merge

40 files changed, 196 insertions, 112 deletions

diff --git a/internal/clients/args.go b/internal/clients/args.go
index 34fcfa2..7f782f1 100644
--- a/internal/clients/args.go
+++ b/internal/clients/args.go
@@ -22,4 +22,5 @@ type Args struct {
 	SSHAuthMethods     []gossh.AuthMethod
 	SSHHostKeyCallback gossh.HostKeyCallback
 	PrivateKeyPathFile string
+	Quiet            bool
 }
diff --git a/internal/clients/baseclient.go b/internal/clients/baseclient.go
index d8d4fde..f20156f 100644
--- a/internal/clients/baseclient.go
+++ b/internal/clients/baseclient.go
@@ -39,7 +39,7 @@ type baseClient struct {
 }
 
 func (c *baseClient) init() {
-	logger.Info("Initiating base client")
+	logger.Debug("Initiating base client")
 
 	flag := regex.Default
 	if c.Args.RegexInvert {
@@ -66,11 +66,11 @@ func (c *baseClient) makeConnections(maker maker) {
 	c.stats = newTailStats(len(c.connections))
 }
 
-func (c *baseClient) Start(ctx context.Context, statsCh <-chan struct{}) (status int) {
+func (c *baseClient) Start(ctx context.Context, statsCh <-chan string) (status int) {
 	// Periodically check for unknown hosts, and ask the user whether to trust them or not.
 	go c.hostKeyCallback.PromptAddHosts(ctx)
 	// Print client stats every time something on statsCh is recieved.
-	go c.stats.Start(ctx, c.throttleCh, statsCh)
+	go c.stats.Start(ctx, c.throttleCh, statsCh, c.Args.Quiet)
 	// Keep count of active connections
 	active := make(chan struct{}, len(c.connections))
 
@@ -127,7 +127,7 @@ func (c *baseClient) makeConnection(server string, sshAuthMethods []gossh.AuthMe
 }
 
 func (c *baseClient) waitUntilDone(ctx context.Context, active chan struct{}) {
-	defer logger.Info("Terminated connection")
+	defer logger.Debug("Terminated connection")
 
 	// We want to have at least one active connection
 	<-active
diff --git a/internal/clients/catclient.go b/internal/clients/catclient.go
index d8e9196..b7b6131 100644
--- a/internal/clients/catclient.go
+++ b/internal/clients/catclient.go
@@ -42,8 +42,9 @@ func (c CatClient) makeHandler(server string) handlers.Handler {
 }
 
 func (c CatClient) makeCommands() (commands []string) {
+	options := fmt.Sprintf("quiet=%v", c.Args.Quiet)
 	for _, file := range strings.Split(c.What, ",") {
-		commands = append(commands, fmt.Sprintf("%s %s %s", c.Mode.String(), file, c.Regex.Serialize()))
+		commands = append(commands, fmt.Sprintf("%s:%s %s %s", c.Mode.String(), options, file, c.Regex.Serialize()))
 	}
 	return
 }
diff --git a/internal/clients/client.go b/internal/clients/client.go
index eb8452d..4a547e8 100644
--- a/internal/clients/client.go
+++ b/internal/clients/client.go
@@ -4,5 +4,5 @@ import "context"
 
 // Client is the interface for the end user command line client.
 type Client interface {
-	Start(ctx context.Context, statsCh <-chan struct{}) int
+	Start(ctx context.Context, statsCh <-chan string) int
 }
diff --git a/internal/clients/grepclient.go b/internal/clients/grepclient.go
index 4024083..652c31b 100644
--- a/internal/clients/grepclient.go
+++ b/internal/clients/grepclient.go
@@ -41,8 +41,10 @@ func (c GrepClient) makeHandler(server string) handlers.Handler {
 }
 
