Merge branch 'master' into streamify
authorNiki Roo <niki@nikiroo.be>
Wed, 24 Apr 2019 19:42:42 +0000 (21:42 +0200)
committerNiki Roo <niki@nikiroo.be>
Wed, 24 Apr 2019 19:42:42 +0000 (21:42 +0200)
src/be/nikiroo/utils/IOUtils.java
src/be/nikiroo/utils/NextableInputStream.java [new file with mode: 0644]
src/be/nikiroo/utils/NextableInputStreamStep.java [new file with mode: 0755]
src/be/nikiroo/utils/test_code/NextableInputStreamTest.java [new file with mode: 0644]
src/be/nikiroo/utils/test_code/Test.java

index c7cbe259b5abab2e0d65d7639b83641eddd7a357..a263eb1ea17ea59e5a5a605c2cde91337aefe6ac 100644 (file)
@@ -55,7 +55,7 @@ public class IOUtils {
         */
        public static void write(InputStream in, OutputStream out)
                        throws IOException {
-               byte buffer[] = new byte[4069];
+               byte buffer[] = new byte[4096];
                for (int len = 0; (len = in.read(buffer)) > 0;) {
                        out.write(buffer, 0, len);
                }
diff --git a/src/be/nikiroo/utils/NextableInputStream.java b/src/be/nikiroo/utils/NextableInputStream.java
new file mode 100644 (file)
index 0000000..0def936
--- /dev/null
@@ -0,0 +1,180 @@
+package be.nikiroo.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * This {@link InputStream} can be separated into sub-streams (you can process
+ * it as a normal {@link InputStream} but, when it is spent, you can call
+ * {@link NextableInputStream#next()} on it to unlock new data).
+ * <p>
+ * The separation in sub-streams is done via {@link NextableInputStreamStep}.
+ * 
+ * @author niki
+ */
+public class NextableInputStream extends InputStream {
+       private NextableInputStreamStep step;
+       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}.
+        * 
+        * @param in
+        *            the {@link InputStream} to wrap
+        * @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(InputStream in, NextableInputStreamStep step) {
+               this.in = in;
+               this.step = step;
+       }
+
+       /**
+        * Unblock the processing of the next sub-stream.
+        * <p>
+        * It can only be called when the "current" stream is spent (i.e., you must
+        * first process the stream until it is spent).
+        * <p>
+        * We consider that when the under-laying {@link InputStream} is also spent,
+        * we cannot have a next sub-stream (it will thus return FALSE).
+        * <p>
+        * {@link IOException}s can happen when we have no data available in the
+        * buffer; in that case, we fetch more data to know if we can have a next
+        * sub-stream or not.
+        * 
+        * @return TRUE if we unblocked the next sub-stream, FALSE if not
+        * 
+        * @throws IOException
+        *             in case of I/O error
+        */
+       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;
+       }
+
+       @Override
+       public int available() throws IOException {
+               return Math.max(0, len - pos);
+       }
+
+       /**
+        * Check if we still have some data in the buffer and, if not, fetch some.
+        * 
+        * @return TRUE if we fetched some data, FALSE if there are still some in
+        *         the buffer
+        * 
+        * @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);
+                       checkBuffer(true);
+                       hasRead = true;
+               }
+
+               if (pos >= len) {
+                       eof = true;
+               }
+
+               return hasRead;
+       }
+
+       /**
+        * We have more data available in the buffer or we can fetch more.
+        * 
+        * @return TRUE if it is the case, FALSE if not
+        */
+       private boolean hasMoreData() {
+               return !(eof && pos >= len);
+       }
+
+       /**
+        * Check that the buffer didn't overshot to the next item, and fix
+        * {@link NextableInputStream#len} if needed.
+        * <p>
+        * If {@link NextableInputStream#len} is fixed,
+        * {@link NextableInputStream#eof} and {@link NextableInputStream#stopped}
+        * are set to TRUE.
+        * 
+        * @param newBuffer
+        *            we changed the buffer, we need to clear some information in
+        *            the {@link NextableInputStreamStep}
+        */
+       private void checkBuffer(boolean newBuffer) {
+               if (step != null) {
+                       if (newBuffer) {
+                               step.clearBuffer();
+                       }
+
+                       int stopAt = step.stop(buffer, pos, len);
+                       if (stopAt >= 0) {
+                               len = stopAt;
+                               eof = true;
+                               stopped = true;
+                       }
+               }
+       }
+}
diff --git a/src/be/nikiroo/utils/NextableInputStreamStep.java b/src/be/nikiroo/utils/NextableInputStreamStep.java
new file mode 100755 (executable)
index 0000000..a2ee039
--- /dev/null
@@ -0,0 +1,96 @@
+package be.nikiroo.utils;
+
+import java.io.InputStream;
+
+/**
+ * Divide an {@link InputStream} into sub-streams.
+ * 
+ * @author niki
+ */
+public class NextableInputStreamStep {
+       private int stopAt;
+       private int resumeLen;
+       private int last = -1;
+       private int skip;
+
+       /**
+        * 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)
+        * 
+        * @return the index at which to stop, or -1
+        */
+       public int stop(byte[] buffer, int pos, int len) {
+               for (int i = pos; i < len; i++) {
+                       if (buffer[i] == stopAt) {
+                               if (i > this.last) {
+                                       // we skip the sep
+                                       this.skip = 1;
+
+                                       this.resumeLen = len;
+                                       this.last = i;
+                                       return i;
+                               }
+                       }
+               }
+
+               return -1;
+       }
+
+       /**
+        * Get the maximum index to use in the buffer used in
+        * {@link NextableInputStreamStep#stop(byte[], int, int)} 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 skip;
+       }
+
+       /**
+        * 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)}.
