SQLite Android Bindings

#include <JNIHelp.h>
#include "ALog-priv.h"


#include <sys/mman.h>
#include <string.h>
#include <unistd.h>
#include <assert.h>

#if 0
#include <androidfw/CursorWindow.h>
#endif

#include <sqlite3.h>
#if 0

                return createAshmemRegionWithData(env, blob, length);
            }
        }
    }
    return -1;
}

/*
** Note: The following symbols must be in the same order as the corresponding
** elements in the aMethod[] array in function nativeExecuteForCursorWindow().
*/
enum CWMethodNames {

  CW_CLEAR         = 0,
  CW_SETNUMCOLUMNS = 1,
  CW_ALLOCROW      = 2,
  CW_FREELASTROW   = 3,
  CW_PUTNULL       = 4,
  CW_PUTLONG       = 5,
  CW_PUTDOUBLE     = 6,
  CW_PUTSTRING     = 7,
  CW_PUTBLOB       = 8
};

/*
** An instance of this structure represents a single CursorWindow java method.









*/
struct CWMethod {
  jmethodID id;                   /* Method id */
  const char *zName;              /* Method name */
  const char *zSig;               /* Method JNI signature */
};








/*
** Append the contents of the row that SQL statement pStmt currently points to


** to the CursorWindow object passed as the second argument. The CursorWindow
** currently contains iRow rows. Return true on success or false if an error
** occurs.
*/
static jboolean copyRowToWindow(
  JNIEnv *pEnv,
  jobject win,
  int iRow,
  sqlite3_stmt *pStmt,
  CWMethod *aMethod
){
  int nCol = sqlite3_column_count(pStmt);

  int i;
  jboolean bOk;

  bOk = pEnv->CallBooleanMethod(win, aMethod[CW_ALLOCROW].id);
  for(i=0; bOk && i<nCol; i++){
    switch( sqlite3_column_type(pStmt, i) ){
      case SQLITE_NULL: {
        bOk = pEnv->CallBooleanMethod(win, aMethod[CW_PUTNULL].id, iRow, i);
        break;
      }


      case SQLITE_INTEGER: {
        jlong val = sqlite3_column_int64(pStmt, i);





        bOk = pEnv->CallBooleanMethod(win, aMethod[CW_PUTLONG].id, val, iRow, i);
        break;
      }


      case SQLITE_FLOAT: {

        jdouble val = sqlite3_column_double(pStmt, i);





        bOk = pEnv->CallBooleanMethod(win, aMethod[CW_PUTDOUBLE].id, val, iRow, i);
        break;
      }

      case SQLITE_TEXT: {

        const char *zVal = (const char*)sqlite3_column_text(pStmt, i);




        jstring val = pEnv->NewStringUTF(zVal);
        bOk = pEnv->CallBooleanMethod(win, aMethod[CW_PUTSTRING].id, val, iRow, i);
        break;
      }

      default: {
        assert( sqlite3_column_type(pStmt, i)==SQLITE_BLOB );

        const jbyte *p = (const jbyte*)sqlite3_column_blob(pStmt, i);
        int n = sqlite3_column_bytes(pStmt, i);

        jbyteArray val = pEnv->NewByteArray(n);
        pEnv->SetByteArrayRegion(val, 0, n, p);
        bOk = pEnv->CallBooleanMethod(win, aMethod[CW_PUTBLOB].id, val, iRow, i);

        break;
      }
    }





    if( bOk==0 ){




      pEnv->CallVoidMethod(win, aMethod[CW_FREELASTROW].id);
    }
  }

  return bOk;
}

static jboolean setWindowNumColumns(
  JNIEnv *pEnv,
  jobject win,
  sqlite3_stmt *pStmt,
  CWMethod *aMethod
){
  int nCol;

  pEnv->CallVoidMethod(win, aMethod[CW_CLEAR].id);
  nCol = sqlite3_column_count(pStmt);
  return pEnv->CallBooleanMethod(win, aMethod[CW_SETNUMCOLUMNS].id, (jint)nCol);
}

/*
** This method has been rewritten for org.sqlite.database.*. The original 
** android implementation used the C++ interface to populate a CursorWindow
** object. Since the NDK does not export this interface, we invoke the Java
** interface using standard JNI methods to do the same thing.
**
** This function executes the SQLite statement object passed as the 4th 
** argument and copies one or more returned rows into the CursorWindow
** object passed as the 5th argument. The set of rows copied into the 
** CursorWindow is always contiguous.

