/* * 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. */ package com.tom_roush.pdfbox.pdfparser; import java.io.Closeable; import java.io.IOException; /** * A SequentialSource provides access to sequential data for parsing. */ interface SequentialSource extends Closeable { /** * Read a single byte of data. * * @return The byte of data that is being read. * @throws IOException If there is an error while reading the data. */ int read() throws IOException; /** * Read a buffer of data. * * @param b The buffer to write the data to. * @return The number of bytes that were actually read. * @throws IOException If there was an error while reading the data. */ int read(byte[] b) throws IOException; /** * Read a buffer of data. * * @param b The buffer to write the data to. * @param offset Offset into the buffer to start writing. * @param length The amount of data to attempt to read. * @return The number of bytes that were actually read. * @throws IOException If there was an error while reading the data. */ int read(byte[] b, int offset, int length) throws IOException; /** * Returns offset of next byte to be returned by a read method. * * @return offset of next byte which will be returned with next {@link #read()} (if no more * bytes are left it returns a value >= length of source). * @throws IOException If there was an error while reading the data. */ long getPosition() throws IOException; /** * This will peek at the next byte. * * @return The next byte on the stream, leaving it as available to read. * @throws IOException If there is an error reading the next byte. */ int peek() throws IOException; /** * Unreads a single byte. * * @param b byte array to push back * @throws IOException If there is an error while seeking */ void unread(int b) throws IOException; /** * Unreads an array of bytes. * * @param bytes byte array to push back * @throws IOException If there is an error while seeking */ void unread(byte[] bytes) throws IOException; /** * Reads a given number of bytes in its entirety. * * @param length the number of bytes to be read * @return a byte array containing the bytes just read * @throws IOException if an I/O error occurs while reading data */ byte[] readFully(int length) throws IOException; /** * Returns true if the end of the data source has been reached. * * @return true if we are at the end of the data. * @throws IOException If there is an error reading the next byte. */ boolean isEOF() throws IOException; }