1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.util;
29
30 import java.io.Serializable;
31 import java.nio.ByteBuffer;
32
33 /**
34 * A resizable byte array.
35 *
36 * @since 4.0
37 */
38 public final class ByteArrayBuffer implements Serializable {
39
40 private static final long serialVersionUID = 4359112959524048036L;
41
42 private byte[] array;
43 private int len;
44
45 /**
46 * Creates an instance of {@link ByteArrayBuffer} with the given initial
47 * capacity.
48 *
49 * @param capacity the capacity
50 */
51 public ByteArrayBuffer(final int capacity) {
52 super();
53 Args.notNegative(capacity, "Buffer capacity");
54 this.array = new byte[capacity];
55 }
56
57 private void expand(final int newlen) {
58 final byte[] newArray = new byte[Math.max(this.array.length << 1, newlen)];
59 System.arraycopy(this.array, 0, newArray, 0, this.len);
60 this.array = newArray;
61 }
62
63 /**
64 * Appends {@code len} bytes to this buffer from the given source
65 * array starting at index {@code off}. The capacity of the buffer
66 * is increased, if necessary, to accommodate all {@code len} bytes.
67 *
68 * @param b the bytes to be appended.
69 * @param off the index of the first byte to append.
70 * @param len the number of bytes to append.
71 * @throws IndexOutOfBoundsException if {@code off} if out of
72 * range, {@code len} is negative, or
73 * {@code off} + {@code len} is out of range.
74 */
75 public void append(final byte[] b, final int off, final int len) {
76 if (b == null) {
77 return;
78 }
79 if ((off < 0) || (off > b.length) || (len < 0) ||
80 ((off + len) < 0) || ((off + len) > b.length)) {
81 throw new IndexOutOfBoundsException("off: "+off+" len: "+len+" b.length: "+b.length);
82 }
83 if (len == 0) {
84 return;
85 }
86 final int newlen = this.len + len;
87 if (newlen > this.array.length) {
88 expand(newlen);
89 }
90 System.arraycopy(b, off, this.array, this.len, len);
91 this.len = newlen;
92 }
93
94 /**
95 * Appends {@code b} byte to this buffer. The capacity of the buffer
96 * is increased, if necessary, to accommodate the additional byte.
97 *
98 * @param b the byte to be appended.
99 */
100 public void append(final int b) {
101 final int newlen = this.len + 1;
102 if (newlen > this.array.length) {
103 expand(newlen);
104 }
105 this.array[this.len] = (byte)b;
106 this.len = newlen;
107 }
108
109 /**
110 * Appends {@code len} chars to this buffer from the given source
111 * array starting at index {@code off}. The capacity of the buffer
112 * is increased if necessary to accommodate all {@code len} chars.
113 * <p>
114 * The chars are converted to bytes using simple cast.
115 *
116 * @param b the chars to be appended.
117 * @param off the index of the first char to append.
118 * @param len the number of bytes to append.
119 * @throws IndexOutOfBoundsException if {@code off} if out of
120 * range, {@code len} is negative, or
121 * {@code off} + {@code len} is out of range.
122 */
123 public void append(final char[] b, final int off, final int len) {
124 if (b == null) {
125 return;
126 }
127 if ((off < 0) || (off > b.length) || (len < 0) ||
128 ((off + len) < 0) || ((off + len) > b.length)) {
129 throw new IndexOutOfBoundsException("off: "+off+" len: "+len+" b.length: "+b.length);
130 }
131 if (len == 0) {
132 return;
133 }
134 final int oldlen = this.len;
135 final int newlen = oldlen + len;
136 if (newlen > this.array.length) {
137 expand(newlen);
138 }
139
140 for (int i1 = off, i2 = oldlen; i2 < newlen; i1++, i2++) {
141 final int c = b[i1];
142 if ((c >= 0x20 && c <= 0x7E) || // Visible ASCII
143 (c >= 0xA0 && c <= 0xFF) || // Visible ISO-8859-1
144 c == 0x09) { // TAB
145 this.array[i2] = (byte) c;
146 } else {
147 this.array[i2] = '?';
148 }
149 }
150 this.len = newlen;
151 }
152
153 /**
154 * Appends {@code len} chars to this buffer from the given source
155 * char array buffer starting at index {@code off}. The capacity
156 * of the buffer is increased if necessary to accommodate all
157 * {@code len} chars.
158 * <p>
159 * The chars are converted to bytes using simple cast.
160 *
161 * @param b the chars to be appended.
162 * @param off the index of the first char to append.
163 * @param len the number of bytes to append.
164 * @throws IndexOutOfBoundsException if {@code off} if out of
165 * range, {@code len} is negative, or
166 * {@code off} + {@code len} is out of range.
167 */
168 public void append(final CharArrayBuffer b, final int off, final int len) {
169 if (b == null) {
170 return;
171 }
172 append(b.array(), off, len);
173 }
174
175 public void append(final ByteBuffer buffer) {
176 if (buffer == null) {
177 return;
178 }
179 final int bufferLength = buffer.remaining();
180 if (bufferLength > 0) {
181 final int newLength = this.len + bufferLength;
182 if (newLength > this.array.length) {
183 expand(newLength);
184 }
185 buffer.get(this.array, this.len, bufferLength);
186 this.len = newLength;
187 }
188 }
189
190 /**
191 * Clears content of the buffer. The underlying byte array is not resized.
