refactor: extract chunk.og & add Reader getter

1 files changed, 47 insertions, 0 deletions

diff --git a/chunk.go b/chunk.go
new file mode 100644
index 0000000..9f09e55
--- /dev/null
+++ b/chunk.go
@@ -0,0 +1,47 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path"
+)
+
+type ChunkId struct {
+	Ver int
+	Idx uint64
+}
+
+func (i *ChunkId) Reader(repo string) io.Reader {
+	p := path.Join(repo, fmt.Sprintf(versionFmt, i.Ver), chunksName, fmt.Sprintf(chunkIdFmt, i.Idx))
+	f, err := os.Open(p)
+	if err != nil {
+		log.Printf("Cannot open chunk %s\n", p)
+	}
+	return f
+}
+
+type Chunk struct {
+	Id    *ChunkId
+	Value []byte
+}
+
+func (c *Chunk) Reader(repo string) (io.Reader, error) {
+	if c.Value != nil {
+		return bytes.NewReader(c.Value), nil
+	}
+	if c.Id != nil {
+		return c.Id.Reader(repo), nil
+	}
+	return nil, &ChunkError{"Uninitialized chunk"}
+}
+
+type ChunkError struct {
+	err string
+}
+
+func (e *ChunkError) Error() string {
+	return fmt.Sprintf("Chunk error: %s", e.err)
+}