rbd: add rbd package

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>

rados/ioctx.go

@@ -36,6 +36,11 @@ type IOContext struct {
     ioctx C.rados_ioctx_t
 }
 
+// Pointer returns a uintptr representation of the IOContext.
+func (ioctx *IOContext) Pointer() uintptr {
+    return uintptr(ioctx.ioctx)
+}
+
 // Write writes len(data) bytes to the object with key oid starting at byte
 // offset offset. It returns an error, if any.
 func (ioctx *IOContext) Write(oid string, data []byte, offset uint64) error {

rbd/rbd.go

@@ -0,0 +1,66 @@
+package rbd
+
+// #cgo LDFLAGS: -lrbd
+// #include <stdlib.h>
+// #include <rados/librados.h>
+// #include <rbd/librbd.h>
+import "C"
+
+import (
+    "github.com/noahdesu/go-rados/rados"
+    "fmt"
+    "unsafe"
+    "bytes"
+)
+
+//
+type RBDError int
+
+//
+func (e RBDError) Error() string {
+    return fmt.Sprintf("rbd: ret=%d", e)
+}
+
+//
+func Version() (int, int, int) {
+    var c_major, c_minor, c_patch C.int
+    C.rbd_version(&c_major, &c_minor, &c_patch)
+    return int(c_major), int(c_minor), int(c_patch)
+}
+
+// Create
+func Create(ioctx *rados.IOContext, name string, size uint64) error {
+    var c_order C.int
+    c_name := C.CString(name)
+    defer C.free(unsafe.Pointer(c_name))
+    ret := C.rbd_create(C.rados_ioctx_t(ioctx.Pointer()), c_name, C.uint64_t(size), &c_order)
+    if ret < 0 {
+        return RBDError(ret)
+    } else {
+        return nil
+    }
+}
+
+// GetImageNames returns the list of current RBD images.
+func GetImageNames(ioctx *rados.IOContext) (names []string, err error) {
+    buf := make([]byte, 4096)
+    for {
+        size := C.size_t(len(buf))
+        ret := C.rbd_list(C.rados_ioctx_t(ioctx.Pointer()),
+            (*C.char)(unsafe.Pointer(&buf[0])), &size)
+        if ret == -34 { // FIXME
+            buf = make([]byte, size)
+            continue
+        } else if ret < 0 {
+            return nil, RBDError(ret)
+        }
+        tmp := bytes.Split(buf[:size-1], []byte{0})
+        for _, s := range tmp {
+            if len(s) > 0 {
+                name := C.GoString((*C.char)(unsafe.Pointer(&s[0])))
+                names = append(names, name)
+            }
+        }
+        return names, nil
+    }
+}

rbd/rbd_test.go

@@ -0,0 +1,53 @@
+package rbd_test
+
+import (
+    "testing"
+    "github.com/noahdesu/go-rados/rados"
+    "github.com/noahdesu/go-rados/rbd"
+    "github.com/stretchr/testify/assert"
+    "os/exec"
+    "sort"
+)
+
+func GetUUID() string {
+    out, _ := exec.Command("uuidgen").Output()
+    return string(out[:36])
+}
+
+func TestVersion(t *testing.T) {
+    var major, minor, patch = rbd.Version()
+    assert.False(t, major < 0 || major > 1000, "invalid major")
+    assert.False(t, minor < 0 || minor > 1000, "invalid minor")
+    assert.False(t, patch < 0 || patch > 1000, "invalid patch")
+}
+
+func TestGetImageNames(t *testing.T) {
+    conn, _ := rados.NewConn()
+    conn.ReadDefaultConfigFile()
+    conn.Connect()
+
+    poolname := GetUUID()
+    err := conn.MakePool(poolname)
+    assert.NoError(t, err)
+
+    ioctx, err := conn.OpenIOContext(poolname)
+    assert.NoError(t, err)
+
+    createdList := []string{}
+    for i := 0; i < 10; i++ {
+        name := GetUUID()
+        err = rbd.Create(ioctx, name, 1<<22)
+        assert.NoError(t, err)
+        createdList = append(createdList, name)
+    }
+
+    imageNames, err := rbd.GetImageNames(ioctx)
+    assert.NoError(t, err)
+
+    sort.Strings(createdList)
+    sort.Strings(imageNames)
+    assert.Equal(t, createdList, imageNames)
+
+    ioctx.Destroy()
+    conn.Shutdown()
+}