Security-55163.44.tar.gz

[apple/security.git] / libsecurity_utilities / lib / streams.cpp

diff --git a/libsecurity_utilities/lib/streams.cpp b/libsecurity_utilities/lib/streams.cpp
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+/*
+ * Copyright (c) 2000-2001,2003-2004 Apple Computer, Inc. All Rights Reserved.
+ * 
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+//
+// streams.h - lightweight source and sink objects
+//
+#include "streams.h"
+#include <security_utilities/memutils.h>
+
+
+namespace Security {
+
+
+//
+// Source and Sink abstract superclasses
+//
+Source::State Source::state() const
+{
+    return mState;
+}
+
+size_t Source::getSize()
+{
+    return unknownSize;
+}
+
+void Sink::setSize(size_t)
+{
+    // ignored
+}
+
+
+//
+// Null sources and sinks
+//
+void NullSource::produce(void *, size_t &length)
+{
+    length = 0;
+}
+
+Source::State NullSource::state() const
+{
+    return endOfData;
+}
+
+void NullSink::consume(const void *, size_t)
+{
+    // ignore the data
+}
+
+
+//
+// File sources and sinks
+//
+void FileSource::produce(void *data, size_t &length)
+{
+    if ((length = read(data, length)) == 0)
+        mState = endOfData;
+}
+
+size_t FileSource::getSize()
+{
+    return fileSize();
+}
+
+
+void FileSink::consume(const void *data, size_t length)
+{
+       write(data, length);
+}
+
+
+//
+// Memory sources
+//
+void MemorySource::produce(void *data, size_t &length)
+{
+    if (mRemaining < length)
+        length = mRemaining;
+    memcpy(data, mData, length);
+    mData = LowLevelMemoryUtilities::increment(mData, length);
+    mRemaining -= length;
+}
+
+size_t MemorySource::getSize()
+{
+    return mRemaining;
+}
+
+Source::State MemorySource::state() const
+{
+    return mRemaining ? producing : endOfData;
+}
+
+
+//
+// Memory sinks
+//
+void MemorySink::consume(const void *data, size_t length)
+{
+    if (mSize + length > mMax)
+        grow(mSize * 3 / 2);
+    assert(mSize + length <= mMax);
+    memcpy(((char *)mBuffer) + mSize, data, length);
+    mSize += length;
+}
+
+void MemorySink::setSize(size_t expectedSize)
+{
+    grow(expectedSize);
+}
+
+void MemorySink::grow(size_t newSize)
+{
+    if (void *p = realloc(mBuffer, newSize)) {
+        mBuffer = p;
+        mMax = newSize;
+    } else
+        UnixError::throwMe();
+}
+
+
+}      // end namespace Security