go-ceph/internal/cutil/command_output.go

101 lines
2.6 KiB
Go
Raw Normal View History

package cutil
/*
#include <stdlib.h>
*/
import "C"
import (
"unsafe"
)
// CommandOutput can be used to manage the outputs of ceph's *_command
// functions.
type CommandOutput struct {
free FreeFunc
outBuf *C.char
outBufLen C.size_t
outs *C.char
outsLen C.size_t
}
// NewCommandOutput returns an empty CommandOutput. The pointers that
// a CommandOutput provides can be used to get the results of ceph's
// *_command functions.
func NewCommandOutput() *CommandOutput {
return &CommandOutput{
free: free,
}
}
// SetFreeFunc sets the function used to free memory held by CommandOutput.
// Not all uses of CommandOutput expect to use the basic C.free function
// and either require or prefer the use of a custom deallocation function.
// Use SetFreeFunc to change the free function and return the modified
// CommandOutput object.
func (co *CommandOutput) SetFreeFunc(f FreeFunc) *CommandOutput {
co.free = f
return co
}
// Free any C memory tracked by this object.
func (co *CommandOutput) Free() {
if co.outBuf != nil {
co.free(unsafe.Pointer(co.outBuf))
}
if co.outs != nil {
co.free(unsafe.Pointer(co.outs))
}
}
// OutBuf returns an unsafe wrapper around a pointer to a `char*`.
func (co *CommandOutput) OutBuf() CharPtrPtr {
return CharPtrPtr(&co.outBuf)
}
// OutBufLen returns an unsafe wrapper around a pointer to a size_t.
func (co *CommandOutput) OutBufLen() SizeTPtr {
return SizeTPtr(&co.outBufLen)
}
// Outs returns an unsafe wrapper around a pointer to a `char*`.
func (co *CommandOutput) Outs() CharPtrPtr {
return CharPtrPtr(&co.outs)
}
// OutsLen returns an unsafe wrapper around a pointer to a size_t.
func (co *CommandOutput) OutsLen() SizeTPtr {
return SizeTPtr(&co.outsLen)
}
// GoValues returns native go values converted from the internal C-language
// values tracked by this object.
func (co *CommandOutput) GoValues() (buf []byte, status string) {
if co.outBufLen > 0 {
buf = C.GoBytes(unsafe.Pointer(co.outBuf), C.int(co.outBufLen))
}
if co.outsLen > 0 {
status = C.GoStringN(co.outs, C.int(co.outsLen))
}
return buf, status
}
// testSetString is only used by the unit tests for this file.
// It is located here due to the restriction on having import "C" in
// go test files. :-(
// It mimics a C function that takes a pointer to a
// string and length and allocates memory and sets the pointers
// to the new string and its length.
func testSetString(strp CharPtrPtr, lenp SizeTPtr, s string) {
sp := (**C.char)(strp)
lp := (*C.size_t)(lenp)
*sp = C.CString(s)
*lp = C.size_t(len(s))
}
// free wraps C.free.
// Required for unit tests that may not use cgo directly.
func free(p unsafe.Pointer) {
C.free(p)
}