XOY-Leveldb

作者：谢瑞阳 10225101483 徐翔宇 10225101535

gabor@google.com ccf0fcd5c2 A number of smaller fixes and performance improvements: - Implemented Get() directly instead of building on top of a full merging iterator stack. This speeds up the "readrandom" benchmark by up to 15-30%. - Fixed an opensource compilation problem. Added --db=<name> flag to control where the database is placed. - Automatically compact a file when we have done enough overlapping seeks to that file. - Fixed a performance bug where we would read from at least one file in a level even if none of the files overlapped the key being read. - Makefile fix for Mac OSX installations that have XCode 4 without XCode 3. - Unified the two occurrences of binary search in a file-list into one routine. - Found and fixed a bug where we would unnecessarily search the last file when looking for a key larger than all data in the level. - A fix to avoid the need for trivial move compactions and therefore gets rid of two out of five syncs in "fillseq". - Removed the MANIFEST file write when switching to a new memtable/log-file for a 10-20% improvement on fill speed on ext4. - Adding a SNAPPY setting in the Makefile for folks who have Snappy installed. Snappy compresses values and speeds up writes. git-svn-id: https://leveldb.googlecode.com/svn/trunk@32 62dab493-f737-651d-591e-8d6aee1b9529		vor 14 Jahren
..
block.cc	fix build on at least linux	vor 14 Jahren
block.h	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
block_builder.cc	sync with upstream @ 21409451	vor 14 Jahren
block_builder.h	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
format.cc	@20776309	vor 14 Jahren
format.h	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
iterator.cc	Update from upstream @21551990	vor 14 Jahren
iterator_wrapper.h	sync with upstream @21627589	vor 14 Jahren
merger.cc	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
merger.h	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
table.cc	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
table_builder.cc	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
table_test.cc	A number of smaller fixes and performance improvements:	vor 14 Jahren
two_level_iterator.cc	reverting disastrous MOE commit, returning to r21	vor 14 Jahren
two_level_iterator.h	reverting disastrous MOE commit, returning to r21	vor 14 Jahren