ctf: BitBuffer.java api overhaul

* Now 3 getters are public: get(length, extendSign), getInt(), and getLong().

Change-Id: I6848b2bde4e37580c1327f03cd025ea2bae4e134
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/18908
Tested-by: Hudson CI
IP-Clean: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Tested-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Reviewed-by: Etienne Bergeron <etienne.bergeron@gmail.com>

5 files changed, 361 insertions, 41 deletions

diff --git a/lttng/org.eclipse.linuxtools.ctf.core.tests/src/org/eclipse/linuxtools/ctf/core/tests/io/BitBufferIntTest.java b/lttng/org.eclipse.linuxtools.ctf.core.tests/src/org/eclipse/linuxtools/ctf/core/tests/io/BitBufferIntTest.java
index 3350db8580..49b551bb08 100644
--- a/lttng/org.eclipse.linuxtools.ctf.core.tests/src/org/eclipse/linuxtools/ctf/core/tests/io/BitBufferIntTest.java
+++ b/lttng/org.eclipse.linuxtools.ctf.core.tests/src/org/eclipse/linuxtools/ctf/core/tests/io/BitBufferIntTest.java
@@ -7,6 +7,7 @@
  *
  * Contributors:
  *     Alexandre Montplaisir - Initial API and implementation
+ *     Matthew Khouzam - additional tests
  *******************************************************************************/
 
 package org.eclipse.linuxtools.ctf.core.tests.io;
@@ -25,7 +26,7 @@ import org.junit.Test;
  * Part of the BitBuffer tests which test the methods to read/write integers.
  * These are separated from the main file because the fixture is different.
  *
- * @author alexmont
+ * @author Alexandre Montplaisir
  */
 public class BitBufferIntTest {
 
@@ -91,7 +92,7 @@ public class BitBufferIntTest {
         int length = 1;
         boolean signed = true;
 
-        int result = fixture.getInt(length, signed);
+        long result = fixture.get(length, signed);
         assertEquals(0, result);
     }
 
@@ -107,12 +108,12 @@ public class BitBufferIntTest {
         int length = 0;
         boolean signed = true;
 
-        int result = fixture.getInt(length, signed);
+        long result = fixture.get(length, signed);
         assertEquals(0, result);
     }
 
     /**
-     * Run the int getInt(int,int,boolean) method test.
+     * Run the get method test.
      *
      * @throws CTFReaderException
      *             Not expected
@@ -123,12 +124,12 @@ public class BitBufferIntTest {
         int length = 0;
         boolean signed = true;
 
-        int result = fixture.getInt(length, signed);
+        long result = fixture.get(length, signed);
         assertEquals(0, result);
     }
 
     /**
-     * Run the int getInt(int,int,boolean) method test.
+     * Run the get method test.
      *
      * @throws CTFReaderException
      *             Not expected
@@ -139,13 +140,12 @@ public class BitBufferIntTest {
         int length = 1;
         boolean signed = true;
 
-        int result = fixture.getInt(length, signed);
+        long result = fixture.get(length, signed);
         assertEquals(0, result);
     }
 
     /**
-     * Run the int getInt(int,int,boolean) method test with a little-endian
-     * BitBuffer.
+     * Run the get method test with a little-endian BitBuffer.
      *
      * @throws CTFReaderException
      *             Not expected
@@ -157,15 +157,14 @@ public class BitBufferIntTest {
         createBuffer(le_fixture);
         le_fixture.position(1);
         int length = 24;
-        int result = le_fixture.getInt(length, false);
+        long result = le_fixture.get(length, false);
 
         /* 0x020100 downshifted */
         assertEquals(0x810080, result);
     }
 
     /**
-     * Run the int getInt(int,int,boolean) method test with a little-endian
-     * BitBuffer.
+     * Run the get method test with a little-endian BitBuffer.
      *
      * @throws CTFReaderException
      *             Not expected
@@ -177,7 +176,7 @@ public class BitBufferIntTest {
         createBuffer(le_fixture);
         le_fixture.position(0);
         int length = 24;
-        int result = le_fixture.getInt(length, false);
+        long result = le_fixture.get(length, false);
         assertEquals(0x020100, result);
     }
 
