Example usage for java.nio ByteBuffer getShort

List of usage examples for java.nio ByteBuffer getShort

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Introduction

In this page you can find the example usage for java.nio ByteBuffer getShort.

Prototype

public abstract short getShort(int index);

Source Link

Document

Returns the short at the specified index.

Usage

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * @usage _advanced_method_// w ww  . j  av  a 2  s  .  co  m
 */
public static short findRowStart(ByteBuffer buffer, int rowNum, JetFormat format) {
    return cleanRowStart(buffer.getShort(getRowStartOffset(rowNum, format)));
}

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * @usage _advanced_method_/*from  w  w w . j  a  v a 2s  . c  o m*/
 */
public static short findRowEnd(ByteBuffer buffer, int rowNum, JetFormat format) {
    return (short) ((rowNum == 0) ? format.PAGE_SIZE
            : cleanRowStart(buffer.getShort(getRowEndOffset(rowNum, format))));
}

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * Returns {@code true} if a row of the given size will fit on the given
 * data page, {@code false} otherwise.//from  w ww  . jav  a2  s.  c o m
 * @usage _advanced_method_
 */
public static boolean rowFitsOnDataPage(int rowLength, ByteBuffer dataPage, JetFormat format)
        throws IOException {
    int rowSpaceUsage = getRowSpaceUsage(rowLength, format);
    short freeSpaceInPage = dataPage.getShort(format.OFFSET_FREE_SPACE);
    int rowsOnPage = getRowsOnDataPage(dataPage, format);
    return ((rowSpaceUsage <= freeSpaceInPage) && (rowsOnPage < format.MAX_NUM_ROWS_ON_DATA_PAGE));
}

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * Returns the row count for the current page.  If the page is invalid
 * ({@code null}) or the page is not a DATA page, 0 is returned.
 *///from w w w .j av  a2  s.  c o m
static int getRowsOnDataPage(ByteBuffer rowBuffer, JetFormat format) throws IOException {
    int rowsOnPage = 0;
    if ((rowBuffer != null) && (rowBuffer.get(0) == PageTypes.DATA)) {
        rowsOnPage = rowBuffer.getShort(format.OFFSET_NUM_ROWS_ON_DATA_PAGE);
    }
    return rowsOnPage;
}

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * Updates free space and row info for a new row of the given size in the
 * given data page.  Positions the page for writing the row data.
 * @return the row number of the new row
 * @usage _advanced_method_// ww  w.  ja va  2s.c  o  m
 */
public static int addDataPageRow(ByteBuffer dataPage, int rowSize, JetFormat format, int rowFlags) {
    int rowSpaceUsage = getRowSpaceUsage(rowSize, format);

    // Decrease free space record.
    short freeSpaceInPage = dataPage.getShort(format.OFFSET_FREE_SPACE);
    dataPage.putShort(format.OFFSET_FREE_SPACE, (short) (freeSpaceInPage - rowSpaceUsage));

    // Increment row count record.
    short rowCount = dataPage.getShort(format.OFFSET_NUM_ROWS_ON_DATA_PAGE);
    dataPage.putShort(format.OFFSET_NUM_ROWS_ON_DATA_PAGE, (short) (rowCount + 1));

    // determine row position
    short rowLocation = findRowEnd(dataPage, rowCount, format);
    rowLocation -= rowSize;

    // write row position
    dataPage.putShort(getRowStartOffset(rowCount, format), (short) (rowLocation | rowFlags));

    // set position for row data
    dataPage.position(rowLocation);

    return rowCount;
}

From source file:com.healthmarketscience.jackcess.Table.java

/**
 * Sets a new buffer to the correct row header page using the given rowState
 * according to the given rowId.  Deleted state is
 * determined, but overflow row pointers are not followed.
 * /* ww w. j  a va  2  s  .c  o m*/
 * @return a ByteBuffer of the relevant page, or null if row was invalid
 * @usage _advanced_method_
 */
public static ByteBuffer positionAtRowHeader(RowState rowState, RowId rowId) throws IOException {
    ByteBuffer rowBuffer = rowState.setHeaderRow(rowId);

    if (rowState.isAtHeaderRow()) {
        // this task has already been accomplished
        return rowBuffer;
    }

    if (!rowState.isValid()) {
        // this was an invalid page/row
        rowState.setStatus(RowStateStatus.AT_HEADER);
        return null;
    }

    // note, we don't use findRowStart here cause we need the unmasked value
    short rowStart = rowBuffer
            .getShort(getRowStartOffset(rowId.getRowNumber(), rowState.getTable().getFormat()));

