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/** @file
Internal file explorer helper functions for RamDiskDxe driver.
Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#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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