Add Sqlite.prepareMulti() to JNI wrapper1, for preparing multiple statements from a single input.

FossilOrigin-Name: e4670d68b52233ab376a1725983e148aaf2a2c3658a41f5768e37a0f1f87428a

ext/jni/src/org/sqlite/jni/capi/CApi.java

@@ -1202,26 +1202,26 @@ public final class CApi {
   */
   public static int sqlite3_prepare_multi(
     @NotNull sqlite3 db, @NotNull byte[] sqlUtf8,
-    int preFlags,
+    int prepFlags,
     @NotNull PrepareMultiCallback p){
     final OutputPointer.Int32 oTail = new OutputPointer.Int32();
     int pos = 0, n = 1;
     byte[] sqlChunk = sqlUtf8;
     int rc = 0;
     final OutputPointer.sqlite3_stmt outStmt = new OutputPointer.sqlite3_stmt();
-    while(0==rc && pos<sqlChunk.length){
+    while( 0==rc && pos<sqlChunk.length ){
       sqlite3_stmt stmt = null;
-      if(pos > 0){
+      if( pos>0 ){
         sqlChunk = Arrays.copyOfRange(sqlChunk, pos,
                                       sqlChunk.length);
       }
       if( 0==sqlChunk.length ) break;
-      rc = sqlite3_prepare_v3(db, sqlChunk, preFlags, outStmt, oTail);
+      rc = sqlite3_prepare_v3(db, sqlChunk, prepFlags, outStmt, oTail);
       if( 0!=rc ) break;
       pos = oTail.value;
       stmt = outStmt.take();
-      if( null == stmt ){
+      if( null==stmt ){
-        // empty statement was parsed.
+        // empty statement (whitespace/comments)
         continue;
       }
       rc = p.call(stmt);

ext/jni/src/org/sqlite/jni/wrapper1/Sqlite.java

@@ -510,19 +510,27 @@ public final class Sqlite implements AutoCloseable  {
   }
 
   /**
+     Analog to sqlite3_prepare_v3(), this prepares the first SQL
+     statement from the given input string and returns it as a
+     Stmt. It throws an SqliteException if preparation fails or an
+     IllegalArgumentException if the input is empty (e.g. contains
+     only comments or whitespace).
+
+     The first argument must be SQL input in UTF-8 encoding.
+
      prepFlags must be 0 or a bitmask of the PREPARE_... constants.
 
-     prepare() TODOs include:
+     For processing multiple statements from a single input, use
+     prepareMulti().
 
-     - overloads taking byte[] and ByteBuffer.
+     Design note: though the C-level API succeeds with a null
-
+     statement object for empty inputs, that approach is cumbersome to
-     - multi-statement processing, like CApi.sqlite3_prepare_multi()
+     use in higher-level APIs because every prepared statement has to
-     but using a callback specific to the higher-level Stmt class
+     be checked for null before using it.
-     rather than the sqlite3_stmt class.
   */
-  public Stmt prepare(String sql, int prepFlags){
+  public Stmt prepare(byte utf8Sql[], int prepFlags){
     final OutputPointer.sqlite3_stmt out = new OutputPointer.sqlite3_stmt();
-    final int rc = CApi.sqlite3_prepare_v3(thisDb(), sql, prepFlags, out);
+    final int rc = CApi.sqlite3_prepare_v3(thisDb(), utf8Sql, prepFlags, out);
     checkRc(rc);
     final sqlite3_stmt q = out.take();
     if( null==q ){
@@ -539,10 +547,113 @@ public final class Sqlite implements AutoCloseable  {
     return new Stmt(this, q);
   }
 
+  /**
+     Equivalent to prepare(X, prepFlags), where X is
+     sql.getBytes(StandardCharsets.UTF_8).
+  */
+  public Stmt prepare(String sql, int prepFlags){
+    return prepare( sql.getBytes(StandardCharsets.UTF_8), prepFlags );
+  }
+
+  /**
+     Equivalent to prepare(sql, 0).
+  */
   public Stmt prepare(String sql){
     return prepare(sql, 0);
   }
 
