/*
 * Copyright 2005-2009, Ingo Weinhold, ingo_weinhold@gmx.de.
 * Copyright 2016, Axel Dörfler, axeld@pinc-software.de.
 * Distributed under the terms of the MIT License.
 */


#include "AttributeUtilities.h"

#include <fs_attr.h>
#include <Node.h>
#include <StorageDefs.h>


static const int kCopyBufferSize = 64 * 1024;
        // 64 KB


namespace BPrivate {


status_t
CopyAttributes(BNode& source, BNode& destination)
{
        char attrName[B_ATTR_NAME_LENGTH];
        while (source.GetNextAttrName(attrName) == B_OK) {
                // get attr info
                attr_info attrInfo;
                status_t status = source.GetAttrInfo(attrName, &attrInfo);
                if (status != B_OK)
                        return status;

                // copy the attribute
                char buffer[kCopyBufferSize];
                off_t offset = 0;
                off_t bytesLeft = attrInfo.size;

                // Go at least once through the loop, so that an empty attribute will be
                // created as well
                do {
                        size_t toRead = kCopyBufferSize;
                        if ((off_t)toRead > bytesLeft)
                                toRead = bytesLeft;

                        // read
                        ssize_t bytesRead = source.ReadAttr(attrName, attrInfo.type,
                                offset, buffer, toRead);
                        if (bytesRead < 0)
                                return bytesRead;

                        // write
                        ssize_t bytesWritten = destination.WriteAttr(attrName,
                                attrInfo.type, offset, buffer, bytesRead);
                        if (bytesWritten < 0)
                                return bytesWritten;

                        bytesLeft -= bytesRead;
                        offset += bytesRead;
                } while (bytesLeft > 0);
        }
        return B_OK;
}


}       // namespace BPrivate