go-ceph/rados/conn.go

401 lines
11 KiB
Go

package rados
// #cgo LDFLAGS: -lrados
// #include <stdlib.h>
// #include <rados/librados.h>
import "C"
import (
"bytes"
"errors"
"unsafe"
)
var (
// ErrNotConnected is returned when functions are called without a RADOS connection
ErrNotConnected = errors.New("RADOS not connected")
)
// ClusterStat represents Ceph cluster statistics.
type ClusterStat struct {
Kb uint64
Kb_used uint64
Kb_avail uint64
Num_objects uint64
}
// Conn is a connection handle to a Ceph cluster.
type Conn struct {
cluster C.rados_t
connected bool
}
// PingMonitor sends a ping to a monitor and returns the reply.
func (c *Conn) PingMonitor(id string) (string, error) {
c_id := C.CString(id)
defer C.free(unsafe.Pointer(c_id))
var strlen C.size_t
var strout *C.char
ret := C.rados_ping_monitor(c.cluster, c_id, &strout, &strlen)
defer C.rados_buffer_free(strout)
if ret == 0 {
reply := C.GoStringN(strout, (C.int)(strlen))
return reply, nil
}
return "", RadosError(int(ret))
}
// Connect establishes a connection to a RADOS cluster. It returns an error,
// if any.
func (c *Conn) Connect() error {
ret := C.rados_connect(c.cluster)
if ret != 0 {
return RadosError(int(ret))
}
c.connected = true
return nil
}
// Shutdown disconnects from the cluster.
func (c *Conn) Shutdown() {
if err := c.ensure_connected(); err != nil {
return
}
freeConn(c)
}
// ReadConfigFile configures the connection using a Ceph configuration file.
func (c *Conn) ReadConfigFile(path string) error {
c_path := C.CString(path)
defer C.free(unsafe.Pointer(c_path))
ret := C.rados_conf_read_file(c.cluster, c_path)
return getRadosError(int(ret))
}
// ReadDefaultConfigFile configures the connection using a Ceph configuration
// file located at default locations.
func (c *Conn) ReadDefaultConfigFile() error {
ret := C.rados_conf_read_file(c.cluster, nil)
return getRadosError(int(ret))
}
// OpenIOContext creates and returns a new IOContext for the given pool.
//
// Implements:
// int rados_ioctx_create(rados_t cluster, const char *pool_name,
// rados_ioctx_t *ioctx);
func (c *Conn) OpenIOContext(pool string) (*IOContext, error) {
c_pool := C.CString(pool)
defer C.free(unsafe.Pointer(c_pool))
ioctx := &IOContext{}
ret := C.rados_ioctx_create(c.cluster, c_pool, &ioctx.ioctx)
if ret == 0 {
return ioctx, nil
}
return nil, RadosError(int(ret))
}
// ListPools returns the names of all existing pools.
func (c *Conn) ListPools() (names []string, err error) {
buf := make([]byte, 4096)
for {
ret := int(C.rados_pool_list(c.cluster,
(*C.char)(unsafe.Pointer(&buf[0])), C.size_t(len(buf))))
if ret < 0 {
return nil, RadosError(int(ret))
}
if ret > len(buf) {
buf = make([]byte, ret)
continue
}
tmp := bytes.SplitAfter(buf[:ret-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
}
}
// SetConfigOption sets the value of the configuration option identified by
// the given name.
func (c *Conn) SetConfigOption(option, value string) error {
c_opt, c_val := C.CString(option), C.CString(value)
defer C.free(unsafe.Pointer(c_opt))
defer C.free(unsafe.Pointer(c_val))
ret := C.rados_conf_set(c.cluster, c_opt, c_val)
return getRadosError(int(ret))
}
// GetConfigOption returns the value of the Ceph configuration option
// identified by the given name.
func (c *Conn) GetConfigOption(name string) (value string, err error) {
buf := make([]byte, 4096)
c_name := C.CString(name)
defer C.free(unsafe.Pointer(c_name))
ret := int(C.rados_conf_get(c.cluster, c_name,
(*C.char)(unsafe.Pointer(&buf[0])), C.size_t(len(buf))))
// FIXME: ret may be -ENAMETOOLONG if the buffer is not large enough. We
// can handle this case, but we need a reliable way to test for
// -ENAMETOOLONG constant. Will the syscall/Errno stuff in Go help?