+
+  /**
+     Callback type for use with prepareMulti().
+  */
+  public interface PrepareMulti {
+    /**
+       Gets passed a Stmt which it may handle in arbitrary ways.
+       Ownership of st is passed to this function. It must throw on
+       error.
+    */
+    void call(Sqlite.Stmt st);
+  }
+
+  /**
+     A PrepareMulti implementation which calls another PrepareMulti
+     object and then finalizes its statement.
+  */
+  public static class PrepareMultiFinalize implements PrepareMulti {
+    private final PrepareMulti pm;
+    /**
+       Proxies the given PrepareMulti via this object's call() method.
+    */
+    public PrepareMultiFinalize(PrepareMulti proxy){
+      this.pm = proxy;
+    }
+    /**
+       Passes st to the call() method of the object this one proxies,
+       then finalizes st, propagating any exceptions from call() after
+       finalizing st.
+    */
+    @Override public void call(Stmt st){
+      try{ pm.call(st); }
+      finally{ st.finalizeStmt(); }
+    }
+  }
+
+  /**
+     Equivalent to prepareMulti(sql,0,visitor).
+  */
+  public void prepareMulti(String sql, PrepareMulti visitor){
+    prepareMulti( sql, 0, visitor );
+  }
+
+  /**
+     A variant of prepare() which can handle multiple SQL statements
+     in a single input string. For each statement in the given string,
+     the statement is passed to visitor.call() a single time, passing
+     ownership of the statement to that function. This function does
+     not step() or close() statements - those operations are left to
+     caller or the visitor function.
+
+     Unlike prepare(), this function does not fail if the input
+     contains only whitespace or SQL comments. In that case it is up
+     to the caller to arrange for that to be an error (if desired).
+
+     PrepareMultiFinalize offers a proxy which finalizes each
+     statement after it is passed to another client-defined visitor.
+  */
+  public void prepareMulti(byte sqlUtf8[], int prepFlags, PrepareMulti visitor){
+    int pos = 0, n = 1;
+    byte[] sqlChunk = sqlUtf8;
+    final org.sqlite.jni.capi.OutputPointer.sqlite3_stmt outStmt =
+      new org.sqlite.jni.capi.OutputPointer.sqlite3_stmt();
+    final org.sqlite.jni.capi.OutputPointer.Int32 oTail =
+      new org.sqlite.jni.capi.OutputPointer.Int32();
+    while( pos < sqlChunk.length ){
+      sqlite3_stmt stmt = null;
+      if( pos>0 ){
+        sqlChunk = java.util.Arrays.copyOfRange(sqlChunk, pos, sqlChunk.length);
+      }
+      if( 0==sqlChunk.length ) break;
+      checkRc(
+        CApi.sqlite3_prepare_v3(db, sqlChunk, prepFlags, outStmt, oTail)
+      );
+      pos = oTail.value;
+      stmt = outStmt.take();
+      if( null==stmt ){
+        /* empty statement, e.g. only comments or whitespace, was parsed. */
+        continue;
+      }
+      visitor.call(new Stmt(this, stmt));
+    }
+  }
+
+  /**
+     Equivallent to prepareMulti(X,prepFlags,visitor), where X is
+     sql.getBytes(StandardCharsets.UTF_8).
+  */
+  public void prepareMulti(String sql, int prepFlags, PrepareMulti visitor){
+    prepareMulti(sql.getBytes(StandardCharsets.UTF_8), prepFlags, visitor);
+  }
+
   public void createFunction(String name, int nArg, int eTextRep, ScalarFunction f){
     int rc = CApi.sqlite3_create_function(thisDb(), name, nArg, eTextRep,
                                            new SqlFunction.ScalarAdapter(f));

ext/jni/src/org/sqlite/jni/wrapper1/Tester2.java

@@ -125,7 +125,7 @@ public class Tester2 implements Runnable {
   }
 
 
-  public static void execSql(Sqlite db, String[] sql){
+  public static void execSql(Sqlite db, String sql[]){
     execSql(db, String.join("", sql));
   }
 
@@ -938,6 +938,37 @@ public class Tester2 implements Runnable {
     db.close();
   }
 
