Пример #1
0
func ExampleSortEntries() {
	c := &SliceCursor{
		sstable.Entry{[]byte{3}, []byte{}},
		sstable.Entry{[]byte{2}, []byte{}},
		sstable.Entry{[]byte{4}, []byte{}},
		sstable.Entry{[]byte{1}, []byte{}},
	}
	f, _ := ioutil.TempFile("", "")
	name := f.Name()
	defer os.Remove(name)
	w := sstable.NewWriter(f)
	fmt.Println(SortEntries(c, 100, w))
	fmt.Println("Cursor is done:", c.Done())
	outf, _ := os.Open(name)
	defer outf.Close()
	s, _ := sstable.NewSSTable(outf)
	results := s.ScanFrom([]byte{})
	if results == nil {
		fmt.Println(results)
		return
	}
	for !results.Done() {
		fmt.Println(results.Entry())
		results.Next()
	}
	// Output:
	// 4 <nil>
	// Cursor is done: true
	// &{[1] []}
	// &{[2] []}
	// &{[3] []}
	// &{[4] []}
}
Пример #2
0
func ExampleMerge() {
	f, _ := ioutil.TempFile("", "")
	name := f.Name()
	defer os.Remove(name)
	w := sstable.NewWriter(f)
	cs := []sstable.Cursor{&SliceCursor{
		sstable.Entry{[]byte{2}, []byte{}},
		sstable.Entry{[]byte{5}, []byte{}},
		sstable.Entry{[]byte{10}, []byte{}},
		sstable.Entry{[]byte{15}, []byte{}},
	}, &SliceCursor{
		sstable.Entry{[]byte{1}, []byte{}},
		sstable.Entry{[]byte{4}, []byte{}},
		sstable.Entry{[]byte{11}, []byte{}},
		sstable.Entry{[]byte{12}, []byte{}},
	}, &SliceCursor{
		sstable.Entry{[]byte{6}, []byte{}},
		sstable.Entry{[]byte{8}, []byte{}},
		sstable.Entry{[]byte{9}, []byte{}},
		sstable.Entry{[]byte{14}, []byte{}},
	}}
	if err := Merge(cs, w); err != nil {
		fmt.Println(err)
		return
	}
	w.Close()
	f2, _ := os.Open(name)
	defer f2.Close()
	s, err := sstable.NewSSTable(f2)
	if err != nil {
		fmt.Println(err)
		return
	}
	c := s.ScanFrom([]byte{})
	if c == nil {
		fmt.Println(c)
		return
	}
	for !c.Done() {
		fmt.Println(c.Entry())
		c.Next()
	}
	// Output:
	// &{[1] []}
	// &{[2] []}
	// &{[4] []}
	// &{[5] []}
	// &{[6] []}
	// &{[8] []}
	// &{[9] []}
	// &{[10] []}
	// &{[11] []}
	// &{[12] []}
	// &{[14] []}
	// &{[15] []}
}
Пример #3
0
// lss prints the list of keys of each path in the SSTable.
func lss(tablePaths []string) {
	for _, tablePath := range tablePaths {
		f, err := os.Open(tablePath)
		if err != nil {
			log.Println("Error on opening path:", err)
		}
		defer f.Close()
		tbl, err := sstable.NewSSTable(f)
		if err != nil {
			log.Println("Error on path", tablePath, ":", err)
			return
		}
		for c := tbl.ScanFrom(nil); !c.Done(); c.Next() {
			fmt.Println(string(c.Entry().Key))
		}
	}
}
Пример #4
0
// cats prints the value of the key in the SSTable.
func cats(tablePath string, key string) {
	f, err := os.Open(tablePath)
	if err != nil {
		log.Println("Error on opening path", tablePath, ":", err)
		return
	}
	defer f.Close()
	tbl, err := sstable.NewSSTable(f)
	if err != nil {
		log.Println(err)
		return
	}
	c := tbl.ScanFrom([]byte(key))
	if c.Done() || bytes.Compare(c.Entry().Key, []byte(key)) != 0 {
		return
	}
	value := c.Entry().Value
	fmt.Println(string(value))
}
Пример #5
0
func main() {
	flag.Parse()
	if *path == "" {
		log.Fatal("Please specify --path flag.")
	}
	f, err := os.Open(*path)
	if err != nil {
		log.Fatal("Open file failed:", err)
	}
	tbl, err = sstable.NewSSTable(f)
	if err != nil {
		log.Fatal("SSTable creation failed:", err)
	}

	http.HandleFunc("/", indexHandler)
	http.HandleFunc("/lookup", lookupHandler)
	if err := http.ListenAndServe(*addr, nil); err != nil {
		log.Fatal("ListenAndServe failed: ", err)
	}
}
Пример #6
0
func ExampleSort() {
	c := &SliceCursor{
		sstable.Entry{[]byte{3}, []byte{}},
		sstable.Entry{[]byte{2}, []byte{}},
		sstable.Entry{[]byte{4}, []byte{}},
		sstable.Entry{[]byte{1}, []byte{}},
	}
	var files []*os.File
	defer func() {
		for _, f := range files {
			f.Close()
		}
	}()
	for !c.Done() {
		f, _ := ioutil.TempFile("", "")
		name := f.Name()
		defer os.Remove(name)
		w := sstable.NewWriter(f)
		defer w.Close()
		fmt.Println(SortEntries(c, 20, w))
		fmt.Println("Cursor is done:", c.Done())
		r, _ := os.Open(name)
		files = append(files, r)
	}

	var cursors []sstable.Cursor
	for _, f := range files {
		s, _ := sstable.NewSSTable(f)
		c := s.ScanFrom(nil)
		if c == nil {
			fmt.Println(c)
			return
		}
		cursors = append(cursors, c)
	}

	f, _ := ioutil.TempFile("", "")
	name := f.Name()
	defer os.Remove(name)
	w := sstable.NewWriter(f)
	if err := Merge(cursors, w); err != nil {
		fmt.Println(err)
		return
	}
	w.Close()

	f2, _ := os.Open(name)
	s, _ := sstable.NewSSTable(f2)
	results := s.ScanFrom(nil)
	if results == nil {
		fmt.Println(results)
		return
	}
	for !results.Done() {
		fmt.Println(results.Entry())
		results.Next()
	}
	// Output:
	// 3 <nil>
	// Cursor is done: false
	// 1 <nil>
	// Cursor is done: true
	// &{[1] []}
	// &{[2] []}
	// &{[3] []}
	// &{[4] []}
}