Get the maximum memory size available for the GDAL block cache

get_cache_max() returns the maximum amount of memory available to the GDALRasterBlock caching system for caching raster read/write data. Wrapper of GDALGetCacheMax64() with return value in MB by default.

Usage

get_cache_max(units = "MB")

Arguments

units

Character string specifying units for the return value. One of "MB" (the default), "GB", "KB" or "bytes" (values of "byte", "B" and empty string "" are also recognized to mean bytes).

Value

A numeric value carrying the integer64 class attribute. Maximum cache memory available in the requested units.

Details

The first time this function is called, it will read the GDAL_CACHEMAX configuration option to initialize the maximum cache memory. The value of the configuration option can be expressed as x% of the usable physical RAM (which may potentially be used by other processes). Otherwise it is expected to be a value in MB. As of GDAL 3.10, the default value, if GDAL_CACHEMAX has not been set explicitly, is 5% of usable physical RAM.

Note

The value of the GDAL_CACHEMAX configuration option is only consulted the first time the cache size is requested (i.e., it must be set as a configuration option prior to any raster I/O during the current session). To change this value programmatically during operation of the program it is better to use set_cache_max() (in which case, always given in bytes).

See also

GDAL_CACHEMAX configuration option

get_config_option(), set_config_option(), get_usable_physical_ram(), get_cache_used(), set_cache_max()

Examples

get_cache_max()
#> integer64
#> [1] 838