 func (c GrepClient) makeCommands() (commands []string) {
+	options := fmt.Sprintf("quiet=%v", c.Args.Quiet)
 	for _, file := range strings.Split(c.What, ",") {
-		commands = append(commands, fmt.Sprintf("%s %s %s", c.Mode.String(), file, c.Regex.Serialize()))
+		commands = append(commands, fmt.Sprintf("%s:%s %s %s", c.Mode.String(), options, file, c.Regex.Serialize()))
 	}
+
 	return
 }
diff --git a/internal/clients/handlers/basehandler.go b/internal/clients/handlers/basehandler.go
index b5045e2..f07fd90 100644
--- a/internal/clients/handlers/basehandler.go
+++ b/internal/clients/handlers/basehandler.go
@@ -4,7 +4,6 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io"
-	"strconv"
 	"strings"
 	"time"
 
@@ -78,6 +77,7 @@ func (h *baseHandler) Read(p []byte) (n int, err error) {
 	case <-h.Done():
 		return 0, io.EOF
 	}
+
 	return
 }
 
@@ -111,21 +111,5 @@ func (h *baseHandler) handleHiddenMessage(message string) {
 		case <-h.Done():
 			return
 		}
-
-	case strings.HasPrefix(message, ".run exitstatus"):
-		splitted := strings.Split(strings.TrimSuffix(message, "\n"), " ")
-		if len(splitted) != 3 {
-			logger.Error("Unable to retrieve exitstatus", message)
-			return
-		}
-		i, err := strconv.Atoi(splitted[2])
-		if err != nil {
-			logger.Error("Unable to retrieve exitstatus", message, err)
-			return
-		}
-		logger.Debug("Retrieved exitstatus", h.status)
-		if i > h.status {
-			h.status = i
-		}
 	}
 }
diff --git a/internal/clients/handlers/healthhandler.go b/internal/clients/handlers/healthhandler.go
index 95693ab..0440706 100644
--- a/internal/clients/handlers/healthhandler.go
+++ b/internal/clients/handlers/healthhandler.go
@@ -19,6 +19,7 @@ type HealthHandler struct {
 	receive chan<- string
 	// The remote server address
 	server string
+	// The return status.
 	status int
 }
 
@@ -45,10 +46,12 @@ func (h *HealthHandler) Status() int {
 	return h.status
 }
 
+// Done returns done channel of the handler.
 func (h *HealthHandler) Done() <-chan struct{} {
 	return h.done.Done()
 }
 
+// Shutdown the handler.
 func (h *HealthHandler) Shutdown() {
 	h.done.Shutdown()
 }
diff --git a/internal/clients/maker.go b/internal/clients/maker.go
index 1ba6482..d5ffd8b 100644
--- a/internal/clients/maker.go
+++ b/internal/clients/maker.go
@@ -4,6 +4,9 @@ import (
 	"github.com/mimecast/dtail/internal/clients/handlers"
 )
 
+// maker interface helps to re-use code in all DTail client implementations.
+// All clients share the baseClient but have different connection handlers
+// and send different commands to the DTail server.
 type maker interface {
 	makeHandler(server string) handlers.Handler
 	makeCommands() (commands []string)
diff --git a/internal/clients/maprclient.go b/internal/clients/maprclient.go
index 149129d..1c0c2cc 100644
--- a/internal/clients/maprclient.go
+++ b/internal/clients/maprclient.go
@@ -94,12 +94,12 @@ func NewMaprClient(args Args, queryStr string, maprClientMode MaprClientMode) (*
 }
 
 // Start starts the mapreduce client.
-func (c *MaprClient) Start(ctx context.Context, statsCh <-chan struct{}) (status int) {
+func (c *MaprClient) Start(ctx context.Context, statsCh <-chan string) (status int) {
 	go c.periodicReportResults(ctx)
 
 	status = c.baseClient.Start(ctx, statsCh)
 	if c.cumulative {
-		logger.Info("Received final mapreduce result")
+		logger.Debug("Received final mapreduce result")
 		c.reportResults()
 	}
 
