go-ceph/rados/omap.go

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package rados
/*
#cgo LDFLAGS: -lrados
#include <stdlib.h>
#include <rados/librados.h>
typedef void* voidptr;
*/
import "C"
import (
"runtime"
"unsafe"
)
const (
ptrSize = C.sizeof_voidptr
sizeTSize = C.sizeof_size_t
)
// setOmapStep is a write op step. It holds C memory used in the operation.
type setOmapStep struct {
withRefs
withoutUpdate
// C arguments
cKeys **C.char
cValues **C.char
cLengths *C.size_t
cNum C.size_t
}
func newSetOmapStep(pairs map[string][]byte) *setOmapStep {
maplen := C.size_t(len(pairs))
cKeys := C.malloc(maplen * ptrSize)
cValues := C.malloc(maplen * ptrSize)
cLengths := C.malloc(maplen * sizeTSize)
sos := &setOmapStep{
cKeys: (**C.char)(cKeys),
cValues: (**C.char)(cValues),
cLengths: (*C.size_t)(cLengths),
cNum: C.size_t(len(pairs)),
}
sos.add(cKeys)
sos.add(cValues)
sos.add(cLengths)
var i uintptr
for key, value := range pairs {
// key
ck := C.CString(key)
sos.add(unsafe.Pointer(ck))
ckp := (**C.char)(unsafe.Pointer(uintptr(cKeys) + i*ptrSize))
*ckp = ck
// value and its length
cvp := (**C.char)(unsafe.Pointer(uintptr(cValues) + i*ptrSize))
vlen := C.size_t(len(value))
if vlen > 0 {
cv := C.CBytes(value)
sos.add(cv)
*cvp = (*C.char)(cv)
} else {
*cvp = nil
}
clp := (*C.size_t)(unsafe.Pointer(uintptr(cLengths) + i*ptrSize))
*clp = vlen
i++
}
runtime.SetFinalizer(sos, opStepFinalizer)
return sos
}
func (sos *setOmapStep) free() {
sos.cKeys = nil
sos.cValues = nil
sos.cLengths = nil
sos.withRefs.free()
}
// SetOmap appends the map `pairs` to the omap `oid`
func (ioctx *IOContext) SetOmap(oid string, pairs map[string][]byte) error {
op := CreateWriteOp()
defer op.Release()
op.SetOmap(pairs)
return op.operateCompat(ioctx, oid)
}
// OmapListFunc is the type of the function called for each omap key
// visited by ListOmapValues
type OmapListFunc func(key string, value []byte)
// ListOmapValues iterates over the keys and values in an omap by way of
// a callback function.
//
// `startAfter`: iterate only on the keys after this specified one
// `filterPrefix`: iterate only on the keys beginning with this prefix
// `maxReturn`: iterate no more than `maxReturn` key/value pairs
// `listFn`: the function called at each iteration
func (ioctx *IOContext) ListOmapValues(oid string, startAfter string, filterPrefix string, maxReturn int64, listFn OmapListFunc) error {
c_oid := C.CString(oid)
c_start_after := C.CString(startAfter)
c_filter_prefix := C.CString(filterPrefix)
c_max_return := C.uint64_t(maxReturn)
defer C.free(unsafe.Pointer(c_oid))
defer C.free(unsafe.Pointer(c_start_after))
defer C.free(unsafe.Pointer(c_filter_prefix))
op := C.rados_create_read_op()
var c_iter C.rados_omap_iter_t
var c_prval C.int
C.rados_read_op_omap_get_vals2(
op,
c_start_after,
c_filter_prefix,
c_max_return,
&c_iter,
nil,
&c_prval,
)
ret := C.rados_read_op_operate(op, ioctx.ioctx, c_oid, 0)
if int(ret) != 0 {
return getError(ret)
} else if int(c_prval) != 0 {
return getError(c_prval)
}
for {
var c_key *C.char
var c_val *C.char
var c_len C.size_t
ret = C.rados_omap_get_next(c_iter, &c_key, &c_val, &c_len)
if int(ret) != 0 {
return getError(ret)
}
if c_key == nil {
break
}
listFn(C.GoString(c_key), C.GoBytes(unsafe.Pointer(c_val), C.int(c_len)))
}
C.rados_omap_get_end(c_iter)
C.rados_release_read_op(op)
return nil
}
// GetOmapValues fetches a set of keys and their values from an omap and returns then as a map
// `startAfter`: retrieve only the keys after this specified one
// `filterPrefix`: retrieve only the keys beginning with this prefix
// `maxReturn`: retrieve no more than `maxReturn` key/value pairs
func (ioctx *IOContext) GetOmapValues(oid string, startAfter string, filterPrefix string, maxReturn int64) (map[string][]byte, error) {
omap := map[string][]byte{}
err := ioctx.ListOmapValues(
oid, startAfter, filterPrefix, maxReturn,
func(key string, value []byte) {
omap[key] = value
},
)
return omap, err
}
// GetAllOmapValues fetches all the keys and their values from an omap and returns then as a map
// `startAfter`: retrieve only the keys after this specified one
// `filterPrefix`: retrieve only the keys beginning with this prefix
// `iteratorSize`: internal number of keys to fetch during a read operation
func (ioctx *IOContext) GetAllOmapValues(oid string, startAfter string, filterPrefix string, iteratorSize int64) (map[string][]byte, error) {
omap := map[string][]byte{}
omapSize := 0
for {
err := ioctx.ListOmapValues(
oid, startAfter, filterPrefix, iteratorSize,
func(key string, value []byte) {
omap[key] = value
startAfter = key
},
)
if err != nil {
return omap, err
}
// End of omap
if len(omap) == omapSize {
break
}
omapSize = len(omap)
}
return omap, nil
}
// RmOmapKeys removes the specified `keys` from the omap `oid`
func (ioctx *IOContext) RmOmapKeys(oid string, keys []string) error {
c_oid := C.CString(oid)
defer C.free(unsafe.Pointer(c_oid))
var c *C.char
ptrSize := unsafe.Sizeof(c)
c_keys := C.malloc(C.size_t(len(keys)) * C.size_t(ptrSize))
defer C.free(unsafe.Pointer(c_keys))
i := 0
for _, key := range keys {
c_key_ptr := (**C.char)(unsafe.Pointer(uintptr(c_keys) + uintptr(i)*ptrSize))
*c_key_ptr = C.CString(key)
defer C.free(unsafe.Pointer(*c_key_ptr))
i++
}
op := C.rados_create_write_op()
C.rados_write_op_omap_rm_keys(
op,
(**C.char)(c_keys),
C.size_t(len(keys)))
ret := C.rados_write_op_operate(op, ioctx.ioctx, c_oid, nil, 0)
C.rados_release_write_op(op)
return getError(ret)
}
// CleanOmap clears the omap `oid`
func (ioctx *IOContext) CleanOmap(oid string) error {
c_oid := C.CString(oid)
defer C.free(unsafe.Pointer(c_oid))
op := C.rados_create_write_op()
C.rados_write_op_omap_clear(op)
ret := C.rados_write_op_operate(op, ioctx.ioctx, c_oid, nil, 0)
C.rados_release_write_op(op)
return getError(ret)
}