6d17442380
- Changed operations to take only two arguments - No more hacks regarding log argument sizes - Set pageid = INVALID_PAGE if you want a logical operation - Ported operation implementations to new api; exposed + fixed a number of concurrency bugs - More fixes to prepare - Fixed to nested top actions - More coherent operations api / recovery implmentation - TnaiveHash* and Tinstant* are (and were already) broken, and are set for removal - Removed some instances of fail_unless - Fixed design flaws in blob implementation. - New naming convention for operation callback functions.
76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
#ifndef __BLOB_MANAGER_H
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#define __BLOB_MANAGER_H
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#include <stasis/common.h>
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#include <stasis/page.h>
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BEGIN_C_DECLS
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/**
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@file
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blobManager - Provides blob handling.
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Plan for modularity: Exactly one blob manager per storeFile.
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Alternatively, we could use the bufferManager's record length
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field to allow for more than one blob manager per buffer
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manager. (Right now, this field is set to a special value for
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blobs; thie could be extended for other types of records.)
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Blob manager interacts with page manger via page manager's
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public api.
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Blob updates work as follows:
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(1) A transaction obtains an exclusive write lock on a blob
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(not implemented yet.)
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(2) When it requests a write, the blob it writes to is added to
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a data structure that lists all dirty blobs by transaction,
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and the page containing the blob entry is updated. (The fd
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bit in the record is flipped, and the LSN is updated.) The
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write to the blob store is not flushed to disk.
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(3) All subsequent writes to the same blob just update the
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backing file.
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(4) On commit and rollback, the data structure containing the xid's
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dirty blobs is destroyed.
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(5) recovery2.c handles the restoration of the fd bits using
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physical logging (this is automatic, since we use Tset()
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calls to update the records.)
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@todo Set range??
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@todo Update blobManager to (partially) provide a page api
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@todo Move blobManager to page and/or operations directory
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@ingroup LLADD_CORE
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*/
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/**
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Read the blob from the recordid rid into buf.
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*/
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void readBlob(int xid, Page * p, recordid rid, void * buf);
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/**
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Write the contents of buf to the blob in recordid rid.
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*/
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void writeBlob(int xid, Page * p, recordid rid, const void * buf);
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compensated_function recordid preAllocBlob(int xid, long blobsize);
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compensated_function recordid preAllocBlobFromPage(int xid, long page, long blobsize);
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/**
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Allocate a blob of size blobSize.
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*/
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void allocBlob(int xid, recordid rid);
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page_impl blobImpl();
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END_C_DECLS
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#endif
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