@@ -112,6 +112,7 @@ func (c MaprClient) makeHandler(server string) handlers.Handler {
 
 func (c MaprClient) makeCommands() (commands []string) {
 	commands = append(commands, fmt.Sprintf("map %s", c.query.RawQuery))
+	options := fmt.Sprintf("quiet=%v", c.Args.Quiet)
 
 	modeStr := "cat"
 	if c.Mode == omode.TailClient {
@@ -123,7 +124,7 @@ func (c MaprClient) makeCommands() (commands []string) {
 			commands = append(commands, fmt.Sprintf("timeout %d %s %s %s", c.Timeout, modeStr, file, c.Regex.Serialize()))
 			continue
 		}
-		commands = append(commands, fmt.Sprintf("%s %s %s", modeStr, file, c.Regex.Serialize()))
+		commands = append(commands, fmt.Sprintf("%s:%s %s %s", modeStr, options, file, c.Regex.Serialize()))
 	}
 
 	return
@@ -133,7 +134,7 @@ func (c *MaprClient) periodicReportResults(ctx context.Context) {
 	for {
 		select {
 		case <-time.After(c.query.Interval):
-			logger.Info("Gathering interim mapreduce result")
+			logger.Debug("Gathering interim mapreduce result")
 			c.reportResults()
 		case <-ctx.Done():
 			return
@@ -165,7 +166,7 @@ func (c *MaprClient) printResults() {
 	}
 
 	if numLines == 0 {
-		logger.Info("Empty result set this time...")
+		logger.Warn("Empty result set this time...")
 		return
 	}
 
diff --git a/internal/clients/stats.go b/internal/clients/stats.go
index e7eabd8..d8163d4 100644
--- a/internal/clients/stats.go
+++ b/internal/clients/stats.go
@@ -8,6 +8,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/mimecast/dtail/internal/config"
 	"github.com/mimecast/dtail/internal/io/logger"
 )
 
@@ -33,16 +34,18 @@ func newTailStats(connectionsTotal int) *stats {
 
 // Start starts printing client connection stats every time a signal is recieved or
 // connection count has changed.
-func (s *stats) Start(ctx context.Context, throttleCh, statsCh <-chan struct{}) {
+func (s *stats) Start(ctx context.Context, throttleCh <-chan struct{}, statsCh <-chan string, quiet bool) {
 	var connectedLast int
 
 	for {
 		var force bool
+		var messages []string
 
 		select {
-		case <-statsCh:
+		case message := <-statsCh:
+			messages = append(messages, message)
 			force = true
-		case <-time.After(time.Second * 2):
+		case <-time.After(time.Second * 3):
 		case <-ctx.Done():
 			return
 		}
@@ -52,11 +55,18 @@ func (s *stats) Start(ctx context.Context, throttleCh, statsCh <-chan struct{})
 
 		newConnections := connected - connectedLast
 
-		if connected == connectedLast && !force {
+		if (connected == connectedLast || quiet) && !force {
 			continue
 		}
 
-		logger.Info(s.statsLine(connected, newConnections, throttle))
+		stats := s.statsLine(connected, newConnections, throttle)
+		switch force {
+		case true:
+			messages = append(messages, fmt.Sprintf("Connection stats: %s", stats))
+			s.printStatsDueInterrupt(messages)
+		default:
+			logger.Info(stats)
+		}
 
 		connectedLast = connected
 		s.mutex.Lock()
@@ -65,6 +75,15 @@ func (s *stats) Start(ctx context.Context, throttleCh, statsCh <-chan struct{})
 	}
 }
 
+func (s *stats) printStatsDueInterrupt(messages []string) {
+	logger.Pause()
+	for _, message := range messages {
+		fmt.Println(fmt.Sprintf(" %s", message))
+	}
+	time.Sleep(time.Second * time.Duration(config.InterruptTimeoutS))
+	logger.Resume()
+}
+
 func (s *stats) statsLine(connected, newConnections int, throttle int) string {
 	percConnected := percentOf(float64(s.connectionsTotal), float64(connected))
 
