Package org.apache.ignite.internal.processors.cache.persistence.tree.io

Class PageIO

  • Direct Known Subclasses:
    AbstractDataPageIO, BPlusIO, BPlusMetaIO, PageMetaIO, PagePartitionCountersIO, PagesListMetaIO, PagesListNodeIO, TrackingPageIO
    public abstract class PageIO
extends Object
    Base format for all the page types. Checklist for page IO implementations and usage (The Rules): 1. IO should not have any `public static` methods. We have versioned IOs and any static method will mean that it have to always work in backward compatible way between all the IO versions. The base class PageIO has static methods (like {@link #getPageId(long)}) intentionally: this base format can not be changed between versions. 2. IO must correctly override initNewPage(long, long, int, PageMetrics) method and call super. We have logic that relies on this behavior. 3. Page IO type ID constant must be declared in this class to have a list of all the existing IO types in a single place. 4. IO must be added to getBPlusIO(int, int) or to getPageIO(int, int). 5. Always keep in mind that IOs are versioned and their format can change from version to version. In this respect it is a good practice to avoid exposing details of IO internal format on it's API. The API should be minimalistic and abstract, so that internal format in future IO version can be completely changed without any changes to the API of this page IO. 6. Page IO API should not have any version dependent semantics and should not change API semantics in newer versions. 7. It is almost always preferable to read or write (especially write) page contents using static methods on PageHandler. To just initialize new page use PageHandler.initPage(PageMemory, int, long, PageIO, IgniteWriteAheadLogManager, PageLockListener, IoStatisticsHolder) method with needed IO instance.

    • Constructor Detail

      • PageIO

        protected PageIO​(int type,
                 int ver)
        Parameters:
        type - Page type.
        ver - Page format version.

    • Method Detail

      • getType

        public static int getType​(ByteBuffer buf)
        Parameters:
        buf - Buffer.
        Returns:
        Page type.

      • getType

        public static int getType​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Page type.

      • setType

        public static void setType​(long pageAddr,
                           int type)
        Parameters:
        pageAddr - Page address.
        type - Type.

      • getVersion

        public static int getVersion​(ByteBuffer buf)
        Parameters:
        buf - Buffer.
        Returns:
        Version.

      • getVersion

        public static int getVersion​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Version.

      • setVersion

        protected static void setVersion​(long pageAddr,
                                 int ver)
        Parameters:
        pageAddr - Page address.
        ver - Version.

      • getPageId

        public static long getPageId​(ByteBuffer buf)
        Parameters:
        buf - Buffer.
        Returns:
        Page ID.

      • getPageId

        public static long getPageId​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Page ID.

      • setPageId

        public static void setPageId​(long pageAddr,
                             long pageId)
        Parameters:
        pageAddr - Page address.
        pageId - Page ID.

      • getRotatedIdPart

        public static int getRotatedIdPart​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Rotated page ID part.

      • setRotatedIdPart

        public static void setRotatedIdPart​(long pageAddr,
                                    int rotatedIdPart)
        Parameters:
        pageAddr - Page address.
        rotatedIdPart - Rotated page ID part.

      • setCompressionType

        public static void setCompressionType​(ByteBuffer page,
                                      byte compressType)
        Parameters:
        page - Page buffer.
        compressType - Compression type.

      • getCompressionType

        public static byte getCompressionType​(ByteBuffer page)
        Parameters:
        page - Page buffer.
        Returns:
        Compression type.

      • getCompressionType

        public static byte getCompressionType​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Compression type.

      • setCompressedSize

        public static void setCompressedSize​(ByteBuffer page,
                                     short compressedSize)
        Parameters:
        page - Page buffer.
        compressedSize - Compressed size.

      • getCompressedSize

        public static short getCompressedSize​(ByteBuffer page)
        Parameters:
        page - Page buffer.
        Returns:
        Compressed size.

      • getCompressedSize

        public static short getCompressedSize​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Compressed size.

      • setCompactedSize

        public static void setCompactedSize​(ByteBuffer page,
                                    short compactedSize)
        Parameters:
        page - Page buffer.
        compactedSize - Compacted size.

      • getCompactedSize

        public static short getCompactedSize​(ByteBuffer page)
        Parameters:
        page - Page buffer.
        Returns:
        Compacted size.

      • getCompactedSize

        public static short getCompactedSize​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Compacted size.

      • getCrc

        public static int getCrc​(long pageAddr)
        Parameters:
        pageAddr - Page address.
        Returns:
        Checksum.

