Added files from the first prototype.

cmd/csaf_provider/indices.go

@@ -0,0 +1,158 @@
+package main
+
+import (
+	"bufio"
+	"encoding/csv"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"time"
+)
+
+func updateIndex(dir, fname string) error {
+
+	index := filepath.Join(dir, "index.txt")
+
+	lines, err := func() ([]string, error) {
+		f, err := os.Open(index)
+		if err != nil {
+			if os.IsNotExist(err) {
+				return []string{fname}, nil
+			} else {
+				return nil, err
+			}
+		}
+		defer f.Close()
+		var lines []string
+		scanner := bufio.NewScanner(f)
+		for scanner.Scan() {
+			// stop scanning when we found it.
+			if line := scanner.Text(); line != fname {
+				lines = append(lines, line)
+			} else {
+				return nil, nil
+			}
+		}
+		return append(lines, fname), nil
+	}()
+	if err != nil {
+		return err
+	}
+	if len(lines) == 0 {
+		return nil
+	}
+	// Create new to break hard link.
+	f, err := os.Create(index)
+	if err != nil {
+		return err
+	}
+	sort.Strings(lines)
+	out := bufio.NewWriter(f)
+	for _, line := range lines {
+		fmt.Fprintln(out, line)
+	}
+	if err := out.Flush(); err != nil {
+		f.Close()
+		return err
+	}
+	return f.Close()
+}
+
+func updateChanges(dir, fname string, releaseDate time.Time) error {
+
+	type change struct {
+		time time.Time
+		path string
+	}
+
+	changes := filepath.Join(dir, "changes.csv")
+
+	chs, err := func() ([]change, error) {
+		f, err := os.Open(changes)
+		if err != nil {
+			if os.IsNotExist(err) {
+				return []change{{releaseDate, fname}}, nil
+			}
+			return nil, err
+		}
+		defer f.Close()
+		var chs []change
+		r := csv.NewReader(f)
+		r.FieldsPerRecord = 2
+		r.ReuseRecord = true
+		replaced := false
+		for {
+			record, err := r.Read()
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return nil, err
+			}
+			// Check if new is already in.
+			if record[1] == fname {
+				// Identical -> no change at all.
+				if record[0] == releaseDate.Format(dateFormat) {
+					return nil, nil
+				}
+				// replace old entry
+				replaced = true
+				chs = append(chs, change{releaseDate, fname})
+				continue
+			}
+			t, err := time.Parse(dateFormat, record[0])
+			if err != nil {
+				return nil, err
+			}
+			chs = append(chs, change{t, record[1]})
+		}
+		if !replaced {
+			chs = append(chs, change{releaseDate, fname})
+		}
+		return chs, nil
+	}()
+
+	if err != nil {
+		return err
+	}
+	if len(chs) == 0 {
+		return nil
+	}
+	// Sort descending
+	sort.Slice(chs, func(i, j int) bool {
+		return chs[j].time.Before(chs[i].time)
+	})
+	// Create new to break hard link.
+	o, err := os.Create(changes)
+	if err != nil {
+		return err
+	}
+	c := csv.NewWriter(o)
+	record := make([]string, 2)
+	for _, ch := range chs {
+		record[0] = ch.time.Format(dateFormat)
+		record[1] = ch.path
+		if err := c.Write(record); err != nil {
+			o.Close()
+			return err
+		}
+	}
+	c.Flush()
+	err1 := c.Error()
+	err2 := o.Close()
+	if err1 != nil {
+		return err1
+	}
+	return err2
+}
+
+func updateIndices(dir, fname string, releaseDate time.Time) error {
+
+	if err := updateIndex(dir, fname); err != nil {
+		return err
+	}
+
+	return updateChanges(dir, fname, releaseDate)
+}