Move storagedriver package to registry/storage/driver

This change is slightly more complex than previous package maves in that the
package name changed. To address this, we simply always reference the package
driver as storagedriver to avoid compatbility issues with existing code. While
unfortunate, this can be cleaned up over time.

Signed-off-by: Stephen J Day <stephen.day@docker.com>

docs/storage/driver/azure/blockid_test.go

@@ -0,0 +1,74 @@
+package azure
+
+import (
+	"math"
+	"testing"
+
+	azure "github.com/MSOpenTech/azure-sdk-for-go/clients/storage"
+)
+
+func Test_blockIdGenerator(t *testing.T) {
+	r := newBlockIDGenerator()
+
+	for i := 1; i <= 10; i++ {
+		if expected := i - 1; len(r.pool) != expected {
+			t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
+		}
+		if id := r.Generate(); id == "" {
+			t.Fatal("returned empty id")
+		}
+		if expected := i; len(r.pool) != expected {
+			t.Fatalf("rand pool has wrong number of items: %d, expected:%d", len(r.pool), expected)
+		}
+	}
+}
+
+func Test_blockIdGenerator_Feed(t *testing.T) {
+	r := newBlockIDGenerator()
+	if expected := 0; len(r.pool) != expected {
+		t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
+	}
+
+	// feed empty list
+	blocks := azure.BlockListResponse{}
+	r.Feed(blocks)
+	if expected := 0; len(r.pool) != expected {
+		t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
+	}
+
+	// feed blocks
+	blocks = azure.BlockListResponse{
+		CommittedBlocks: []azure.BlockResponse{
+			{"1", 1},
+			{"2", 2},
+		},
+		UncommittedBlocks: []azure.BlockResponse{
+			{"3", 3},
+		}}
+	r.Feed(blocks)
+	if expected := 3; len(r.pool) != expected {
+		t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
+	}
+
+	// feed same block IDs with committed/uncommitted place changed
+	blocks = azure.BlockListResponse{
+		CommittedBlocks: []azure.BlockResponse{
+			{"3", 3},
+		},
+		UncommittedBlocks: []azure.BlockResponse{
+			{"1", 1},
+		}}
+	r.Feed(blocks)
+	if expected := 3; len(r.pool) != expected {
+		t.Fatalf("rand pool had wrong number of items: %d, expected:%d", len(r.pool), expected)
+	}
+}
+
+func Test_toBlockId(t *testing.T) {
+	min := 0
+	max := math.MaxInt64
+
+	if len(toBlockID(min)) != len(toBlockID(max)) {
+		t.Fatalf("different-sized blockIDs are returned")
+	}
+}