Limit train samples (#2809)

* Limit training samples size to 2GB

* simplified DISPLAYLEVEL() macro to use global vqriable instead of local.

* refactored training samples loading

* fixed compiler warning

* addressed comments from the pull request

* addressed @terrelln comments

* missed some fixes

* fixed type mismatch

* Fixed bug passing estimated number of samples rather insted of the loaded number of samples.
Changed unit conversion not to use bit-shifts.

* fixed a declaration after code

* fixed type conversion compile errors

* fixed more type castting

* fixed more type mismatching

* changed sizes type to size_t

* move type casting

* more type cast fixes

lib/dictBuilder/cover.c

@@ -40,6 +40,13 @@
 /*-*************************************
 *  Constants
 ***************************************/
+/**
+* There are 32bit indexes used to ref samples, so limit samples size to 4GB
+* on 64bit builds.
+* For 32bit builds we choose 1 GB.
+* Most 32bit platforms have 2GB user-mode addressable space and we allocate a large
+* contiguous buffer, so 1GB is already a high limit.
+*/
 #define COVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
 #define COVER_DEFAULT_SPLITPOINT 1.0
 

lib/dictBuilder/fastcover.c

@@ -32,6 +32,13 @@
 /*-*************************************
 *  Constants
 ***************************************/
+/**
+* There are 32bit indexes used to ref samples, so limit samples size to 4GB
+* on 64bit builds.
+* For 32bit builds we choose 1 GB.
+* Most 32bit platforms have 2GB user-mode addressable space and we allocate a large
+* contiguous buffer, so 1GB is already a high limit.
+*/
 #define FASTCOVER_MAX_SAMPLES_SIZE (sizeof(size_t) == 8 ? ((unsigned)-1) : ((unsigned)1 GB))
 #define FASTCOVER_MAX_F 31
 #define FASTCOVER_MAX_ACCEL 10