@@ -195,13 +194,11 @@ public class BitBufferIntTest {
         small_fixture.position(10);
         int length = 32;
         boolean signed = true;
-
-        int result = small_fixture.getInt(length, signed);
-        assertEquals(0, result);
+        small_fixture.get(length, signed);
     }
 
     /**
-     * Run the int getInt(int,int,boolean) method test and expect an overflow.
+     * Run the get method test and expect an overflow.
      *
      * @throws CTFReaderException
      *             Expected
@@ -215,8 +212,268 @@ public class BitBufferIntTest {
         int length = 64;
         boolean signed = true;
 
-        int result = small_fixture.getInt(length, signed);
-        assertEquals(0, result);
+        small_fixture.get(length, signed);
+    }
+
+    /**
+     * Run the getLong method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong_pos0() throws CTFReaderException {
+        fixture.position(0);
+        long result = fixture.getLong();
+        assertEquals(0x01020304050607L, result);
+    }
+
+    /**
+     * Run the getLong method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong_pos7() throws CTFReaderException {
+        fixture.position(7);
+        long result = fixture.getLong();
+        assertEquals(0x81018202830384L, result);
+    }
+
+    /**
+     * Run the getLong method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong_pos8() throws CTFReaderException {
+        fixture.position(8);
+        long result = fixture.getLong();
+        assertEquals(result, 0x0102030405060708L);
+    }
+
+    /**
+     * Run the getLong method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong_pos0LE() throws CTFReaderException {
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.getLong();
+        assertEquals(result, 0x0706050403020100L);
+    }
+
+    /**
+     * Run the getLong method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong_pos7LE() throws CTFReaderException {
+        fixture.position(7);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.getLong();
+        assertEquals(result, 0x100e0c0a08060402L);
+    }
+
+    /**
+     * Run the getLong method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong_pos8LE() throws CTFReaderException {
+        fixture.position(8);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.getLong();
+        assertEquals(result, 0x0807060504030201L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGet35_pos0BE() throws CTFReaderException {
+        fixture.position(0);
+        long result = fixture.get(35, false);
+        assertEquals(result, 0x081018L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGet35_pos8BE() throws CTFReaderException {
+        fixture.position(8);
+        long result = fixture.get(35, false);
+        assertEquals(result, 0x08101820L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGet35_pos0LE() throws CTFReaderException {
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(35, false);
+
+        assertEquals(result, 0x0403020100L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong35_pos7LE() throws CTFReaderException {
+        fixture.position(7);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(35, false);
+        assertEquals(result, 0x0208060402L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong35_pos8LE() throws CTFReaderException {
+        fixture.position(8);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(35, false);
+        assertEquals(result, 0x0504030201L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong35s_pos0LE() throws CTFReaderException {
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(35, true);
+        assertEquals(result, 0xfffffffc03020100L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong35s_pos7LE() throws CTFReaderException {
+        fixture.position(7);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(35, true);
+        assertEquals(result, 0x0208060402L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetLong35s_pos8LE() throws CTFReaderException {
+        fixture.position(8);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(35, true);
+        assertEquals(result, 0xfffffffd04030201L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetSigned() throws CTFReaderException {
+        fixture.position(0);
+        fixture.putInt(-1);
+        fixture.putInt(-1);
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(32, true);
+        assertEquals(result, -1L);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGetUnsigned() throws CTFReaderException {
+        fixture.position(0);
+        fixture.putInt(-1);
+        fixture.putInt(-1);
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(32, false);
+        assertEquals(0xFFFFFFFFL, result);
+    }
+
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGet24Signed() throws CTFReaderException {
+        fixture.position(0);
+        fixture.putInt(-1);
+        fixture.putInt(-1);
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(24, true);
+        assertEquals(-1L, result);
+    }
+
+    /**
+     * Run the get method test.
+     *
+     * @throws CTFReaderException
+     *             error
+     */
+    @Test
+    public void testGet24Unsigned() throws CTFReaderException {
+        fixture.position(0);
+        fixture.putInt(-1);
+        fixture.putInt(-1);
+        fixture.position(0);
+        fixture.setByteOrder(ByteOrder.LITTLE_ENDIAN);
+        long result = fixture.get(24, false);
+        assertEquals(0xFFFFFFL, result);
     }
 
