mirror of https://github.com/ceph/go-ceph
73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
package rados
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// #cgo LDFLAGS: -lrados
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// #include <rados/librados.h>
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// #include <stdlib.h>
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//
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import "C"
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import (
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"unsafe"
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)
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// ReadOpReadStep holds the result of the Read read operation.
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// Result is valid only after Operate() was called.
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type ReadOpReadStep struct {
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// C returned data:
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bytesRead *C.size_t
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prval *C.int
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BytesRead int64 // Bytes read by this action.
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Result int // Result of this action.
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}
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func (s *ReadOpReadStep) update() error {
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s.BytesRead = (int64)(*s.bytesRead)
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s.Result = (int)(*s.prval)
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return nil
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}
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func (s *ReadOpReadStep) free() {
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C.free(unsafe.Pointer(s.bytesRead))
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C.free(unsafe.Pointer(s.prval))
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s.bytesRead = nil
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s.prval = nil
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}
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func newReadOpReadStep() *ReadOpReadStep {
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return &ReadOpReadStep{
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bytesRead: (*C.size_t)(C.malloc(C.sizeof_size_t)),
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prval: (*C.int)(C.malloc(C.sizeof_int)),
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}
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}
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// Read bytes from offset into buffer.
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// len(buffer) is the maximum number of bytes read from the object.
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// buffer[:ReadOpReadStep.BytesRead] then contains object data.
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//
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// Implements:
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//
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// void rados_read_op_read(rados_read_op_t read_op,
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// uint64_t offset,
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// size_t len,
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// char * buffer,
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// size_t * bytes_read,
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// int * prval)
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func (r *ReadOp) Read(offset uint64, buffer []byte) *ReadOpReadStep {
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oe := newReadStep(buffer, offset)
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readStep := newReadOpReadStep()
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r.steps = append(r.steps, oe, readStep)
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C.rados_read_op_read(
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r.op,
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oe.cOffset,
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oe.cReadLen,
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oe.cBuffer,
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readStep.bytesRead,
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readStep.prval,
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)
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return readStep
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}
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