@@ -88,5 +107,6 @@ func percentOf(total float64, value float64) float64 {
 	if total == 0 || total == value {
 		return 100
 	}
+
 	return value / (total / 100.0)
 }
diff --git a/internal/clients/tailclient.go b/internal/clients/tailclient.go
index 53b5ba4..cefbaa7 100644
--- a/internal/clients/tailclient.go
+++ b/internal/clients/tailclient.go
@@ -29,6 +29,7 @@ func NewTailClient(args Args) (*TailClient, error) {
 
 	c.init()
 	c.makeConnections(c)
+
 	return &c, nil
 }
 
@@ -37,8 +38,9 @@ func (c TailClient) makeHandler(server string) handlers.Handler {
 }
 
 func (c TailClient) makeCommands() (commands []string) {
+	options := fmt.Sprintf("quiet=%v", c.Args.Quiet)
 	for _, file := range strings.Split(c.What, ",") {
-		commands = append(commands, fmt.Sprintf("%s %s %s", c.Mode.String(), file, c.Regex.Serialize()))
+		commands = append(commands, fmt.Sprintf("%s:%s %s %s", c.Mode.String(), options, file, c.Regex.Serialize()))
 	}
 	logger.Debug(commands)
 
diff --git a/internal/color/colorfy.go b/internal/color/colorfy.go
index 9ae46f5..a2beb7a 100644
--- a/internal/color/colorfy.go
+++ b/internal/color/colorfy.go
@@ -41,16 +41,14 @@ func paintClientStats(line string) string {
 
 // Colorfy a given line based on the line's content.
 func Colorfy(line string) string {
-	if strings.HasPrefix(line, "REMOTE") {
+	switch {
+	case strings.HasPrefix(line, "REMOTE"):
 		return paintRemote(line)
-	}
-	if strings.HasPrefix(line, "CLIENT") && strings.Contains(line, "|stats|") {
+	case strings.HasPrefix(line, "CLIENT") && strings.Contains(line, "|stats|"):
 		return paintClientStats(line)
-	}
-	if strings.Contains(line, "ERROR") {
+	case strings.Contains(line, "ERROR"):
 		return Paint(Magenta, line)
-	}
-	if strings.Contains(line, "WARN") {
+	case strings.Contains(line, "WARN"):
 		return Paint(Magenta, line)
 	}
 
diff --git a/internal/config/common.go b/internal/config/common.go
index 103b390..c3e203e 100644
--- a/internal/config/common.go
+++ b/internal/config/common.go
@@ -2,10 +2,14 @@ package config
 
 // CommonConfig stores configuration keys shared by DTail server and client.
 type CommonConfig struct {
-	SSHPort                    int
+	// The SSH port number
+	SSHPort int
+	// Enable experimental features (mainly for dev purposes)
 	ExperimentalFeaturesEnable bool `json:",omitempty"`
-	DebugEnable                bool `json:",omitempty"`
-	TraceEnable                bool `json:",omitempty"`
+	// Enable debug logging. Don't enable in production.
+	DebugEnable bool `json:",omitempty"`
+	// Enable trace logging. Don't enable in production.
+	TraceEnable bool `json:",omitempty"`
 	// The log strategy to use, one of
 	//   stdout: only log to stdout (useful when used with systemd)
 	//   daily: create a log file for every day
diff --git a/internal/config/config.go b/internal/config/config.go
index dc96d6b..276ddcf 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -15,6 +15,9 @@ const ScheduleUser string = "DTAIL-SCHEDULE"
 // ContinuousUser is used for non-interactive continuous mapreduce queries.
 const ContinuousUser string = "DTAIL-CONTINUOUS"
 
+// InterruptTimeoutS is used to terminate DTail when Ctrl+C was pressed twice within a given interval.
+const InterruptTimeoutS int = 3
+
 // Client holds a DTail client configuration.
 var Client *ClientConfig
 
diff --git a/internal/config/server.go b/internal/config/server.go
index db12cec..dc0d587 100644
--- a/internal/config/server.go
+++ b/internal/config/server.go
@@ -61,6 +61,7 @@ type ServerConfig struct {
 	Continuous []Continuous `json:",omitempty"`
 }
 
