add: logparser v5 shared record

logparser/v5/main.go

@@ -27,6 +27,7 @@ func main() {
 		// pipe.NewJSONReport(os.Stdout),
 		pipe.FilterBy(pipe.DomainExtFilter("com", "io")),
 		pipe.GroupBy(pipe.DomainGrouper),
+		// new(passThrough),
 	)
 
 	if err := p.Run(); err != nil {

logparser/v5/passthrough.go

@@ -0,0 +1,31 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"github.com/inancgumus/learngo/logparser/v5/pipe"
+)
+
+type passThrough struct {
+	pipe.Iterator
+}
+
+func (t *passThrough) Consume(results pipe.Iterator) error {
+	t.Iterator = results
+	return nil
+}
+
+func (t *passThrough) Each(yield func(pipe.Record) error) error {
+
+	return t.Iterator.Each(func(r pipe.Record) error {
+		// fmt.Println(r.Fields())
+		// fmt.Println(r.Int("visits"))
+		return yield(r)
+	})
+
+}

logparser/v5/pipe/filter.go

@@ -8,6 +8,7 @@
 package pipe
 
 // FilterFunc represents a filtering pipeline func.
+// The type alias frees us from binding to a named type.
 type FilterFunc = func(Record) (pass bool)
 
 // Filter the records.

logparser/v5/pipe/filters.go

@@ -20,7 +20,7 @@ func NotFilter(filter FilterFunc) FilterFunc {
 func DomainExtFilter(domains ...string) FilterFunc {
 	return func(r Record) bool {
 		for _, domain := range domains {
-			if strings.HasSuffix(r.Domain, "."+domain) {
+			if strings.HasSuffix(r.domain, "."+domain) {
 				return true
 			}
 		}
@@ -31,11 +31,11 @@ func DomainExtFilter(domains ...string) FilterFunc {
 // DomainFilter filters a domain if it contains the given text.
 func DomainFilter(text string) FilterFunc {
 	return func(r Record) bool {
-		return strings.Contains(r.Domain, text)
+		return strings.Contains(r.domain, text)
 	}
 }
 
 // DomainOrgFilter filters only the ".org" domains.
 func DomainOrgFilter(r Record) bool {
-	return strings.HasSuffix(r.Domain, ".org")
+	return strings.HasSuffix(r.domain, ".org")
 }

logparser/v5/pipe/group.go

@@ -12,6 +12,7 @@ import (
 )
 
 // GroupFunc represents a grouping func that returns a grouping key.
+// The type alias frees us from binding to a named type.
 type GroupFunc = func(Record) (key string)
 
 // Group records by a key.

logparser/v5/pipe/groupers.go

@@ -12,10 +12,10 @@ package pipe
 // For example: It returns the page field as well.
 // Exercise: Write a solution that removes the unnecessary data.
 func DomainGrouper(r Record) string {
-	return r.Domain
+	return r.domain
 }
 
 // Page groups records by page.
 func Page(r Record) string {
-	return r.Domain + r.Page
+	return r.domain + r.page
 }

logparser/v5/pipe/record.go

@@ -10,18 +10,18 @@ import (
 
 const fieldsLength = 4
 
-// Record stores fields of a log line.
-type Record struct {
-	Domain  string
-	Page    string
-	Visits  int
-	Uniques int
+// record stores fields of a log line.
+type record struct {
+	domain  string
+	page    string
+	visits  int
+	uniques int
 }
 
 // Sum the numeric fields with another record.
 func (r Record) Sum(other Record) Record {
-	r.Visits += other.Visits
-	r.Uniques += other.Uniques
+	r.visits += other.visits
+	r.uniques += other.uniques
 	return r
 }
 
@@ -32,12 +32,12 @@ func (r *Record) UnmarshalText(p []byte) (err error) {
 		return fmt.Errorf("wrong number of fields %q", fields)
 	}
 
-	r.Domain, r.Page = fields[0], fields[1]
+	r.domain, r.page = fields[0], fields[1]
 
-	if r.Visits, err = parseStr("visits", fields[2]); err != nil {
+	if r.visits, err = parseStr("visits", fields[2]); err != nil {
 		return err
 	}
-	if r.Uniques, err = parseStr("uniques", fields[3]); err != nil {
+	if r.uniques, err = parseStr("uniques", fields[3]); err != nil {
 		return err
 	}
 	return validate(*r)
@@ -72,13 +72,13 @@ func parseStr(name, v string) (int, error) {
 // validate whether a parsed record is valid or not.
 func validate(r Record) (err error) {
 	switch {
-	case r.Domain == "":
+	case r.domain == "":
 		err = errors.New("record.domain cannot be empty")
-	case r.Page == "":
+	case r.page == "":
 		err = errors.New("record.page cannot be empty")
-	case r.Visits < 0:
+	case r.visits < 0:
 		err = errors.New("record.visits cannot be negative")
-	case r.Uniques < 0:
+	case r.uniques < 0:
 		err = errors.New("record.uniques cannot be negative")
 	}
 	return

logparser/v5/pipe/recordshare.go

@@ -0,0 +1,58 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package pipe
+
+import (
+	"fmt"
+	"reflect"
+)
+
+// Record stores the log line fields.
+// The underlying fields are kept hidden.
+// The users of the package are decoupled from the underlying record fields.
+// When the fields change, the client won't feel the difference (at least in compile-time).
+type Record struct {
+	record
+}
+
+// String returns a string field. Panics when the field doesn't exist.
+func (r Record) String(field string) string {
+	return r.mustGet(field, reflect.String).String()
+}
+
+// Int returns an int field. Panics when the field doesn't exist.
+func (r Record) Int(field string) int {
+	return int(r.mustGet(field, reflect.Int).Int())
+}
+
+// Fields returns all the field names.
+// The names can be used to query the Record.
+func (r Record) Fields() (fields []string) {
+	t := reflect.TypeOf(record{})
+
+	for i := 0; i < t.NumField(); i++ {
+		f := t.Field(i)
+		s := fmt.Sprintf("(%s: %s)", f.Name, f.Type.Name())
+
+		fields = append(fields, s)
+	}
+
+	return
+}
+
+// mustGet the field with the same kind or panics.
+func (r Record) mustGet(field string, kind reflect.Kind) reflect.Value {
+	v := reflect.ValueOf(r.record).FieldByName(field)
+	if !v.IsValid() {
+		panic(fmt.Errorf("record.%s does not exist", field))
+	}
+	if v.Kind() != kind {
+		panic(fmt.Errorf("record.%s is not %q", field, kind))
+	}
+	return v
+}

logparser/v5/pipe/textreport.go

@@ -45,8 +45,8 @@ func (t *TextReport) Consume(records Iterator) error {
 		total = r.Sum(total)
 
 		write(w, "%s\t%s\t%d\t%d\n",
-			r.Domain, r.Page,
-			r.Visits, r.Uniques,
+			r.domain, r.page,
+			r.visits, r.uniques,
 		)
 
 		return nil
@@ -57,8 +57,8 @@ func (t *TextReport) Consume(records Iterator) error {
 
 	write(w, "\t\t\t\n")
 	write(w, "%s\t%s\t%d\t%d\n", "TOTAL", "",
-		total.Visits,
-		total.Uniques,
+		total.visits,
+		total.uniques,
 	)
 
 	return w.Flush()