server side support for new regex package

10 files changed, 60 insertions, 46 deletions

diff --git a/internal/clients/args.go b/internal/clients/args.go
index 1145a4b..34fcfa2 100644
--- a/internal/clients/args.go
+++ b/internal/clients/args.go
@@ -13,7 +13,8 @@ type Args struct {
 	UserName           string
 	What               string
 	Arguments          []string
-	Regex              string
+	RegexStr           string
+	RegexInvert        bool
 	TrustAllHosts      bool
 	Discovery          string
 	ConnectionsPerCPU  int
diff --git a/internal/clients/baseclient.go b/internal/clients/baseclient.go
index 7c6bce5..102fd7c 100644
--- a/internal/clients/baseclient.go
+++ b/internal/clients/baseclient.go
@@ -50,7 +50,11 @@ func (c *baseClient) init(maker maker) {
 		c.connections = append(c.connections, c.makeConnection(server, c.sshAuthMethods, c.hostKeyCallback))
 	}
 
-	regex, err := regex.New(c.Args.Regex, regex.Default)
+	flag := regex.Default
+	if c.Args.RegexInvert {
+		flag = regex.Invert
+	}
+	regex, err := regex.New(c.Args.RegexStr, flag)
 	if err != nil {
 		logger.FatalExit(c.Regex, "invalid regex!", err, regex)
 	}
diff --git a/internal/clients/catclient.go b/internal/clients/catclient.go
index 7fd6bdc..f089e32 100644
--- a/internal/clients/catclient.go
+++ b/internal/clients/catclient.go
@@ -17,11 +17,10 @@ type CatClient struct {
 
 // NewCatClient returns a new cat client.
 func NewCatClient(args Args) (*CatClient, error) {
-	if args.Regex != "" {
+	if args.RegexStr != "" {
 		return nil, errors.New("Can't use regex with 'cat' operating mode")
 	}
 
-	args.Regex = "."
 	args.Mode = omode.CatClient
 
 	c := CatClient{
diff --git a/internal/clients/grepclient.go b/internal/clients/grepclient.go
index 8d11458..9f6b666 100644
--- a/internal/clients/grepclient.go
+++ b/internal/clients/grepclient.go
@@ -17,7 +17,7 @@ type GrepClient struct {
 
 // NewGrepClient creates a new grep client.
 func NewGrepClient(args Args) (*GrepClient, error) {
-	if args.Regex == "" {
+	if args.RegexStr == "" {
 		return nil, errors.New("No regex specified, use '-regex' flag")
 	}
 	args.Mode = omode.GrepClient
@@ -41,7 +41,7 @@ func (c GrepClient) makeHandler(server string) handlers.Handler {
 
 func (c GrepClient) makeCommands() (commands []string) {
 	for _, file := range strings.Split(c.What, ",") {
-		commands = append(commands, fmt.Sprintf("%s %s regex %s", c.Mode.String(), file, c.Regex))
+		commands = append(commands, fmt.Sprintf("%s %s %s", c.Mode.String(), file, c.Regex.Serialize()))
 	}
 	return
 }
diff --git a/internal/clients/maprclient.go b/internal/clients/maprclient.go
index c6c341b..85fa7ee 100644
--- a/internal/clients/maprclient.go
+++ b/internal/clients/maprclient.go
@@ -79,11 +79,11 @@ func NewMaprClient(args Args, queryStr string, maprClientMode MaprClientMode) (*
 
 	switch c.query.Table {
 	case "", ".":
-		c.Regex = "."
+		c.RegexStr = "."
 	case "*":
-		c.Regex = fmt.Sprintf("\\|MAPREDUCE:\\|")
+		c.RegexStr = fmt.Sprintf("\\|MAPREDUCE:\\|")
 	default:
-		c.Regex = fmt.Sprintf("\\|MAPREDUCE:%s\\|", c.query.Table)
+		c.RegexStr = fmt.Sprintf("\\|MAPREDUCE:%s\\|", c.query.Table)
 	}
 
 	c.globalGroup = mapr.NewGlobalGroupSet()
diff --git a/internal/io/fs/filereader.go b/internal/io/fs/filereader.go
index 05e58a1..0774837 100644
--- a/internal/io/fs/filereader.go
+++ b/internal/io/fs/filereader.go
@@ -4,11 +4,12 @@ import (
 	"context"
 
 	"github.com/mimecast/dtail/internal/io/line"
+	"github.com/mimecast/dtail/internal/regex"
 )
 
