git-commit-vandalism/t/helper/test-path-utils.c
Garima Singh a62f9d1ace test-path-utils: offer to run a protectNTFS/protectHFS benchmark
In preparation to flipping the default on `core.protectNTFS`, let's have
some way to measure the speed impact of this config setting reliably
(and for comparison, the `core.protectHFS` config setting).

For now, this is a manual performance benchmark:

	./t/helper/test-path-utils protect_ntfs_hfs [arguments...]

where the arguments are an optional number of file names to test with,
optionally followed by minimum and maximum length of the random file
names. The default values are one million, 3 and 20, respectively.

Just like `sqrti()` in `bisect.c`, we introduce a very simple function
to approximation the square root of a given value, in order to avoid
having to introduce the first user of `<math.h>` in Git's source code.

Note: this is _not_ implemented as a Unix shell script in t/perf/
because we really care about _very_ precise timings here, and Unix shell
scripts are simply unsuited for precise and consistent benchmarking.

Signed-off-by: Garima Singh <garima.singh@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2019-12-05 15:36:40 +01:00

393 lines
10 KiB
C

#include "cache.h"
#include "string-list.h"
#include "utf8.h"
/*
* A "string_list_each_func_t" function that normalizes an entry from
* GIT_CEILING_DIRECTORIES. If the path is unusable for some reason,
* die with an explanation.
*/
static int normalize_ceiling_entry(struct string_list_item *item, void *unused)
{
char *ceil = item->string;
if (!*ceil)
die("Empty path is not supported");
if (!is_absolute_path(ceil))
die("Path \"%s\" is not absolute", ceil);
if (normalize_path_copy(ceil, ceil) < 0)
die("Path \"%s\" could not be normalized", ceil);
return 1;
}
static void normalize_argv_string(const char **var, const char *input)
{
if (!strcmp(input, "<null>"))
*var = NULL;
else if (!strcmp(input, "<empty>"))
*var = "";
else
*var = input;
if (*var && (**var == '<' || **var == '('))
die("Bad value: %s\n", input);
}
struct test_data {
const char *from; /* input: transform from this ... */
const char *to; /* output: ... to this. */
const char *alternative; /* output: ... or this. */
};
/*
* Compatibility wrappers for OpenBSD, whose basename(3) and dirname(3)
* have const parameters.
*/
static char *posix_basename(char *path)
{
return basename(path);
}
static char *posix_dirname(char *path)
{
return dirname(path);
}
static int test_function(struct test_data *data, char *(*func)(char *input),
const char *funcname)
{
int failed = 0, i;
char buffer[1024];
char *to;
for (i = 0; data[i].to; i++) {
if (!data[i].from)
to = func(NULL);
else {
xsnprintf(buffer, sizeof(buffer), "%s", data[i].from);
to = func(buffer);
}
if (!strcmp(to, data[i].to))
continue;
if (!data[i].alternative)
error("FAIL: %s(%s) => '%s' != '%s'\n",
funcname, data[i].from, to, data[i].to);
else if (!strcmp(to, data[i].alternative))
continue;
else
error("FAIL: %s(%s) => '%s' != '%s', '%s'\n",
funcname, data[i].from, to, data[i].to,
data[i].alternative);
failed = 1;
}
return failed;
}
static struct test_data basename_data[] = {
/* --- POSIX type paths --- */
{ NULL, "." },
{ "", "." },
{ ".", "." },
{ "..", ".." },
{ "/", "/" },
{ "//", "/", "//" },
{ "///", "/", "//" },
{ "////", "/", "//" },
{ "usr", "usr" },
{ "/usr", "usr" },
{ "/usr/", "usr" },
{ "/usr//", "usr" },
{ "/usr/lib", "lib" },
{ "usr/lib", "lib" },
{ "usr/lib///", "lib" },
#if defined(__MINGW32__) || defined(_MSC_VER)