if ret == 0 {
value = C.GoString((*C.char)(unsafe.Pointer(&buf[0])))
return value, nil
}
return "", RadosError(ret)
}
// WaitForLatestOSDMap blocks the caller until the latest OSD map has been
// retrieved.
func (c *Conn) WaitForLatestOSDMap() error {
ret := C.rados_wait_for_latest_osdmap(c.cluster)
return getRadosError(int(ret))
}
func (c *Conn) ensure_connected() error {
if c.connected {
return nil
}
return ErrNotConnected
}
// GetClusterStats returns statistics about the cluster associated with the
// connection.
func (c *Conn) GetClusterStats() (stat ClusterStat, err error) {
if err := c.ensure_connected(); err != nil {
return ClusterStat{}, err
}
c_stat := C.struct_rados_cluster_stat_t{}
ret := C.rados_cluster_stat(c.cluster, &c_stat)
if ret < 0 {
return ClusterStat{}, RadosError(int(ret))
}
return ClusterStat{
Kb: uint64(c_stat.kb),
Kb_used: uint64(c_stat.kb_used),
Kb_avail: uint64(c_stat.kb_avail),
Num_objects: uint64(c_stat.num_objects),
}, nil
}
// ParseCmdLineArgs configures the connection from command line arguments.
func (c *Conn) ParseCmdLineArgs(args []string) error {
// add an empty element 0 -- Ceph treats the array as the actual contents
// of argv and skips the first element (the executable name)
argc := C.int(len(args) + 1)
argv := make([]*C.char, argc)
// make the first element a string just in case it is ever examined
argv[0] = C.CString("placeholder")
defer C.free(unsafe.Pointer(argv[0]))
for i, arg := range args {
argv[i+1] = C.CString(arg)
defer C.free(unsafe.Pointer(argv[i+1]))
}
ret := C.rados_conf_parse_argv(c.cluster, argc, &argv[0])
return getRadosError(int(ret))
}
// ParseDefaultConfigEnv configures the connection from the default Ceph
// environment variable(s).
func (c *Conn) ParseDefaultConfigEnv() error {
ret := C.rados_conf_parse_env(c.cluster, nil)
return getRadosError(int(ret))
}
// GetFSID returns the fsid of the cluster as a hexadecimal string. The fsid
// is a unique identifier of an entire Ceph cluster.
func (c *Conn) GetFSID() (fsid string, err error) {
buf := make([]byte, 37)
ret := int(C.rados_cluster_fsid(c.cluster,
(*C.char)(unsafe.Pointer(&buf[0])), C.size_t(len(buf))))
// FIXME: the success case isn't documented correctly in librados.h
if ret == 36 {
fsid = C.GoString((*C.char)(unsafe.Pointer(&buf[0])))
return fsid, nil
}
return "", RadosError(int(ret))
}
// GetInstanceID returns a globally unique identifier for the cluster
// connection instance.
func (c *Conn) GetInstanceID() uint64 {
// FIXME: are there any error cases for this?
return uint64(C.rados_get_instance_id(c.cluster))
}
// MakePool creates a new pool with default settings.
func (c *Conn) MakePool(name string) error {
c_name := C.CString(name)
defer C.free(unsafe.Pointer(c_name))
ret := int(C.rados_pool_create(c.cluster, c_name))
return getRadosError(int(ret))
}
// DeletePool deletes a pool and all the data inside the pool.
func (c *Conn) DeletePool(name string) error {
if err := c.ensure_connected(); err != nil {
return err
}
c_name := C.CString(name)
defer C.free(unsafe.Pointer(c_name))
ret := int(C.rados_pool_delete(c.cluster, c_name))
return getRadosError(int(ret))
}
// GetPoolByName returns the ID of the pool with a given name.
func (c *Conn) GetPoolByName(name string) (int64, error) {
if err := c.ensure_connected(); err != nil {
return 0, err
}
c_name := C.CString(name)
defer C.free(unsafe.Pointer(c_name))
ret := int64(C.rados_pool_lookup(c.cluster, c_name))
if ret < 0 {
return 0, RadosError(ret)
}
return ret, nil
}
// GetPoolByID returns the name of a pool by a given ID.
