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mirror of https://github.com/ceph/go-ceph synced 2024-12-29 09:42:08 +00:00
go-ceph/rados/omap.go
Robert Vasek 3eba56ce60 rados: use rados_write_op_omap_rm_keys2()
WriteOp.RmOmapKeys now uses rados_write_op_omap_rm_keys2().

The entirety of removeOmapKeysStep struct was removed as it's not necessary for
it to own the various C-allocated values passed to
rados_write_op_omap_rm_keys2() as arguments. rados_write_op_omap_rm_keys2()
makes copies of all the string-based args [1], so it's sufficient for them to
be short lived.

[1] 2bd3dd512a/src/librados/librados_c.cc (L3888-L3902)
2022-03-09 14:02:56 +00:00

206 lines
5.3 KiB
Go

package rados
/*
#cgo LDFLAGS: -lrados
#include <stdlib.h>
#include <rados/librados.h>
*/
import "C"
import (
"runtime"
"unsafe"
)
// OmapKeyValue items are returned by the GetOmapStep's Next call.
type OmapKeyValue struct {
Key string
Value []byte
}
// GetOmapStep values are used to get the results of an GetOmapValues call
// on a WriteOp. Until the Operate method of the WriteOp is called the Next
// call will return an error. After Operate is called, the Next call will
// return valid results.
//
// The life cycle of the GetOmapStep is bound to the ReadOp, if the ReadOp
// Release method is called the public methods of the step must no longer be
// used and may return errors.
type GetOmapStep struct {
// C returned data:
iter C.rados_omap_iter_t
more *C.uchar
rval *C.int
// internal state:
// canIterate is only set after the operation is performed and is
// intended to prevent premature fetching of data
canIterate bool
}
func newGetOmapStep() *GetOmapStep {
gos := &GetOmapStep{
more: (*C.uchar)(C.malloc(C.sizeof_uchar)),
rval: (*C.int)(C.malloc(C.sizeof_int)),
}
runtime.SetFinalizer(gos, opStepFinalizer)
return gos
}
func (gos *GetOmapStep) free() {
gos.canIterate = false
if gos.iter != nil {
C.rados_omap_get_end(gos.iter)
}
gos.iter = nil
C.free(unsafe.Pointer(gos.more))
gos.more = nil
C.free(unsafe.Pointer(gos.rval))
gos.rval = nil
}
func (gos *GetOmapStep) update() error {
err := getError(*gos.rval)
gos.canIterate = (err == nil)
return err
}
// Next returns the next key value pair or nil if iteration is exhausted.
func (gos *GetOmapStep) Next() (*OmapKeyValue, error) {
if !gos.canIterate {
return nil, ErrOperationIncomplete
}
var (
cKey *C.char
cVal *C.char
cKeyLen C.size_t
cValLen C.size_t
)
ret := C.rados_omap_get_next2(gos.iter, &cKey, &cVal, &cKeyLen, &cValLen)
if ret != 0 {
return nil, getError(ret)
}
if cKey == nil {
return nil, nil
}
return &OmapKeyValue{
Key: string(C.GoBytes(unsafe.Pointer(cKey), C.int(cKeyLen))),
Value: C.GoBytes(unsafe.Pointer(cVal), C.int(cValLen)),
}, nil
}
// More returns true if there are more matching keys available.
func (gos *GetOmapStep) More() bool {
// tad bit hacky, but go can't automatically convert from
// unsigned char to bool
return *gos.more != 0
}
// 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 {
op := CreateReadOp()
defer op.Release()
gos := op.GetOmapValues(startAfter, filterPrefix, uint64(maxReturn))
err := op.operateCompat(ioctx, oid)
if err != nil {
return err
}
for {
kv, err := gos.Next()
if err != nil {
return err
}
if kv == nil {
break
}
listFn(kv.Key, kv.Value)
}
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 {
op := CreateWriteOp()
defer op.Release()
op.RmOmapKeys(keys)
return op.operateCompat(ioctx, oid)
}
// CleanOmap clears the omap `oid`
func (ioctx *IOContext) CleanOmap(oid string) error {
op := CreateWriteOp()
defer op.Release()
op.CleanOmap()
return op.operateCompat(ioctx, oid)
}