1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "SimpleBuffer.h"
8 #include <algorithm>
9
10 namespace mozilla {
11 namespace net {
12
SimpleBuffer()13 SimpleBuffer::SimpleBuffer() : mStatus(NS_OK), mAvailable(0) {}
14
Write(char * src,size_t len)15 nsresult SimpleBuffer::Write(char* src, size_t len) {
16 NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
17 if (NS_FAILED(mStatus)) {
18 return mStatus;
19 }
20
21 while (len > 0) {
22 SimpleBufferPage* p = mBufferList.getLast();
23 if (p && (p->mWriteOffset == SimpleBufferPage::kSimpleBufferPageSize)) {
24 // no room.. make a new page
25 p = nullptr;
26 }
27 if (!p) {
28 p = new (fallible) SimpleBufferPage();
29 if (!p) {
30 mStatus = NS_ERROR_OUT_OF_MEMORY;
31 return mStatus;
32 }
33 mBufferList.insertBack(p);
34 }
35 size_t roomOnPage =
36 SimpleBufferPage::kSimpleBufferPageSize - p->mWriteOffset;
37 size_t toWrite = std::min(roomOnPage, len);
38 memcpy(p->mBuffer + p->mWriteOffset, src, toWrite);
39 src += toWrite;
40 len -= toWrite;
41 p->mWriteOffset += toWrite;
42 mAvailable += toWrite;
43 }
44 return NS_OK;
45 }
46
Read(char * dest,size_t maxLen)47 size_t SimpleBuffer::Read(char* dest, size_t maxLen) {
48 NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
49 if (NS_FAILED(mStatus)) {
50 return 0;
51 }
52
53 size_t rv = 0;
54 for (SimpleBufferPage* p = mBufferList.getFirst(); p && (rv < maxLen);
55 p = mBufferList.getFirst()) {
56 size_t avail = p->mWriteOffset - p->mReadOffset;
57 size_t toRead = std::min(avail, (maxLen - rv));
58 memcpy(dest + rv, p->mBuffer + p->mReadOffset, toRead);
59 rv += toRead;
60 p->mReadOffset += toRead;
61 if (p->mReadOffset == p->mWriteOffset) {
62 p->remove();
63 delete p;
64 }
65 }
66
67 MOZ_ASSERT(mAvailable >= rv);
68 mAvailable -= rv;
69 return rv;
70 }
71
Available()72 size_t SimpleBuffer::Available() {
73 NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
74 return NS_SUCCEEDED(mStatus) ? mAvailable : 0;
75 }
76
Clear()77 void SimpleBuffer::Clear() {
78 NS_ASSERT_OWNINGTHREAD(SimpleBuffer);
79 SimpleBufferPage* p;
80 while ((p = mBufferList.popFirst())) {
81 delete p;
82 }
83 mAvailable = 0;
84 }
85
86 } // namespace net
87 } // namespace mozilla
88