Vendor dependencies with dep

vendor/github.com/peterbourgon/diskv/examples/content-addressable-store/cas.go

@@ -0,0 +1,63 @@
+package main
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+
+	"github.com/peterbourgon/diskv"
+)
+
+const transformBlockSize = 2 // grouping of chars per directory depth
+
+func blockTransform(s string) []string {
+	var (
+		sliceSize = len(s) / transformBlockSize
+		pathSlice = make([]string, sliceSize)
+	)
+	for i := 0; i < sliceSize; i++ {
+		from, to := i*transformBlockSize, (i*transformBlockSize)+transformBlockSize
+		pathSlice[i] = s[from:to]
+	}
+	return pathSlice
+}
+
+func main() {
+	d := diskv.New(diskv.Options{
+		BasePath:     "data",
+		Transform:    blockTransform,
+		CacheSizeMax: 1024 * 1024, // 1MB
+	})
+
+	for _, valueStr := range []string{
+		"I am the very model of a modern Major-General",
+		"I've information vegetable, animal, and mineral",
+		"I know the kings of England, and I quote the fights historical",
+		"From Marathon to Waterloo, in order categorical",
+		"I'm very well acquainted, too, with matters mathematical",
+		"I understand equations, both the simple and quadratical",
+		"About binomial theorem I'm teeming with a lot o' news",
+		"With many cheerful facts about the square of the hypotenuse",
+	} {
+		d.Write(md5sum(valueStr), []byte(valueStr))
+	}
+
+	var keyCount int
+	for key := range d.Keys(nil) {
+		val, err := d.Read(key)
+		if err != nil {
+			panic(fmt.Sprintf("key %s had no value", key))
+		}
+		fmt.Printf("%s: %s\n", key, val)
+		keyCount++
+	}
+	fmt.Printf("%d total keys\n", keyCount)
+
+	// d.EraseAll() // leave it commented out to see how data is kept on disk
+}
+
+func md5sum(s string) string {
+	h := md5.New()
+	io.WriteString(h, s)
+	return fmt.Sprintf("%x", h.Sum(nil))
+}