projects / apple / security.git / blame
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|---|---|---|
| b1ab9ed8 A |
1 | /* |
| 2 | * Copyright (c) 2000-2004 Apple Computer, Inc. All Rights Reserved. | |
| 3 | * | |
| 4 | * @APPLE_LICENSE_HEADER_START@ | |
| 5 | * | |
| 6 | * This file contains Original Code and/or Modifications of Original Code | |
| 7 | * as defined in and that are subject to the Apple Public Source License | |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in | |
| 9 | * compliance with the License. Please obtain a copy of the License at | |
| 10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
| 11 | * file. | |
| 12 | * | |
| 13 | * The Original Code and all software distributed under the License are | |
| 14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
| 15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
| 16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
| 17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
| 18 | * Please see the License for the specific language governing rights and | |
| 19 | * limitations under the License. | |
| 20 | * | |
| 21 | * @APPLE_LICENSE_HEADER_END@ | |
| 22 | */ | |
| 23 | ||
| 24 | ||
| 25 | // | |
| 26 | // bufferfifo - a Sink that queues data in a FIFO of buffers for retrieval | |
| 27 | // | |
| 28 | #include "bufferfifo.h" | |
| 29 | #include <security_utilities/memutils.h> | |
| 30 | ||
| 31 | ||
| 32 | namespace Security { | |
| 33 | ||
| 34 | ||
| 35 | // | |
| 36 | // On destruction, throw away all queued buffers (that haven't been picked up) | |
| 37 | // | |
| 38 | BufferFifo::~BufferFifo() | |
| 39 | { | |
| 40 | while (!mBuffers.empty()) { | |
| 41 | delete mBuffers.front(); | |
| 42 | mBuffers.pop(); | |
| 43 | } | |
| 44 | } | |
| 45 | ||
| 46 | void BufferFifo::clearBuffer() | |
| 47 | { | |
| 48 | while (!mBuffers.empty()) { | |
| 49 | delete mBuffers.front(); | |
| 50 | mBuffers.pop(); | |
| 51 | } | |
| 52 | mSize = 0; | |
| 53 | } | |
| 54 | ||
| 55 | // | |
| 56 | // This is the put function of a Sink. We store the data in at most two buffers: | |
| 57 | // First we append to the last (partially filled) one; then we allocate a new one | |
| 58 | // (if needed) to hold the rest. | |
| 59 | // | |
| 60 | void BufferFifo::consume(const void *data, size_t size) | |
| 61 | { | |
| 62 | mSize += size; | |
| 63 | ||
| 64 | // step 1: fill the rearmost (partially filled) buffer | |
| 65 | if (size > 0 && !mBuffers.empty()) { | |
| 66 | Buffer *current = mBuffers.back(); | |
| 67 | size_t length = current->put(data, size); | |
| 68 | data = LowLevelMemoryUtilities::increment(data, length); | |
| 69 | size -= length; | |
| 70 | } | |
| 71 | // step 2: if there's anything left, make a new buffer and fill it | |
| 72 | if (size > 0) { // not done | |
| 73 | Buffer *current = new Buffer(max(bufferLength, size)); | |
| 74 | mBuffers.push(current); | |
| 75 | assert(current->available() >= size); | |
| 76 | current->put(data, size); | |
| 77 | } | |
| 78 | } | |
| 79 | ||
| 80 | ||
| 81 | // | |
| 82 | // Pull the first (FI) buffer off the queue and deliver it. | |
| 83 | // We retain no memory of it; it belongs to the caller now. | |
| 84 | // | |
| 85 | Buffer *BufferFifo::pop() | |
| 86 | { | |
| 87 | assert(!mBuffers.empty()); | |
| 88 | Buffer *top = mBuffers.front(); | |
| 89 | mBuffers.pop(); | |
| 90 | return top; | |
| 91 | } | |
| 92 | ||
| 93 | ||
| 94 | } // end namespace Security |