OSX/libsecurity_utilities/lib/streams.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2003-2004,2011,2014 Apple 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 // streams.h - lightweight source and sink objects
  27 //
  28 #include "streams.h"
  29 #include <security_utilities/memutils.h>
  30
  31
  32 namespace Security {
  33
  34
  35 //
  36 // Source and Sink abstract superclasses
  37 //
  38 Source::State Source::state() const
  39 {
  40     return mState;
  41 }
  42
  43 size_t Source::getSize()
  44 {
  45     return unknownSize;
  46 }
  47
  48 void Sink::setSize(size_t)
  49 {
  50     // ignored
  51 }
  52
  53
  54 //
  55 // Null sources and sinks
  56 //
  57 void NullSource::produce(void *, size_t &length)
  58 {
  59     length = 0;
  60 }
  61
  62 Source::State NullSource::state() const
  63 {
  64     return endOfData;
  65 }
  66
  67 void NullSink::consume(const void *, size_t)
  68 {
  69     // ignore the data
  70 }
  71
  72
  73 //
  74 // File sources and sinks
  75 //
  76 void FileSource::produce(void *data, size_t &length)
  77 {
  78     if ((length = read(data, length)) == 0)
  79         mState = endOfData;
  80 }
  81
  82 size_t FileSource::getSize()
  83 {
  84     return fileSize();
  85 }
  86
  87
  88 void FileSink::consume(const void *data, size_t length)
  89 {
  90         write(data, length);
  91 }
  92
  93
  94 //
  95 // Memory sources
  96 //
  97 void MemorySource::produce(void *data, size_t &length)
  98 {
  99     if (mRemaining < length)
 100         length = mRemaining;
 101     memcpy(data, mData, length);
 102     mData = LowLevelMemoryUtilities::increment(mData, length);
 103     mRemaining -= length;
 104 }
 105
 106 size_t MemorySource::getSize()
 107 {
 108     return mRemaining;
 109 }
 110
 111 Source::State MemorySource::state() const
 112 {
 113     return mRemaining ? producing : endOfData;
 114 }
 115
 116
 117 //
 118 // Memory sinks
 119 //
 120 void MemorySink::consume(const void *data, size_t length)
 121 {
 122     if (mSize + length > mMax)
 123         grow(mSize * 3 / 2);
 124     assert(mSize + length <= mMax);
 125     memcpy(((char *)mBuffer) + mSize, data, length);
 126     mSize += length;
 127 }
 128
 129 void MemorySink::setSize(size_t expectedSize)
 130 {
 131     grow(expectedSize);
 132 }
 133
 134 void MemorySink::grow(size_t newSize)
 135 {
 136     if (void *p = realloc(mBuffer, newSize)) {
 137         mBuffer = p;
 138         mMax = newSize;
 139     } else
 140         UnixError::throwMe();
 141 }
 142
 143
 144 }       // end namespace Security