     /**
@@ -317,8 +574,6 @@ public class BitBufferIntTest {
         int value = 1;
 
         fixture2.putInt(length, value);
-
-        int read = fixture2.getInt(1, true);
-        assertEquals(value, read);
+        fixture2.get(1, true);
     }
 }
diff --git a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java
index 8be8954427..bb43c10f5b 100644
--- a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java
+++ b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/io/BitBuffer.java
@@ -6,10 +6,11 @@
  * accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
- * Contributors: Matthew Khouzam - Initial Design and implementation
- * Contributors: Francis Giraldeau - Initial API and implementation
- * Contributors: Philippe Proulx - Some refinement and optimization
- * Contributors: Etienne Bergeron <Etienne.Bergeron@gmail.com> - fix zero size read + cleanup
+ * Contributors:
+ *  Matthew Khouzam - Initial Design and implementation + overhaul
+ *  Francis Giraldeau - Initial API and implementation
+ *  Philippe Proulx - Some refinement and optimization
+ *  Etienne Bergeron <Etienne.Bergeron@gmail.com> - fix zero size read + cleanup
  *******************************************************************************/
 
 package org.eclipse.linuxtools.ctf.core.event.io;
@@ -23,6 +24,7 @@ import org.eclipse.linuxtools.ctf.core.trace.CTFReaderException;
  * <b><u>BitBuffer</u></b>
  * <p>
  * A bitwise buffer capable of accessing fields with bit offsets.
+ *
  * @since 2.0
  */
 public final class BitBuffer {
@@ -95,16 +97,73 @@ public final class BitBuffer {
      * Reads next four bytes from the current bit position according to current
      * byte order.
      *
-     * @return The int value read from the buffer
+     * @return The int value (signed) read from the buffer
      * @throws CTFReaderException
-     *             An error occurred reading the data. When the buffer is read
-     *             beyond its end, this exception will be raised.
+     *             An error occurred reading the long. This exception can be
+     *             raised if the buffer tries to read out of bounds
      */
     public int getInt() throws CTFReaderException {
         return getInt(BIT_INT, true);
     }
 
     /**
+     * Relative <i>get</i> method for reading 64-bit integer.
+     *
+     * Reads next eight bytes from the current bit position according to current
+     * byte order.
+     *
+     * @return The long value (signed) read from the buffer
+     * @throws CTFReaderException
+     *             An error occurred reading the long. This exception can be
+     *             raised if the buffer tries to read out of bounds
+     */
+    public long getLong() throws CTFReaderException {
+        return get(BIT_LONG, true);
+    }
+
+    /**
+     * Relative <i>get</i> method for reading long of <i>length</i> bits.
+     *
+     * Reads <i>length</i> bits starting at the current position. The result is
+     * signed extended if <i>signed</i> is true. The current position is
+     * increased of <i>length</i> bits.
+     *
+     * @param length
+     *            The length in bits of this integer
+     * @param signed
+     *            The sign extended flag
+     * @return The long value read from the buffer
+     * @throws CTFReaderException
+     *             An error occurred reading the data. If more than 64 bits at a
+     *             time are read, or the buffer is read beyond its end, this
+     *             exception will be raised.
+     */
+    public long get(int length, boolean signed) throws CTFReaderException {
+        if (length > BIT_LONG) {
+            throw new CTFReaderException("Cannot read a long longer than 64 bits. Rquested: " + length); //$NON-NLS-1$
+        }
+        if (length > BIT_INT) {
+            final int highShift = length - BIT_INT;
+            long a = getInt();
+            long b = getInt(highShift, false);
+            long retVal;
+            /* Cast the signed-extended int into a unsigned int. */
+            a &= 0xFFFFFFFFL;
+            b &= (1L << highShift) - 1L;
+
+            retVal = (this.byteOrder == ByteOrder.BIG_ENDIAN) ? ((a << highShift) | b) : ((b << BIT_INT) | a);
+            /* sign extend */
+            if (signed) {
+                int signExtendBits = BIT_LONG - length;
+                retVal = (retVal << signExtendBits) >> signExtendBits;
+            }
+            return retVal;
+        }
+        long retVal = getInt(length, signed);
+        return (signed ? retVal : (retVal & 0xFFFFFFFFL));
+    }
+
+    /**
      * Relative <i>get</i> method for reading integer of <i>length</i> bits.
      *
      * Reads <i>length</i> bits starting at the current position. The result is
@@ -120,7 +179,7 @@ public final class BitBuffer {
      *             An error occurred reading the data. When the buffer is read
      *             beyond its end, this exception will be raised.
      */
-    public int getInt(int length, boolean signed) throws CTFReaderException {
+    private int getInt(int length, boolean signed) throws CTFReaderException {
 