 // FileReader is the interface used on the dtail server to read/cat/grep/mapr... a file.
 type FileReader interface {
-	Start(ctx context.Context, lines chan<- line.Line, regex string) error
+	Start(ctx context.Context, lines chan<- line.Line, re regex.Regex) error
 	FilePath() string
 	Retry() bool
 }
diff --git a/internal/io/fs/readfile.go b/internal/io/fs/readfile.go
index cb16ec1..6757bd6 100644
--- a/internal/io/fs/readfile.go
+++ b/internal/io/fs/readfile.go
@@ -8,13 +8,13 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"regexp"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/mimecast/dtail/internal/io/line"
 	"github.com/mimecast/dtail/internal/io/logger"
+	"github.com/mimecast/dtail/internal/regex"
 
 	"github.com/DataDog/zstd"
 )
@@ -25,8 +25,6 @@ type readFile struct {
 	stats
 	// Path of log file to tail.
 	filePath string
-	// Only consider all log lines matching this regular expression.
-	re *regexp.Regexp
 	// The glob identifier of the file.
 	globID string
 	// Channel to send a server message to the dtail client
@@ -61,7 +59,7 @@ func (f readFile) Retry() bool {
 }
 
 // Start tailing a log file.
-func (f readFile) Start(ctx context.Context, lines chan<- line.Line, regex string) error {
+func (f readFile) Start(ctx context.Context, lines chan<- line.Line, re regex.Regex) error {
 	logger.Debug("readFile", f)
 	defer func() {
 		select {
@@ -98,7 +96,7 @@ func (f readFile) Start(ctx context.Context, lines chan<- line.Line, regex strin
 	wg.Add(1)
 
 	go f.periodicTruncateCheck(ctx, truncate)
-	go f.filter(ctx, &wg, rawLines, lines, regex)
+	go f.filter(ctx, &wg, rawLines, lines, re)
 
 	err = f.read(ctx, fd, rawLines, truncate)
 	close(rawLines)
@@ -229,20 +227,9 @@ func (f readFile) read(ctx context.Context, fd *os.File, rawLines chan []byte, t
 }
 
 // Filter log lines matching a given regular expression.
-func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup, rawLines <-chan []byte, lines chan<- line.Line, regex string) {
+func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup, rawLines <-chan []byte, lines chan<- line.Line, re regex.Regex) {
 	defer wg.Done()
 
-	if regex == "" {
-		regex = "."
-	}
-
-	re, err := regexp.Compile(regex)
-	if err != nil {
-		logger.Error(regex, "Can't compile regex, using '.' instead", err)
-		re = regexp.MustCompile(".")
-	}
-	f.re = re
-
 	for {
 		select {
 		case line, ok := <-rawLines:
@@ -250,7 +237,7 @@ func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup, rawLines <-cha
 			if !ok {
 				return
 			}
-			if filteredLine, ok := f.transmittable(line, len(lines), cap(lines)); ok {
+			if filteredLine, ok := f.transmittable(line, len(lines), cap(lines), re); ok {
 				select {
 				case lines <- filteredLine:
 				case <-ctx.Done():
@@ -261,10 +248,10 @@ func (f readFile) filter(ctx context.Context, wg *sync.WaitGroup, rawLines <-cha
 	}
 }
 
-func (f readFile) transmittable(lineBytes []byte, length, capacity int) (line.Line, bool) {
+func (f readFile) transmittable(lineBytes []byte, length, capacity int, re regex.Regex) (line.Line, bool) {
 	var read line.Line
 
-	if !f.re.Match(lineBytes) {
+	if !re.Match(lineBytes) {
 		f.updateLineNotMatched()
 		f.updateLineNotTransmitted()
 		return read, false
diff --git a/internal/regex/regex.go b/internal/regex/regex.go
index 800bc31..e870797 100644
--- a/internal/regex/regex.go
+++ b/internal/regex/regex.go
@@ -27,6 +27,9 @@ func NewNoop() Regex {
 }
 
 func New(regexStr string, flag Flag) (Regex, error) {
+	if regexStr == "" || regexStr == "." || regexStr == ".*" {
+		return NewNoop(), nil
+	}
 	return new(regexStr, []Flag{flag})
 }
 
@@ -46,11 +49,24 @@ func new(regexStr string, flags []Flag) (Regex, error) {
 	return r, nil
 }
 
+func (r Regex) Match(bytes []byte) bool {
+	switch r.flags[0] {
+	case Default:
+		return r.re.Match(bytes)
+	case Invert:
+		return !r.re.Match(bytes)
+	case Noop:
+		return true
+	default:
+		return false
+	}
+}
+
 func (r Regex) MatchString(str string) bool {
 	switch r.flags[0] {
 	case Default:
 		return r.re.MatchString(str)
-	case Negate:
+	case Invert:
 		return !r.re.MatchString(str)
 	case Noop:
 		return true
@@ -72,7 +88,8 @@ func Deserialize(str string) (Regex, error) {
 	// Get regex string
 	s := strings.SplitN(str, " ", 2)
 	if len(s) < 2 {
-		return Regex{}, fmt.Errorf("unable to deserialize regex '%s'", str)
+		logger.Debug("Using noop regex", str)
+		return NewNoop(), nil
 	}
 
 	flagsStr := s[0]
diff --git a/internal/regex/regex_test.go b/internal/regex/regex_test.go
index acdd518..a5e7faf 100644
--- a/internal/regex/regex_test.go
+++ b/internal/regex/regex_test.go
@@ -29,7 +29,7 @@ func TestRegex(t *testing.T) {
 			r2.String(), r.String())
 	}
 
