これらのキャッシュの目的については、githubページを参照してください。
GEOIP_STANDARD - Read database from file system. This uses the least memory.
GEOIP_MEMORY_CACHE - Load database into memory. Provides faster performance but uses more memory.
GEOIP_CHECK_CACHE - Check for updated database. If database has been updated, reload file handle and/or memory cache.
GEOIP_INDEX_CACHE - Cache only the the most frequently accessed index portion of the database, resulting in faster lookups than GEOIP_STANDARD, but less memory usage than GEOIP_MEMORY_CACHE. This is useful for larger databases such as GeoIP Organization and GeoIP City. Note: for GeoIP Country, Region and Netspeed databases, GEOIP_INDEX_CACHE is equivalent to GEOIP_MEMORY_CACHE.
GEOIP_MMAP_CACHE - Load database into mmap shared memory. MMAP is not available for 32bit Windows.
これらのオプションは、ビット演算子を使用して組み合わせることができます。たとえば、電話番号: GeoIP_open( "/ path/to/GeoIP.dat"、GEOIP_MEMORY_CACHE | GEOIP_CHECK_CACHE)を呼び出して、GEOIP_MEMORY_CACHEとGEOIP_CHECK_CACHEの両方を使用できます。
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