+// ServerRelaxedAuthEnable should be used for development and testing purposes only.
 var ServerRelaxedAuthEnable bool
 
 // Create a new default server configuration.
diff --git a/internal/discovery/comma.go b/internal/discovery/comma.go
index 94276c7..4344240 100644
--- a/internal/discovery/comma.go
+++ b/internal/discovery/comma.go
@@ -1,8 +1,9 @@
 package discovery
 
 import (
-	"github.com/mimecast/dtail/internal/io/logger"
 	"strings"
+
+	"github.com/mimecast/dtail/internal/io/logger"
 )
 
 // ServerListFromCOMMA retrieves a list of servers from comma separated input list.
diff --git a/internal/discovery/file.go b/internal/discovery/file.go
index c04173e..1250755 100644
--- a/internal/discovery/file.go
+++ b/internal/discovery/file.go
@@ -2,8 +2,9 @@ package discovery
 
 import (
 	"bufio"
-	"github.com/mimecast/dtail/internal/io/logger"
 	"os"
+
+	"github.com/mimecast/dtail/internal/io/logger"
 )
 
 // ServerListFromFILE retrieves a list of servers from a file.
diff --git a/internal/io/fs/permissions/permission_linux.go b/internal/io/fs/permissions/permission_linux.go
index feae729..bbc039b 100644
--- a/internal/io/fs/permissions/permission_linux.go
+++ b/internal/io/fs/permissions/permission_linux.go
@@ -11,7 +11,7 @@ import (
 	"unsafe"
 )
 
-// To check whether user has Linux file system permissions to read a given file.
+// ToRead checks whether user has Linux file system permissions to read a given file.
 func ToRead(user, filePath string) (bool, error) {
 	cUser := C.CString(user)
 	cFilePath := C.CString(filePath)
diff --git a/internal/io/line/line.go b/internal/io/line/line.go
index 9db93c0..715be34 100644
--- a/internal/io/line/line.go
+++ b/internal/io/line/line.go
@@ -15,7 +15,11 @@ type Line struct {
 	// lines if that happens but it will signal to the client how
 	// many log lines in % could be transmitted to the client.
 	TransmittedPerc int
-	SourceID        string
+	// Contains the unique identifier of the source log file.
+	// It could be the name of the log or it could be one of the parent
+	// directories in case multiple log files with the same basename are
+	// followed.
+	SourceID string
 }
 
 // Return a human readable representation of the followed line.
diff --git a/internal/io/logger/logger.go b/internal/io/logger/logger.go
index b7db0a7..4254eef 100644
--- a/internal/io/logger/logger.go
+++ b/internal/io/logger/logger.go
@@ -72,12 +72,15 @@ type buf struct {
 func Start(ctx context.Context, mode Modes) {
 	Mode = mode
 
-	if Mode.Nothing {
+	switch {
+	case Mode.Nothing:
 		return
-	}
-
-	if Mode.Trace {
+	case Mode.Quiet:
+		Mode.Trace = false
+		Mode.Debug = false
+	case Mode.Trace:
 		Mode.Debug = true
+	default:
 	}
 
 	strategy := logStrategy()
@@ -87,7 +90,7 @@ func Start(ctx context.Context, mode Modes) {
 	case DailyStrategy:
 		_, err := os.Stat(config.Common.LogDir)
 		Mode.logToFile = !os.IsNotExist(err)
-		Mode.logToStdout = !Mode.Server || Mode.Debug || Mode.Trace
+		Mode.logToStdout = !Mode.Server || Mode.Debug || Mode.Trace || Mode.Quiet
 	case StdoutStrategy:
 		fallthrough
 	default:
@@ -131,11 +134,14 @@ func Info(args ...interface{}) string {
 
