OSD class method execution

docs/api-status.json

@@ -1156,7 +1156,26 @@
         "became_stable_version": "v0.19.0"
       }
     ],
-    "preview_api": []
+    "preview_api": [
+      {
+        "name": "ReadOpExecStep.Bytes",
+        "comment": "Bytes returns the result of the executed command as a byte slice.\n",
+        "added_in_version": "$NEXT_RELEASE",
+        "expected_stable_version": "$NEXT_RELEASE_STABLE"
+      },
+      {
+        "name": "ReadOp.Exec",
+        "comment": "Exec executes an OSD class method on an object.\nSee rados_exec() in the RADOS C api documentation for a general description.\n\nImplements:\n\n\tvoid rados_read_op_exec(rados_read_op_t read_op,\n\t                        const char *cls,\n\t                        const char *method,\n\t                        const char *in_buf,\n\t                        size_t in_len,\n\t                        char **out_buf,\n\t                        size_t *out_len,\n\t                        int *prval);\n",
+        "added_in_version": "$NEXT_RELEASE",
+        "expected_stable_version": "$NEXT_RELEASE_STABLE"
+      },
+      {
+        "name": "WriteOp.Exec",
+        "comment": "Exec executes an OSD class method on an object.\nSee rados_exec() in the RADOS C api documentation for a general description.\n\nImplements:\n\n\tvoid rados_write_op_exec(rados_write_op_t write_op,\n\t                         const char *cls,\n\t                         const char *method,\n\t                         const char *in_buf,\n\t                         size_t in_len,\n\t                         int *prval)\n",
+        "added_in_version": "$NEXT_RELEASE",
+        "expected_stable_version": "$NEXT_RELEASE_STABLE"
+      }
+    ]
   },
   "rbd": {
     "deprecated_api": [

docs/api-status.md

@@ -16,7 +16,13 @@ FSAdmin.FSQuiesce | v0.27.0 | v0.29.0 |
 
 ## Package: rados
 
-No Preview/Deprecated APIs found. All APIs are considered stable.
+### Preview APIs
+
+Name | Added in Version | Expected Stable Version | 
+---- | ---------------- | ----------------------- | 
+ReadOpExecStep.Bytes | $NEXT_RELEASE | $NEXT_RELEASE_STABLE | 
+ReadOp.Exec | $NEXT_RELEASE | $NEXT_RELEASE_STABLE | 
+WriteOp.Exec | $NEXT_RELEASE | $NEXT_RELEASE_STABLE | 
 
 ## Package: rbd
 

rados/read_op_exec.go

@@ -0,0 +1,111 @@
+//go:build ceph_preview
+// +build ceph_preview
+
+package rados
+
+// #cgo LDFLAGS: -lrados
+// #include <stdlib.h>
+// #include <rados/librados.h>
+//
+import "C"
+
+import (
+	"runtime"
+	"unsafe"
+)
+
+// ReadOpExecStep - step for exec operation code.
+type ReadOpExecStep struct {
+	withoutFree
+
+	inBuffPtr     *C.char
+	inBuffLen     C.size_t
+	outBuffPtr    *C.char
+	outBuffLen    C.size_t
+	prval         C.int
+	canReadOutput bool
+}
+
+// newExecStepOp - init new *execStepOp.
+func newReadOpExecStep(in []byte) *ReadOpExecStep {
+	es := &ReadOpExecStep{
+		outBuffPtr: nil,
+		outBuffLen: 0,
+		prval:      0,
+	}
+
+	if len(in) > 0 {
+		es.inBuffPtr = (*C.char)(unsafe.Pointer(&in[0]))
+		es.inBuffLen = C.size_t(len(in))
+	}
+
+	runtime.SetFinalizer(es, func(es *ReadOpExecStep) {
+		if es != nil {
+			es.freeBuffer()
+			es = nil
+		}
+	})
+	return es
+}
+
+// freeBuffer - releases C allocated buffer. It is separated from es.free() because lifespan of C allocated buffer is
+// longer than lifespan of read operation.
+func (es *ReadOpExecStep) freeBuffer() {
+	if es.outBuffPtr != nil {
+		C.free(unsafe.Pointer(es.outBuffPtr))
+		es.outBuffPtr = nil
+		es.canReadOutput = false
+	}
+}
+
+// update - update state operation.
+func (es *ReadOpExecStep) update() error {
+	err := getError(es.prval)
+	es.canReadOutput = err == nil
+	return err
+}
+
+// Bytes returns the result of the executed command as a byte slice.
+func (es *ReadOpExecStep) Bytes() ([]byte, error) {
+	if !es.canReadOutput {
+		return nil, ErrOperationIncomplete
+	}
+
+	return C.GoBytes(unsafe.Pointer(es.outBuffPtr), C.int(es.outBuffLen)), nil
+}
+
+// Exec executes an OSD class method on an object.
+// See rados_exec() in the RADOS C api documentation for a general description.
+//
+// Implements:
+//
+//	void rados_read_op_exec(rados_read_op_t read_op,
+//	                        const char *cls,
+//	                        const char *method,
+//	                        const char *in_buf,
+//	                        size_t in_len,
+//	                        char **out_buf,
+//	                        size_t *out_len,
+//	                        int *prval);
+func (r *ReadOp) Exec(clsName, method string, in []byte) *ReadOpExecStep {
+	cClsName := C.CString(clsName)
+	defer C.free(unsafe.Pointer(cClsName))
+
+	cMethod := C.CString(method)
+	defer C.free(unsafe.Pointer(cMethod))
+
+	es := newReadOpExecStep(in)
+	r.steps = append(r.steps, es)
+	C.rados_read_op_exec(
+		r.op,
+		cClsName,
+		cMethod,
+		es.inBuffPtr,
+		es.inBuffLen,
+		&es.outBuffPtr,
+		&es.outBuffLen,
+		&es.prval,
+	)
+
+	return es
+}

