Adding the challenge 0404

2026-08-06 21:26:45 +02:00
parent 2973ccd2b4
commit 715e66ca65
15 changed files with 1825 additions and 0 deletions
@@ -0,0 +1,212 @@
+package db0404
+
+import (
+	"bytes"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestKVBasic(t *testing.T) {
+	kv := KV{}
+	kv.log.FileName = ".test_db"
+	defer os.Remove(kv.log.FileName)
+
+	os.Remove(kv.log.FileName)
+	err := kv.Open()
+	assert.Nil(t, err)
+	defer kv.Close()
+
+	updated, err := kv.Set([]byte("k1"), []byte("v1"))
+	assert.True(t, updated && err == nil)
+
+	val, ok, err := kv.Get([]byte("k1"))
+	assert.True(t, string(val) == "v1" && ok && err == nil)
+
+	_, ok, err = kv.Get([]byte("xxx"))
+	assert.True(t, !ok && err == nil)
+
+	updated, err = kv.Del([]byte("xxx"))
+	assert.True(t, !updated && err == nil)
+
+	updated, err = kv.Del([]byte("k1"))
+	assert.True(t, updated && err == nil)
+
+	_, ok, err = kv.Get([]byte("xxx"))
+	assert.True(t, !ok && err == nil)
+
+	updated, err = kv.Set([]byte("k2"), []byte("v2"))
+	assert.True(t, updated && err == nil)
+
+	// reopen
+	kv.Close()
+	err = kv.Open()
+	assert.Nil(t, err)
+
+	_, ok, err = kv.Get([]byte("k1"))
+	assert.True(t, !ok && err == nil)
+	val, ok, err = kv.Get([]byte("k2"))
+	assert.True(t, string(val) == "v2" && ok && err == nil)
+}
+
+func TestKVUpdateMode(t *testing.T) {
+	kv := KV{}
+	kv.log.FileName = ".test_db"
+	defer os.Remove(kv.log.FileName)
+
+	os.Remove(kv.log.FileName)
+	err := kv.Open()
+	assert.Nil(t, err)
+	defer kv.Close()
+
+	updated, err := kv.SetEx([]byte("k1"), []byte("v1"), ModeUpdate)
+	assert.True(t, !updated && err == nil)
+
+	updated, err = kv.SetEx([]byte("k1"), []byte("v1"), ModeUpdate)
+	assert.True(t, !updated && err == nil)
+
+	updated, err = kv.SetEx([]byte("k1"), []byte("v1"), ModeInsert)
+	assert.True(t, updated && err == nil)
+
+	updated, err = kv.SetEx([]byte("k1"), []byte("xx"), ModeInsert)
+	assert.True(t, !updated && err == nil)
+
+	updated, err = kv.SetEx([]byte("k1"), []byte("yy"), ModeUpdate)
+	assert.True(t, updated && err == nil)
+
+	updated, err = kv.SetEx([]byte("k1"), []byte("zz"), ModeUpsert)
+	assert.True(t, updated && err == nil)
+
+	updated, err = kv.SetEx([]byte("k2"), []byte("tt"), ModeUpsert)
+	assert.True(t, updated && err == nil)
+}
+
+func TestKVRecovery(t *testing.T) {
+	kv := KV{}
+	kv.log.FileName = ".test_db"
+	defer os.Remove(kv.log.FileName)
+
+	prepare := func() {
+		os.Remove(kv.log.FileName)
+
+		err := kv.Open()
+		assert.Nil(t, err)
+		defer kv.Close()
+
+		updated, err := kv.Set([]byte("k1"), []byte("v1"))
+		assert.True(t, updated && err == nil)
+		updated, err = kv.Set([]byte("k2"), []byte("v2"))
+		assert.True(t, updated && err == nil)
+	}
+
+	prepare()
+	// simulate truncated log