+  void testPrepareMulti(){
+    final ValueHolder<Integer> fCount = new ValueHolder<>(0);
+    final ValueHolder<Integer> mCount = new ValueHolder<>(0);
+    try (Sqlite db = openDb()) {
+      execSql(db, "create table t(a); insert into t(a) values(1),(2),(3)");
+      db.createFunction("counter", -1, new ScalarFunction(){
+          @Override public void xFunc(SqlFunction.Arguments args){
+            ++fCount.value;
+            args.resultNull();
+          }
+          public void xDestroy(){}
+        }
+      );
+      final Sqlite.PrepareMulti pm = new Sqlite.PrepareMultiFinalize(
+        new Sqlite.PrepareMulti() {
+          @Override public void call(Sqlite.Stmt q){
+            ++mCount.value;
+            while(q.step()){}
+          }
+        }
+      );
+      final String sql = "select counter(*) from t;"+
+        "select counter(*) from t; /* comment */"+
+        "select counter(*) from t; -- comment\n"
+        ;
+      db.prepareMulti(sql, pm);
+    }
+    affirm( 3 == mCount.value );
+    affirm( 9 == fCount.value );
+  }
+
   private void runTests(boolean fromThread) throws Exception {
     List<java.lang.reflect.Method> mlist = testMethods;
     affirm( null!=mlist );

manifest

@@ -1,5 +1,5 @@
-C Diverse\sminor\scleanups\sin\sthe\sJNI\spieces.
+C Add\sSqlite.prepareMulti()\sto\sJNI\swrapper1,\sfor\spreparing\smultiple\sstatements\sfrom\sa\ssingle\sinput.
-D 2023-11-07T13:44:29.266
+D 2023-11-07T15:56:39.576
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -251,7 +251,7 @@ F ext/jni/src/org/sqlite/jni/capi/AggregateFunction.java 0b72cdff61533b564d65b63
 F ext/jni/src/org/sqlite/jni/capi/AuthorizerCallback.java c045a5b47e02bb5f1af91973814a905f12048c428a3504fbc5266d1c1be3de5a
 F ext/jni/src/org/sqlite/jni/capi/AutoExtensionCallback.java 74cc4998a73d6563542ecb90804a3c4f4e828cb4bd69e61226d1a51f4646e759
 F ext/jni/src/org/sqlite/jni/capi/BusyHandlerCallback.java 7b8e19810c42b0ad21a04b5d8c804b32ee5905d137148703f16a75b612c380ca
-F ext/jni/src/org/sqlite/jni/capi/CApi.java 27e3c73685e1068e51331cd083152e0a6357b02278cb67b7c103240dbc262a5d
+F ext/jni/src/org/sqlite/jni/capi/CApi.java 170cfd6501f6a4e68073808f3046970a6dd73d2faf478cbc9bd23f159ff3a646
 F ext/jni/src/org/sqlite/jni/capi/CallbackProxy.java 57e2d275dcebe690b1fc1f3d34eb96879b2d7039bce30b563aee547bf45d8a8b
 F ext/jni/src/org/sqlite/jni/capi/CollationCallback.java e29bcfc540fdd343e2f5cca4d27235113f2886acb13380686756d5cabdfd065a
 F ext/jni/src/org/sqlite/jni/capi/CollationNeededCallback.java 5bfa226a8e7a92e804fd52d6e42b4c7b875fa7a94f8e2c330af8cc244a8920ab
@@ -296,9 +296,9 @@ F ext/jni/src/org/sqlite/jni/test-script-interpreter.md f9f25126127045d051e918fe
 F ext/jni/src/org/sqlite/jni/wrapper1/AggregateFunction.java d5c108b02afd3c63c9e5e53f71f85273c1bfdc461ae526e0a0bb2b25e4df6483
 F ext/jni/src/org/sqlite/jni/wrapper1/ScalarFunction.java 43c43adfb7866098aadaaca1620028a6ec82d5193149970019b1cce9eb59fb03
 F ext/jni/src/org/sqlite/jni/wrapper1/SqlFunction.java 2833afdb9af5c1949bb35f4c926a5351fba9d1cdf0996864caa7b47827a346c7
-F ext/jni/src/org/sqlite/jni/wrapper1/Sqlite.java 6a310fe422d0daf79f7841c9b341f64d843ca7e85ef31829530623a81ecd25fa
+F ext/jni/src/org/sqlite/jni/wrapper1/Sqlite.java 0ef62b43b1d6a9f044e106b56c9ea42bc7150b82ebeb79cff58f5be08cb9a435
 F ext/jni/src/org/sqlite/jni/wrapper1/SqliteException.java 982538ddb4c0719ef87dfa664cd137b09890b546029a7477810bd64d4c47ee35
-F ext/jni/src/org/sqlite/jni/wrapper1/Tester2.java a944fd0a9047a51a5074bffd707452d80cf06e715ebc78b541480ee98629fb93
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manifest.uuid

@@ -1 +1 @@
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