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Remove closure and inline dataset calls (see #2)

This commit is contained in:
mratsim 2018-02-28 10:44:27 +01:00
parent 4d1cc3a359
commit 833a26c8c7
1 changed files with 22 additions and 17 deletions
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39
src/proof_of_work.nim
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@ -139,11 +139,13 @@ proc calc_dataset*(full_size: Natural, cache: seq[Hash[512]]): seq[Hash[512]] {.
type HashimotoHash = tuple[mix_digest: Hash[256], value: Hash[256]]
type DatasetLookup = proc(i: Natural): Hash[512] {.noSideEffect.}
proc hashimoto(header: Hash[256],
template hashimoto(header: Hash[256],
nonce: uint64,
full_size: Natural,
dataset_lookup: DatasetLookup
): HashimotoHash {.noInit, noSideEffect.}=
dataset_lookup_p: untyped,
dataset_lookup_p1: untyped,
result: var HashimotoHash
) =
let
n = uint32 full_size div HASH_BYTES
w = uint32 MIX_BYTES div WORD_BYTES
@ -157,13 +159,14 @@ proc hashimoto(header: Hash[256],
let s_bytes = cast[ptr array[64, byte]](addr s) # Alias for to interpret s as a byte array
let s_words = cast[ptr array[16, uint32]](addr s) # Alias for to interpret s as an uint32 array
s_bytes[0..<32] = header.data # We first populate the first 40 bytes of s with the concatenation
s_bytes[][0..<32] = header.data # We first populate the first 40 bytes of s with the concatenation
# In template we need to dereference first otherwise it's not considered as var
var nonceLE{.noInit.}: array[8, byte] # the nonce should be concatenated with its LITTLE ENDIAN representation
littleEndian64(addr nonceLE, unsafeAddr nonce)
s_bytes[32..<40] = cast[array[8,byte]](nonceLE)
s_bytes[][32..<40] = cast[array[8,byte]](nonceLE)
s = keccak_512 s_bytes[0..<40] # TODO: Does this allocate a seq?
s = keccak_512 s_bytes[][0..<40] # TODO: Does this allocate a seq?
# start the mix with replicated s
assert MIX_BYTES div HASH_BYTES == 2
@ -173,12 +176,13 @@ proc hashimoto(header: Hash[256],
# mix in random dataset nodes
for i in 0'u32 ..< ACCESSES:
let p = fnv(i xor s_words[0], mix[i mod w]) mod (n div mixhashes) * mixhashes
let p{.inject.} = fnv(i xor s_words[0], mix[i mod w]) mod (n div mixhashes) * mixhashes
let p1{.inject.} = p + 1
# Unrolled: for j in range(MIX_BYTES / HASH_BYTES): => for j in 0 ..< 2
var newdata{.noInit.}: type mix
newdata[0..<16] = cast[array[16, uint32]](dataset_lookup(p))
newdata[16..<32] = cast[array[16, uint32]](dataset_lookup(p+1))
newdata[0..<16] = cast[array[16, uint32]](dataset_lookup_p)
newdata[16..<32] = cast[array[16, uint32]](dataset_lookup_p1)
mix = zipMap(mix, newdata, fnv(x, y))
@ -197,26 +201,27 @@ proc hashimoto(header: Hash[256],
result.value = keccak_256(concat)
proc hashimoto_light*(full_size:Natural, cache: seq[Hash[512]],
header: Hash[256], nonce: uint64): HashimotoHash {.noSideEffect, inline.} =
header: Hash[256], nonce: uint64): HashimotoHash {.noSideEffect.} =
let light: DatasetLookup = proc(x: Natural): Hash[512] = calc_data_set_item(cache, x)
hashimoto(header,
nonce,
full_size,
light)
calc_data_set_item(cache, p),
calc_data_set_item(cache, p1),
result)
proc hashimoto_full*(full_size:Natural, dataset: seq[Hash[512]],
header: Hash[256], nonce: uint64): HashimotoHash {.noSideEffect, inline.} =
header: Hash[256], nonce: uint64): HashimotoHash {.noSideEffect.} =
# TODO spec mentions full_size but I don't think we need it (retrieve it from dataset.len)
let full: DatasetLookup = proc(x: Natural): Hash[512] = dataset[x]
hashimoto(header,
nonce,
full_size,
full)
dataset[int(p)],
dataset[int(p1)],
result)
# ###############################################################################
# Defining the seed hash
proc get_seedhash*(block_number: uint64): Hash[256] {.noSideEffect.} =
for i in 0 ..< int(block_number div EPOCH_LENGTH):
result = keccak256 result.data
result = keccak256 result.data