fix: improve insert values(...) batch rewrite

Now it supports VALUES (?,1), and splits very long batch into series of smaller ones
to keep overall number of bind variables <32768 (that is PG's limit in v3 protocol)

Trigger property: reWriteBatchedInserts=true. Default value is still "false".

closes #580
closes #584

pgjdbc/src/main/java/org/postgresql/core/DMLCommand.java

@@ -14,12 +14,21 @@
  * Data Modification Language inspection support.
  *
  * @author Jeremy Whiting jwhiting@redhat.com
+ * @author Christopher Deckers (chrriis@gmail.com)
  *
  */
 public class DMLCommand {
 
   public boolean isBatchedReWriteCompatible() {
-    return batchedReWriteCompatible;
+    return valuesBraceOpenPosition >= 0;
+  }
+
+  public int getBatchRewriteValuesBraceOpenPosition() {
+    return valuesBraceOpenPosition;
+  }
+
+  public int getBatchRewriteValuesBraceClosePosition() {
+    return valuesBraceClosePosition;
   }
 
   public DMLCommandType getType() {
@@ -32,33 +41,37 @@ public boolean isReturningKeywordPresent() {
 
   public static DMLCommand createStatementTypeInfo(DMLCommandType type,
       boolean isBatchedReWritePropertyConfigured,
-      boolean isBatchedReWriteCompatible, boolean isRETURNINGkeywordPresent,
-      boolean autocommit, int priorQueryCount) {
+      int valuesBraceOpenPosition, int valuesBraceClosePosition, boolean isRETURNINGkeywordPresent,
+      int priorQueryCount) {
     return new DMLCommand(type, isBatchedReWritePropertyConfigured,
-        isBatchedReWriteCompatible, isRETURNINGkeywordPresent, autocommit,
+        valuesBraceOpenPosition, valuesBraceClosePosition, isRETURNINGkeywordPresent,
         priorQueryCount);
   }
 
   public static DMLCommand createStatementTypeInfo(DMLCommandType type) {
-    return new DMLCommand(type, false, false, false, false,0);
+    return new DMLCommand(type, false, -1, -1, false, 0);
   }
 
   public static DMLCommand createStatementTypeInfo(DMLCommandType type,
       boolean isRETURNINGkeywordPresent) {
-    return new DMLCommand(type, false, false, isRETURNINGkeywordPresent, false,0);
+    return new DMLCommand(type, false, -1, -1, isRETURNINGkeywordPresent, 0);
   }
 
   private DMLCommand(DMLCommandType type, boolean isBatchedReWriteConfigured,
-      boolean isCompatible, boolean isPresent, boolean isautocommitConfigured,
+      int valuesBraceOpenPosition, int valuesBraceClosePosition, boolean isPresent,
       int priorQueryCount) {
     commandType = type;
     parsedSQLhasRETURNINGKeyword = isPresent;
-    batchedReWriteCompatible = (type == INSERT) && isBatchedReWriteConfigured
-        && isCompatible && !isautocommitConfigured
+    boolean batchedReWriteCompatible = (type == INSERT) && isBatchedReWriteConfigured
+        && valuesBraceOpenPosition >= 0 && valuesBraceClosePosition > valuesBraceOpenPosition
         && !isPresent && priorQueryCount == 0;
+    this.valuesBraceOpenPosition = batchedReWriteCompatible ? valuesBraceOpenPosition : -1;
+    this.valuesBraceClosePosition = batchedReWriteCompatible ? valuesBraceClosePosition : -1;
   }
 
   private final DMLCommandType commandType;
   private final boolean parsedSQLhasRETURNINGKeyword;
-  private final boolean batchedReWriteCompatible;
+  private final int valuesBraceOpenPosition;
+  private final int valuesBraceClosePosition;
+
 }

pgjdbc/src/main/java/org/postgresql/core/NativeQuery.java

@@ -14,7 +14,7 @@
  * replaced with $1, $2, etc.
  */
 public class NativeQuery {
-  private final static String[] BIND_NAMES = new String[128];
+  private final static String[] BIND_NAMES = new String[128 * 10];
   private final static int[] NO_BINDS = new int[0];
 
   public final String nativeSql;
@@ -79,8 +79,36 @@ public static String bindName(int index) {
     return index < BIND_NAMES.length ? BIND_NAMES[index] : "$" + index;
   }
 
-  public static int bindCount() {
-    return BIND_NAMES.length;
+  public static StringBuilder appendBindName(StringBuilder sb, int index) {
+    if (index < BIND_NAMES.length) {
+      return sb.append(bindName(index));
+    }
+    sb.append('$');
+    sb.append(index);
+    return sb;
+  }
+
+  /**
+   * Calculate the text length required for the given number of bind variables
+   * including dollars.
+   * Do this to avoid repeated calls to
+   * AbstractStringBuilder.expandCapacity(...) and Arrays.copyOf
+   *
+   * @param bindCount total number of parameters in a query
+   * @return int total character length for $xyz kind of binds
+   */
+  public static int calculateBindLength(int bindCount) {
+    int res = 0;
+    int bindLen = 2; // $1
+    int maxBindsOfLen = 9; // $0 .. $9
+    while (bindCount > 0) {
+      int numBinds = Math.min(maxBindsOfLen, bindCount);
+      bindCount -= numBinds;
+      res += bindLen * numBinds;
+      bindLen++;
+      maxBindsOfLen *= 10; // $0..$9 (9 items) -> $10..$99 (90 items)
+    }
+    return res;
   }
 
   public DMLCommand getCommand() {