/* --- win32 type paths --- */
{ "\\usr", "usr" },
{ "\\usr\\", "usr" },
{ "\\usr\\\\", "usr" },
{ "\\usr\\lib", "lib" },
{ "usr\\lib", "lib" },
{ "usr\\lib\\\\\\", "lib" },
{ "C:/usr", "usr" },
{ "C:/usr", "usr" },
{ "C:/usr/", "usr" },
{ "C:/usr//", "usr" },
{ "C:/usr/lib", "lib" },
{ "C:usr/lib", "lib" },
{ "C:usr/lib///", "lib" },
{ "C:", "." },
{ "C:a", "a" },
{ "C:/", "/" },
{ "C:///", "/" },
{ "\\", "\\", "/" },
{ "\\\\", "\\", "/" },
{ "\\\\\\", "\\", "/" },
#endif
{ NULL, NULL }
};
static struct test_data dirname_data[] = {
/* --- POSIX type paths --- */
{ NULL, "." },
{ "", "." },
{ ".", "." },
{ "..", "." },
{ "/", "/" },
{ "//", "/", "//" },
{ "///", "/", "//" },
{ "////", "/", "//" },
{ "usr", "." },
{ "/usr", "/" },
{ "/usr/", "/" },
{ "/usr//", "/" },
{ "/usr/lib", "/usr" },
{ "usr/lib", "usr" },
{ "usr/lib///", "usr" },
#if defined(__MINGW32__) || defined(_MSC_VER)
/* --- win32 type paths --- */
{ "\\", "\\" },
{ "\\\\", "\\\\" },
{ "\\usr", "\\" },
{ "\\usr\\", "\\" },
{ "\\usr\\\\", "\\" },
{ "\\usr\\lib", "\\usr" },
{ "usr\\lib", "usr" },
{ "usr\\lib\\\\\\", "usr" },
{ "C:a", "C:." },
{ "C:/", "C:/" },
{ "C:///", "C:/" },
{ "C:/usr", "C:/" },
{ "C:/usr/", "C:/" },
{ "C:/usr//", "C:/" },
{ "C:/usr/lib", "C:/usr" },
{ "C:usr/lib", "C:usr" },
{ "C:usr/lib///", "C:usr" },
{ "\\\\\\", "\\" },
{ "\\\\\\\\", "\\" },
{ "C:", "C:.", "." },
#endif
{ NULL, NULL }
};
static int is_dotgitmodules(const char *path)
{
return is_hfs_dotgitmodules(path) || is_ntfs_dotgitmodules(path);
}
/*
* A very simple, reproducible pseudo-random generator. Copied from
* `test-genrandom.c`.
*/
static uint64_t my_random_value = 1234;
static uint64_t my_random(void)
{
my_random_value = my_random_value * 1103515245 + 12345;
return my_random_value;
}
/*
* A fast approximation of the square root, without requiring math.h.
*
* It uses Newton's method to approximate the solution of 0 = x^2 - value.
*/
static double my_sqrt(double value)
{
const double epsilon = 1e-6;
double x = value;
if (value == 0)
return 0;
for (;;) {
double delta = (value / x - x) / 2;
if (delta < epsilon && delta > -epsilon)
return x + delta;
x += delta;
}
}
static int protect_ntfs_hfs_benchmark(int argc, const char **argv)
{
size_t i, j, nr, min_len = 3, max_len = 20;
char **names;
int repetitions = 15, file_mode = 0100644;
uint64_t begin, end;
double m[3][2], v[3][2];
uint64_t cumul;
double cumul2;
if (argc > 1 && !strcmp(argv[1], "--with-symlink-mode")) {
file_mode = 0120000;
argc--;
argv++;
}
nr = argc > 1 ? strtoul(argv[1], NULL, 0) : 1000000;
ALLOC_ARRAY(names, nr);
if (argc > 2) {
min_len = strtoul(argv[2], NULL, 0);
if (argc > 3)
max_len = strtoul(argv[3], NULL, 0);
if (min_len > max_len)
die("min_len > max_len");
}
for (i = 0; i < nr; i++) {
size_t len = min_len + (my_random() % (max_len + 1 - min_len));
names[i] = xmallocz(len);
while (len > 0)
names[i][--len] = (char)(' ' + (my_random() % ('\x7f' - ' ')));
}
for (protect_ntfs = 0; protect_ntfs < 2; protect_ntfs++)
for (protect_hfs = 0; protect_hfs < 2; protect_hfs++) {
cumul = 0;
cumul2 = 0;
for (i = 0; i < repetitions; i++) {
begin = getnanotime();
for (j = 0; j < nr; j++)
verify_path(names[j], file_mode);
end = getnanotime();
printf("protect_ntfs = %d, protect_hfs = %d: %lfms\n", protect_ntfs, protect_hfs, (end-begin) / (double)1e6);
cumul += end - begin;
cumul2 += (end - begin) * (end - begin);
}
m[protect_ntfs][protect_hfs] = cumul / (double)repetitions;
