xpcom/io/nsScriptableInputStream.cpp@97036ab72558
xpcom/io/nsScriptableInputStream.cpp
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #include "nsScriptableInputStream.h"
7 #include "nsMemory.h"
8 #include "nsString.h"
10 NS_IMPL_ISUPPORTS(nsScriptableInputStream, nsIScriptableInputStream)
12 // nsIScriptableInputStream methods
13 NS_IMETHODIMP
14 nsScriptableInputStream::Close(void) {
15 if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
16 return mInputStream->Close();
17 }
19 NS_IMETHODIMP
20 nsScriptableInputStream::Init(nsIInputStream *aInputStream) {
21 if (!aInputStream) return NS_ERROR_NULL_POINTER;
22 mInputStream = aInputStream;
23 return NS_OK;
24 }
26 NS_IMETHODIMP
27 nsScriptableInputStream::Available(uint64_t *_retval) {
28 if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
29 return mInputStream->Available(_retval);
30 }
32 NS_IMETHODIMP
33 nsScriptableInputStream::Read(uint32_t aCount, char **_retval) {
34 nsresult rv = NS_OK;
35 uint64_t count64 = 0;
36 char *buffer = nullptr;
38 if (!mInputStream) return NS_ERROR_NOT_INITIALIZED;
40 rv = mInputStream->Available(&count64);
41 if (NS_FAILED(rv)) return rv;
43 // bug716556 - Ensure count+1 doesn't overflow
44 uint32_t count = XPCOM_MIN((uint32_t)XPCOM_MIN<uint64_t>(count64, aCount), UINT32_MAX - 1);
45 buffer = (char*)moz_malloc(count+1); // make room for '\0'
46 if (!buffer) return NS_ERROR_OUT_OF_MEMORY;
48 rv = ReadHelper(buffer, count);
49 if (NS_FAILED(rv)) {
50 nsMemory::Free(buffer);
51 return rv;
52 }
54 buffer[count] = '\0';
55 *_retval = buffer;
56 return NS_OK;
57 }
59 NS_IMETHODIMP
60 nsScriptableInputStream::ReadBytes(uint32_t aCount, nsACString &_retval) {
61 if (!mInputStream) {
62 return NS_ERROR_NOT_INITIALIZED;
63 }
65 _retval.SetLength(aCount);
66 if (_retval.Length() != aCount) {
67 return NS_ERROR_OUT_OF_MEMORY;
68 }
70 char *ptr = _retval.BeginWriting();
71 nsresult rv = ReadHelper(ptr, aCount);
72 if (NS_FAILED(rv)) {
73 _retval.Truncate();
74 }
75 return rv;
76 }
78 nsresult
79 nsScriptableInputStream::ReadHelper(char* aBuffer, uint32_t aCount)
80 {
81 uint32_t totalBytesRead = 0;
82 while (1) {
83 uint32_t bytesRead;
84 nsresult rv = mInputStream->Read(aBuffer + totalBytesRead,
85 aCount - totalBytesRead,
86 &bytesRead);
87 if (NS_FAILED(rv)) {
88 return rv;
89 }
91 totalBytesRead += bytesRead;
92 if (totalBytesRead == aCount) {
93 break;
94 }
96 // If we have read zero bytes, we have hit EOF.
97 if (bytesRead == 0) {
98 return NS_ERROR_FAILURE;
99 }
101 }
102 return NS_OK;
103 }
105 nsresult
106 nsScriptableInputStream::Create(nsISupports *aOuter, REFNSIID aIID, void **aResult) {
107 if (aOuter) return NS_ERROR_NO_AGGREGATION;
109 nsScriptableInputStream *sis = new nsScriptableInputStream();
110 if (!sis) return NS_ERROR_OUT_OF_MEMORY;
112 NS_ADDREF(sis);
113 nsresult rv = sis->QueryInterface(aIID, aResult);
114 NS_RELEASE(sis);
115 return rv;
116 }
