*
* @author niki
*/
-public class NextableInputStream extends InputStream {
+public class NextableInputStream extends BufferedInputStream {
private NextableInputStreamStep step;
+ private boolean started;
private boolean stopped;
- private InputStream in;
- private boolean eof;
- private int pos = 0;
- private int len = 0;
- private byte[] buffer = new byte[4096];
-
/**
* Create a new {@link NextableInputStream} that wraps the given
* {@link InputStream}.
* case it will behave as a normal {@link InputStream})
*/
public NextableInputStream(InputStream in, NextableInputStreamStep step) {
- this.in = in;
+ super(in);
this.step = step;
}
+ /**
+ * Create a new {@link NextableInputStream} that wraps the given bytes array
+ * as a data source.
+ *
+ * @param in
+ * the array to wrap, cannot be NULL
+ * @param step
+ * how to separate it into sub-streams (can be NULL, but in that
+ * case it will behave as a normal {@link InputStream})
+ */
+ public NextableInputStream(byte[] in, NextableInputStreamStep step) {
+ this(in, step, 0, in.length);
+ }
+
+ /**
+ * Create a new {@link NextableInputStream} that wraps the given bytes array
+ * as a data source.
+ *
+ * @param in
+ * the array to wrap, cannot be NULL
+ * @param step
+ * how to separate it into sub-streams (can be NULL, but in that
+ * case it will behave as a normal {@link InputStream})
+ * @param offset
+ * the offset to start the reading at
+ * @param length
+ * the number of bytes to take into account in the array,
+ * starting from the offset
+ *
+ * @throws NullPointerException
+ * if the array is NULL
+ * @throws IndexOutOfBoundsException
+ * if the offset and length do not correspond to the given array
+ */
+ public NextableInputStream(byte[] in, NextableInputStreamStep step,
+ int offset, int length) {
+ super(in, offset, length);
+ this.step = step;
+ checkBuffer(true);
+ }
+
/**
* Unblock the processing of the next sub-stream.
* <p>
* @return TRUE if we unblocked the next sub-stream, FALSE if not
*
* @throws IOException
- * in case of I/O error
+ * in case of I/O error or if the stream is closed
*/
public boolean next() throws IOException {
- if (!hasMoreData() && stopped) {
- len = step.getResumeLen();
- pos += step.getResumeSkip();
- eof = false;
-
- if (!preRead()) {
- checkBuffer(false);
- }
-
- // consider that if EOF, there is no next
- return hasMoreData();
- }
-
- return false;
- }
-
- @Override
- public int read() throws IOException {
- preRead();
- if (eof) {
- return -1;
- }
-
- return buffer[pos++];
- }
-
- @Override
- public int read(byte[] b) throws IOException {
- return read(b, 0, b.length);
- }
-
- @Override
- public int read(byte[] b, int boff, int blen) throws IOException {
- if (b == null) {
- throw new NullPointerException();
- } else if (boff < 0 || blen < 0 || blen > b.length - boff) {
- throw new IndexOutOfBoundsException();
- } else if (blen == 0) {
- return 0;
- }
-
- int done = 0;
- while (hasMoreData() && done < blen) {
- preRead();
- if (hasMoreData()) {
- for (int i = pos; i < blen && i < len; i++) {
- b[boff + done] = buffer[i];
- pos++;
- done++;
- }
- }
- }
-
- return done > 0 ? done : -1;
+ return next(false);
}
- @Override
- public int available() throws IOException {
- return Math.max(0, len - pos);
+ /**
+ * Unblock the next sub-stream as would have done
+ * {@link NextableInputStream#next()}, but disable the sub-stream systems.
+ * <p>
+ * That is, the next stream, if any, will be the last one and will not be
+ * subject to the {@link NextableInputStreamStep}.
+ *
+ * @return TRUE if we unblocked the next sub-stream, FALSE if not
+ *
+ * @throws IOException
+ * in case of I/O error or if the stream is closed
+ */
+ public boolean nextAll() throws IOException {
+ return next(true);
}
/**
* @throws IOException
* in case of I/O error
*/
- private boolean preRead() throws IOException {
- boolean hasRead = false;
- if (!eof && in != null && pos >= len && !stopped) {
- pos = 0;
- len = in.read(buffer);
+ @Override
+ protected boolean preRead() throws IOException {
+ if (!stopped) {
+ boolean bufferChanged = super.preRead();
checkBuffer(true);
- hasRead = true;
+ return bufferChanged;
}
if (pos >= len) {
eof = true;
}
- return hasRead;
+ return false;
}
/**
*
* @return TRUE if it is the case, FALSE if not
*/
- private boolean hasMoreData() {
- return !(eof && pos >= len);
+ @Override
+ protected boolean hasMoreData() {
+ return started && super.hasMoreData();
}
/**
* the {@link NextableInputStreamStep}
*/
private void checkBuffer(boolean newBuffer) {
- if (step != null) {
+ if (step != null && len > 0) {
if (newBuffer) {
step.clearBuffer();
}
}
}
}
+
+ /**
+ * The implementation of {@link NextableInputStream#next()} and
+ * {@link NextableInputStream#nextAll()}.
+ *
+ * @param all
+ * TRUE for {@link NextableInputStream#nextAll()}, FALSE for
+ * {@link NextableInputStream#next()}
+ *
+ * @return TRUE if we unblocked the next sub-stream, FALSE if not
+ *
+ * @throws IOException
+ * in case of I/O error or if the stream is closed
+ */
+ private boolean next(boolean all) throws IOException {
+ checkClose();
+
+ if (!started) {
+ // First call before being allowed to read
+ started = true;
+
+ if (all) {
+ step = null;
+ }
+
+ return true;
+ }
+
+ if (step != null && !hasMoreData() && stopped) {
+ len = step.getResumeLen();
+ pos += step.getResumeSkip();
+ eof = false;
+
+ if (all) {
+ step = null;
+ }
+
+ if (!preRead()) {
+ checkBuffer(false);
+ }
+
+ // consider that if EOF, there is no next
+ return hasMoreData();
+ }
+
+ return false;
+ }
}
git://git.nikiroo.be / nikiroo-utils.git / blobdiff