v[protect_ntfs][protect_hfs] = my_sqrt(cumul2 / (double)repetitions - m[protect_ntfs][protect_hfs] * m[protect_ntfs][protect_hfs]);
printf("mean: %lfms, stddev: %lfms\n", m[protect_ntfs][protect_hfs] / (double)1e6, v[protect_ntfs][protect_hfs] / (double)1e6);
}
for (protect_ntfs = 0; protect_ntfs < 2; protect_ntfs++)
for (protect_hfs = 0; protect_hfs < 2; protect_hfs++)
printf("ntfs=%d/hfs=%d: %lf%% slower\n", protect_ntfs, protect_hfs, (m[protect_ntfs][protect_hfs] - m[0][0]) * 100 / m[0][0]);
return 0;
}
int cmd_main(int argc, const char **argv)
{
if (argc == 3 && !strcmp(argv[1], "normalize_path_copy")) {
char *buf = xmallocz(strlen(argv[2]));
int rv = normalize_path_copy(buf, argv[2]);
if (rv)
buf = "++failed++";
puts(buf);
return 0;
}
if (argc >= 2 && !strcmp(argv[1], "real_path")) {
while (argc > 2) {
puts(real_path(argv[2]));
argc--;
argv++;
}
return 0;
}
if (argc >= 2 && !strcmp(argv[1], "absolute_path")) {
while (argc > 2) {
puts(absolute_path(argv[2]));
argc--;
argv++;
}
return 0;
}
if (argc == 4 && !strcmp(argv[1], "longest_ancestor_length")) {
int len;
struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
char *path = xstrdup(argv[2]);
/*
* We have to normalize the arguments because under
* Windows, bash mangles arguments that look like
* absolute POSIX paths or colon-separate lists of
* absolute POSIX paths into DOS paths (e.g.,
* "/foo:/foo/bar" might be converted to
* "D:\Src\msysgit\foo;D:\Src\msysgit\foo\bar"),
* whereas longest_ancestor_length() requires paths
* that use forward slashes.
*/
if (normalize_path_copy(path, path))
die("Path \"%s\" could not be normalized", argv[2]);
string_list_split(&ceiling_dirs, argv[3], PATH_SEP, -1);
filter_string_list(&ceiling_dirs, 0,
normalize_ceiling_entry, NULL);
len = longest_ancestor_length(path, &ceiling_dirs);
string_list_clear(&ceiling_dirs, 0);
free(path);
printf("%d\n", len);
return 0;
}
if (argc >= 4 && !strcmp(argv[1], "prefix_path")) {
const char *prefix = argv[2];
int prefix_len = strlen(prefix);
int nongit_ok;
setup_git_directory_gently(&nongit_ok);
while (argc > 3) {
puts(prefix_path(prefix, prefix_len, argv[3]));
argc--;
argv++;
}
return 0;
}
if (argc == 4 && !strcmp(argv[1], "strip_path_suffix")) {
char *prefix = strip_path_suffix(argv[2], argv[3]);
printf("%s\n", prefix ? prefix : "(null)");
return 0;
}
if (argc == 3 && !strcmp(argv[1], "print_path")) {
puts(argv[2]);
return 0;
}
if (argc == 4 && !strcmp(argv[1], "relative_path")) {
struct strbuf sb = STRBUF_INIT;
const char *in, *prefix, *rel;
normalize_argv_string(&in, argv[2]);
normalize_argv_string(&prefix, argv[3]);
rel = relative_path(in, prefix, &sb);
if (!rel)
puts("(null)");
else
puts(strlen(rel) > 0 ? rel : "(empty)");
strbuf_release(&sb);
return 0;
}
if (argc == 2 && !strcmp(argv[1], "basename"))
return test_function(basename_data, posix_basename, argv[1]);
if (argc == 2 && !strcmp(argv[1], "dirname"))
return test_function(dirname_data, posix_dirname, argv[1]);
if (argc > 2 && !strcmp(argv[1], "is_dotgitmodules")) {
int res = 0, expect = 1, i;
for (i = 2; i < argc; i++)
if (!strcmp("--not", argv[i]))
expect = !expect;
else if (expect != is_dotgitmodules(argv[i]))
res = error("'%s' is %s.gitmodules", argv[i],
expect ? "not " : "");
else
fprintf(stderr, "ok: '%s' is %s.gitmodules\n",
argv[i], expect ? "" : "not ");
return !!res;
}
if (argc > 1 && !strcmp(argv[1], "protect_ntfs_hfs"))
return !!protect_ntfs_hfs_benchmark(argc - 1, argv + 1);
fprintf(stderr, "%s: unknown function name: %s\n", argv[0],
argv[1] ? argv[1] : "(there was none)");
return 1;
}