| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef _DECAF_IO_BLOCKINGBYTEARRAYINPUTSTREAM_H_ |
| #define _DECAF_IO_BLOCKINGBYTEARRAYINPUTSTREAM_H_ |
| |
| #include <decaf/io/InputStream.h> |
| #include <decaf/util/concurrent/Mutex.h> |
| #include <vector> |
| |
| namespace decaf{ |
| namespace io{ |
| |
| /** |
| * This is a blocking version of a byte buffer stream. Read operations |
| * block until the requested data becomes available in the internal |
| * buffer via a call to setByteArray. |
| */ |
| class DECAF_API BlockingByteArrayInputStream : public InputStream { |
| private: |
| |
| /** |
| * Default buffer to use, if none provided. |
| */ |
| std::vector<unsigned char> buffer; |
| |
| /** |
| * iterator to current position in buffer. |
| */ |
| std::vector<unsigned char>::const_iterator pos; |
| |
| /** |
| * Synchronization object. |
| */ |
| util::concurrent::Mutex mutex; |
| |
| /** |
| * Indicates that this stream is in the process of shutting |
| * down. |
| */ |
| bool closing; |
| |
| public: |
| |
| /** |
| * Default Constructor - uses a default internal buffer |
| */ |
| BlockingByteArrayInputStream(); |
| |
| /** |
| * Constructor that initializes the internal buffer. |
| * @see setByteArray. |
| */ |
| BlockingByteArrayInputStream( const unsigned char* buffer, |
| std::size_t bufferSize ); |
| |
| /** |
| * Destructor |
| */ |
| virtual ~BlockingByteArrayInputStream(); |
| |
| /** |
| * Sets the data that this reader uses. Replaces any existing |
| * data and resets the read index to the beginning of the buffer. |
| * When this method is called, it notifies any other threads that |
| * data is now available to be read. |
| * @param buffer The new data to be copied to the internal buffer. |
| * @param bufferSize The size of the new buffer. |
| */ |
| virtual void setByteArray( const unsigned char* buffer, |
| std::size_t bufferSize ); |
| |
| /** |
| * Indicates the number of bytes available to be read without |
| * blocking. |
| * @return the data available in the internal buffer. |
| * @throws IOException if an error occurs. |
| */ |
| virtual std::size_t available() const throw ( IOException ){ |
| return std::distance( pos, buffer.end() ); |
| } |
| |
| /** |
| * Reads a single byte from the buffer. This operation will |
| * block until data has been added to the buffer via a call |
| * to setByteArray. |
| * @return the next byte. |
| * @throws IOException if an error occurs. |
| */ |
| virtual unsigned char read() throw ( IOException ); |
| |
| /** |
| * Reads an array of bytes from the buffer. If the desired amount |
| * of data is not currently available, this operation |
| * will block until the appropriate amount of data is available |
| * in the buffer via a call to setByteArray. |
| * @param buffer (out) the target buffer |
| * @param offset the position in the buffer to start from. |
| * @param bufferSize the size of the output buffer. |
| * @return the number of bytes read. or -1 if EOF |
| * @throws IOException f an error occurs. |
| */ |
| virtual int read( unsigned char* buffer, |
| std::size_t offset, |
| std::size_t bufferSize ) |
| throw ( IOException, lang::exceptions::NullPointerException ); |
| |
| /** |
| * Closes the target input stream. |
| * @throws IOException if an error occurs. |
| */ |
| virtual void close() throw ( lang::Exception ); |
| |
| /** |
| * Skips over and discards n bytes of data from this input stream. The |
| * skip method may, for a variety of reasons, end up skipping over some |
| * smaller number of bytes, possibly 0. This may result from any of a |
| * number of conditions; reaching end of file before n bytes have been |
| * skipped is only one possibility. The actual number of bytes skipped |
| * is returned. If n is negative, no bytes are skipped. |
| * <p> |
| * The skip method of InputStream creates a byte array and then |
| * repeatedly reads into it until n bytes have been read or the end |
| * of the stream has been reached. Subclasses are encouraged to |
| * provide a more efficient implementation of this method. |
| * @param num - the number of bytes to skip |
| * @returns total butes skipped |
| * @throws IOException if an error occurs |