rados/rw_op_exec_test.go

@@ -0,0 +1,38 @@
+package rados
+
+import (
+	"github.com/gofrs/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func (suite *RadosTestSuite) TestReadWriteOpExec() {
+	suite.SetupConnection()
+
+	oid, err := uuid.NewV4()
+	assert.NoError(suite.T(), err)
+
+	data := "cls data"
+
+	wrOp := CreateWriteOp()
+	defer wrOp.Release()
+	wrOp.Exec("hello", "record_hello", []byte(data))
+	assert.NoError(suite.T(), err)
+	err = wrOp.Operate(suite.ioctx, oid.String(), OperationNoFlag)
+	assert.NoError(suite.T(), err)
+
+	rdOp := CreateReadOp()
+	defer rdOp.Release()
+
+	es := rdOp.Exec("hello", "replay", nil)
+	result, err := es.Bytes()
+	require.ErrorIs(suite.T(), err, ErrOperationIncomplete)
+	require.Nil(suite.T(), result)
+
+	err = rdOp.Operate(suite.ioctx, oid.String(), OperationNoFlag)
+	assert.NoError(suite.T(), err)
+
+	result, err = es.Bytes()
+	assert.NoError(suite.T(), err)
+	assert.Equal(suite.T(), []byte("Hello, "+data+"!"), result)
+}

rados/write_op_exec.go

@@ -0,0 +1,71 @@
+//go:build ceph_preview
+// +build ceph_preview
+
+package rados
+
+// #cgo LDFLAGS: -lrados
+// #include <stdlib.h>
+// #include <rados/librados.h>
+//
+import "C"
+
+import (
+	"unsafe"
+)
+
+// writeOpExecStep - exec step in write operation.
+type writeOpExecStep struct {
+	withoutFree
+
+	inBuffPtr *C.char
+	inBuffLen C.size_t
+	prval     C.int
+}
+
+// newWriteOpExecStep - init new *writeOpExecStep.
+func newWriteOpExecStep(in []byte) *writeOpExecStep {
+	es := &writeOpExecStep{
+		prval: 0,
+	}
+	if len(in) > 0 {
+		es.inBuffPtr = (*C.char)(unsafe.Pointer(&in[0]))
+		es.inBuffLen = C.size_t(len(in))
+	}
+
+	return es
+}
+
+// update - update state operation.
+func (es *writeOpExecStep) update() error {
+	return getError(es.prval)
+}
+
+// Exec executes an OSD class method on an object.
+// See rados_exec() in the RADOS C api documentation for a general description.
+//
+// Implements:
+//
+//	void rados_write_op_exec(rados_write_op_t write_op,
+//	                         const char *cls,
+//	                         const char *method,
+//	                         const char *in_buf,
+//	                         size_t in_len,
+//	                         int *prval)
+func (w *WriteOp) Exec(clsName, method string, in []byte) {
+	cClsName := C.CString(clsName)
+	defer C.free(unsafe.Pointer(cClsName))
+
+	cMethod := C.CString(method)
+	defer C.free(unsafe.Pointer(cMethod))
+
+	es := newWriteOpExecStep(in)
+	w.steps = append(w.steps, es)
+	C.rados_write_op_exec(
+		w.op,
+		cClsName,
+		cMethod,
+		es.inBuffPtr,
+		es.inBuffLen,
+		&es.prval,
+	)
+}