    // check the deleted, overflow flags for the row (the "real" flags are
    // always set on the header row)
    RowStatus rowStatus = RowStatus.NORMAL;
    if (isDeletedRow(rowStart)) {
        rowStatus = RowStatus.DELETED;
    } else if (isOverflowRow(rowStart)) {
        rowStatus = RowStatus.OVERFLOW;
    }

    rowState.setRowStatus(rowStatus);
    rowState.setStatus(RowStateStatus.AT_HEADER);
    return rowBuffer;
}

From source file:edu.mbl.jif.imaging.mmtiff.MultipageTiffReader.java

private TaggedImage readTaggedImage(IFDData data) throws IOException {
    ByteBuffer pixelBuffer = ByteBuffer.allocate((int) data.bytesPerImage);
    ByteBuffer mdBuffer = ByteBuffer.allocate((int) data.mdLength);
    fileChannel_.read(pixelBuffer, data.pixelOffset);
    fileChannel_.read(mdBuffer, data.mdOffset);
    JSONObject md = null;//from   w ww .  j  a  v  a 2s  .c om
    try {
        md = new JSONObject(getString(mdBuffer));
    } catch (JSONException ex) {
        ReportingUtils.logError("Error reading image metadata from file");
    }

    if (byteDepth_ == 0) {
        getRGBAndByteDepth(md);
    }

    if (rgb_) {
        if (byteDepth_ == 1) {
            byte[] pixels = new byte[(int) (4 * data.bytesPerImage / 3)];
            int i = 0;
            for (byte b : pixelBuffer.array()) {
                pixels[i] = b;
                i++;
                if ((i + 1) % 4 == 0) {
                    pixels[i] = 0;
                    i++;
                }
            }
            return new TaggedImage(pixels, md);
        } else {
            short[] pixels = new short[(int) (2 * (data.bytesPerImage / 3))];
            int i = 0;
            while (i < pixels.length) {
                pixels[i] = pixelBuffer.getShort(2 * ((i / 4) * 3 + (i % 4)));
                i++;
                if ((i + 1) % 4 == 0) {
                    pixels[i] = 0;
                    i++;
                }
            }
            return new TaggedImage(pixels, md);
        }
    } else {
        if (byteDepth_ == 1) {
            return new TaggedImage(pixelBuffer.array(), md);
        } else {
            short[] pix = new short[pixelBuffer.capacity() / 2];
            for (int i = 0; i < pix.length; i++) {
                pix[i] = pixelBuffer.getShort(i * 2);
            }
            return new TaggedImage(pix, md);
        }
    }
}

From source file:com.healthmarketscience.jackcess.Table.java

/**
 * Sets the position and limit in a new buffer using the given rowState
 * according to the given row number and row end, following overflow row
 * pointers as necessary./*from w w w .  j a v a2  s  .  c  o  m*/
 * 
 * @return a ByteBuffer narrowed to the actual row data, or null if row was
 *         invalid or deleted
 * @usage _advanced_method_
 */
public static ByteBuffer positionAtRowData(RowState rowState, RowId rowId) throws IOException {
    positionAtRowHeader(rowState, rowId);
    if (!rowState.isValid() || rowState.isDeleted()) {
        // row is invalid or deleted
        rowState.setStatus(RowStateStatus.AT_FINAL);
        return null;
    }

    ByteBuffer rowBuffer = rowState.getFinalPage();
    int rowNum = rowState.getFinalRowId().getRowNumber();
    JetFormat format = rowState.getTable().getFormat();

    if (rowState.isAtFinalRow()) {
        // we've already found the final row data
        return PageChannel.narrowBuffer(rowBuffer, findRowStart(rowBuffer, rowNum, format),
                findRowEnd(rowBuffer, rowNum, format));
    }

    while (true) {

        // note, we don't use findRowStart here cause we need the unmasked value
        short rowStart = rowBuffer.getShort(getRowStartOffset(rowNum, format));
        short rowEnd = findRowEnd(rowBuffer, rowNum, format);

        // note, at this point we know the row is not deleted, so ignore any
        // subsequent deleted flags (as overflow rows are always marked deleted
        // anyway)
        boolean overflowRow = isOverflowRow(rowStart);

        // now, strip flags from rowStart offset
        rowStart = (short) (rowStart & OFFSET_MASK);

        if (overflowRow) {

            if ((rowEnd - rowStart) < 4) {
                throw new IOException("invalid overflow row info");
            }

