X-Git-Url: http://git.nikiroo.be/?p=fanfix.git;a=blobdiff_plain;f=src%2Fbe%2Fnikiroo%2Futils%2Fstreams%2FNextableInputStreamStep.java;fp=src%2Fbe%2Fnikiroo%2Futils%2Fstreams%2FNextableInputStreamStep.java;h=fda998d1ce8990abe48539293e9a7d84613d0cf8;hp=0000000000000000000000000000000000000000;hb=d46b7b96f94e88a776bcd2dfd756549ffb300cc9;hpb=c9994f27667bc421bcd448d39e55774fddf5c431

diff --git a/src/be/nikiroo/utils/streams/NextableInputStreamStep.java b/src/be/nikiroo/utils/streams/NextableInputStreamStep.java
new file mode 100644
index 0000000..fda998d
--- /dev/null
+++ b/src/be/nikiroo/utils/streams/NextableInputStreamStep.java
@@ -0,0 +1,112 @@
+package be.nikiroo.utils.streams;
+
+import java.io.InputStream;
+
+/**
+ * Divide an {@link InputStream} into sub-streams.
+ * 
+ * @author niki
+ */
+public class NextableInputStreamStep {
+	private int stopAt;
+	private int last = -1;
+	private int resumeLen;
+	private int resumeSkip;
+	private boolean resumeEof;
+
+	/**
+	 * Create a new divider that will separate the sub-streams each time it sees
+	 * this byte.
+	 * <p>
+	 * Note that the byte will be bypassed by the {@link InputStream} as far as
+	 * the consumers will be aware.
+	 * 
+	 * @param byt
+	 *            the byte at which to separate two sub-streams
+	 */
+	public NextableInputStreamStep(int byt) {
+		stopAt = byt;
+	}
+
+	/**
+	 * Check if we need to stop the {@link InputStream} reading at some point in
+	 * the current buffer.
+	 * <p>
+	 * If we do, return the index at which to stop; if not, return -1.
+	 * <p>
+	 * This method will <b>not</b> return the same index a second time (unless
+	 * we cleared the buffer).
+	 * 
+	 * @param buffer
+	 *            the buffer to check
+	 * @param pos
+	 *            the current position of what was read in the buffer
+	 * @param len
+	 *            the maximum index to use in the buffer (anything above that is
+	 *            not to be used)
+	 * @param eof
+	 *            the current state of the under-laying stream
+	 * 
+	 * @return the index at which to stop, or -1
+	 */
+	public int stop(byte[] buffer, int pos, int len, boolean eof) {
+		for (int i = pos; i < len; i++) {
+			if (buffer[i] == stopAt) {
+				if (i > this.last) {
+					// we skip the sep
+					this.resumeSkip = 1;
+
+					this.resumeLen = len;
+					this.resumeEof = eof;
+					this.last = i;
+					return i;
+				}
+			}
+		}
+
+		return -1;
+	}
+
+	/**
+	 * Get the maximum index to use in the buffer used in
+	 * {@link NextableInputStreamStep#stop(byte[], int, int, boolean)} at resume
+	 * time.
+	 * 
+	 * @return the index
+	 */
+	public int getResumeLen() {
+		return resumeLen;
+	}
+
+	/**
+	 * Get the number of bytes to skip at resume time.
+	 * 
+	 * @return the number of bytes to skip
+	 */
+	public int getResumeSkip() {
+		return resumeSkip;
+	}
+
+	/**
+	 * Get the under-laying stream state at resume time.
+	 * 
+	 * @return the EOF state
+	 */
+	public boolean getResumeEof() {
+		return resumeEof;
+	}
+
+	/**
+	 * Clear the information we may have kept about the current buffer
+	 * <p>
+	 * You should call this method each time you change the content of the
+	 * buffer used in
+	 * {@link NextableInputStreamStep#stop(byte[], int, int, boolean)}.
+	 */
+	public void clearBuffer() {
+		this.last = -1;
+		this.resumeSkip = 0;
+		this.resumeLen = 0;
+		this.resumeEof = false;
+	}
+}