-	r, err = New(".hello", Negate)
+	r, err = New(".hello", Invert)
 	if err != nil {
 		t.Errorf("unable to create regex: %v\n", err)
 	}
diff --git a/internal/server/handlers/readcommand.go b/internal/server/handlers/readcommand.go
index d4c871c..d59afe7 100644
--- a/internal/server/handlers/readcommand.go
+++ b/internal/server/handlers/readcommand.go
@@ -10,6 +10,7 @@ import (
 	"github.com/mimecast/dtail/internal/io/fs"
 	"github.com/mimecast/dtail/internal/io/logger"
 	"github.com/mimecast/dtail/internal/omode"
+	"github.com/mimecast/dtail/internal/regex"
 )
 
 type readCommand struct {
@@ -25,21 +26,25 @@ func newReadCommand(server *ServerHandler, mode omode.Mode) *readCommand {
 }
 
 func (r *readCommand) Start(ctx context.Context, argc int, args []string) {
-	regex := "."
+	re := regex.NewNoop()
+
 	if argc >= 4 {
-		switch args[2] {
+		deserializedRegex, err := regex.Deserialize(strings.Join(args[3:], " "))
+		if err != nil {
+			logger.Error(err)
+			r.server.sendServerMessage(logger.Error(r.server.user, commandParseWarning, err))
+			return
 		}
-		regex = strings.Join(args[3:], " ")
-		logger.Debug("Joined regex", regex)
+		re = deserializedRegex
 	}
 	if argc < 3 {
 		r.server.sendServerMessage(logger.Warn(r.server.user, commandParseWarning, args, argc))
 		return
 	}
-	r.readGlob(ctx, args[1], regex)
+	r.readGlob(ctx, args[1], re)
 }
 
-func (r *readCommand) readGlob(ctx context.Context, glob string, regex string) {
+func (r *readCommand) readGlob(ctx context.Context, glob string, re regex.Regex) {
 	retryInterval := time.Second * 5
 	glob = filepath.Clean(glob)
 
@@ -70,23 +75,23 @@ func (r *readCommand) readGlob(ctx context.Context, glob string, regex string) {
 			continue
 		}
 
-		r.readFiles(ctx, paths, glob, regex, retryInterval)
+		r.readFiles(ctx, paths, glob, re, retryInterval)
 		break
 	}
 }
 
-func (r *readCommand) readFiles(ctx context.Context, paths []string, glob string, regex string, retryInterval time.Duration) {
+func (r *readCommand) readFiles(ctx context.Context, paths []string, glob string, re regex.Regex, retryInterval time.Duration) {
 	var wg sync.WaitGroup
 	wg.Add(len(paths))
 
 	for _, path := range paths {
-		go r.readFileIfPermissions(ctx, &wg, path, glob, regex)
+		go r.readFileIfPermissions(ctx, &wg, path, glob, re)
 	}
 
 	wg.Wait()
 }
 
-func (r *readCommand) readFileIfPermissions(ctx context.Context, wg *sync.WaitGroup, path, glob, regex string) {
+func (r *readCommand) readFileIfPermissions(ctx context.Context, wg *sync.WaitGroup, path, glob string, re regex.Regex) {
 	defer wg.Done()
 	globID := r.makeGlobID(path, glob)
 
@@ -96,10 +101,10 @@ func (r *readCommand) readFileIfPermissions(ctx context.Context, wg *sync.WaitGr
 		return
 	}
 
-	r.readFile(ctx, path, globID, regex)
+	r.readFile(ctx, path, globID, re)
 }
 
-func (r *readCommand) readFile(ctx context.Context, path, globID, regex string) {
+func (r *readCommand) readFile(ctx context.Context, path, globID string, re regex.Regex) {
 	logger.Info(r.server.user, "Start reading file", path, globID)
 
 	var reader fs.FileReader
@@ -120,7 +125,7 @@ func (r *readCommand) readFile(ctx context.Context, path, globID, regex string)
 	}
 
 	for {
-		if err := reader.Start(ctx, lines, regex); err != nil {
+		if err := reader.Start(ctx, lines, re); err != nil {
 			logger.Error(r.server.user, path, globID, err)
 		}