            // Overflow page.  the "row" data in the current page points to
            // another page/row
            int overflowRowNum = ByteUtil.getUnsignedByte(rowBuffer, rowStart);
            int overflowPageNum = ByteUtil.get3ByteInt(rowBuffer, rowStart + 1);
            rowBuffer = rowState.setOverflowRow(new RowId(overflowPageNum, overflowRowNum));
            rowNum = overflowRowNum;

        } else {

            rowState.setStatus(RowStateStatus.AT_FINAL);
            return PageChannel.narrowBuffer(rowBuffer, rowStart, rowEnd);
        }
    }
}

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * Sets a new buffer to the correct row header page using the given rowState
 * according to the given rowId.  Deleted state is
 * determined, but overflow row pointers are not followed.
 * //from  w  w w.  j  av a2 s  .  com
 * @return a ByteBuffer of the relevant page, or null if row was invalid
 * @usage _advanced_method_
 */
public static ByteBuffer positionAtRowHeader(RowState rowState, RowIdImpl rowId) throws IOException {
    ByteBuffer rowBuffer = rowState.setHeaderRow(rowId);

    if (rowState.isAtHeaderRow()) {
        // this task has already been accomplished
        return rowBuffer;
    }

    if (!rowState.isValid()) {
        // this was an invalid page/row
        rowState.setStatus(RowStateStatus.AT_HEADER);
        return null;
    }

    // note, we don't use findRowStart here cause we need the unmasked value
    short rowStart = rowBuffer
            .getShort(getRowStartOffset(rowId.getRowNumber(), rowState.getTable().getFormat()));

    // check the deleted, overflow flags for the row (the "real" flags are
    // always set on the header row)
    RowStatus rowStatus = RowStatus.NORMAL;
    if (isDeletedRow(rowStart)) {
        rowStatus = RowStatus.DELETED;
    } else if (isOverflowRow(rowStart)) {
        rowStatus = RowStatus.OVERFLOW;
    }

    rowState.setRowStatus(rowStatus);
    rowState.setStatus(RowStateStatus.AT_HEADER);
    return rowBuffer;
}

From source file:com.healthmarketscience.jackcess.impl.TableImpl.java

/**
 * Sets the position and limit in a new buffer using the given rowState
 * according to the given row number and row end, following overflow row
 * pointers as necessary.// w w  w . java2s .c o  m
 * 
 * @return a ByteBuffer narrowed to the actual row data, or null if row was
 *         invalid or deleted
 * @usage _advanced_method_
 */
public static ByteBuffer positionAtRowData(RowState rowState, RowIdImpl rowId) throws IOException {
    positionAtRowHeader(rowState, rowId);
    if (!rowState.isValid() || rowState.isDeleted()) {
        // row is invalid or deleted
        rowState.setStatus(RowStateStatus.AT_FINAL);
        return null;
    }

    ByteBuffer rowBuffer = rowState.getFinalPage();
    int rowNum = rowState.getFinalRowId().getRowNumber();
    JetFormat format = rowState.getTable().getFormat();

    if (rowState.isAtFinalRow()) {
        // we've already found the final row data
        return PageChannel.narrowBuffer(rowBuffer, findRowStart(rowBuffer, rowNum, format),
                findRowEnd(rowBuffer, rowNum, format));
    }

    while (true) {

        // note, we don't use findRowStart here cause we need the unmasked value
        short rowStart = rowBuffer.getShort(getRowStartOffset(rowNum, format));
        short rowEnd = findRowEnd(rowBuffer, rowNum, format);

        // note, at this point we know the row is not deleted, so ignore any
        // subsequent deleted flags (as overflow rows are always marked deleted
        // anyway)
        boolean overflowRow = isOverflowRow(rowStart);

        // now, strip flags from rowStart offset
        rowStart = (short) (rowStart & OFFSET_MASK);

        if (overflowRow) {

            if ((rowEnd - rowStart) < 4) {
                throw new IOException("invalid overflow row info");
            }

            // Overflow page.  the "row" data in the current page points to
            // another page/row
            int overflowRowNum = ByteUtil.getUnsignedByte(rowBuffer, rowStart);
            int overflowPageNum = ByteUtil.get3ByteInt(rowBuffer, rowStart + 1);
            rowBuffer = rowState.setOverflowRow(new RowIdImpl(overflowPageNum, overflowRowNum));
            rowNum = overflowRowNum;

        } else {

            rowState.setStatus(RowStateStatus.AT_FINAL);
            return PageChannel.narrowBuffer(rowBuffer, rowStart, rowEnd);
        }
    }
}