**
** The only row that *must* be copied into the CursorWindow is row 
** iRowRequired. Ideally, all rows from iRowStart through to the end
** of the query are copied into the CursorWindow. If this is not possible
** (CursorWindow objects have a finite capacity), some compromise position
** is found (see comments embedded in the code below for details).
**
** The return value is a 64-bit integer calculated as follows:

**
**      (iStart << 32) | nRow
**
** where iStart is the index of the first row copied into the CursorWindow.
** If the countAllRows argument is true, nRow is the total number of rows
** returned by the query. Otherwise, nRow is one greater than the index of 
** the last row copied into the CursorWindow.
*/
static jlong nativeExecuteForCursorWindow(
  JNIEnv *pEnv, 
  jclass clazz,
  jint connectionPtr,             /* Pointer to SQLiteConnection C++ object */


  jint statementPtr,              /* Pointer to sqlite3_stmt object */
  jobject win,                    /* The CursorWindow object to populate */
  jint startPos,                  /* First row to add (advisory) */









  jint iRowRequired,              /* Required row */
  jboolean countAllRows

) {
  SQLiteConnection *pConnection = reinterpret_cast<SQLiteConnection*>(connectionPtr);
  sqlite3_stmt *pStmt = reinterpret_cast<sqlite3_stmt*>(statementPtr);

  CWMethod aMethod[] = {
    {0, "clear",         "()V"},
    {0, "setNumColumns", "(I)Z"},


    {0, "allocRow",      "()Z"},
    {0, "freeLastRow",   "()V"},

    {0, "putNull",       "(II)Z"},
    {0, "putLong",       "(JII)Z"},
    {0, "putDouble",     "(DII)Z"},
    {0, "putString",     "(Ljava/lang/String;II)Z"},
    {0, "putBlob",       "([BII)Z"},
  };
  jclass cls;                     /* Class android.database.CursorWindow */
  int i;                          /* Iterator variable */
  int nCol;                       /* Number of columns returned by pStmt */
  int nRow;

  jboolean bOk;







  int iStart;                     /* First row copied to CursorWindow */




  /* Locate all required CursorWindow methods. */
  cls = pEnv->FindClass("android/database/CursorWindow");
  for(i=0; i<(sizeof(aMethod)/sizeof(struct CWMethod)); i++){
    aMethod[i].id = pEnv->GetMethodID(cls, aMethod[i].zName, aMethod[i].zSig);
    if( aMethod[i].id==NULL ){
      jniThrowExceptionFmt(pEnv, "java/lang/Exception", 
          "Failed to find method CursorWindow.%s()", aMethod[i].zName


      );


      return 0;

    }
  }

























  /* Set the number of columns in the window */
  bOk = setWindowNumColumns(pEnv, win, pStmt, aMethod);
  if( bOk==0 ) return 0;


  nRow = 0;

  iStart = startPos;
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    /* Only copy in rows that occur at or after row index iStart. */
    if( nRow>=iStart && bOk ){
      bOk = copyRowToWindow(pEnv, win, (nRow - iStart), pStmt, aMethod);
      if( bOk==0 ){
        /* The CursorWindow object ran out of memory. If row iRowRequired was

        ** not successfully added before this happened, clear the CursorWindow
        ** and try to add the current row again.  */
        if( nRow<=iRowRequired ){
          bOk = setWindowNumColumns(pEnv, win, pStmt, aMethod);
          if( bOk==0 ){
            sqlite3_reset(pStmt);
            return 0;
          }
          iStart = nRow;
          bOk = copyRowToWindow(pEnv, win, (nRow - iStart), pStmt, aMethod);
        }

        /* If the CursorWindow is still full and the countAllRows flag is not
        ** set, break out of the loop here. If countAllRows is set, continue
        ** so as to set variable nRow correctly.  */
        if( bOk==0 && countAllRows==0 ) break;
      }
    }

    nRow++;
  }

  /* Finalize the statement. If this indicates an error occurred, throw an
  ** SQLiteException exception.  */
  int rc = sqlite3_reset(pStmt);
  if( rc!=SQLITE_OK ){
    throw_sqlite3_exception(pEnv, sqlite3_db_handle(pStmt));
    return 0;
  }

  jlong lRet = jlong(iStart) << 32 | jlong(nRow);
  return lRet;
}

static jint nativeGetDbLookaside(JNIEnv* env, jobject clazz, jint connectionPtr) {
    SQLiteConnection* connection = reinterpret_cast<SQLiteConnection*>(connectionPtr);

    int cur = -1;
    int unused;
    sqlite3_db_status(connection->db, SQLITE_DBSTATUS_LOOKASIDE_USED, &cur, &unused, 0);