+        */
+       public void clearBuffer() {
+               this.last = -1;
+               this.skip = 0;
+               this.resumeLen = 0;
+       }
+}
diff --git a/src/be/nikiroo/utils/test_code/NextableInputStreamTest.java b/src/be/nikiroo/utils/test_code/NextableInputStreamTest.java
new file mode 100644 (file)
index 0000000..87d64ac
--- /dev/null
@@ -0,0 +1,111 @@
+package be.nikiroo.utils.test_code;
+
+import java.io.ByteArrayInputStream;
+
+import be.nikiroo.utils.IOUtils;
+import be.nikiroo.utils.NextableInputStream;
+import be.nikiroo.utils.NextableInputStreamStep;
+import be.nikiroo.utils.test.TestCase;
+import be.nikiroo.utils.test.TestLauncher;
+
+public class NextableInputStreamTest extends TestLauncher {
+       public NextableInputStreamTest(String[] args) {
+               super("NextableInputStream test", args);
+
+               addTest(new TestCase("Simple byte array reading") {
+                       @Override
+                       public void test() throws Exception {
+                               byte[] expected = new byte[] { 42, 12, 0, 127 };
+                               NextableInputStream in = new NextableInputStream(
+                                               new ByteArrayInputStream(expected), null);
+                               byte[] actual = IOUtils.toByteArray(in);
+
+                               assertEquals(
+                                               "The resulting array has not the same number of items",
+                                               expected.length, actual.length);
+                               for (int i = 0; i < expected.length; i++) {
+                                       assertEquals("Item " + i + " (0-based) is not the same",
+                                                       expected[i], actual[i]);
+                               }
+                       }
+               });
+
+               addTest(new TestCase("Stop at 12") {
+                       @Override
+                       public void test() throws Exception {
+                               byte[] expected = new byte[] { 42, 12, 0, 127 };
+                               NextableInputStream in = new NextableInputStream(
+                                               new ByteArrayInputStream(expected),
+                                               new NextableInputStreamStep(12));
+
+                               checkNext(this, false, "FIRST", in, new byte[] { 42 });
+                       }
+               });
+
+               addTest(new TestCase("Stop at 12, resume, stop again, resume") {
+                       @Override
+                       public void test() throws Exception {
+                               byte[] data = new byte[] { 42, 12, 0, 127, 12, 51, 11, 12 };
+                               NextableInputStream in = new NextableInputStream(
+                                               new ByteArrayInputStream(data),
+                                               new NextableInputStreamStep(12));
+
+                               checkNext(this, false, "FIRST", in, new byte[] { 42 });
+                               checkNext(this, true, "SECOND", in, new byte[] { 0, 127 });
+                               checkNext(this, true, "THIRD", in, new byte[] { 51, 11 });
+                       }
+               });
+
+               addTest(new TestCase("Encapsulation") {
+                       @Override
+                       public void test() throws Exception {
+                               byte[] data = new byte[] { 42, 12, 0, 4, 127, 12, 5 };
+                               NextableInputStream in4 = new NextableInputStream(
+                                               new ByteArrayInputStream(data),
+                                               new NextableInputStreamStep(4));
+                               NextableInputStream subIn12 = new NextableInputStream(in4,
+                                               new NextableInputStreamStep(12));
+
+                               checkNext(this, false, "SUB FIRST", subIn12, new byte[] { 42 });
+                               checkNext(this, true, "SUB SECOND", subIn12, new byte[] { 0 });
+
+                               assertEquals("The subIn still has some data", false,
+                                               subIn12.next());
+
+                               checkNext(this, true, "MAIN LAST", in4,
+                                               new byte[] { 127, 12, 5 });
+                       }
+               });
+
+               addTest(new TestCase("UTF-8 text lines test") {
+                       @Override
+                       public void test() throws Exception {
+                               String ln1 = "Ligne première";
+                               String ln2 = "Ligne la deuxième du nom";
+                               byte[] data = (ln1 + "\n" + ln2).getBytes("UTF-8");
+                               NextableInputStream in = new NextableInputStream(
+                                               new ByteArrayInputStream(data),
+                                               new NextableInputStreamStep('\n'));
+
+                               checkNext(this, false, "FIRST", in, ln1.getBytes("UTF-8"));
+                               checkNext(this, true, "SECOND", in, ln2.getBytes("UTF-8"));
+                       }
+               });
+       }
+
+       static void checkNext(TestCase test, boolean callNext, String prefix,
+                       NextableInputStream in, byte[] expected) throws Exception {
+               if (callNext) {
+                       test.assertEquals("Cannot get " + prefix + " entry", true,
+                                       in.next());
+               }
+               byte[] actual = IOUtils.toByteArray(in);
+               test.assertEquals("The " + prefix
+                               + " resulting array has not the correct number of items",
+                               expected.length, actual.length);
+               for (int i = 0; i < actual.length; i++) {
+                       test.assertEquals("Item " + i + " (0-based) is not the same",
+                                       expected[i], actual[i]);
+               }
+       }
+}
index f25c02db8573a723761819a1b5f403a1344f2c31..01766ac031535b33f04886ba6405dd2e6e4688ec 100644 (file)
@@ -33,6 +33,7 @@ public class Test extends TestLauncher {
                addSeries(new StringUtilsTest(args));
                addSeries(new TempFilesTest(args));
                addSeries(new CryptUtilsTest(args));
+               addSeries(new NextableInputStreamTest(args));
 
                // TODO: test cache and downloader
                Cache cache = null;