ndt.h

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#ifndef NDNDPDK_NDT_NDT_H
#define NDNDPDK_NDT_NDT_H

 
#include "../ndni/name.h"

typedef struct Ndt {
  uint64_t indexMask;
  uint64_t sampleMask;
  uint16_t prefixLen;
  _Atomic uint8_t table[];
} Ndt;

__attribute__((returns_nonnull)) Ndt*
Ndt_New(uint64_t nEntries, int numaSocket);

__attribute__((nonnull)) static inline void
Ndt_Update(Ndt* ndt, uint64_t index, uint8_t value) {
  atomic_store_explicit(&ndt->table[index], value, memory_order_relaxed);
}

__attribute__((nonnull)) static __rte_always_inline uint8_t
Ndt_Read(Ndt* ndt, uint64_t index) {
  return atomic_load_explicit(&ndt->table[index], memory_order_relaxed);
}

__attribute__((nonnull)) static inline uint8_t
Ndt_Lookup(Ndt* ndt, const PName* name, uint64_t* index) {
  uint16_t prefixLen = RTE_MIN(name->nComps, ndt->prefixLen);
  LName prefix = PName_GetPrefix(name, prefixLen);
  // compute hash in 'uncached' mode, to reduce workload of FwInput thread
  uint64_t hash = LName_ComputeHash(prefix);
  *index = hash & ndt->indexMask;
  return Ndt_Read(ndt, *index);
}

typedef struct NdtQuerier {
  Ndt* ndt;
  uint64_t nLookups;
  uint32_t* nHits;
} NdtQuerier;

__attribute__((nonnull)) static inline uint8_t
NdtQuerier_Lookup(NdtQuerier* ndq, const PName* name) {
  uint64_t index;
  uint8_t value = Ndt_Lookup(ndq->ndt, name, &index);
  if ((++ndq->nLookups & ndq->ndt->sampleMask) == 0) {
    ++ndq->nHits[index];
  }
  return value;
}
 
#endif // NDNDPDK_NDT_NDT_H