feat: add .rdb file parser & KEYS command (#5)

* feat: .rdb parser

* feat: support pattern matching for KEYS

* refactor: default dir

* fix: lint err

app/server.go

@@ -22,9 +22,10 @@ var (
 )
 
 func run(ctx context.Context, _ io.Writer, _ []string) error {
-	flag.Parse()
-	ctx, cancel := context.WithCancel(context.Background())
+	ctx, cancel := context.WithCancel(ctx)
 	sigCh := make(chan os.Signal, 1)
+	logger.Info(ctx, "oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo")
+	flag.Parse()
 	signal.Notify(sigCh, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT)
 	defer signal.Stop(sigCh)
 	cfg := config.NewConfig()
@@ -38,8 +39,8 @@ func run(ctx context.Context, _ io.Writer, _ []string) error {
 	}
 	server := server.NewServer(cfg)
 	go func() {
-		if err := server.Listen(ctx); err != nil {
-			logger.Error(ctx, "failed to listen, err: %v", err)
+		if err := server.Start(ctx); err != nil {
+			logger.Error(ctx, "failed to start the server, err: %v", err)
 		}
 		cancel()
 	}()
@@ -48,15 +49,15 @@ func run(ctx context.Context, _ io.Writer, _ []string) error {
 	case <-ctx.Done():
 		logger.Info(ctx, "context done, shutting down")
 	case <-sigCh:
-		logger.Info(ctx, "received signal, shutting down")
+		logger.Info(ctx, "Received signal, shutting down")
 	}
 	ctx, cancel = context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 	if err := server.Close(ctx); err != nil {
 		logger.Error(ctx, "failed to close server, err: %v", err)
 	}
 
-	logger.Info(ctx, "server shutdown")
+	logger.Info(ctx, "Redis is now ready to exit, bye bye...")
 	return nil
 }
 

go.mod

@@ -18,5 +18,6 @@ require (
 	github.com/redis/go-redis/v9 v9.5.3 // indirect
 	github.com/stretchr/testify v1.9.0 // indirect
 	github.com/test-go/testify v1.1.4 // indirect
+	github.com/zhuyie/golzf v0.0.0-20161112031142-8387b0307ade // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -12,6 +12,8 @@ github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsT
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/test-go/testify v1.1.4 h1:Tf9lntrKUMHiXQ07qBScBTSA0dhYQlu83hswqelv1iE=
 github.com/test-go/testify v1.1.4/go.mod h1:rH7cfJo/47vWGdi4GPj16x3/t1xGOj2YxzmNQzk2ghU=
+github.com/zhuyie/golzf v0.0.0-20161112031142-8387b0307ade h1:bafvQukPrIYwYWcft4rl3WpHo3qO0/voaAgnCwgdhi0=
+github.com/zhuyie/golzf v0.0.0-20161112031142-8387b0307ade/go.mod h1:juNhYdla04C276MyU4zR0BA7t90ziLKPwkjDgddGYV0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/app/server/config/config.go

@@ -63,7 +63,7 @@ func (c *Config) Get(key string) (string, error) {
 	seachKey := strings.ToUpper(key)
 	value, exists := c.options[seachKey]
 	if !exists {
-		return "", ErrOptionNotFound
+		return "", fmt.Errorf("%s for %s", ErrOptionNotFound, key)
 	}
 	return value, nil
 }

internal/app/server/server.go

@@ -4,12 +4,14 @@ import (
 	"context"
 	"fmt"
 	"net"
+	"os"
 	"sync"
 