      • setCrc

        public static void setCrc​(long pageAddr,
                          int crc)
        Parameters:
        pageAddr - Page address.
        crc - Checksum.

      • getCrc

        public static int getCrc​(ByteBuffer buf)
        Parameters:
        buf - Buffer.
        Returns:
        Checksum.

      • setCrc

        public static void setCrc​(ByteBuffer buf,
                          int crc)
        Parameters:
        buf - Buffer.
        crc - Checksum.

      • registerH2

        public static void registerH2​(IOVersions<? extends BPlusInnerIO<?>> innerIOs,
                              IOVersions<? extends BPlusLeafIO<?>> leafIOs)
        Registers this B+Tree IO versions.
        Parameters:
        innerIOs - Inner IO versions.
        leafIOs - Leaf IO versions.

      • registerH2ExtraInner

        public static void registerH2ExtraInner​(IOVersions<? extends BPlusInnerIO<?>> innerExtIOs)
        Registers extra inner IO versions.
        Parameters:
        innerExtIOs - Extra versions.

      • registerH2ExtraLeaf

        public static void registerH2ExtraLeaf​(IOVersions<? extends BPlusLeafIO<?>> leafExtIOs)
        Registers extra inner IO versions.
        Parameters:
        leafExtIOs - Extra versions.

      • getInnerVersions

        public static IOVersions<? extends BPlusInnerIO<?>> getInnerVersions​(int idx)
        Parameters:
        idx - Index.
        Returns:
        IOVersions for given idx.

      • getLeafVersions

        public static IOVersions<? extends BPlusLeafIO<?>> getLeafVersions​(int idx)
        Parameters:
        idx - Index.
        Returns:
        IOVersions for given idx.

      • registerTest

        public static void registerTest​(BPlusInnerIO<?> innerIO,
                                BPlusLeafIO<?> leafIO)
        Registers IOs for testing.
        Parameters:
        innerIO - Inner IO.
        leafIO - Leaf IO.

      • registerTest

        public static void registerTest​(PageIO io)
        Registers IO for testing.
        Parameters:
        io - Page IO.

      • getType

        public final int getType()
        Returns:
        Type.

      • getVersion

        public final int getVersion()
        Returns:
        Version.

      • initNewPage

        public void initNewPage​(long pageAddr,
                        long pageId,
                        int pageSize,
                        @Nullable
                        @Nullable PageMetrics metrics)
        Parameters:
        pageAddr - Page address.
        pageId - Page ID.
        pageSize - Page size.
        metrics - Page metrics for tracking page allocation. Can be null if no tracking is required.
        See Also:
        EncryptionSpi.encryptedSize(int)

      • isIndexPage

        public static boolean isIndexPage​(int pageType)
        Returns true if the given page type is related to SQL index data pages.
        Parameters:
        pageType - Page type (can be obtained by getType(long) or getType(ByteBuffer) methods).

      • getBPlusIO

        public static <Q extends BPlusIO<?>> Q getBPlusIO​(int type,
                                                  int ver)
                                           throws IgniteCheckedException
        Parameters:
        type - IO Type.
        ver - IO Version.
        Returns:
        IO for either inner or leaf B+Tree page.
        Throws:
        IgniteCheckedException - If failed.

      • deriveIndexPageType

        public static IndexPageType deriveIndexPageType​(long pageAddr)
        Parameters:
        pageAddr - Address of page.
        Returns:
        Index page type.

      • isDataPageType

        public static boolean isDataPageType​(int type)
        Parameters:
        type - Type to test.
        Returns:
        True if data page.

      • getFreeSpace

        public abstract int getFreeSpace​(int pageSize,
                                 long pageAddr)
        Count of bytes that is currently free in this page and possibly can be used to place additional payload.
        Parameters:
        pageSize - Page size.
        pageAddr - Page address.
        Returns:
        Free space.

      • copyPage

        protected final void copyPage​(ByteBuffer page,
                              ByteBuffer out,
                              int pageSize)
        Parameters:
        page - Page.
        out - Output buffer.
        pageSize - Page size.

      • printPage

        public static String printPage​(long addr,
                               int pageSize)
        Parameters:
        addr - Address.

      • assertPageType

        protected final void assertPageType​(long pageAddr)
        Asserts that page type of the page stored at pageAddr matches page type of this PageIO.
        Parameters:
        pageAddr - address of a page to use for assertion

      • assertPageType

        protected final void assertPageType​(ByteBuffer buf)
        Asserts that page type of the page stored in the given buffer matches page type of this PageIO.
        Parameters:
        buf - buffer where the page for assertion is stored