192 */
193 public void clear() {
194 this.len = 0;
195 }
196
197 /**
198 * Converts the content of this buffer to an array of bytes.
199 *
200 * @return byte array
201 */
202 public byte[] toByteArray() {
203 final byte[] b = new byte[this.len];
204 if (this.len > 0) {
205 System.arraycopy(this.array, 0, b, 0, this.len);
206 }
207 return b;
208 }
209
210 /**
211 * Returns the {@code byte} value in this buffer at the specified
212 * index. The index argument must be greater than or equal to
213 * {@code 0}, and less than the length of this buffer.
214 *
215 * @param i the index of the desired byte value.
216 * @return the byte value at the specified index.
217 * @throws IndexOutOfBoundsException if {@code index} is
218 * negative or greater than or equal to {@link #length()}.
219 */
220 public int byteAt(final int i) {
221 return this.array[i];
222 }
223
224 /**
225 * Returns the current capacity. The capacity is the amount of storage
226 * available for newly appended bytes, beyond which an allocation
227 * will occur.
228 *
229 * @return the current capacity
230 */
231 public int capacity() {
232 return this.array.length;
233 }
234
235 /**
236 * Returns the length of the buffer (byte count).
237 *
238 * @return the length of the buffer
239 */
240 public int length() {
241 return this.len;
242 }
243
244 /**
245 * Ensures that the capacity is at least equal to the specified minimum.
246 * If the current capacity is less than the argument, then a new internal
247 * array is allocated with greater capacity. If the {@code required}
248 * argument is non-positive, this method takes no action.
249 *
250 * @param required the minimum required capacity.
251 *
252 * @since 4.1
253 */
254 public void ensureCapacity(final int required) {
255 if (required <= 0) {
256 return;
257 }
258 final int available = this.array.length - this.len;
259 if (required > available) {
260 expand(this.len + required);
261 }
262 }
263
264 /**
265 * Returns reference to the underlying byte array.
266 *
267 * @return the byte array.
268 */
269 public byte[] array() {
270 return this.array;
271 }
272
273 /**
274 * Sets the length of the buffer. The new length value is expected to be
275 * less than the current capacity and greater than or equal to
276 * {@code 0}.
277 *
278 * @param len the new length
279 * @throws IndexOutOfBoundsException if the
280 * {@code len} argument is greater than the current
281 * capacity of the buffer or less than {@code 0}.
282 */
283 public void setLength(final int len) {
284 if (len < 0 || len > this.array.length) {
285 throw new IndexOutOfBoundsException("len: "+len+" < 0 or > buffer len: "+this.array.length);
286 }
287 this.len = len;
288 }
289
290 /**
291 * Returns {@code true} if this buffer is empty, that is, its
292 * {@link #length()} is equal to {@code 0}.
293 * @return {@code true} if this buffer is empty, {@code false}
294 * otherwise.
295 */
296 public boolean isEmpty() {
297 return this.len == 0;
298 }
299
300 /**
301 * Returns {@code true} if this buffer is full, that is, its
302 * {@link #length()} is equal to its {@link #capacity()}.
303 * @return {@code true} if this buffer is full, {@code false}
304 * otherwise.
305 */
306 public boolean isFull() {
307 return this.len == this.array.length;
308 }
309
310 /**
311 * Returns the index within this buffer of the first occurrence of the
312 * specified byte, starting the search at the specified
313 * {@code beginIndex} and finishing at {@code endIndex}.
314 * If no such byte occurs in this buffer within the specified bounds,
315 * {@code -1} is returned.
316 * <p>
317 * There is no restriction on the value of {@code beginIndex} and
318 * {@code endIndex}. If {@code beginIndex} is negative,
319 * it has the same effect as if it were zero. If {@code endIndex} is
320 * greater than {@link #length()}, it has the same effect as if it were
321 * {@link #length()}. If the {@code beginIndex} is greater than
322 * the {@code endIndex}, {@code -1} is returned.
323 *
324 * @param b the byte to search for.
325 * @param from the index to start the search from.
326 * @param to the index to finish the search at.
327 * @return the index of the first occurrence of the byte in the buffer
328 * within the given bounds, or {@code -1} if the byte does
329 * not occur.
330 *
331 * @since 4.1
332 */
333 public int indexOf(final byte b, final int from, final int to) {
334 int beginIndex = from;
335 if (beginIndex < 0) {
336 beginIndex = 0;
337 }
338 int endIndex = to;
339 if (endIndex > this.len) {
340 endIndex = this.len;
341 }
342 if (beginIndex > endIndex) {
343 return -1;
344 }
345 for (int i = beginIndex; i < endIndex; i++) {
346 if (this.array[i] == b) {
347 return i;
348 }
349 }
350 return -1;
351 }
352
353 /**
354 * Returns the index within this buffer of the first occurrence of the
355 * specified byte, starting the search at {@code 0} and finishing
356 * at {@link #length()}. If no such byte occurs in this buffer within
357 * those bounds, {@code -1} is returned.
358 *
359 * @param b the byte to search for.
360 * @return the index of the first occurrence of the byte in the
361 * buffer, or {@code -1} if the byte does not occur.
362 *
363 * @since 4.1
364 */
365 public int indexOf(final byte b) {
366 return indexOf(b, 0, this.len);
367 }
368 }