 	"github.com/codecrafters-io/redis-starter-go/internal/app/server/config"
 	"github.com/codecrafters-io/redis-starter-go/internal/client"
 	"github.com/codecrafters-io/redis-starter-go/pkg/command"
 	"github.com/codecrafters-io/redis-starter-go/pkg/keyval"
+	"github.com/codecrafters-io/redis-starter-go/pkg/rdb"
 	"github.com/codecrafters-io/redis-starter-go/pkg/resp"
 	"github.com/codecrafters-io/redis-starter-go/pkg/telemetry/logger"
 )
@@ -23,31 +25,67 @@ type Server struct {
 	mu       sync.Mutex
 	cfg      *config.Config
 	done     chan struct{}
+	store    keyval.KV
 	clients  map[*client.Client]struct{}
 	cFactory *command.CommandFactory
 }
 
 func NewServer(cfg *config.Config) *Server {
+	store := keyval.NewStore()
 	return &Server{
 		mu:       sync.Mutex{},
 		cfg:      cfg,
 		done:     make(chan struct{}),
-		cFactory: command.NewCommandFactory(keyval.NewStore(), cfg),
+		store:    store,
+		cFactory: command.NewCommandFactory(store, cfg),
 		clients:  make(map[*client.Client]struct{}),
 	}
 }
 
+func (s *Server) Start(ctx context.Context) error {
+	logger.Info(ctx, "Server initialized")
+	dir, _ := s.cfg.Get(config.DirKey)
+	dbFilename, _ := s.cfg.Get(config.DBFilenameKey)
+	file, openErr := os.Open(dir + "/" + dbFilename)
+	if openErr != nil && !os.IsNotExist(openErr) {
+		return fmt.Errorf("failed to open file, err: %v", openErr)
+	}
+	var isValidRDBFile bool
+	var stat os.FileInfo
+	var err error
+	if !os.IsNotExist(openErr) {
+		stat, err = file.Stat()
+		if err != nil {
+			return fmt.Errorf("failed to get file stat, err: %v", err)
+		}
+		isValidRDBFile = !stat.IsDir()
+	}
+
+	if isValidRDBFile {
+		defer file.Close()
+		rdb := rdb.NewRDBParser(file)
+		if err := rdb.ParseRDB(ctx); err != nil {
+			return fmt.Errorf("failed to parse rdb, err: %v", err)
+		}
+		s.store.RestoreRDB(rdb.GetData(), rdb.GetExpiry())
+	}
+	if err := s.Listen(ctx); err != nil {
+		return fmt.Errorf("failed to listen, err: %v", err)
+	}
+	return nil
+}
+
 func (s *Server) Listen(ctx context.Context) error {
 	listenAddr, err := s.cfg.Get(config.ListenAddrKey)
 	if err != nil {
 		listenAddr = defaultListenAddr
 	}
 	ln, err := net.Listen("tcp", listenAddr)
-	logger.Info(ctx, "listening, addr: %s", ln.Addr())
 	if err != nil {
 		return err
 	}
 	s.ln = ln
+	logger.Info(ctx, "Ready to accept connections tcp on %s", listenAddr)
 	return s.loop(ctx)
 }
 
@@ -127,6 +165,9 @@ func (s *Server) handleMessage(ctx context.Context, cl *client.Client, r *resp.R
 
 func (s *Server) Close(_ context.Context) error {
 	close(s.done)
+	if s.ln == nil {
+		return nil
+	}
 	if err := s.ln.Close(); err != nil {
 		return fmt.Errorf("failed to close listener: %w", err)
 	}

internal/app/server/server_test.go

@@ -38,7 +38,7 @@ func startServer(ctx context.Context) (*Server, int, error) {
 	}
 	srv := NewServer(cfg)
 	go func() {
-		if err := srv.Listen(ctx); err != nil {
+		if err := srv.Start(ctx); err != nil {
 			panic(err)
 		}
 	}()

pkg/command/command.go

@@ -31,7 +31,7 @@ func (ec *EchoCommand) Execute(c *client.Client, wr *resp.Writer, args []*resp.R
 		return wr.WriteError(errors.New("wrong number of arguments for 'echo' command"))
 	}
 
