Add relative_performance

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 20 insertions, 0 deletions

diff --git a/libhashsum_init_keccak__.c b/libhashsum_init_keccak__.c
index f9c8be1..53a9e52 100644
--- a/libhashsum_init_keccak__.c
+++ b/libhashsum_init_keccak__.c
@@ -140,6 +140,25 @@ destroy(struct libhashsum_hasher *this)
 }
 
 
+static uint64_t
+estimate_performance(long int r, long int c)
+{
+	uint64_t base = 22517998136852480ULL / (uint64_t)r;
+	switch (r + c) {
+	case 1600:
+		return base / 368ULL;
+	case 800:
+		return base / 2042ULL;
+	case 400:
+		return base / 1858ULL;
+	case 200:
+		return base / 1747ULL;
+	default:
+		return 0;
+	}
+}
+
+
 int
 libhashsum_init_keccak__(struct libhashsum_hasher *this, size_t hashbits, void *spec_, size_t squeezes, const char *suffix)
 {
@@ -170,6 +189,7 @@ libhashsum_init_keccak__(struct libhashsum_hasher *this, size_t hashbits, void *
 	}
 
 	this->input_block_size = libkeccak_zerocopy_chunksize(&this->state.keccak.s);
+	this->relative_performance = estimate_performance(spec->bitrate, spec->capacity);
 	this->process = &process;
 	this->finalise_const = &finalise_const;
 	this->finalise = &finalise;