 // Warn message logging.
 func Warn(args ...interface{}) string {
-	if Mode.Server {
-		return log(serverStr, warnStr, args)
+	if !Mode.Quiet {
+		if Mode.Server {
+			return log(serverStr, warnStr, args)
+		}
+		return log(clientStr, warnStr, args)
 	}
 
-	return log(clientStr, warnStr, args)
+	return ""
 }
 
 // Error message logging.
@@ -242,7 +248,7 @@ func log(what string, severity string, args []interface{}) string {
 	message := strings.Join(messages, "|")
 	write(what, severity, message)
 
-	return message
+	return fmt.Sprintf("%s|%s", severity, message)
 }
 
 // Raw message logging.
diff --git a/internal/io/logger/modes.go b/internal/io/logger/modes.go
index 47dadfe..8864179 100644
--- a/internal/io/logger/modes.go
+++ b/internal/io/logger/modes.go
@@ -6,6 +6,7 @@ type Modes struct {
 	Trace       bool
 	Debug       bool
 	Nothing     bool
+	Quiet       bool
 	logToStdout bool
 	logToFile   bool
 }
diff --git a/internal/io/prompt/prompt.go b/internal/io/prompt/prompt.go
index a438d33..36ebdb5 100644
--- a/internal/io/prompt/prompt.go
+++ b/internal/io/prompt/prompt.go
@@ -3,9 +3,10 @@ package prompt
 import (
 	"bufio"
 	"fmt"
-	"github.com/mimecast/dtail/internal/io/logger"
 	"os"
 	"strings"
+
+	"github.com/mimecast/dtail/internal/io/logger"
 )
 
 // Answer is a user input of a prompt question.
@@ -18,8 +19,7 @@ type Answer struct {
 	Callback func()
 	// Runs after Callback and after logging resumes
 	EndCallback func()
-
-	AskAgain bool
+	AskAgain    bool
 }
 
 // Prompt used for interactive user input.
diff --git a/internal/io/signal/signal.go b/internal/io/signal/signal.go
index 3785d71..500c530 100644
--- a/internal/io/signal/signal.go
+++ b/internal/io/signal/signal.go
@@ -4,33 +4,38 @@ import (
 	"context"
 	"os"
 	gosignal "os/signal"
+	"syscall"
 	"time"
 
-	"github.com/mimecast/dtail/internal/io/logger"
+	"github.com/mimecast/dtail/internal/config"
 )
 
-// StatsCh returns a channel for "please print stats" signalling.
-func InterruptCh(ctx context.Context) <-chan struct{} {
-	sigCh := make(chan os.Signal)
-	gosignal.Notify(sigCh, os.Interrupt)
+// InterruptCh returns a channel for "please print stats" signalling.
+func InterruptCh(ctx context.Context) <-chan string {
+	sigIntCh := make(chan os.Signal)
+	gosignal.Notify(sigIntCh, os.Interrupt)
 
-	statsCh := make(chan struct{})
+	sigOtherCh := make(chan os.Signal)
+	gosignal.Notify(sigOtherCh, syscall.SIGHUP, syscall.SIGTERM, syscall.SIGQUIT)
+
+	statsCh := make(chan string)
 
 	go func() {
 		for {
 			select {
-			case <-sigCh:
+			case <-sigIntCh:
 				select {
-				case statsCh <- struct{}{}:
-					logger.Info("Hit Ctrl+C twice to exit")
+				case statsCh <- "Hint: Hit Ctrl+C again to exit":
 					select {
-					case <-sigCh:
+					case <-sigIntCh:
 						os.Exit(0)
-					case <-time.After(time.Second):
+					case <-time.After(time.Second * time.Duration(config.InterruptTimeoutS)):
 					}
 				default:
-					// Stats currently already printed.
+					// Stats already printed.
 				}
+			case <-sigOtherCh:
+				os.Exit(0)
 			case <-ctx.Done():
 				return
 			}
diff --git a/internal/mapr/funcs/function.go b/internal/mapr/funcs/function.go
index 52aaa98..1a89c3a 100644
--- a/internal/mapr/funcs/function.go
+++ b/internal/mapr/funcs/function.go
@@ -12,6 +12,7 @@ type CallbackFunc func(text string) string
 type Function struct {
 	// Name of the callback function
 	Name string
+	// The Go-callback function to call for this DTail function.
 	call CallbackFunc
 }
 
