redesign for better IO performance
enhanced database seek-time by avoiding write operations at distant
positions of a database file. until now, a USEDC counter was written
at the head-section of a kelondroRecords database file (which is the
basic data structure of all kelondro database files) to store the
actual number of records that are contained in the database. Now, this
value is computed from the database file size. This is either done
only once at start-time, or continuously when run in asserts enabled.
The counter is then updated only in RAM, and written at close of the
file. If the close fails, the correct number can be computed from the
file size, and if this is not equal to the stored number it is a strong
evidence that YaCY was not shut down properly.
To preserve consistency, the complete storage-routine had to be re-written.
Another change enhances read of nodes in some cases, where the data-tail
can be read together with the data-head. This saves another IO lookup during
each DB node fetch.
Includes also many small bugfixes.
IF ANYTHING GOES WRONG, ALL YOUR DATA IS LOST: PLEASE MAKE A BACK-UP
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@3375 6c8d7289-2bf4-0310-a012-ef5d649a1542
- generalized object caching and added new object caching class
- added object caching wherever kelondroTree was used
- added object caching also to usage of kelondroFlex
- added object buffering (a write cache) to NURLs
- added many assert statements; fixed bugs here and there
- added missing close methods to latest added classes
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2858 6c8d7289-2bf4-0310-a012-ef5d649a1542
- added new image 'B' in front of search results for bookmark generation
- added news generation when a public bookmark is added
- the '+' in front of search results has new meaning: positive rating for that result
- added news generation when a '+' is hit
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2613 6c8d7289-2bf4-0310-a012-ef5d649a1542
indexContainers from RAM must be cloned explicitely to prevent
side-effects on stored indexContainer objects in Cache
* changed behaviour of urlReference deletion from indexContainers:
deletion does not user retrieval of all Elements from the assortments
* added textual configuration of kelondroRow and kelondroColumn definition
* update of kelondroRow usage in yacyNews
* modified kelondroAttrSeq to use modified kelondroColumn parser
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2339 6c8d7289-2bf4-0310-a012-ef5d649a1542
this was done because testing showed that cache-delete operations
slowed down record access most, even more that actual IO operations.
Cache-delete operations appeared when entries were shifted from low-priority
positions to high-priority positions. During a fill of x entries to a database,
x/2 delete situation happen which caused two or more delete operations.
removing the cache control means that these delete operations are not
necessary any more, but it is more difficult to decide which cache elements
shall be removed in case that the cache is full. There is not yet a stable
solution for this case, but the advantage of a faster cache is more important
that the flush problem.
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@2244 6c8d7289-2bf4-0310-a012-ef5d649a1542
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