/* * Copyright 2005 The Apache Software Foundation * * Licensed 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. */ using System; namespace Lucene.Net.Store { /// Abstract base class for output to a file in a Directory. A random-access /// output stream. Used for all Lucene index output operations. /// /// /// /// /// public abstract class IndexOutput { /// Writes a single byte. /// /// public abstract void WriteByte(byte b); /// Writes an array of bytes. /// the bytes to write /// /// the number of bytes to write /// /// /// public abstract void WriteBytes(byte[] b, int length); /// Writes an int as four bytes. /// /// public virtual void WriteInt(int i) { WriteByte((byte) (i >> 24)); WriteByte((byte) (i >> 16)); WriteByte((byte) (i >> 8)); WriteByte((byte) i); } /// Writes an int in a variable-length format. Writes between one and /// five bytes. Smaller values take fewer bytes. Negative numbers are not /// supported. /// /// /// public virtual void WriteVInt(int i) { while ((i & ~ 0x7F) != 0) { WriteByte((byte) ((i & 0x7f) | 0x80)); i = (int) (((uint) i) >> 7); } WriteByte((byte) i); } /// Writes a long as eight bytes. /// /// public virtual void WriteLong(long i) { WriteInt((int) (i >> 32)); WriteInt((int) i); } /// Writes an long in a variable-length format. Writes between one and five /// bytes. Smaller values take fewer bytes. Negative numbers are not /// supported. /// /// /// public virtual void WriteVLong(long i) { while ((i & ~ 0x7F) != 0) { WriteByte((byte) ((i & 0x7f) | 0x80)); i = (int) (((uint) i) >> 7); } WriteByte((byte) i); } /// Writes a string. /// /// public virtual void WriteString(System.String s) { int length = s.Length; WriteVInt(length); WriteChars(s, 0, length); } /// Writes a sequence of UTF-8 encoded characters from a string. /// the source of the characters /// /// the first character in the sequence /// /// the number of characters in the sequence /// /// /// public virtual void WriteChars(System.String s, int start, int length) { int end = start + length; for (int i = start; i < end; i++) { int code = (int) s[i]; if (code >= 0x01 && code <= 0x7F) WriteByte((byte) code); else if (((code >= 0x80) && (code <= 0x7FF)) || code == 0) { WriteByte((byte) (0xC0 | (code >> 6))); WriteByte((byte) (0x80 | (code & 0x3F))); } else { WriteByte((byte) (0xE0 | ((int) (((uint) code) >> 12)))); WriteByte((byte) (0x80 | ((code >> 6) & 0x3F))); WriteByte((byte) (0x80 | (code & 0x3F))); } } } /// Forces any buffered output to be written. public abstract void Flush(); /// Closes this stream to further operations. public abstract void Close(); /// Returns the current position in this file, where the next write will /// occur. /// /// /// public abstract long GetFilePointer(); /// Sets current position in this file, where the next write will occur. /// /// public abstract void Seek(long pos); /// The number of bytes in the file. public abstract long Length(); } }