diff --git a/internal/mapr/query.go b/internal/mapr/query.go
index 7f6b63c..01852da 100644
--- a/internal/mapr/query.go
+++ b/internal/mapr/query.go
@@ -177,12 +177,6 @@ func (q *Query) parse(tokens []token) error {
 		}
 	}
 
-	// Comment out for empty table support, which is "all" log lines.
-	/*
-		if q.Table == "" {
-			return errors.New(invalidQuery + "Empty table specified in 'from' clause")
-		}
-	*/
 	if len(q.Select) < 1 {
 		return errors.New(invalidQuery + "Expected at least one field in 'select' clause but got none")
 	}
diff --git a/internal/mapr/selectcondition.go b/internal/mapr/selectcondition.go
index 1882b7e..d6aa0d4 100644
--- a/internal/mapr/selectcondition.go
+++ b/internal/mapr/selectcondition.go
@@ -92,5 +92,6 @@ func makeSelectConditions(tokens []token) ([]selectCondition, error) {
 		}
 		sel = append(sel, sc)
 	}
+
 	return sel, nil
 }
diff --git a/internal/mapr/server/aggregate.go b/internal/mapr/server/aggregate.go
index cd59b63..28bb074 100644
--- a/internal/mapr/server/aggregate.go
+++ b/internal/mapr/server/aggregate.go
@@ -80,6 +80,7 @@ func NewAggregate(queryStr string) (*Aggregate, error) {
 	return &a, nil
 }
 
+// Shutdown the aggregation engine.
 func (a *Aggregate) Shutdown() {
 	a.Flush()
 	a.done.Shutdown()
diff --git a/internal/mapr/token.go b/internal/mapr/token.go
index d337bd2..8972188 100644
--- a/internal/mapr/token.go
+++ b/internal/mapr/token.go
@@ -22,6 +22,7 @@ func (t token) isKeyword() bool {
 			return true
 		}
 	}
+
 	return false
 }
 
@@ -94,6 +95,7 @@ func tokensConsumeStr(tokens []token) ([]token, []string) {
 	for _, token := range found {
 		strings = append(strings, token.str)
 	}
+
 	return tokens, strings
 }
 
@@ -104,5 +106,6 @@ func tokensConsumeOptional(tokens []token, optional string) []token {
 	if strings.ToLower(tokens[0].str) == strings.ToLower(optional) {
 		return tokens[1:]
 	}
+
 	return tokens
 }
diff --git a/internal/mapr/wherecondition.go b/internal/mapr/wherecondition.go
index ff1b489..7a60dba 100644
--- a/internal/mapr/wherecondition.go
+++ b/internal/mapr/wherecondition.go
@@ -19,6 +19,10 @@ const (
 	StringNe            QueryOperation = iota
 	StringContains      QueryOperation = iota
 	StringNotContains   QueryOperation = iota
+	StringHasPrefix     QueryOperation = iota
+	StringNotHasPrefix  QueryOperation = iota
+	StringHasSuffix     QueryOperation = iota
+	StringNotHasSuffix  QueryOperation = iota
 	FloatOperation      QueryOperation = iota
 	FloatEq             QueryOperation = iota
 	FloatNe             QueryOperation = iota
@@ -78,7 +82,17 @@ func makeWhereConditions(tokens []token) (where []whereCondition, err error) {
 		case "contains":
 			wc.Operation = StringContains
 		case "lacks":
+			fallthrough
+		case "ncontains":
 			wc.Operation = StringNotContains
+