SegmentAllocationNode Struct Reference

SegmentAllocationNode is the allocation map for a run of extents in a RandomAllocationSegmentBase. More...

#include <RandomAllocationSegmentBaseImpl.h>

Inheritance diagram for SegmentAllocationNode:


Public Member Functions
ExtentEntry &	getExtentEntry (uint i)
ExtentEntry const &	getExtentEntry (uint i) const
Public Attributes
BlockNum	nPagesPerExtent
	Number of pages in one extent, including the extent allocation node itself (so actual data capacity per extent is one less).
PageId	nextSegAllocPageId
	Forward link to the next SegmentAllocationNode, or NULL_PAGE_ID for the last one.
uint	nExtents
	Number of extents mapped by this node.
MagicNumber	magicNumber
	Magic number identifying the derived StoredNode class.
Static Public Attributes
static const MagicNumber	MAGIC_NUMBER = 0xa3db80b98208bfd4LL
Classes
struct	ExtentEntry
	Allocation status for a single extent mapped by this node. More...

Detailed Description

SegmentAllocationNode is the allocation map for a run of extents in a RandomAllocationSegmentBase.

Definition at line 44 of file RandomAllocationSegmentBaseImpl.h.

Member Function Documentation

ExtentEntry& SegmentAllocationNode::getExtentEntry ( uint i ) [inline]

Definition at line 84 of file RandomAllocationSegmentBaseImpl.h.

00085     {
00086         assert(i < nExtents);
00087         return reinterpret_cast<ExtentEntry *>(this+1)[i];
00088     }

ExtentEntry const& SegmentAllocationNode::getExtentEntry ( uint i ) const [inline]

Definition at line 90 of file RandomAllocationSegmentBaseImpl.h.

00091     {
00092         assert(i < nExtents);
00093         return reinterpret_cast<ExtentEntry const *>(this+1)[i];
00094     }

Member Data Documentation

const MagicNumber SegmentAllocationNode::MAGIC_NUMBER = 0xa3db80b98208bfd4LL [static]

Definition at line 47 of file RandomAllocationSegmentBaseImpl.h.

BlockNum SegmentAllocationNode::nPagesPerExtent

Number of pages in one extent, including the extent allocation node itself (so actual data capacity per extent is one less).

This is redundant across all SegmentAllocationNodes in the same RandomAllocationSegment.

Definition at line 67 of file RandomAllocationSegmentBaseImpl.h.

Referenced by VersionedRandomAllocationSegment::allocateAllocNodes(), RandomAllocationSegmentBase::allocatePageIdFromSegment(), and RandomAllocationSegmentBase::format().

PageId SegmentAllocationNode::nextSegAllocPageId

Forward link to the next SegmentAllocationNode, or NULL_PAGE_ID for the last one.

This is mostly redundant, since the PageId's of SegmentAllocationNodes can always be computed. However, it is not completely redundant since it marks the last node (rather than inferring it from the underlying segment size, which may be unreliable after recovery).

Definition at line 77 of file RandomAllocationSegmentBaseImpl.h.

Referenced by VersionedRandomAllocationSegment::allocateAllocNodes(), RandomAllocationSegmentBase::allocatePageIdFromSegment(), VersionedRandomAllocationSegment::backupAllocationNodes(), RandomAllocationSegmentBase::format(), VersionedRandomAllocationSegment::getOldPageIds(), VersionedRandomAllocationSegment::locateDataPages(), VersionedRandomAllocationSegment::restoreFromBackup(), and RandomAllocationSegmentBase::tallySegAllocNodePages().