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 this.array[i2] = TextUtils.castAsByte(b[i1]);
142 }
143 this.len = newlen;
144 }
145
146 /**
147 * Appends {@code len} chars to this buffer from the given source
148 * char array buffer starting at index {@code off}. The capacity
149 * of the buffer is increased if necessary to accommodate all
150 * {@code len} chars.
151 * <p>
152 * The chars are converted to bytes using simple cast.
153 *
154 * @param b the chars to be appended.
155 * @param off the index of the first char to append.
156 * @param len the number of bytes to append.
157 * @throws IndexOutOfBoundsException if {@code off} if out of
158 * range, {@code len} is negative, or
159 * {@code off} + {@code len} is out of range.
160 */
161 public void append(final CharArrayBuffer b, final int off, final int len) {
162 if (b == null) {
163 return;
164 }
165 append(b.array(), off, len);
166 }
167
168 public void append(final ByteBuffer buffer) {
169 if (buffer == null) {
170 return;
171 }
172 final int bufferLength = buffer.remaining();
173 if (bufferLength > 0) {
174 final int newLength = this.len + bufferLength;
175 if (newLength > this.array.length) {
176 expand(newLength);
177 }
178 buffer.get(this.array, this.len, bufferLength);
179 this.len = newLength;
180 }
181 }
182
183 /**
184 * Clears content of the buffer. The underlying byte array is not resized.
185 */
186 public void clear() {
187 this.len = 0;
188 }
189
190 /**
191 * Converts the content of this buffer to an array of bytes.
192 *
193 * @return byte array
194 */
195 public byte[] toByteArray() {
196 final byte[] b = new byte[this.len];
197 if (this.len > 0) {
198 System.arraycopy(this.array, 0, b, 0, this.len);
199 }
200 return b;
201 }
202
203 /**
204 * Returns the {@code byte} value in this buffer at the specified
205 * index. The index argument must be greater than or equal to
206 * {@code 0}, and less than the length of this buffer.
207 *
208 * @param i the index of the desired byte value.
209 * @return the byte value at the specified index.
210 * @throws IndexOutOfBoundsException if {@code index} is
211 * negative or greater than or equal to {@link #length()}.
212 */
213 public int byteAt(final int i) {
214 return this.array[i];
215 }
216
217 /**
218 * Returns the current capacity. The capacity is the amount of storage
219 * available for newly appended bytes, beyond which an allocation
220 * will occur.
221 *
222 * @return the current capacity
223 */
224 public int capacity() {
225 return this.array.length;
226 }
227
228 /**
229 * Returns the length of the buffer (byte count).
230 *
231 * @return the length of the buffer
232 */
233 public int length() {
234 return this.len;
235 }
236
237 /**
238 * Ensures that the capacity is at least equal to the specified minimum.
239 * If the current capacity is less than the argument, then a new internal
240 * array is allocated with greater capacity. If the {@code required}
241 * argument is non-positive, this method takes no action.
242 *
243 * @param required the minimum required capacity.
244 *
245 * @since 4.1
246 */
247 public void ensureCapacity(final int required) {
248 if (required <= 0) {
249 return;
250 }
251 final int available = this.array.length - this.len;
252 if (required > available) {
253 expand(this.len + required);
254 }
255 }
256
257 /**
258 * Returns reference to the underlying byte array.
259 *
260 * @return the byte array.
261 */
262 public byte[] array() {
263 return this.array;
264 }
265
266 /**
267 * Sets the length of the buffer. The new length value is expected to be
268 * less than the current capacity and greater than or equal to
269 * {@code 0}.
270 *
271 * @param len the new length
272 * @throws IndexOutOfBoundsException if the
273 * {@code len} argument is greater than the current
274 * capacity of the buffer or less than {@code 0}.
275 */
276 public void setLength(final int len) {
277 if (len < 0 || len > this.array.length) {
278 throw new IndexOutOfBoundsException("len: "+len+" < 0 or > buffer len: "+this.array.length);
279 }
280 this.len = len;
281 }
282
283 /**
284 * Returns {@code true} if this buffer is empty, that is, its
285 * {@link #length()} is equal to {@code 0}.
286 * @return {@code true} if this buffer is empty, {@code false}
287 * otherwise.
288 */
289 public boolean isEmpty() {
290 return this.len == 0;
291 }
292
293 /**
294 * Returns {@code true} if this buffer is full, that is, its
295 * {@link #length()} is equal to its {@link #capacity()}.
296 * @return {@code true} if this buffer is full, {@code false}
297 * otherwise.
298 */
299 public boolean isFull() {
300 return this.len == this.array.length;
301 }
302
303 /**
304 * Returns the index within this buffer of the first occurrence of the
305 * specified byte, starting the search at the specified
306 * {@code beginIndex} and finishing at {@code endIndex}.
307 * If no such byte occurs in this buffer within the specified bounds,
308 * {@code -1} is returned.
309 * <p>
310 * There is no restriction on the value of {@code beginIndex} and
311 * {@code endIndex}. If {@code beginIndex} is negative,
312 * it has the same effect as if it were zero. If {@code endIndex} is
313 * greater than {@link #length()}, it has the same effect as if it were
314 * {@link #length()}. If the {@code beginIndex} is greater than
315 * the {@code endIndex}, {@code -1} is returned.
316 *
317 * @param b the byte to search for.
318 * @param from the index to start the search from.
319 * @param to the index to finish the search at.
320 * @return the index of the first occurrence of the byte in the buffer
321 * within the given bounds, or {@code -1} if the byte does
322 * not occur.
323 *
324 * @since 4.1
325 */
326 public int indexOf(final byte b, final int from, final int to) {
327 int beginIndex = from;
328 if (beginIndex < 0) {
329 beginIndex = 0;
330 }
331 int endIndex = to;
332 if (endIndex > this.len) {
333 endIndex = this.len;
334 }
335 if (beginIndex > endIndex) {
336 return -1;
337 }
338 for (int i = beginIndex; i < endIndex; i++) {
339 if (this.array[i] == b) {
340 return i;
341 }
342 }
343 return -1;
344 }
345
346 /**
347 * Returns the index within this buffer of the first occurrence of the
348 * specified byte, starting the search at {@code 0} and finishing
349 * at {@link #length()}. If no such byte occurs in this buffer within
350 * those bounds, {@code -1} is returned.
351 *
352 * @param b the byte to search for.
353 * @return the index of the first occurrence of the byte in the
354 * buffer, or {@code -1} if the byte does not occur.
355 *
356 * @since 4.1
357 */
358 public int indexOf(final byte b) {
359 return indexOf(b, 0, this.len);
360 }
361 }