-/*
- * Copyright (c) 2000-2002,2004,2011,2014 Apple 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
-//
-#ifndef _H_STREAMS
-#define _H_STREAMS
-
-#include "unix++.h"
-
-
-namespace Security {
-
-using UnixPlusPlus::FileDesc;
-
-
-//
-// An abstract Source object.
-// Source can yield data when its produce method is called. Produce can yield
-// anything between zero and length bytes and sets length accordingly.
-// If the last call to produce returned zero bytes (and only then), the state method
-// will yield an explanation:
-// producing -> we're in business; there just no data quite yet (try again)
-// stalled -> there may be more data coming, but not in the near future;
-// wait a while then call state again to see
-// endOfData -> no more data will be produced by this Source
-// When called *before* the first call to produce, getSize may return the number
-// of bytes that all calls to produce will yield together. If getSize returns unknownSize,
-// this value cannot be determined beforehand. GetSize *may* yield the number of bytes
-// yet to come when called after produce, but this is not guaranteed for all Sources.
-//
-class Source {
-public:
- virtual void produce(void *data, size_t &length) = 0;
- virtual ~Source() { }
-
- static const size_t unknownSize = size_t(-1);
- virtual size_t getSize();
-
- enum State {
- producing, // yielding data (go ahead)
- stalled, // no data now, perhaps more later
- endOfData // end of data (no more data)
- };
- virtual State state() const;
-
-protected:
- State mState; // auto-regulated state (can be overridden)
-};
-
-
-//
-// An abstract Sink object.
-// Sinks can cansume data when their consume method is called.
-// Sinks cannot refuse data; they always consume all data given to consume.
-// There is currently no flow control/throttle mechanism (one will probably
-// be added soon).
-//
-class Sink {
-public:
- Sink() : mSize(0) {}
- virtual ~Sink() { }
- virtual void consume(const void *data, size_t length) = 0;
- virtual void setSize(size_t expectedSize);
- size_t getSize() {return mSize;}
-
-protected:
- size_t mSize;
-
-};
-
-
-//
-// The NullSource produces no data.
-//
-class NullSource : public Source {
-public:
- void produce(void *addr, size_t &len);
- State state() const;
-};
-
-
-//
-// A FileSource reads from a UNIX file or file descriptor.
-// Note that getSize will yield the size of the underlying i-node,
-// which is usually correct but may not be in the case of simultaneous
-// access.
-//
-class FileSource : public Source, public FileDesc {
-public:
- FileSource(const char *path, int mode = O_RDONLY) : FileDesc(path, mode) { mState = producing; }
- FileSource(int fd) : FileDesc(fd) { mState = producing; }
- void produce(void *data, size_t &length);
- size_t getSize();
-};
-
-
-//
-// A MemorySource yields the contents of a preset contiguous memory block.
-//
-class MemorySource : public Source {
-public:
- MemorySource(const void *data, size_t length) : mData(data), mRemaining(length) { }
-
- template <class Data>
- MemorySource(const Data &data) : mData(data.data()), mRemaining(data.length()) { }
-
- void produce(void *data, size_t &length);
- size_t getSize();
- State state() const;
-
-private:
- const void *mData;
- size_t mRemaining;
-};
-
-
-//
-// A NullSink eats all data and discards it quietly.
-//
-class NullSink : public Sink {
-public:
- void consume(const void *data, size_t length);
-};
-
-
-//
-// A FileSink writes its received data to a UNIX file or file descriptor.
-//
-class FileSink : public Sink, public FileDesc {
-public:
- FileSink(const char *path, int mode = O_WRONLY | O_CREAT | O_TRUNC)
- : FileDesc(path, mode) { }
- FileSink(int fd) : FileDesc(fd) { }
- void consume(const void *data, size_t length);
-};
-
-
-//
-// MemorySinks collect output in a contiguous memory block.
-// This is not often a good idea, so if you find yourself using this,
-// consider consuming on-the-fly or streaming to secondary media,
-// or (at least) use a BufferFifo instead.
-//
-class MemorySink : public Sink {
-public:
- MemorySink() : mBuffer(NULL), mMax(0) { }
- ~MemorySink() { free(mBuffer); }
-
- void consume(const void *data, size_t length);
- void setSize(size_t expectedSize);
-
- void *data() const { return mBuffer; }
- size_t length() const { return mSize; }
-
- void clear() { free(mBuffer); mBuffer = NULL; mSize = mMax = 0; }
-
-private:
- void grow(size_t newSize);
-
-private:
- void *mBuffer; // buffer base
- size_t mMax; // currently allocated
-};
-
-
-} // end namespace Security
-
-
-#endif /* _H_STREAMS */
projects / apple / security.git / blobdiff