Add clock offset parser

src/emu/clkoff.c

@@ -0,0 +1,138 @@
+#include "clkoff.h"
+
+#include "common.h"
+#include <errno.h>
+
+static struct clkoff_entry *
+cfind(struct clkoff *off, const char *name)
+{
+	struct clkoff_entry *entry = NULL;
+
+	HASH_FIND_STR(off->entries, name, entry);
+	return entry;
+}
+
+static int
+cadd(struct clkoff *table, struct clkoff_entry e)
+{
+	if (cfind(table, e.name) != NULL) {
+		err("entry with name '%s' already exists\n", e.name);
+		return -1;
+	}
+
+	struct clkoff_entry *entry = calloc(1, sizeof(struct clkoff_entry));
+	if (entry == NULL) {
+		err("calloc failed\n");
+		return -1;
+	}
+
+	memcpy(entry, &e, sizeof(*entry));
+	
+	HASH_ADD_STR(table->entries, name, entry);
+	table->nentries++;
+
+	return 0;
+}
+
+static int
+cparse(struct clkoff *table, FILE *file)
+{
+	/* Ignore header line */
+	char buf[1024];
+	if (fgets(buf, 1024, file) == NULL) {
+		err("missing header line in clock offset\n");
+		return -1;
+	}
+
+	for (int line = 1; ; line++) {
+		errno = 0;
+		struct clkoff_entry e = { 0 };
+
+		if (fgets(buf, 1024, file) == NULL)
+			break;
+
+		/* Empty line */
+		if (buf[0] == '\n')
+			continue;
+
+		int ret = sscanf(buf, "%ld %s %lf %lf %lf",
+				&e.index, e.name,
+				&e.median, &e.mean, &e.stdev);
+
+		if (ret == EOF && errno == 0)
+			break;
+
+		if (ret == EOF && errno != 0) {
+			err("fscanf() failed in line %d\n", line);
+			return -1;
+		}
+
+		if (ret != 5) {
+			err("fscanf() read %d instead of 5 fields in line %d\n",
+					ret, line);
+			return -1;
+		}
+
+		if (cadd(table, e) != 0) {
+			err("cannot add entry of line %d\n",
+					line);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int
+cindex(struct clkoff *table)
+{
+	if (table->nentries < 1) {
+		err("no entries\n");
+		return -1;
+	}
+
+	table->index = calloc(table->nentries, sizeof(struct clkoff_entry *));
+
+	if (table->index == NULL) {
+		err("calloc failed\n");
+		return -1;
+	}
+
+	struct clkoff_entry *e;
+	int i = 0;
+	for (e = table->entries; e; e = e->hh.next)
+		table->index[i++] = e;
+
+	return 0;
+}
+
+int
+clkoff_init(struct clkoff *table, FILE *file)
+{
+	memset(table, 0, sizeof(struct clkoff));
+
+	if (cparse(table, file) != 0) {
+		err("clkoff_init: failed parsing clock table\n");
+		return -1;
+	}
+
+	/* Create index array */
+	if (cindex(table) != 0) {
+		err("clkoff_init: failed indexing table\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+clkoff_count(struct clkoff *table)
+{
+	return table->nentries;
+}
+
+struct clkoff_entry *
+clkoff_get(struct clkoff *table, int i)
+{
+	return table->index[i];
+}

src/emu/clkoff.h

@@ -0,0 +1,31 @@
+/* Copyright (c) 2021-2023 Barcelona Supercomputing Center (BSC)
+ * SPDX-License-Identifier: GPL-3.0-or-later */
+
+#ifndef CLKOFF_H
+#define CLKOFF_H
+
+#include "uthash.h"
+
+#include <stdio.h>
+#include <linux/limits.h>
+
+struct clkoff_entry {
+	int64_t index;
+	char name[PATH_MAX];
+	double median;
+	double mean;
+	double stdev;
+	UT_hash_handle hh;
+};
+
+struct clkoff {
+	int nentries;
+	struct clkoff_entry *entries;
+	struct clkoff_entry **index;
+};
+
+int clkoff_init(struct clkoff *table, FILE *file);
+int clkoff_count(struct clkoff *table);
+struct clkoff_entry *clkoff_get(struct clkoff *table, int i);
+
+#endif /* CLKOFF_H */

test/unit/CMakeLists.txt

@@ -17,3 +17,4 @@ unit_test(prv.c)
 #unit_test(ovni_model.c)
 unit_test(emu_trace.c)
 unit_test(emu.c)
+unit_test(clkoff.c)

test/unit/clkoff.c

@@ -0,0 +1,73 @@
+#define _POSIX_C_SOURCE 200809L
+
+#include "emu/clkoff.h"
+#include "common.h"
+#include <stdio.h>
+
+static int
+test_ok(void)
+{
+	char table_str[] =
+	"rank       hostname             offset_median        offset_mean          offset_std\n"
+	"0          s09r2b21             0                    0.000000             0.000000\n"
+	"1          s09r2b22             -451607967           -451608083.500000    316.087397\n"
+	"2          s09r2b23             4526                 4542.200000          124.33432\n"
+	"3          s09r2b24             342455               342462.300000        342.39755\n";
+
+	FILE *f = fmemopen(table_str, ARRAYLEN(table_str), "r");
+
+	if (f == NULL)
+		die("fmemopen failed\n");
+
+	struct clkoff table;
+	clkoff_init(&table);
+	if (clkoff_load(&table, f) != 0)
+		die("clkoff_load failed\n");
+
+	if (clkoff_count(&table) != 4)
+		die("clkoff_count failed\n");
+
+	struct clkoff_entry *entry = clkoff_get(&table, 3);
+	if (entry == NULL)
+		die("clkoff_get returned NULL\n");
+
+	if (entry->index != 3)
+		die("clkoff_get returned wrong index\n");
+
+	fclose(f);
+
+	return 0;
+}
+
+static int
+test_dup(void)
+{
+	static char table_str[] =
+	"rank       hostname             offset_median        offset_mean          offset_std\n"
+	"0          s09r2b21             0                    0.000000             0.000000\n"
+	"1          s09r2b22             -451607967           -451608083.500000    316.087397\n"
+	"2          s09r2b23             4526                 4542.200000          124.33432\n"
+	"3          s09r2b23             342455               342462.300000        342.39755\n";
+
+	FILE *f = fmemopen(table_str, ARRAYLEN(table_str), "r");
+
+	if (f == NULL)
+		die("fmemopen failed\n");
+
+	struct clkoff table;
+
+	clkoff_init(&table);
+	if (clkoff_load(&table, f) == 0)
+		die("clkoff_load didn't fail\n");
+
+	fclose(f);
+
+	return 0;
+}
+
+int main(void)
+{
+	test_ok();
+	test_dup();
+	return 0;
+}