            (void*)nativeExecuteForString },
    { "nativeExecuteForBlobFileDescriptor", "(II)I",
            (void*)nativeExecuteForBlobFileDescriptor },
    { "nativeExecuteForChangedRowCount", "(II)I",
            (void*)nativeExecuteForChangedRowCount },
    { "nativeExecuteForLastInsertedRowId", "(II)J",
            (void*)nativeExecuteForLastInsertedRowId },
    { "nativeExecuteForCursorWindow", "(IILandroid/database/CursorWindow;IIZ)J",
            (void*)nativeExecuteForCursorWindow },
    { "nativeGetDbLookaside", "(I)I",
            (void*)nativeGetDbLookaside },
    { "nativeCancel", "(I)V",
            (void*)nativeCancel },
    { "nativeResetCancel", "(IZ)V",
            (void*)nativeResetCancel },

// Called each time a message is logged.
static void sqliteLogCallback(void* data, int iErrCode, const char* zMsg) {
    bool verboseLog = !!data;
    if (iErrCode == 0 || iErrCode == SQLITE_CONSTRAINT || iErrCode == SQLITE_SCHEMA) {
        if (verboseLog) {
            ALOG(LOG_VERBOSE, SQLITE_LOG_TAG, "(%d) %s\n", iErrCode, zMsg);
        }
    } else {
        ALOG(LOG_ERROR, SQLITE_LOG_TAG, "(%d) %s\n", iErrCode, zMsg);
    }
}

// Sets the global SQLite configuration.

<?xml version="1.0" encoding="utf-8"?>
<ScrollView
  xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
      android:layout_height="fill_parent">

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

<TextView

    android:id="@+id/tv_widget"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="<this text should be replaced by the test output>"
    android:typeface="monospace"
    />
</LinearLayout>
</ScrollView>

    db = SQLiteDatabase.openOrCreateDatabase(":memory:", null);
    st = db.compileStatement("SELECT sqlite_version()");
    res = st.simpleQueryForString();

    myTV.append("SQLite version " + res + "\n\n");
  }

  public void test_warning(String name, String warning){
    myTV.append("WARNING:" + name + ": " + warning + "\n");
  }

  public void test_result(String name, String res, String expected){
    myTV.append(name + "... ");
    myNTest++;

    if( res.equals(expected) ){
      myTV.append("ok\n");

    Cursor c = db.rawQuery("SELECT x FROM t1", null);
    if( c!=null ){
      boolean bRes;
      for(bRes=c.moveToFirst(); bRes; bRes=c.moveToNext()){
        String x = c.getString(0);
        res = res + "." + x;
      }
    }else{
      test_warning("csr_test_1", "c==NULL");
    }

    test_result("csr_test_1", res, ".one.two.three");
  }

  public void run_the_tests(View view){
    System.loadLibrary("sqliteX");

    myTV.setText("");
    myNErr = 0;
    myNTest = 0;

    try {
      report_version();
      csr_test_1();

      myTV.append("\n" + myNErr + " errors from " + myNTest + " tests\n");
    } catch(Exception e) {
      myTV.append("Exception: " + e.toString() + "\n");
      myTV.append(android.util.Log.getStackTraceString(e) + "\n");
    }
  }
}

        for (int i = 0; i < length; i++) {
            if (columnNames[i].equals("_id")) {
                return i;
            }
        }
        return -1;
    }

    /**
     * Picks a start position for {@link Cursor#fillWindow} such that the
     * window will contain the requested row and a useful range of rows
     * around it.
     *
     * When the data set is too large to fit in a cursor window, seeking the
     * cursor can become a very expensive operation since we have to run the
     * query again when we move outside the bounds of the current window.
     *
     * We try to choose a start position for the cursor window such that
     * 1/3 of the window's capacity is used to hold rows before the requested
     * position and 2/3 of the window's capacity is used to hold rows after the
     * requested position.
     *
     * @param cursorPosition The row index of the row we want to get.
     * @param cursorWindowCapacity The estimated number of rows that can fit in
     * a cursor window, or 0 if unknown.
     * @return The recommended start position, always less than or equal to
     * the requested row.
     * @hide
     */
    public static int cursorPickFillWindowStartPosition(
            int cursorPosition, int cursorWindowCapacity) {
        return Math.max(cursorPosition - cursorWindowCapacity / 3, 0);
    }
}

