+++ /dev/null
-package org.apache.lucene.benchmark.byTask.utils;
-
-/**
- * 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.
- */
-
-import java.io.IOException;
-import java.io.Reader;
-
-/**
- * Implements a {@link Reader} over a {@link StringBuilder} instance. Although
- * one can use {@link java.io.StringReader} by passing it
- * {@link StringBuilder#toString()}, it is better to use this class, as it
- * doesn't mark the passed-in {@link StringBuilder} as shared (which will cause
- * inner char[] allocations at the next append() attempt).<br>
- * Notes:
- * <ul>
- * <li>This implementation assumes the underlying {@link StringBuilder} is not
- * changed during the use of this {@link Reader} implementation.
- * <li>This implementation is thread-safe.
- * <li>The implementation looks very much like {@link java.io.StringReader} (for
- * the right reasons).
- * <li>If one wants to reuse that instance, then the following needs to be done:
- * <pre>
- * StringBuilder sb = new StringBuilder("some text");
- * Reader reader = new StringBuilderReader(sb);
- * ... read from reader - don't close it ! ...
- * sb.setLength(0);
- * sb.append("some new text");
- * reader.reset();
- * ... read the new string from the reader ...
- * </pre>
- * </ul>
- */
-public class StringBuilderReader extends Reader {
-
- // The StringBuilder to read from.
- private StringBuilder sb;
-
- // The length of 'sb'.
- private int length;
-
- // The next position to read from the StringBuilder.
- private int next = 0;
-
- // The mark position. The default value 0 means the start of the text.
- private int mark = 0;
-
- public StringBuilderReader(StringBuilder sb) {
- set(sb);
- }
-
- /** Check to make sure that the stream has not been closed. */
- private void ensureOpen() throws IOException {
- if (sb == null) {
- throw new IOException("Stream has already been closed");
- }
- }
-
- @Override
- public void close() {
- synchronized (lock) {
- sb = null;
- }
- }
-
- /**
- * Mark the present position in the stream. Subsequent calls to reset() will
- * reposition the stream to this point.
- *
- * @param readAheadLimit Limit on the number of characters that may be read
- * while still preserving the mark. Because the stream's input comes
- * from a StringBuilder, there is no actual limit, so this argument
- * must not be negative, but is otherwise ignored.
- * @exception IllegalArgumentException If readAheadLimit is < 0
- * @exception IOException If an I/O error occurs
- */
- @Override
- public void mark(int readAheadLimit) throws IOException {
- if (readAheadLimit < 0){
- throw new IllegalArgumentException("Read-ahead limit cannpt be negative: " + readAheadLimit);
- }
- synchronized (lock) {
- ensureOpen();
- mark = next;
- }
- }
-
- @Override
- public boolean markSupported() {
- return true;
- }
-
- @Override
- public int read() throws IOException {
- synchronized (lock) {
- ensureOpen();
- return next >= length ? -1 : sb.charAt(next++);
- }
- }
-
- @Override
- public int read(char cbuf[], int off, int len) throws IOException {
- synchronized (lock) {
- ensureOpen();
-
- // Validate parameters
- if (off < 0 || off > cbuf.length || len < 0 || off + len > cbuf.length) {
- throw new IndexOutOfBoundsException("off=" + off + " len=" + len + " cbuf.length=" + cbuf.length);
- }
-
- if (len == 0) {
- return 0;
- }
-
- if (next >= length) {
- return -1;
- }
-
- int n = Math.min(length - next, len);
- sb.getChars(next, next + n, cbuf, off);
- next += n;
- return n;
- }
- }
-
- @Override
- public boolean ready() throws IOException {
- synchronized (lock) {
- ensureOpen();
- return true;
- }
- }
-
- @Override
- public void reset() throws IOException {
- synchronized (lock) {
- ensureOpen();
- next = mark;
- length = sb.length();
- }
- }
-
- public void set(StringBuilder sb) {
- synchronized (lock) {
- this.sb = sb;
- length = sb.length();
- next = mark = 0;
- }
- }
-
- @Override
- public long skip(long ns) throws IOException {
- synchronized (lock) {
- ensureOpen();
- if (next >= length) {
- return 0;
- }
-
- // Bound skip by beginning and end of the source
- long n = Math.min(length - next, ns);
- n = Math.max(-next, n);
- next += n;
- return n;
- }
- }
-
-}
fnp / pylucene.git / blobdiff