Add incremental blob I/O support to JNI wrapper1.

FossilOrigin-Name: 7f1c76fe930d69a0274f70fa7b7e68e0db6226b731a065fa57d0936c8400ffb0

ext/jni/src/org/sqlite/jni/capi/Tester1.java

@@ -1633,7 +1633,7 @@ public class Tester1 implements Runnable {
     sqlite3_finalize(stmt);
 
     b = sqlite3_blob_open(db, "main", "t", "a",
-                          sqlite3_last_insert_rowid(db), 1);
+                          sqlite3_last_insert_rowid(db), 0);
     affirm( null!=b );
     rc = sqlite3_blob_reopen(b, 2);
     affirm( 0==rc );

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

@@ -17,6 +17,7 @@ import org.sqlite.jni.capi.CApi;
 import org.sqlite.jni.capi.sqlite3;
 import org.sqlite.jni.capi.sqlite3_stmt;
 import org.sqlite.jni.capi.sqlite3_backup;
+import org.sqlite.jni.capi.sqlite3_blob;
 import org.sqlite.jni.capi.OutputPointer;
 
 /**
@@ -473,7 +474,7 @@ public final class Sqlite implements AutoCloseable  {
     if( 0!=rc ){
       if( CApi.SQLITE_NOMEM==rc ){
         throw new OutOfMemoryError();
-      }else if( null==db || 0==CApi.sqlite3_errcode(db)){
+      }else if( null==db || 0==CApi.sqlite3_errcode(db) ){
         throw new SqliteException(rc);
       }else{
         throw new SqliteException(db);
@@ -1630,4 +1631,76 @@ public final class Sqlite implements AutoCloseable  {
     checkRc( CApi.sqlite3_set_authorizer( thisDb(), ac ) );
   }
 
+  /**
+     Object type for use with blobOpen()
+  */
+  public final class Blob implements AutoCloseable {
+    private Sqlite db;
+    private sqlite3_blob b;
+    Blob(Sqlite db, sqlite3_blob b){
+      this.db = db;
+      this.b = b;
+    }
+
+    /**
+       Analog to sqlite3_blob_close().
+    */
+    @Override public void close(){
+      if( null!=b ){
+        CApi.sqlite3_blob_close(b);
+        b = null;
+        db = null;
+      }
+    }
+
+    /**
+       Analog to sqlite3_blob_reopen() but throws on error.
+    */
+    public void reopen(long newRowId){
+      db.checkRc( CApi.sqlite3_blob_reopen(b, newRowId) );
+    }
+
+    /**
+       Analog to sqlite3_blob_write() but throws on error.
+    */
+    public void write( byte[] bytes, int atOffset ){
+      db.checkRc( CApi.sqlite3_blob_write(b, bytes, atOffset) );
+    }
+
+    /**
+       Analog to sqlite3_blob_read() but throws on error.
+    */
+    public void read( byte[] dest, int atOffset ){
+      db.checkRc( CApi.sqlite3_blob_read(b, dest, atOffset) );
+    }
+
+    /**
+       Analog to sqlite3_blob_bytes().
+    */
+    public int bytes(){
+      return CApi.sqlite3_blob_bytes(b);
+    }
+  }
+
+  /**
+     Analog to sqlite3_blob_open(). Returns a Blob object for the
+     given database, table, column, and rowid. The blob is opened for
+     read-write mode if writeable is true, else it is read-only.
+
+     The returned object must eventually be freed, before this
+     database is closed, by either arranging for it to be auto-closed
+     or calling its close() method.
+
+     Throws on error.
+  */
+  public Blob blobOpen(String dbName, String tableName, String columnName,
+                       long iRow, boolean writeable){
+    final OutputPointer.sqlite3_blob out = new OutputPointer.sqlite3_blob();
+    checkRc(
+      CApi.sqlite3_blob_open(thisDb(), dbName, tableName, columnName,
+                             iRow, writeable ? 1 : 0, out)
+    );
+    return new Blob(this, out.take());
+  }
+
 }

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

@@ -912,6 +912,32 @@ public class Tester2 implements Runnable {
     db.close();
   }
 
+  private void testBlobOpen(){
+    final Sqlite db = openDb();
+
+    execSql(db, "CREATE TABLE T(a BLOB);"
+            +"INSERT INTO t(rowid,a) VALUES(1, 'def'),(2, 'XYZ');"
+    );
+    Sqlite.Blob b = db.blobOpen("main", "t", "a",
+                                db.lastInsertRowId(), true);
+    affirm( 3==b.bytes() );
+    b.write(new byte[] {100, 101, 102 /*"DEF"*/}, 0);
+    b.close();
+    Sqlite.Stmt stmt = db.prepare("SELECT length(a), a FROM t ORDER BY a");
+    affirm( stmt.step() );
+    affirm( 3 == stmt.columnInt(0) );
+    affirm( "def".equals(stmt.columnText16(1)) );
+    stmt.finalizeStmt();
+
+    b = db.blobOpen("main", "t", "a", db.lastInsertRowId(), false);
+    b.reopen(2);
+    final byte[] tgt = new byte[3];
+    b.read( tgt, 0 );
+    affirm( 100==tgt[0] && 101==tgt[1] && 102==tgt[2], "DEF" );
+    b.close();
+    db.close();
+  }
+
   private void runTests(boolean fromThread) throws Exception {
     List<java.lang.reflect.Method> mlist = testMethods;
     affirm( null!=mlist );