| */ |
| virtual std::size_t skip( std::size_t num ) |
| throw ( io::IOException, lang::exceptions::UnsupportedOperationException ); |
| |
| /** |
| * Marks the current position in the stream A subsequent call to the |
| * reset method repositions this stream at the last marked position so |
| * that subsequent reads re-read the same bytes. |
| * |
| * If a stream instance reports that marks are supported then the stream |
| * will ensure that the same bytes can be read again after the reset method |
| * is called so long the readLimit is not reached. |
| * @param readLimit - max bytes read before marked position is invalid. |
| */ |
| virtual void mark( int readLimit DECAF_UNUSED ) {} |
| |
| /** |
| * Repositions this stream to the position at the time the mark method was |
| * last called on this input stream. |
| * |
| * If the method markSupported returns true, then: |
| * * If the method mark has not been called since the stream was created, |
| * or the number of bytes read from the stream since mark was last called |
| * is larger than the argument to mark at that last call, then an |
| * IOException might be thrown. |
| * * If such an IOException is not thrown, then the stream is reset to a |
| * state such that all the bytes read since the most recent call to mark |
| * (or since the start of the file, if mark has not been called) will be |
| * resupplied to subsequent callers of the read method, followed by any |
| * bytes that otherwise would have been the next input data as of the |
| * time of the call to reset. |
| * If the method markSupported returns false, then: |
| * * The call to reset may throw an IOException. |
| * * If an IOException is not thrown, then the stream is reset to a fixed |
| * state that depends on the particular type of the input stream and how |
| * it was created. The bytes that will be supplied to subsequent callers |
| * of the read method depend on the particular type of the input stream. |
| * @throws IOException |
| */ |
| virtual void reset() throw ( IOException ) { |
| throw IOException( |
| __FILE__, __LINE__, |
| "BufferedInputStream::reset - mark no yet supported." ); |
| } |
| |
| /** |
| * Determines if this input stream supports the mark and reset methods. |
| * Whether or not mark and reset are supported is an invariant property of |
| * a particular input stream instance. |
| * @returns true if this stream instance supports marks |
| */ |
| virtual bool markSupported() const{ return false; } |
| |
| public: |
| |
| /** |
| * Waits on a signal from this object, which is generated |
| * by a call to Notify. Must have this object locked before |
| * calling. |
| * @throws Exception |
| */ |
| virtual void lock() throw( lang::Exception ){ |
| mutex.lock(); |
| } |
| |
| /** |
| * Unlocks the object. |
| * @throws Exception |
| */ |
| virtual void unlock() throw( lang::Exception ){ |
| mutex.unlock(); |
| } |
| |
| /** |
| * Waits on a signal from this object, which is generated |
| * by a call to Notify. Must have this object locked before |
| * calling. |
| * @throws Exception |
| */ |
| virtual void wait() throw( lang::Exception ){ |
| mutex.wait(); |
| } |
| |
| /** |
| * Waits on a signal from this object, which is generated |
| * by a call to Notify. Must have this object locked before |
| * calling. This wait will timeout after the specified time |
| * interval. |
| * @param time in millisecsonds to wait, or WAIT_INIFINITE |
| * @throws Exception |
| */ |
| virtual void wait( unsigned long millisecs ) throw( lang::Exception ){ |
| mutex.wait(millisecs); |
| } |
| |
| /** |
| * Signals a waiter on this object that it can now wake |
| * up and continue. Must have this object locked before |
| * calling. |
| * @throws Exception |
| */ |
| virtual void notify() throw( lang::Exception ){ |
| mutex.notify(); |
| } |
| |
| /** |
| * Signals the waiters on this object that it can now wake |
| * up and continue. Must have this object locked before |
| * calling. |
| * @throws Exception |
| */ |
| virtual void notifyAll() throw( lang::Exception ){ |
| mutex.notifyAll(); |
| } |
| |
| }; |
| |
| }} |
| |
| #endif /*_DECAF_IO_BLOCKINGBYTEARRAYINPUTSTREAM_H_*/ |