This optimization changes the index.TermFieldReader.Next() interface
API, adding an optional, pre-allocated *TermFieldDoc parameter, which
can help prevent garbage creation.
Before this change, upside down's reader would alloc a new
TermFrequencyRow on every Next(), which would be immediately
transformed into an index.TermFieldDoc{}. This change reuses a
pre-allocated TermFrequencyRow that's a field in the reader.
From some bleve-query perf profiling, term field vectors appeared to
be alloc'ed, which was unnecessary as term field vectors are disabled
in the bleve-blast/bleve-query tests.
Currently bleve batch is build by user goroutine
Then read by bleve gourinte
This is still safe when used correctly
However, Reset() will modify the map, which is now a data race
This fix is to simply make batch.Reset() alloc new maps.
This provides a data-access pattern that can be used safely.
Also, this thread argues that creating a new map may be faster
than trying to reuse an existing one:
https://groups.google.com/d/msg/golang-nuts/UvUm3LA1u8g/jGv_FobNpN0J
Separate but related, I have opted to remove the "unsafe batch"
checking that we did. This was always limited anyway, and now
users of Go 1.6 are just as likely to get a panic from the
runtime for concurrent map access anyway. So, the price paid
by us (additional mutex) is not worth it.
fixes#360 and #260
several data structures had a pointer at the start of the struct
on some 32-bit systems, this causes the remaining fields no longer
be aligned on 64-bit boundaries
the fix identifed by @pmezard is to put the counters first in the
struct, which guarantees correct alignment
fixes#359
The moss RegistryCollectionOptions allows applications to register
moss-related callback API functions and other advanced feature usage
at process initialization time.
For example, this could be used for moss's OnError(), OnEvent() and
logging callback options.
This is somewhat unlikely, but if a term is (incredibly) popular, its
uvarint count value representation might go beyond 8 bytes.
Some KVStore implementations (like forestdb) provide a BatchEx cgo
optimization that depends on proper preallocated counting, so this
change provides a proper worst-case estimate based on the max-unvarint
of 10 bytes instead of the previously incorrect 8 bytes.
Performance optimization. Before this change, by using Merge()
instead of AllocMerge(), moss's internal batch buf's would be
wastefully, dramatically grown during append()'s to a mis-sized buf.
