proxmark3/common/bucketsort.c
2022-01-08 00:40:52 +01:00

60 lines
2.4 KiB
C

//-----------------------------------------------------------------------------
// Copyright (C) Proxmark3 contributors. See AUTHORS.md for details.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// See LICENSE.txt for the text of the license.
//-----------------------------------------------------------------------------
#include "bucketsort.h"
extern void bucket_sort_intersect(uint32_t *const estart, uint32_t *const estop,
uint32_t *const ostart, uint32_t *const ostop,
bucket_info_t *bucket_info, bucket_array_t bucket) {
uint32_t *p1, *p2;
uint32_t *start[2];
uint32_t *stop[2];
start[0] = estart;
stop[0] = estop;
start[1] = ostart;
stop[1] = ostop;
// init buckets to be empty
for (uint32_t i = 0; i < 2; i++) {
for (uint32_t j = 0x00; j <= 0xff; j++) {
bucket[i][j].bp = bucket[i][j].head;
}
}
// sort the lists into the buckets based on the MSB (contribution bits)
for (uint32_t i = 0; i < 2; i++) {
for (p1 = start[i]; p1 <= stop[i]; p1++) {
uint32_t bucket_index = (*p1 & 0xff000000) >> 24;
*(bucket[i][bucket_index].bp++) = *p1;
}
}
// write back intersecting buckets as sorted list.
// fill in bucket_info with head and tail of the bucket contents in the list and number of non-empty buckets.
for (uint32_t i = 0; i < 2; i++) {
p1 = start[i];
uint32_t nonempty_bucket = 0;
for (uint32_t j = 0x00; j <= 0xff; j++) {
if (bucket[0][j].bp != bucket[0][j].head && bucket[1][j].bp != bucket[1][j].head) { // non-empty intersecting buckets only
bucket_info->bucket_info[i][nonempty_bucket].head = p1;
for (p2 = bucket[i][j].head; p2 < bucket[i][j].bp; *p1++ = *p2++);
bucket_info->bucket_info[i][nonempty_bucket].tail = p1 - 1;
nonempty_bucket++;
}
}
bucket_info->numbuckets = nonempty_bucket;
}
}