VirtualBox

source: vbox/trunk/src/VBox/Runtime/generic/RTFileReadAllByHandleEx-generic.cpp@ 14716

Last change on this file since 14716 was 8954, checked in by vboxsync, 17 years ago

Don't fail on 0 byte files.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 3.8 KB
Line 
1/* $Id: RTFileReadAllByHandleEx-generic.cpp 8954 2008-05-20 14:02:01Z vboxsync $ */
2/** @file
3 * IPRT - RTFileReadAllByHandleEx, generic implementation.
4 */
5
6/*
7 * Copyright (C) 2008 Sun Microsystems, Inc.
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 *
17 * The contents of this file may alternatively be used under the terms
18 * of the Common Development and Distribution License Version 1.0
19 * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20 * VirtualBox OSE distribution, in which case the provisions of the
21 * CDDL are applicable instead of those of the GPL.
22 *
23 * You may elect to license modified versions of this file under the
24 * terms and conditions of either the GPL or the CDDL or both.
25 *
26 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
27 * Clara, CA 95054 USA or visit http://www.sun.com if you need
28 * additional information or have any questions.
29 */
30
31
32
33/*******************************************************************************
34* Header Files *
35*******************************************************************************/
36#include <iprt/file.h>
37#include <iprt/mem.h>
38#include <iprt/assert.h>
39#include <iprt/string.h>
40#include <iprt/err.h>
41
42
43RTDECL(int) RTFileReadAllByHandleEx(RTFILE File, RTFOFF off, RTFOFF cbMax, uint32_t fFlags, void **ppvFile, size_t *pcbFile)
44{
45 AssertReturn(!fFlags, VERR_INVALID_PARAMETER);
46
47 /*
48 * Save the current offset first.
49 */
50 RTFOFF offOrg;
51 int rc = RTFileSeek(File, 0, RTFILE_SEEK_CURRENT, (uint64_t *)&offOrg);
52 if (RT_SUCCESS(rc))
53 {
54 /*
55 * Get the file size, adjust it and check that it might fit into memory.
56 */
57 RTFOFF cbFile;
58 rc = RTFileSeek(File, 0,RTFILE_SEEK_END, (uint64_t *)&cbFile);
59 if (RT_SUCCESS(rc))
60 {
61 RTFOFF cbAllocFile = cbFile > off ? cbFile - off : 0;
62 if (cbAllocFile > cbMax)
63 cbAllocFile = cbMax;
64 size_t cbAllocMem = (size_t)cbAllocFile;
65 if ((RTFOFF)cbAllocMem == cbAllocFile)
66 {
67 /*
68 * Try allocate the required memory and initialize the header (hardcoded fun).
69 */
70 void *pvHdr = RTMemAlloc(cbAllocMem + 32);
71 if (pvHdr)
72 {
73 memset(pvHdr, 0xff, 32);
74 *(size_t *)pvHdr = cbAllocMem;
75
76 /*
77 * Seek and read.
78 */
79 rc = RTFileSeek(File, off, RTFILE_SEEK_BEGIN, NULL);
80 if (RT_SUCCESS(rc))
81 {
82 void *pvFile = (uint8_t *)pvHdr + 32;
83 rc = RTFileRead(File, pvFile, cbAllocMem, NULL);
84 if (RT_SUCCESS(rc))
85 {
86 /*
87 * Success - fill in the return values.
88 */
89 *ppvFile = pvFile;
90 *pcbFile = cbAllocFile;
91 }
92 }
93
94 if (RT_FAILURE(rc))
95 RTMemFree(pvHdr);
96 }
97 else
98 rc = VERR_NO_MEMORY;
99 }
100 else
101 rc = VERR_TOO_MUCH_DATA;
102 }
103 /* restore the position. */
104 RTFileSeek(File, offOrg, RTFILE_SEEK_BEGIN, NULL);
105 }
106 return rc;
107}
108
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