PARQUET-862: Provide defaut cache size values

This patch allows to port parquet-cpp on non-intel architectures
and/or linux/unix flavors where CPU info is different or not
available. Tested on Alpinelinux (musl libc).

Author: Marc Vertes <mvertes@free.fr>

Closes apache#234 from mvertes/master and squashes the following commits:

1b087be [Marc Vertes] PARQUET-862: Provide defaut cache size values

Change-Id: I600915833d8f942f96e2cf38240493709c95b28c

cpp/src/parquet/util/cpu-info.cc

@@ -129,11 +129,18 @@ void CpuInfo::Init() {
   for (size_t i = 0; i < 3; ++i) {
     cache_sizes_[i] = data[i];
   }
+#else
+#ifndef _SC_LEVEL1_DCACHE_SIZE
+  // Provide reasonable default values if no info
+  cache_sizes_[0] = 32 * 1024;   // Level 1: 32k
+  cache_sizes_[1] = 256 * 1024;  // Level 2: 256k
+  cache_sizes_[2] = 3072 * 1024; // Level 3: 3M
 #else
   // Call sysconf to query for the cache sizes
   cache_sizes_[0] = sysconf(_SC_LEVEL1_DCACHE_SIZE);
   cache_sizes_[1] = sysconf(_SC_LEVEL2_CACHE_SIZE);
   cache_sizes_[2] = sysconf(_SC_LEVEL3_CACHE_SIZE);
+#endif
 #endif
 
   if (max_mhz != 0) {