Add basic parallel implementation

This commit is contained in:
Raffaele Mignone 2021-03-18 17:47:32 +01:00
parent 24535aff47
commit f6cfc87ce1
Signed by: norangebit
GPG Key ID: F5255658CB220573

155
main.c
View File

@ -2,24 +2,159 @@
#include <string.h>
#include "kmp.h"
#include "util.h"
#include <mpi.h>
#include <malloc.h>
#define MASTER 0
#define DEFAULT_TAG 17
char *read_text();
char *read_pattern();
void find_end(int, char *, char *, int **, int *);
void apply_shift(int, int *, int);
int sum_array(int *, int);
int main() {
char *patter = "acabacacd";
char *text = "acfacabacabacacdac";
int rank, size, private_text_len, text_len, pattern_len;
char *pattern, *text;
int pattern_len = strlen(patter);
MPI_Init(NULL, NULL);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
if (rank == MASTER) {
text = read_text();
pattern = read_pattern();
printf("text: %s\n", text);
printf("pattern: %s\n", pattern);
text_len = strlen(text);
pattern_len = strlen(pattern);
private_text_len = text_len / size; // TODO: size non divisibile
}
MPI_Bcast(&private_text_len, 1, MPI_INT, MASTER, MPI_COMM_WORLD);
char *private_text = (char *) malloc(sizeof(char) * (private_text_len + 1));
MPI_Scatter(text, private_text_len, MPI_CHAR, private_text, private_text_len, MPI_CHAR, MASTER, MPI_COMM_WORLD);
private_text[private_text_len] = '\0';
printf("%d -> input: %s\n", rank, private_text);
MPI_Bcast(&pattern_len, 1, MPI_INT, MASTER, MPI_COMM_WORLD);
if (rank != MASTER) {
pattern = (char *) malloc(sizeof(char) * (pattern_len + 1));
}
MPI_Bcast(pattern, pattern_len + 1, MPI_CHAR, MASTER, MPI_COMM_WORLD);
// long proper suffix array
int lps[pattern_len];
create_lps(patter, pattern_len, lps);
create_lps(pattern, pattern_len, lps);
int match_number = 0;
int residue;
int match_number = 0, residue;
int *matches = search_pattern(private_text, pattern, lps, &match_number, &residue);
int *matches = search_pattern(text, patter, lps, &match_number, &residue);
print_array(matches, match_number);
printf("%d\n", residue);
if (rank + 1 != size) {
MPI_Send(&residue, 1, MPI_INT, rank + 1, DEFAULT_TAG, MPI_COMM_WORLD);
}
if (rank != 0) {
MPI_Recv(&residue, 1, MPI_INT, rank - 1, DEFAULT_TAG, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
if (residue != 0)
find_end(residue, pattern, private_text, &matches, &match_number);
}
int shift = rank * private_text_len;
apply_shift(shift, matches, match_number);
printf("%d -> result number: %d\n", rank, match_number);
if (rank == MASTER) {
int match_numbers[size];
match_numbers[MASTER] = match_number;
for (int i = 0; i < size; ++i) {
if (i == MASTER) continue;
MPI_Recv(match_numbers + i, 1, MPI_INT, i, DEFAULT_TAG, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
}
match_number = sum_array(match_numbers, size);
matches = (int *) realloc(matches, sizeof(int) * match_number);
int offset = 0;
for (int i = 0; i < size; ++i) {
if (i == MASTER) {
offset += match_numbers[i];
continue;
}
MPI_Recv(matches + offset, match_numbers[i], MPI_INT, i, DEFAULT_TAG, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
offset += match_numbers[i];
}
} else {
MPI_Send(&match_number, 1, MPI_INT, MASTER, DEFAULT_TAG, MPI_COMM_WORLD);
MPI_Send(matches, match_number, MPI_INT, MASTER, DEFAULT_TAG, MPI_COMM_WORLD);
}
MPI_Finalize();
if (rank == MASTER) {
printf("total matches: %d\n", match_number);
printf("matches index: ");
print_array(matches, match_number);
}
}
char *read_text() {
// TODO
return "abc";
}
char *read_pattern() {
// TODO
return "mamma";
}
void find_end(int residue, char *pattern, char *text, int **matches, int *match_number) {
int pattern_index = residue;
int text_index = 0;
int text_len = strlen(text);
int pattern_len = strlen(pattern);
if (pattern_len - residue > text_len) return;
while (pattern_index < pattern_len && pattern[pattern_index] == text[text_index]) {
pattern_index++;
text_index++;
}
if (pattern_index != pattern_len) return;
*match_number = *match_number + 1;
*matches = (int *) realloc(*matches, *match_number * sizeof(int));
(*matches)[*match_number - 1] = -residue;
}
void apply_shift(int shift, int *array, int size) {
for (int i = 0; i < size; ++i) {
array[i] += shift;
}
}
int sum_array(int *array, int size) {
int sum = 0;
for (int i = 0; i < size; ++i) {
sum += array[i];
}
return sum;
}