuffer([]byte{1, 2, 3, 4}),
bytes.NewBuffer([]byte{5, 6, 7, 8})}}, bytes.NewBuffer([]byte{5, 6, 7, 8})}},
"U291ci5pcwAAI756XndRZXhdAAYBAgMEAQRhQyZWDDn5BQAGBQYHCAEEAgIg", enc: "U291ci5pcwAAI756XndRZXhdAAYBAgMEAQRhQyZWDDn5BQAGBQYHCAEEAgIg",
[][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}}, out: [][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}},
[][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}}, rev: [][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}},
{ {
"multiple commit", name: "multiple commit",
[][]io.Reader{ in: [][]io.Reader{
{ {
bytes.NewBuffer([]byte{1, 2, 3, 4})}, bytes.NewBuffer([]byte{1, 2, 3, 4})},
{ {
bytes.NewBuffer([]byte{5, 6, 7, 8})}}, bytes.NewBuffer([]byte{5, 6, 7, 8})}},
"U291ci5pcwAAJ756XndRZXhdAAYBAgMEAQQBAhBhQyZWDDn5BQAGBQYHCAEEEAIDIA", enc: "U291ci5pcwAAJr56XndRZXhdAAYBAgMEAQQBAhBhQyZWDDn5BQAGBQYHCAEEAgIQ",
[][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}}, out: [][]byte{{1, 2, 3, 4}, {5, 6, 7, 8}},
[][]byte{{5, 6, 7, 8}, {1, 2, 3, 4}}}, 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 { for _, test := range tests {
@ -65,17 +126,17 @@ func TestAppend(t *testing.T) {
buffers := 0 buffers := 0
if len(test.in) == 0 { if len(test.in) == 0 {
err := WriteLogFile(buf) err := WriteLogFile(buf, slices.Values([]io.Reader{}))
is.NoErr(err) is.NoErr(err)
} }
for i, in := range test.in { for i, in := range test.in {
buffers += len(in) buffers += len(in)
if i == 0 { if i == 0 {
err := WriteLogFile(buf, in...) err := WriteLogFile(buf, slices.Values(in))
is.NoErr(err) is.NoErr(err)
} else { } else {
err := AppendLogFile(buf, in...) err := AppendLogFile(buf, slices.Values(in))
is.NoErr(err) is.NoErr(err)
} }
} }
@ -86,47 +147,52 @@ func TestAppend(t *testing.T) {
is.NoErr(err) is.NoErr(err)
i := 0 i := 0
for fp := range iterOne(files.Iter()) { for j, fp := range files.Iter() {
buf, err := io.ReadAll(fp) buf, err := io.ReadAll(fp)
is.NoErr(err) is.NoErr(err)
is.Equal(buf, test.out[i]) is.True(len(test.out) > int(j))
is.Equal(buf, test.out[j])
i++ i++
} }
is.NoErr(files.Err) is.NoErr(files.Err)
is.Equal(i, buffers) is.Equal(i, buffers)
// i = 0 i = 0
// for fp := range iterOne(files.Rev()) { for j, fp := range files.Rev() {
// buf, err := io.ReadAll(fp) buf, err := io.ReadAll(fp)
// is.NoErr(err) is.NoErr(err)
// is.Equal(buf, test.rev[i]) is.Equal(buf, test.rev[i])
// i++ is.Equal(buf, test.out[j])
// } i++
// is.NoErr(files.Err) }
// is.Equal(i, buffers) is.NoErr(files.Err)
is.Equal(i, buffers)
}) })
} }
} }
// TestArgs tests that the CLI arguments are correctly parsed.
func TestArgs(t *testing.T) { func TestArgs(t *testing.T) {
is := is.New(t) is := is.New(t)
usage := `Usage: lsm2 create <archive> <files>... usage := `Usage: lsm2 create <archive> <files>...`
`
opts, err := docopt.ParseArgs(usage, []string{"create", "archive", "file1", "file2"}, "1.0") arguments, err := docopt.ParseArgs(usage, []string{"create", "archive", "file1", "file2"}, "1.0")
is.NoErr(err) is.NoErr(err)
args := struct { var params struct {
Create bool `docopt:"create"` Create bool `docopt:"create"`
Archive string `docopt:"<archive>"` Archive string `docopt:"<archive>"`
Files []string `docopt:"<files>"` Files []string `docopt:"<files>"`
}{} }
err = opts.Bind(&args) err = arguments.Bind(&params)
is.NoErr(err) 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 { type buffer struct {
@ -155,6 +221,10 @@ func (b *buffer) WriteAt(data []byte, offset int64) (written int, err error) {
return 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) { func (b *buffer) ReadAt(data []byte, offset int64) (int, error) {
if offset < 0 { if offset < 0 {
return 0, errors.New("negative offset") 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 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
}
}
}
}