-	return wr.WriteValue(args[0].Bytes())
+	return wr.WriteBytes(args[0].Bytes())
 }
 
 type PingCommand struct {
@@ -55,6 +55,7 @@ func NewCommandFactory(kv keyval.KV, cfg *config.Config) *CommandFactory {
 			"info":   &Info{},
 			"client": &ClientCmd{},
 			"config": &ConfigCmd{cfg: cfg},
+			"keys":   &Keys{kv: kv},
 		},
 	}
 }

pkg/command/config.go

@@ -64,11 +64,11 @@ func (c *ConfigCmd) handleGet(cl *client.Client, wr *resp.Writer, args []*resp.R
 		}
 		return wr.WriteMap(resp)
 	} else {
-		var resp []any
+		var resp []string
 		for key, value := range valueMap {
 			resp = append(resp, key)
 			resp = append(resp, value)
 		}
-		return wr.WriteArray(resp)
+		return wr.WriteStringSlice(resp)
 	}
 }

pkg/command/get.go

@@ -25,5 +25,5 @@ func (g *Get) Execute(c *client.Client, wr *resp.Writer, args []*resp.Resp) erro
 		return wr.WriteNull(resp.BulkString)
 	}
 
-	return wr.WriteValue(val)
+	return wr.WriteBytes(val)
 }

pkg/command/info.go

@@ -35,7 +35,7 @@ func (h *Info) Execute(c *client.Client, wr *resp.Writer, args []*resp.Resp) err
 	str := strings.Builder{}
 	if argsLen == 1 {
 		str.WriteString(buildSectionString(args[0].String(), sections[args[0].String()]))
-		return wr.WriteValue(str.String())
+		return wr.WriteString(str.String())
 	}
 	for sectionName, section := range sections {
 		str.WriteString(buildSectionString(sectionName, section))

pkg/command/keys.go

@@ -0,0 +1,36 @@
+package command
+
+import (
+	"errors"
+
+	"github.com/codecrafters-io/redis-starter-go/internal/client"
+	"github.com/codecrafters-io/redis-starter-go/pkg/keyval"
+	"github.com/codecrafters-io/redis-starter-go/pkg/resp"
+)
+
+type Keys struct {
+	kv keyval.KV
+}
+
+func (k *Keys) Execute(_ *client.Client, wr *resp.Writer, args []*resp.Resp) error {
+	if len(args) != 1 {
+		return wr.WriteError(errors.New("wrong number of arguments for 'keys' command"))
+	}
+	pattern := args[0].String()
+	keys := k.kv.Keys()
+	if pattern == "*" {
+		return wr.WriteStringSlice(k.kv.Keys())
+	}
+	re, err := resp.TranslatePattern(pattern)
+	if err != nil {
+		return wr.WriteError(err)
+	}
+	var matchedKeys []string
+	for _, key := range keys {
+		if re.MatchString(key) {
+			matchedKeys = append(matchedKeys, key)
+		}
+	}
+
+	return wr.WriteStringSlice(matchedKeys)
+}

pkg/command/set.go

@@ -64,7 +64,7 @@ func (s *Set) Execute(c *client.Client, wr *resp.Writer, args []*resp.Resp) erro
 
 	if opts.NX {
 		if opts.GET && keyExists {
-			return wr.WriteValue(oldVal)
+			return wr.WriteBytes(oldVal)
 		}
 		if keyExists {
 			return wr.WriteNull(resp.BulkString)
@@ -97,7 +97,7 @@ func (s *Set) Execute(c *client.Client, wr *resp.Writer, args []*resp.Resp) erro
 
 	if opts.GET {
 		if keyExists {
-			return wr.WriteValue(oldVal)
+			return wr.WriteBytes(oldVal)
 		} else {
 			return wr.WriteNull(resp.BulkString)
 		}

