github.com/cockroachdb/pebble@v0.0.0-20231214172447-ab4952c5f87b/tool/testdata/mixed/main.go (about)

     1  // Command main generates test fixtures for a DB containing a mixture of point
     2  // and range keys.
     3  //
     4  // Upon running this command, the DB directory will contain:
     5  //
     6  //  1. A single SSTable (000005.sst), containing:
     7  //     a. 26 point keys, a@1 through z@1.
     8  //     b. a RANGEKEYSET [a, z)@1
     9  //     c. a RANGEKEYUNSET [a, z)@2
    10  //     d. a RANGEKEYDEL [a, b)
    11  //  2. A WAL for an unflushed memtable containing:
    12  //     a. A single point key a@2.
    13  //     b. a RANGEKEYSET [a, z)@3
    14  //     c. a RANGEKEYUNSET [a, z)@4
    15  //     d. a RANGEKEYDEL [a, b)
    16  package main
    17  
    18  import (
    19  	"io/fs"
    20  	"os"
    21  	"path/filepath"
    22  
    23  	"github.com/cockroachdb/pebble"
    24  	"github.com/cockroachdb/pebble/internal/testkeys"
    25  	"github.com/cockroachdb/pebble/vfs"
    26  )
    27  
    28  const outDir = "./tool/testdata/mixed"
    29  
    30  func main() {
    31  	err := filepath.WalkDir(outDir, func(path string, d fs.DirEntry, err error) error {
    32  		if err != nil {
    33  			return err
    34  		}
    35  		if filepath.Base(path) == "main.go" || d.IsDir() {
    36  			return nil
    37  		}
    38  		return os.Remove(path)
    39  	})
    40  	if err != nil {
    41  		panic(err)
    42  	}
    43  	lel := pebble.MakeLoggingEventListener(pebble.DefaultLogger)
    44  
    45  	opts := &pebble.Options{
    46  		FS:                          vfs.Default,
    47  		Comparer:                    testkeys.Comparer,
    48  		FormatMajorVersion:          pebble.FormatNewest,
    49  		EventListener:               &lel,
    50  		DisableAutomaticCompactions: true,
    51  	}
    52  	db, err := pebble.Open(outDir, opts)
    53  	if err != nil {
    54  		panic(err)
    55  	}
    56  
    57  	writePoint := func(b *pebble.Batch, k []byte) {
    58  		if err := b.Set(k, nil, nil); err != nil {
    59  			panic(err)
    60  		}
    61  	}
    62  	writeRangeKeySet := func(b *pebble.Batch, start, end, suffix []byte) {
    63  		if err := b.RangeKeySet(start, end, suffix, nil, nil); err != nil {
    64  			panic(err)
    65  		}
    66  	}
    67  	writeRangeKeyUnset := func(b *pebble.Batch, start, end, suffix []byte) {
    68  		if err := b.RangeKeyUnset(start, end, suffix, nil); err != nil {
    69  			panic(err)
    70  		}
    71  	}
    72  	writeRangeKeyDel := func(b *pebble.Batch, start, end []byte) {
    73  		if err := b.RangeKeyDelete(start, end, nil); err != nil {
    74  			panic(err)
    75  		}
    76  	}
    77  
    78  	// Write some point and range keys.
    79  	ks := testkeys.Alpha(1)
    80  	b := db.NewBatch()
    81  	for i := int64(0); i < ks.Count(); i++ {
    82  		writePoint(b, testkeys.KeyAt(ks, i, 1))
    83  	}
    84  	start, end := testkeys.Key(ks, 0), testkeys.Key(ks, ks.Count()-1)
    85  	writeRangeKeySet(b, start, end, testkeys.Suffix(1))   // SET   [a, z)@1
    86  	writeRangeKeyUnset(b, start, end, testkeys.Suffix(2)) // UNSET [a, z)@2
    87  	writeRangeKeyDel(b, start, testkeys.Key(ks, 1))       // DEL   [a, b)
    88  	if err := b.Commit(nil); err != nil {
    89  		panic(err)
    90  	}
    91  
    92  	// Flush memtables.
    93  	if err := db.Flush(); err != nil {
    94  		panic(err)
    95  	}
    96  
    97  	// Write one more point and range key into a memtable before closing, so the
    98  	// WAL is not empty.
    99  	b = db.NewBatch()
   100  	writePoint(b, testkeys.KeyAt(ks, 0, 2))
   101  	writeRangeKeySet(b, start, end, testkeys.Suffix(3))   // SET   [a, z)@3
   102  	writeRangeKeyUnset(b, start, end, testkeys.Suffix(4)) // UNSET [a, z)@4
   103  	writeRangeKeyDel(b, start, testkeys.Key(ks, 1))       // DEL   [a, b)
   104  	if err := b.Commit(nil); err != nil {
   105  		panic(err)
   106  	}
   107  }