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/** @file
Internal file explorer helper functions for RamDiskDxe driver.
Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "RamDiskImpl.h"
/**
Helper function called as part of the code needed to allocate the proper
sized buffer for various EFI interfaces.
@param[in, out] Status Current status.
@param[in, out] Buffer Current allocated buffer, or NULL.
@param[in] BufferSize Current buffer size needed.
@retval TRUE If the buffer was reallocated and the caller should
try the API again.
@retval FALSE The caller should not call this function again.
**/
BOOLEAN
GrowBuffer (
IN OUT EFI_STATUS *Status,
IN OUT VOID **Buffer,
IN UINTN BufferSize
)
{
BOOLEAN TryAgain;
//
// If this is an initial request, buffer will be null with a new buffer size
//
if ((*Buffer == NULL) && (BufferSize != 0)) {
*Status = EFI_BUFFER_TOO_SMALL;
}
//
// If the status code is "buffer too small", resize the buffer
//
TryAgain = FALSE;
if (*Status == EFI_BUFFER_TOO_SMALL) {
if (*Buffer != NULL) {
FreePool (*Buffer);
}
*Buffer = AllocateZeroPool (BufferSize);
if (*Buffer != NULL) {
TryAgain = TRUE;
} else {
*Status = EFI_OUT_OF_RESOURCES;
}
}
//
// If there's an error, free the buffer
//
if (!TryAgain && EFI_ERROR (*Status) && (*Buffer != NULL)) {
FreePool (*Buffer);
*Buffer = NULL;
}
return TryAgain;
}
/**
This function gets the file information from an open file descriptor,
and stores it in a buffer allocated from pool.
@param[in] FHand File Handle.
@return A pointer to a buffer with file information or NULL is returned.
**/
EFI_FILE_INFO *
FileInfo (
IN EFI_FILE_HANDLE FHand
)
{
EFI_STATUS Status;
EFI_FILE_INFO *Buffer;
UINTN BufferSize;
//
// Initialize for GrowBuffer loop
//
Buffer = NULL;
BufferSize = SIZE_OF_EFI_FILE_INFO + 200;
//
// Call the real function
//
while (GrowBuffer (&Status, (VOID **) &Buffer, BufferSize)) {
Status = FHand->GetInfo (
FHand,
&gEfiFileInfoGuid,
&BufferSize,
Buffer
);
}
return Buffer;
}
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