+	fp, _ := os.OpenFile(kv.log.FileName, os.O_RDWR, 0o644)
+	st, _ := fp.Stat()
+	fp.Truncate(st.Size() - 1)
+	fp.Close()
+	// reopen
+	err := kv.Open()
+	assert.Nil(t, err)
+	// test
+	val, ok, err := kv.Get([]byte("k1"))
+	assert.True(t, string(val) == "v1" && ok && err == nil)
+	_, ok, err = kv.Get([]byte("k2")) // bad
+	assert.True(t, !ok && err == nil)
+	kv.Close()
+
+	prepare()
+	// simulate bad checksum
+	fp, _ = os.OpenFile(kv.log.FileName, os.O_RDWR, 0o644)
+	st, _ = fp.Stat()
+	fp.WriteAt([]byte{0}, st.Size()-1)
+	fp.Close()
+	// reopen
+	err = kv.Open()
+	assert.Nil(t, err)
+	// test
+	val, ok, err = kv.Get([]byte("k1"))
+	assert.True(t, string(val) == "v1" && ok && err == nil)
+	_, ok, err = kv.Get([]byte("k2")) // bad
+	assert.True(t, !ok && err == nil)
+	kv.Close()
+}
+
+func TestEntryEncode(t *testing.T) {
+	ent := Entry{key: []byte("k1"), val: []byte("xxx")}
+	data := []byte{0xe9, 0xec, 0x4d, 0x9e, 2, 0, 0, 0, 3, 0, 0, 0, 0, 'k', '1', 'x', 'x', 'x'}
+
+	assert.Equal(t, data, ent.Encode())
+
+	decoded := Entry{}
+	err := decoded.Decode(bytes.NewBuffer(data))
+	assert.Nil(t, err)
+	assert.Equal(t, ent, decoded)
+
+	ent = Entry{key: []byte("k1"), deleted: true}
+	data = []byte{0x4c, 0xd0, 0xfe, 0xe5, 2, 0, 0, 0, 0, 0, 0, 0, 1, 'k', '1'}
+
+	assert.Equal(t, data, ent.Encode())
+
+	decoded = Entry{}
+	err = decoded.Decode(bytes.NewBuffer(data))
+	assert.Nil(t, err)
+	assert.Equal(t, ent, decoded)
+}
+
+func TestKVSeek(t *testing.T) {
+	kv := KV{}
+	kv.log.FileName = ".test_db"
+	defer os.Remove(kv.log.FileName)
+
+	os.Remove(kv.log.FileName)
+	err := kv.Open()
+	assert.Nil(t, err)
+	defer kv.Close()
+
+	keys := []string{"c", "e", "g"}
+	vals := []string{"3", "5", "7"}
+	for i := range keys {
+		_, _ = kv.Set([]byte(keys[i]), []byte(vals[i]))
+	}
+
+	iter, err := kv.Seek([]byte("a"))
+	require.Nil(t, err)
+	for i := range keys {
+		assert.True(t, iter.Valid())
+		assert.Equal(t, []byte(keys[i]), iter.Key())
+		assert.Equal(t, []byte(vals[i]), iter.Val())
+		err = iter.Next()
+		require.Nil(t, err)
+	}
+	assert.False(t, iter.Valid())
+
+	err = iter.Prev()
+	require.Nil(t, err)
+	for i := len(keys) - 1; i >= 0; i-- {
+		assert.True(t, iter.Valid())
+		assert.Equal(t, []byte(keys[i]), iter.Key())
+		assert.Equal(t, []byte(vals[i]), iter.Val())
+		err = iter.Prev()
+		require.Nil(t, err)
+	}
+	assert.False(t, iter.Valid())
+
+	iter, err = kv.Seek([]byte("f"))
+	require.Nil(t, err)
+	assert.True(t, iter.Valid())
+	assert.Equal(t, []byte("g"), iter.Key())
+
+	iter, err = kv.Seek([]byte("g"))
+	require.Nil(t, err)
+	assert.True(t, iter.Valid())
+	assert.Equal(t, []byte("g"), iter.Key())
+
+	iter, err = kv.Seek([]byte("h"))
+	require.Nil(t, err)
+	assert.False(t, iter.Valid())
+}
+
+// QzBQWVJJOUhU https://trialofcode.org/