new: NextableInputStream, step 1

diff --git a/src/be/nikiroo/utils/NextableInputStream.java b/src/be/nikiroo/utils/NextableInputStream.java
new file mode 100644 (file)
index 0000000..0bcbe14
--- /dev/null
+++ b/src/be/nikiroo/utils/NextableInputStream.java
@@ -0,0 +1,66 @@
+package be.nikiroo.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+public class NextableInputStream extends InputStream {
+       private InputStream in;
+       private boolean eof;
+       private int pos = 0;
+       private int len = 0;
+       private byte[] buffer = new byte[4096];
+
+       public NextableInputStream(InputStream in) {
+               this.in = in;
+       }
+
+       @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 (!eof && done < blen) {
+                       preRead();
+                       for (int i = pos; i < blen && i < len; i++) {
+                               b[boff + done] = buffer[i];
+                               pos++;
+                               done++;
+                       }
+               }
+
+               return done > 0 ? done : -1;
+       }
+
+       private void preRead() throws IOException {
+               if (in != null && !eof && pos >= len) {
+                       pos = 0;
+                       len = in.read(buffer);
+                       // checkNexts();
+               }
+
+               if (pos >= len) {
+                       eof = true;
+               }
+       }
+}

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..1b0064d
--- /dev/null
+++ b/src/be/nikiroo/utils/test_code/NextableInputStreamTest.java
@@ -0,0 +1,33 @@
+package be.nikiroo.utils.test_code;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+
+import be.nikiroo.utils.IOUtils;
+import be.nikiroo.utils.NextableInputStream;
+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 };
+                               InputStream bin = new ByteArrayInputStream(expected);
+                               NextableInputStream in = new NextableInputStream(bin);
+                               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]);
+                               }
+                       }
+               });
+       }
+}