pkg/crc64/crc64.go

@@ -0,0 +1,64 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package crc64 implements the Jones coefficients with an init value of 0.
+package crc64
+
+import "hash"
+
+// Redis uses the CRC64 variant with "Jones" coefficients and init value of 0.
+//
+// Specification of this CRC64 variant follows:
+// Name: crc-64-jones
+// Width: 64 bits
+// Poly: 0xad93d23594c935a9
+// Reflected In: True
+// Xor_In: 0xffffffffffffffff
+// Reflected_Out: True
+// Xor_Out: 0x0
+
+var table = [256]uint64{0x0000000000000000, 0x7ad870c830358979, 0xf5b0e190606b12f2, 0x8f689158505e9b8b, 0xc038e5739841b68f, 0xbae095bba8743ff6, 0x358804e3f82aa47d, 0x4f50742bc81f2d04, 0xab28ecb46814fe75, 0xd1f09c7c5821770c, 0x5e980d24087fec87, 0x24407dec384a65fe, 0x6b1009c7f05548fa, 0x11c8790fc060c183, 0x9ea0e857903e5a08, 0xe478989fa00bd371, 0x7d08ff3b88be6f81, 0x07d08ff3b88be6f8, 0x88b81eabe8d57d73, 0xf2606e63d8e0f40a, 0xbd301a4810ffd90e, 0xc7e86a8020ca5077, 0x4880fbd87094cbfc, 0x32588b1040a14285, 0xd620138fe0aa91f4, 0xacf86347d09f188d, 0x2390f21f80c18306, 0x594882d7b0f40a7f, 0x1618f6fc78eb277b, 0x6cc0863448deae02, 0xe3a8176c18803589, 0x997067a428b5bcf0, 0xfa11fe77117cdf02, 0x80c98ebf2149567b, 0x0fa11fe77117cdf0, 0x75796f2f41224489, 0x3a291b04893d698d, 0x40f16bccb908e0f4, 0xcf99fa94e9567b7f, 0xb5418a5cd963f206, 0x513912c379682177, 0x2be1620b495da80e, 0xa489f35319033385, 0xde51839b2936bafc, 0x9101f7b0e12997f8, 0xebd98778d11c1e81, 0x64b116208142850a, 0x1e6966e8b1770c73, 0x8719014c99c2b083, 0xfdc17184a9f739fa, 0x72a9e0dcf9a9a271, 0x08719014c99c2b08, 0x4721e43f0183060c, 0x3df994f731b68f75, 0xb29105af61e814fe, 0xc849756751dd9d87, 0x2c31edf8f1d64ef6, 0x56e99d30c1e3c78f, 0xd9810c6891bd5c04, 0xa3597ca0a188d57d, 0xec09088b6997f879, 0x96d1784359a27100, 0x19b9e91b09fcea8b, 0x636199d339c963f2, 0xdf7adabd7a6e2d6f, 0xa5a2aa754a5ba416, 0x2aca3b2d1a053f9d, 0x50124be52a30b6e4, 0x1f423fcee22f9be0, 0x659a4f06d21a1299, 0xeaf2de5e82448912, 0x902aae96b271006b, 0x74523609127ad31a, 0x0e8a46c1224f5a63, 0x81e2d7997211c1e8, 0xfb3aa75142244891, 0xb46ad37a8a3b6595, 0xceb2a3b2ba0eecec, 0x41da32eaea507767, 0x3b024222da65fe1e, 0xa2722586f2d042ee, 0xd8aa554ec2e5cb97, 0x57c2c41692bb501c, 0x2d1ab4dea28ed965, 0x624ac0f56a91f461, 0x1892b03d5aa47d18, 0x97fa21650afae693, 0xed2251ad3acf6fea, 0x095ac9329ac4bc9b, 0x7382b9faaaf135e2, 0xfcea28a2faafae69, 0x8632586aca9a2710, 0xc9622c4102850a14, 0xb3ba5c8932b0836d, 0x3cd2cdd162ee18e6, 0x460abd1952db919f, 0x256b24ca6b12f26d, 0x5fb354025b277b14, 0xd0dbc55a0b79e09f, 0xaa03b5923b4c69e6, 0xe553c1b9f35344e2, 0x9f8bb171c366cd9b, 0x10e3202993385610, 0x6a3b50e1a30ddf69, 0x8e43c87e03060c18, 0xf49bb8b633338561, 0x7bf329ee636d1eea, 0x012b592653589793, 0x4e7b2d0d9b47ba97, 0x34a35dc5ab7233ee, 0xbbcbcc9dfb2ca865, 0xc113bc55cb19211c, 0x5863dbf1e3ac9dec, 0x22bbab39d3991495, 0xadd33a6183c78f1e, 0xd70b4aa9b3f20667, 0x985b3e827bed2b63, 0xe2834e4a4bd8a21a, 0x6debdf121b863991, 0x1733afda2bb3b0e8, 0xf34b37458bb86399, 0x8993478dbb8deae0, 0x06fbd6d5ebd3716b, 0x7c23a61ddbe6f812, 0x3373d23613f9d516, 0x49aba2fe23cc5c6f, 0xc6c333a67392c7e4, 0xbc1b436e43a74e9d, 0x95ac9329ac4bc9b5, 0xef74e3e19c7e40cc, 0x601c72b9cc20db47, 0x1ac40271fc15523e, 0x5594765a340a7f3a, 0x2f4c0692043ff643, 0xa02497ca54616dc8, 0xdafce7026454e4b1, 0x3e847f9dc45f37c0, 0x445c0f55f46abeb9, 