org.apache.ignite.internal.pagemem.store

Interface PageStore

All Known Implementing Classes:

FilePageStore, FilePageStoreV2

public interface PageStore

Persistent store of pages.

Method Summary

Modifier and Type	Method and Description
long	allocatePage() Allocates next page index.
void	ensure()
boolean	exists() Checks if page exists.
long	pageOffset(long pageId) Gets page offset within the store file.
int	pages() Gets number of allocated pages.
void	read(long pageId, ByteBuffer pageBuf, boolean keepCrc) Reads a page.
void	readHeader(ByteBuffer buf) Reads a header.
void	sync() Sync method used to ensure that the given pages are guaranteed to be written to the store.
int	version()
void	write(long pageId, ByteBuffer pageBuf, int tag, boolean calculateCrc) Writes a page.

Method Detail

exists

boolean exists()

Checks if page exists.

Returns:

True if page exists.

allocatePage

long allocatePage()
           throws IgniteCheckedException

Allocates next page index.

Returns:

Next page index.

Throws:

IgniteCheckedException - If failed to allocate.

pages

int pages()

Gets number of allocated pages.

Returns:

Number of allocated pages.

read

void read(long pageId,
          ByteBuffer pageBuf,
          boolean keepCrc)
   throws IgniteCheckedException

Reads a page.

Parameters:

pageId - Page ID.

pageBuf - Page buffer to read into.

keepCrc - by default reading zeroes CRC which was on file, but you can keep it in pageBuf if set keepCrc

Throws:

IgniteCheckedException - If reading failed (IO error occurred).

readHeader

void readHeader(ByteBuffer buf)
         throws IgniteCheckedException

Reads a header.

Parameters:

buf - Buffer to write to.

Throws:

IgniteCheckedException - If failed.

write

void write(long pageId,
           ByteBuffer pageBuf,
           int tag,
           boolean calculateCrc)
    throws IgniteCheckedException

Writes a page.

Parameters:

pageId - Page ID.

pageBuf - Page buffer to write.

tag - Partition file version, 1-based incrementing counter. For outdated pages tag has lower value, and write does nothing.

calculateCrc - if False crc calculation will be forcibly skipped.

Throws:

IgniteCheckedException - If page writing failed (IO error occurred).

pageOffset

long pageOffset(long pageId)

Gets page offset within the store file.

Parameters:

pageId - Page ID.

Returns:

Page offset.

sync

void sync()
   throws IgniteCheckedException

Sync method used to ensure that the given pages are guaranteed to be written to the store.

Throws:

IgniteCheckedException - If sync failed (IO error occurred).

ensure

void ensure()
     throws IgniteCheckedException

Throws:

IgniteCheckedException - If sync failed (IO error occurred).

version

int version()

Returns:

Page store version.