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-rw-r--r--test/benchmarks/search-rabin-karp.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/test/benchmarks/search-rabin-karp.c b/test/benchmarks/search-rabin-karp.c
new file mode 100644
index 0000000..d9860ee
--- /dev/null
+++ b/test/benchmarks/search-rabin-karp.c
@@ -0,0 +1,81 @@
+struct result_buf {
+ unsigned long array[24*1024*1024];
+ int len;
+};
+
+struct result_buf rbuf;
+
+int read(int fd, void *buf, unsigned long len);
+void *malloc(unsigned long);
+long strlen(char *);
+int open(char *, int flags, long mode);
+int printf(char *, ...);
+void exit(int);
+int strncmp(char *, char *, unsigned long);
+
+void rabin_karp(char *p, int plen, char *t, int tlen)
+{
+ unsigned long d = 129;
+ unsigned long h = 1, p_h = 0, t_h = 0;
+ int i;
+ for (i = 0; i < plen - 1; ++i)
+ h = (h * d);
+
+ for (i = 0; i < plen; ++i) {
+ p_h = (d*p_h + p[i]);
+ t_h = (d*t_h + t[i]);
+ }
+
+
+ for (i = 0; i <= tlen - plen; ++i) {
+
+ if (p_h == t_h && strncmp(t + i, p, plen) == 0) {
+ rbuf.array[rbuf.len] = i;
+ ++rbuf.len;
+ }
+ if (i < tlen - plen) {
+ t_h = (d*(t_h - t[i]*h)) + t[i + plen];
+ }
+ }
+}
+
+void *read_file(int fd, int *len)
+{
+ int size = 1500 * 1024 * 1024;
+ unsigned char *arr = malloc(size);
+ int i;
+ for (i = 0; ;) {
+ int rd = read(fd, arr + i, size - i);
+ if (rd < 0)
+ exit(2);
+ if (rd == 0)
+ break;
+ i += rd;
+ }
+
+ *len = i;
+ return arr;
+}
+
+int main(int argc, char **argv)
+{
+ int i, slen;
+ long sum = 0;
+ int fd;
+ char *buf;
+ char *needle = argv[2];
+
+ fd = open(argv[1], 0, 0);
+ if (fd == -1)
+ return 1;
+ buf = read_file(fd, &slen);
+ printf("len: %d\n", slen);
+
+ rabin_karp(needle, strlen(needle), buf, slen);
+
+ for (i = 0; i < rbuf.len; ++i)
+ sum += rbuf.array[i];
+ printf("%ld\n", sum);
+
+ return 0;
+}