0xcb349e0da4342532, 0xb1eceec59401ac4b, 0xfebc9aee5c1e814f, 0x8464ea266c2b0836, 0x0b0c7b7e3c7593bd, 0x71d40bb60c401ac4, 0xe8a46c1224f5a634, 0x927c1cda14c02f4d, 0x1d148d82449eb4c6, 0x67ccfd4a74ab3dbf, 0x289c8961bcb410bb, 0x5244f9a98c8199c2, 0xdd2c68f1dcdf0249, 0xa7f41839ecea8b30, 0x438c80a64ce15841, 0x3954f06e7cd4d138, 0xb63c61362c8a4ab3, 0xcce411fe1cbfc3ca, 0x83b465d5d4a0eece, 0xf96c151de49567b7, 0x76048445b4cbfc3c, 0x0cdcf48d84fe7545, 0x6fbd6d5ebd3716b7, 0x15651d968d029fce, 0x9a0d8ccedd5c0445, 0xe0d5fc06ed698d3c, 0xaf85882d2576a038, 0xd55df8e515432941, 0x5a3569bd451db2ca, 0x20ed197575283bb3, 0xc49581ead523e8c2, 0xbe4df122e51661bb, 0x3125607ab548fa30, 0x4bfd10b2857d7349, 0x04ad64994d625e4d, 0x7e7514517d57d734, 0xf11d85092d094cbf, 0x8bc5f5c11d3cc5c6, 0x12b5926535897936, 0x686de2ad05bcf04f, 0xe70573f555e26bc4, 0x9ddd033d65d7e2bd, 0xd28d7716adc8cfb9, 0xa85507de9dfd46c0, 0x273d9686cda3dd4b, 0x5de5e64efd965432, 0xb99d7ed15d9d8743, 0xc3450e196da80e3a, 0x4c2d9f413df695b1, 0x36f5ef890dc31cc8, 0x79a59ba2c5dc31cc, 0x037deb6af5e9b8b5, 0x8c157a32a5b7233e, 0xf6cd0afa9582aa47, 0x4ad64994d625e4da, 0x300e395ce6106da3, 0xbf66a804b64ef628, 0xc5bed8cc867b7f51, 0x8aeeace74e645255, 0xf036dc2f7e51db2c, 0x7f5e4d772e0f40a7, 0x05863dbf1e3ac9de, 0xe1fea520be311aaf, 0x9b26d5e88e0493d6, 0x144e44b0de5a085d, 0x6e963478ee6f8124, 0x21c640532670ac20, 0x5b1e309b16452559, 0xd476a1c3461bbed2, 0xaeaed10b762e37ab, 0x37deb6af5e9b8b5b, 0x4d06c6676eae0222, 0xc26e573f3ef099a9, 0xb8b627f70ec510d0, 0xf7e653dcc6da3dd4, 0x8d3e2314f6efb4ad, 0x0256b24ca6b12f26, 0x788ec2849684a65f, 0x9cf65a1b368f752e, 0xe62e2ad306bafc57, 0x6946bb8b56e467dc, 0x139ecb4366d1eea5, 0x5ccebf68aecec3a1, 0x2616cfa09efb4ad8, 0xa97e5ef8cea5d153, 0xd3a62e30fe90582a, 0xb0c7b7e3c7593bd8, 0xca1fc72bf76cb2a1, 0x45775673a732292a, 0x3faf26bb9707a053, 0x70ff52905f188d57, 0x0a2722586f2d042e, 0x854fb3003f739fa5, 0xff97c3c80f4616dc, 0x1bef5b57af4dc5ad, 0x61372b9f9f784cd4, 0xee5fbac7cf26d75f, 0x9487ca0fff135e26, 0xdbd7be24370c7322, 0xa10fceec0739fa5b, 0x2e675fb4576761d0, 0x54bf2f7c6752e8a9, 0xcdcf48d84fe75459, 0xb71738107fd2dd20, 0x387fa9482f8c46ab, 0x42a7d9801fb9cfd2, 0x0df7adabd7a6e2d6, 0x772fdd63e7936baf, 0xf8474c3bb7cdf024, 0x829f3cf387f8795d, 0x66e7a46c27f3aa2c, 0x1c3fd4a417c62355, 0x935745fc4798b8de, 0xe98f353477ad31a7, 0xa6df411fbfb21ca3, 0xdc0731d78f8795da, 0x536fa08fdfd90e51, 0x29b7d047efec8728}
+
+func crc64(crc uint64, b []byte) uint64 {
+	for _, v := range b {
+		crc = table[byte(crc)^v] ^ (crc >> 8)
+	}
+	return crc
+}
+
+func Digest(b []byte) uint64 {
+	return crc64(0, b)
+}
+
+type digest struct {
+	crc uint64
+}
+
+func New() hash.Hash64 {
+	return &digest{}
+}
+
+func (h *digest) Write(p []byte) (int, error) {
+	h.crc = crc64(h.crc, p)
+	return len(p), nil
+}
+
+// Encode in little endian
+func (d *digest) Sum(in []byte) []byte {
+	s := d.Sum64()
+	in = append(in, byte(s))
+	in = append(in, byte(s>>8))
+	in = append(in, byte(s>>16))
+	in = append(in, byte(s>>24))
+	in = append(in, byte(s>>32))
+	in = append(in, byte(s>>40))
+	in = append(in, byte(s>>48))
+	in = append(in, byte(s>>56))
+	return in
+}
+
+func (d *digest) Sum64() uint64  { return d.crc }
+func (d *digest) BlockSize() int { return 1 }
+func (d *digest) Size() int      { return 8 }
+func (d *digest) Reset()         { d.crc = 0 }

