Pull request #125: Improved Oracle compatibility with truncate with timestamps and dates.

h2/src/docsrc/help/help.csv

@@ -2975,11 +2975,13 @@ CALL HASH('SHA256', STRINGTOUTF8('Password'), 1000)
 "
 
 "Functions (Numeric)","TRUNCATE","
-{ TRUNC | TRUNCATE } ( { {numeric, digitsInt} | timestamp } )
+{ TRUNC | TRUNCATE } ( { {numeric, digitsInt} | timestamp | date | timestampString } )
 ","
 Truncates to a number of digits (to the next value closer to 0).
 This method returns a double.
 When used with a timestamp, truncates a timestamp to a date (day) value.
+When used with a date, truncates a date to a date (day) value less time part.
+When used with a timestamp as string, truncates a timestamp to a date (day) value.
 ","
 TRUNCATE(VALUE, 2)
 "

h2/src/docsrc/html/changelog.html

@@ -21,6 +21,8 @@ Change Log
 
 <h2>Next Version (unreleased)</h2>
 <ul>
+<li>Pull request #125: Improved Oracle compatibility with "truncate" with timestamps and dates.
+</li>
 <li>Pull request #127: Linked tables now support geometry columns.
 </li>
 <li>ABS(CAST(0.0 AS DOUBLE)) returned -0.0 instead of 0.0.

h2/src/main/org/h2/expression/Function.java

@@ -1224,6 +1224,24 @@ public class Function extends Expression implements FunctionCall {
                 c.set(Calendar.SECOND, 0);
                 c.set(Calendar.MILLISECOND, 0);
                 result = ValueTimestamp.fromMillis(c.getTimeInMillis());
+            } else if (v0.getType() == Value.DATE) {
+                ValueDate vd = (ValueDate) v0;
+                Calendar c = Calendar.getInstance();
+                c.setTime(vd.getDate());
+                c.set(Calendar.HOUR_OF_DAY, 0);
+                c.set(Calendar.MINUTE, 0);
+                c.set(Calendar.SECOND, 0);
+                c.set(Calendar.MILLISECOND, 0);
+                result = ValueTimestamp.fromMillis(c.getTimeInMillis());
+            } else if (v0.getType() == Value.STRING) {
+                ValueString vd = (ValueString) v0;
+                Calendar c = Calendar.getInstance();
+                c.setTime(ValueTimestamp.parse(vd.getString()).getDate());
+                c.set(Calendar.HOUR_OF_DAY, 0);
+                c.set(Calendar.MINUTE, 0);
+                c.set(Calendar.SECOND, 0);
+                c.set(Calendar.MILLISECOND, 0);
+                result = ValueTimestamp.fromMillis(c.getTimeInMillis());
             } else {
                 double d = v0.getDouble();
                 int p = v1 == null ? 0 : v1.getInt();

h2/src/test/org/h2/test/testSimple.in.txt

+select trunc('2015-05-29 15:00:00');
+> 2015-05-29 00:00:00.0;
+select trunc('2015-05-29');
+> 2015-05-29 00:00:00.0;
+select trunc(timestamp '2000-01-01 10:20:30.0');
+> 2000-01-01 00:00:00.0;
 select 1000L / 10;
 > 100;
 select * from (select x as y from dual order by y);

h2/src/test/org/h2/test/unit/TestBitStream.java

@@ -100,7 +100,9 @@ public class TestBitStream extends TestBase {
             }
         };
         o.writeGolomb(div, value);
+        int size = Out.getGolombSize(div, value);
         String got = buff.toString();
+        assertEquals(size, got.length());
         assertEquals(expected, got);
     }
 

h2/src/tools/org/h2/dev/util/BitStream.java

@@ -126,6 +126,23 @@ public class BitStream {
             }
         }
 
+        /**
+         * Get the size of the Golomb code for this value.
+         *
+         * @param divisor the divisor
+         * @param value the value
+         * @return the number of bits
+         */
+        public static int getGolombSize(int divisor, int value) {
+            int q = value / divisor;
+            int r = value - q * divisor;
+            int bit = 31 - Integer.numberOfLeadingZeros(divisor - 1);
+            if (r < ((2 << bit) - divisor)) {
+                bit--;
+            }
+            return bit + q + 2;
+        }
+
         /**
          * Write a bit.
          *
@@ -195,8 +212,10 @@ public class BitStream {
             }
             codes = new int[frequencies.length];
             tree = queue.poll();
+            if (tree != null) {
                 tree.initCodes(codes, 1);
             }
+        }
 
         /**
          * Write a value.