func (c *Conn) GetPoolByID(id int64) (string, error) {
buf := make([]byte, 4096)
if err := c.ensure_connected(); err != nil {
return "", err
}
c_id := C.int64_t(id)
ret := int(C.rados_pool_reverse_lookup(c.cluster, c_id, (*C.char)(unsafe.Pointer(&buf[0])), C.size_t(len(buf))))
if ret < 0 {
return "", RadosError(ret)
}
return C.GoString((*C.char)(unsafe.Pointer(&buf[0]))), nil
}
// MonCommand sends a command to one of the monitors
func (c *Conn) MonCommand(args []byte) (buffer []byte, info string, err error) {
return c.monCommand(args, nil)
}
// MonCommandWithInputBuffer sends a command to one of the monitors, with an input buffer
func (c *Conn) MonCommandWithInputBuffer(args, inputBuffer []byte) (buffer []byte, info string, err error) {
return c.monCommand(args, inputBuffer)
}
func (c *Conn) monCommand(args, inputBuffer []byte) (buffer []byte, info string, err error) {
argv := C.CString(string(args))
defer C.free(unsafe.Pointer(argv))
var (
outs, outbuf *C.char
outslen, outbuflen C.size_t
)
inbuf := C.CString(string(inputBuffer))
inbufLen := len(inputBuffer)
defer C.free(unsafe.Pointer(inbuf))
ret := C.rados_mon_command(c.cluster,
&argv, 1,
inbuf, // bulk input (e.g. crush map)
C.size_t(inbufLen), // length inbuf
&outbuf, // buffer
&outbuflen, // buffer length
&outs, // status string
&outslen)
if outslen > 0 {
info = C.GoStringN(outs, C.int(outslen))
C.free(unsafe.Pointer(outs))
}
if outbuflen > 0 {
buffer = C.GoBytes(unsafe.Pointer(outbuf), C.int(outbuflen))
C.free(unsafe.Pointer(outbuf))
}
if ret != 0 {
err = RadosError(int(ret))
return nil, info, err
}
return
}
// PGCommand sends a command to one of the PGs
//
// Implements:
// int rados_pg_command(rados_t cluster, const char *pgstr,
// const char **cmd, size_t cmdlen,
// const char *inbuf, size_t inbuflen,
// char **outbuf, size_t *outbuflen,
// char **outs, size_t *outslen);
func (c *Conn) PGCommand(pgid []byte, args [][]byte) (buffer []byte, info string, err error) {
return c.pgCommand(pgid, args, nil)
}
// PGCommandWithInputBuffer sends a command to one of the PGs, with an input buffer
//
// Implements:
// int rados_pg_command(rados_t cluster, const char *pgstr,
// const char **cmd, size_t cmdlen,
// const char *inbuf, size_t inbuflen,
// char **outbuf, size_t *outbuflen,
// char **outs, size_t *outslen);
func (c *Conn) PGCommandWithInputBuffer(pgid []byte, args [][]byte, inputBuffer []byte) (buffer []byte, info string, err error) {
return c.pgCommand(pgid, args, inputBuffer)
}
func (c *Conn) pgCommand(pgid []byte, args [][]byte, inputBuffer []byte) (buffer []byte, info string, err error) {
name := C.CString(string(pgid))
defer C.free(unsafe.Pointer(name))
argc := len(args)
argv := make([]*C.char, argc)
for i, arg := range args {
argv[i] = C.CString(string(arg))
defer C.free(unsafe.Pointer(argv[i]))
}
var (
outs, outbuf *C.char
outslen, outbuflen C.size_t
)
inbuf := C.CString(string(inputBuffer))
inbufLen := len(inputBuffer)
defer C.free(unsafe.Pointer(inbuf))
ret := C.rados_pg_command(c.cluster,
name,
&argv[0],
C.size_t(argc),
inbuf, // bulk input
C.size_t(inbufLen), // length inbuf
&outbuf, // buffer
&outbuflen, // buffer length
&outs, // status string
&outslen)
if outslen > 0 {
info = C.GoStringN(outs, C.int(outslen))
C.free(unsafe.Pointer(outs))
}
if outbuflen > 0 {
buffer = C.GoBytes(unsafe.Pointer(outbuf), C.int(outbuflen))
C.free(unsafe.Pointer(outbuf))
}
if ret != 0 {
err = RadosError(int(ret))
return nil, info, err
}
return
}