pkg/keyval/kv.go

@@ -6,6 +6,7 @@ import (
 )
 
 type KV interface {
+	RestoreRDB(data map[string]string, expiry map[string]uint64)
 	Get(key string) ([]byte, error)
 	Set(key string, value []byte) error
 	Expire(key string, duration time.Duration)
@@ -14,6 +15,7 @@ type KV interface {
 	PExpireAt(key string, expiry time.Time)
 	Exists(key string) bool
 	DeleteTTL(key string)
+	Keys() []string
 }
 
 type kv struct {
@@ -58,6 +60,27 @@ func (kv *kv) Expire(key string, duration time.Duration) {
 	kv.expiry[key] = time.Now().Add(duration)
 }
 
+func (kv *kv) Keys() []string {
+	kv.mu.RLock()
+	defer kv.mu.RUnlock()
+	keys := make([]string, 0, len(kv.store))
+	for key := range kv.store {
+		keys = append(keys, key)
+	}
+	return keys
+}
+
+func (kv *kv) RestoreRDB(data map[string]string, expiry map[string]uint64) {
+	kv.mu.Lock()
+	defer kv.mu.Unlock()
+	for key, value := range data {
+		kv.store[key] = []byte(value)
+		if exp, ok := expiry[key]; ok {
+			kv.expiry[key] = time.UnixMilli(int64(exp))
+		}
+	}
+}
+
 func (kv *kv) PExpire(key string, duration time.Duration) {
 	kv.Expire(key, duration)
 }