    private static native String nativeExecuteForString(int connectionPtr, int statementPtr);
    private static native int nativeExecuteForBlobFileDescriptor(
            int connectionPtr, int statementPtr);
    private static native int nativeExecuteForChangedRowCount(int connectionPtr, int statementPtr);
    private static native long nativeExecuteForLastInsertedRowId(
            int connectionPtr, int statementPtr);
    private static native long nativeExecuteForCursorWindow(
            int connectionPtr, int statementPtr, CursorWindow win,
            int startPos, int requiredPos, boolean countAllRows);
    private static native int nativeGetDbLookaside(int connectionPtr);
    private static native void nativeCancel(int connectionPtr);
    private static native void nativeResetCancel(int connectionPtr, boolean cancelable);

    private SQLiteConnection(SQLiteConnectionPool pool,
            SQLiteDatabaseConfiguration configuration,

     * @throws SQLiteException if an error occurs, such as a syntax error
     * or invalid number of bind arguments.
     * @throws OperationCanceledException if the operation was canceled.
     */
    public int executeForCursorWindow(String sql, Object[] bindArgs,
            CursorWindow window, int startPos, int requiredPos, boolean countAllRows,
            CancellationSignal cancellationSignal) {

        if (sql == null) {
            throw new IllegalArgumentException("sql must not be null.");
        }
        if (window == null) {
            throw new IllegalArgumentException("window must not be null.");
        }

                try {
                    throwIfStatementForbidden(statement);
                    bindArguments(statement, bindArgs);
                    applyBlockGuardPolicy(statement);
                    attachCancellationSignal(cancellationSignal);
                    try {
                        final long result = nativeExecuteForCursorWindow(
                                mConnectionPtr, statement.mStatementPtr, window,
                                startPos, requiredPos, countAllRows);
                        actualPos = (int)(result >> 32);
                        countedRows = (int)result;
                        filledRows = window.getNumRows();
                        window.setStartPosition(actualPos);
                        return countedRows;
                    } finally {

                            + ", filledRows=" + filledRows
                            + ", countedRows=" + countedRows);
                }
            }
        } finally {
            window.releaseReference();
        }


    }

    private PreparedStatement acquirePreparedStatement(String sql) {
        PreparedStatement statement = mPreparedStatementCache.get(sql);
        boolean skipCache = false;
        if (statement != null) {
            if (!statement.mInUse) {

package org.sqlite.database.sqlite;

import org.sqlite.database.ExtraUtils;

import android.database.AbstractWindowedCursor;
import android.database.CursorWindow;


import android.os.StrictMode;
import android.util.Log;

import java.util.HashMap;
import java.util.Map;

/**

    @Override
    public int getCount() {
        if (mCount == NO_COUNT) {
            fillWindow(0);
        }
        return mCount;
    }


    /* 
    ** The AbstractWindowClass contains protected methods clearOrCreateWindow() and
    ** closeWindow(), which are used by the android.database.sqlite.* version of this
    ** class. But, since they are marked with "@hide", the following replacement 
    ** versions are required.
    */
    private void awc_clearOrCreateWindow(String name){
      CursorWindow win = getWindow();
      if( win==null ){
        win = new CursorWindow(name);
        setWindow(win);
      }else{
        win.clear();
      }
    }
    private void awc_closeWindow(){
      setWindow(null);
    }

    private void fillWindow(int requiredPos) {
        awc_clearOrCreateWindow(getDatabase().getPath());

        try {
            if (mCount == NO_COUNT) {
                int startPos = ExtraUtils.cursorPickFillWindowStartPosition(requiredPos, 0);
                mCount = mQuery.fillWindow(mWindow, startPos, requiredPos, true);
                mCursorWindowCapacity = mWindow.getNumRows();
                if (Log.isLoggable(TAG, Log.DEBUG)) {
                    Log.d(TAG, "received count(*) from native_fill_window: " + mCount);
                }
            } else {
                int startPos = ExtraUtils.cursorPickFillWindowStartPosition(requiredPos,
                        mCursorWindowCapacity);
                mQuery.fillWindow(mWindow, startPos, requiredPos, false);
            }
        } catch (RuntimeException ex) {
            // Close the cursor window if the query failed and therefore will
            // not produce any results.  This helps to avoid accidentally leaking
            // the cursor window if the client does not correctly handle exceptions
            // and fails to close the cursor.
            awc_closeWindow();
            throw ex;
        }

    }

    @Override
    public int getColumnIndex(String columnName) {
        // Create mColumnNameMap on demand
        if (mColumnNameMap == null) {
            String[] columns = mColumns;