         /* Nothing to read. */
         if (length == 0) {
@@ -138,9 +197,15 @@ public final class BitBuffer {
         int val = 0;
         boolean gotIt = false;
 
-        /* Try a fast read when the position is byte-aligned by using the */
-        /* native methods of ByteBuffer. */
-        if (this.pos % BitBuffer.BIT_CHAR == 0) {
+        /*
+         * Try a fast read when the position is byte-aligned by using
+         * java.nio.ByteBuffer's native methods
+         */
+        /*
+         * A faster alignment detection as the compiler cannot guaranty that pos
+         * is always positive.
+         */
+        if ((this.pos & (BitBuffer.BIT_CHAR - 1)) == 0) {
             switch (length) {
             case BitBuffer.BIT_CHAR:
                 // Byte
diff --git a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/FloatDefinition.java b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/FloatDefinition.java
index 16b7509e48..9543df4103 100644
--- a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/FloatDefinition.java
+++ b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/FloatDefinition.java
@@ -103,9 +103,9 @@ public class FloatDefinition extends Definition {
 
     private static double readRawFloat64(BitBuffer input, final int manBits,
             final int expBits) throws CTFReaderException {
-        long low = input.getInt(32, false);
+        long low = input.get(32, false);
         low = low & 0x00000000FFFFFFFFL;
-        long high = input.getInt(32, false);
+        long high = input.get(32, false);
         high = high & 0x00000000FFFFFFFFL;
         long temp = (high << 32) | low;
         return createFloat(temp, manBits - 1, expBits);
@@ -135,7 +135,7 @@ public class FloatDefinition extends Definition {
 
     private static double readRawFloat32(BitBuffer input, final int manBits,
             final int expBits) throws CTFReaderException {
-        long temp = input.getInt(32, false);
+        long temp = input.get(32, false);
         return createFloat(temp, manBits - 1, expBits);
     }
 
diff --git a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/IntegerDefinition.java b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/IntegerDefinition.java
index 1cb980c02b..31a9cd501b 100644
--- a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/IntegerDefinition.java
+++ b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/IntegerDefinition.java
@@ -122,9 +122,9 @@ public class IntegerDefinition extends SimpleDatatypeDefinition {
 
         // TODO: use the eventual getLong from BitBuffer
         if (length == 64) {
-            long low = input.getInt(32, false);
+            long low = input.get(32, false);
             low = low & 0x00000000FFFFFFFFL;
-            long high = input.getInt(32, false);
+            long high = input.get(32, false);
             high = high & 0x00000000FFFFFFFFL;
             if (this.declaration.getByteOrder() != ByteOrder.BIG_ENDIAN) {
                 bits = (high << 32) | low;
@@ -132,7 +132,7 @@ public class IntegerDefinition extends SimpleDatatypeDefinition {
                 bits = (low << 32) | high;
             }
         } else {
-            bits = input.getInt(length, signed);
+            bits = input.get(length, signed);
             bits = bits & 0x00000000FFFFFFFFL;
             /*
              * The previous line loses sign information but is necessary, this
diff --git a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/StringDefinition.java b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/StringDefinition.java
index 5e79cef7bf..6ed3c0c87d 100644
--- a/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/StringDefinition.java
+++ b/lttng/org.eclipse.linuxtools.ctf.core/src/org/eclipse/linuxtools/ctf/core/event/types/StringDefinition.java
@@ -115,10 +115,10 @@ public class StringDefinition extends Definition {
         /* Offset the buffer position wrt the current alignment */
         alignRead(input, this.declaration);
         string.setLength(0);
-        char c = (char) input.getInt(8, false);
+        char c = (char) input.get(8, false);
         while (c != 0) {
             string.append(c);
-            c = (char) input.getInt(8, false);
+            c = (char) input.get(8, false);
         }
     }