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-rw-r--r--test/benchmarks/search-kmp.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/test/benchmarks/search-kmp.c b/test/benchmarks/search-kmp.c
new file mode 100644
index 0000000..79ba9c8
--- /dev/null
+++ b/test/benchmarks/search-kmp.c
@@ -0,0 +1,89 @@
+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);
+
+static void compute_pi(char *p, int len, int *pibuf)
+{
+ int k = 0;
+ int q;
+ pibuf[0] = 0;
+ for (q = 1; q < len; ++q) {
+ while (k > 0 && p[k] != p[q])
+ k = pibuf[k];
+ if (p[k] == p[q])
+ ++k;
+ pibuf[q] = k;
+ }
+}
+
+void kmp(char *p, int plen, char *t, int tlen)
+{
+ int i, q = 0;
+ int *pibuf = malloc(sizeof(int) * plen);
+
+ compute_pi(p, plen, pibuf);
+
+ for (i = 0; i < tlen; ++i) {
+ while (q > 0 && p[q] != t[i])
+ q = pibuf[q-1];
+ if (p[q] == t[i])
+ ++q;
+ if (q == plen) {
+ rbuf.array[rbuf.len] = i + 1 - plen;
+ ++rbuf.len;
+ q = pibuf[q-1];
+ }
+ }
+
+}
+
+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;
+ char *needle, *buf;
+ int fd = open(argv[1], 0, 0);
+
+ if (fd == -1)
+ return 1;
+
+ needle = argv[2];
+ buf = read_file(fd, &slen);
+ printf("len: %d\n", slen);
+
+ kmp(needle, strlen(needle), buf, slen);
+
+ for (i = 0; i < rbuf.len; ++i)
+ sum += rbuf.array[i];
+ printf("%ld\n", sum);
+
+ return 0;
+}