int git_hashsig_create_fromfile(
git_hashsig **out,
const char *path,
git_hashsig_option_t opts)
{
char buf[4096];
ssize_t buflen = 0;
int error = 0, fd;
hashsig_in_progress prog = HASHSIG_IN_PROGRESS_INIT;
git_hashsig *sig = hashsig_alloc(opts);
GITERR_CHECK_ALLOC(sig);
if ((fd = git_futils_open_ro(path)) < 0) {
git__free(sig);
return fd;
}
while (!error) {
if ((buflen = p_read(fd, buf, sizeof(buf))) <= 0) {
if ((error = (int)buflen) < 0)
giterr_set(GITERR_OS,
"Read error on '%s' calculating similarity hashes", path);
break;
}
error = hashsig_add_hashes(sig, buf, buflen, &prog);
}
p_close(fd);
if (!error)
error = hashsig_finalize_hashes(sig);
if (!error)
*out = sig;
else
git_hashsig_free(sig);
return error;
}
int git_hashsig_create(
git_hashsig **out,
const char *buf,
size_t buflen,
git_hashsig_option_t opts)
{
int error;
hashsig_in_progress prog = HASHSIG_IN_PROGRESS_INIT;
git_hashsig *sig = hashsig_alloc(opts);
GITERR_CHECK_ALLOC(sig);
error = hashsig_add_hashes(sig, buf, buflen, &prog);
if (!error)
error = hashsig_finalize_hashes(sig);
if (!error)
*out = sig;
else
git_hashsig_free(sig);
return error;
}
void test_core_buffer__similarity_metric_whitespace(void)
{
git_hashsig *a, *b;
git_buf buf = GIT_BUF_INIT;
int sim, i, j;
git_hashsig_option_t opt;
const char *tabbed =
" for (s = 0; s < sizeof(sep) / sizeof(char); ++s) {\n"
" separator = sep[s];\n"
" expect = expect_values[s];\n"
"\n"
" for (j = 0; j < sizeof(b) / sizeof(char*); ++j) {\n"
" for (i = 0; i < sizeof(a) / sizeof(char*); ++i) {\n"
" git_buf_join(&buf, separator, a[i], b[j]);\n"
" cl_assert_equal_s(*expect, buf.ptr);\n"
" expect++;\n"
" }\n"
" }\n"
" }\n";
const char *spaced =
" for (s = 0; s < sizeof(sep) / sizeof(char); ++s) {\n"
" separator = sep[s];\n"
" expect = expect_values[s];\n"
"\n"
" for (j = 0; j < sizeof(b) / sizeof(char*); ++j) {\n"
" for (i = 0; i < sizeof(a) / sizeof(char*); ++i) {\n"
" git_buf_join(&buf, separator, a[i], b[j]);\n"
" cl_assert_equal_s(*expect, buf.ptr);\n"
" expect++;\n"
" }\n"
" }\n"
" }\n";
const char *crlf_spaced2 =
" for (s = 0; s < sizeof(sep) / sizeof(char); ++s) {\r\n"
" separator = sep[s];\r\n"
" expect = expect_values[s];\r\n"
"\r\n"
" for (j = 0; j < sizeof(b) / sizeof(char*); ++j) {\r\n"
" for (i = 0; i < sizeof(a) / sizeof(char*); ++i) {\r\n"
" git_buf_join(&buf, separator, a[i], b[j]);\r\n"
" cl_assert_equal_s(*expect, buf.ptr);\r\n"
" expect++;\r\n"
" }\r\n"
" }\r\n"
" }\r\n";
const char *text[3] = { tabbed, spaced, crlf_spaced2 };
/* let's try variations of our own code with whitespace changes */
for (opt = GIT_HASHSIG_NORMAL; opt <= GIT_HASHSIG_SMART_WHITESPACE; ++opt) {
for (i = 0; i < 3; ++i) {
for (j = 0; j < 3; ++j) {
cl_git_pass(git_buf_sets(&buf, text[i]));
cl_git_pass(git_hashsig_create(&a, buf.ptr, buf.size, opt));
cl_git_pass(git_buf_sets(&buf, text[j]));
cl_git_pass(git_hashsig_create(&b, buf.ptr, buf.size, opt));
sim = git_hashsig_compare(a, b);
if (opt == GIT_HASHSIG_NORMAL) {
if (i == j)
cl_assert_equal_i(100, sim);
else
cl_assert_in_range(0, sim, 30); /* pretty different */
} else {
cl_assert_equal_i(100, sim);
}
git_hashsig_free(a);
git_hashsig_free(b);
}
}
}
git_buf_free(&buf);
}
void test_core_buffer__similarity_metric(void)
{
git_hashsig *a, *b;
git_buf buf = GIT_BUF_INIT;
int sim;
/* in the first case, we compare data to itself and expect 100% match */
cl_git_pass(git_buf_sets(&buf, SIMILARITY_TEST_DATA_1));
cl_git_pass(git_hashsig_create(&a, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
cl_git_pass(git_hashsig_create(&b, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
cl_assert_equal_i(100, git_hashsig_compare(a, b));
git_hashsig_free(a);
git_hashsig_free(b);
/* if we change just a single byte, how much does that change magnify? */
cl_git_pass(git_buf_sets(&buf, SIMILARITY_TEST_DATA_1));
cl_git_pass(git_hashsig_create(&a, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
cl_git_pass(git_buf_sets(&buf,
"000\n001\n002\n003\n004\n005\n006\n007\n008\n009\n" \
"010\n011\n012\n013\n014\n015\n016\n017\n018\n019\n" \
"x020x\n021\n022\n023\n024\n025\n026\n027\n028\n029\n" \
"030\n031\n032\n033\n034\n035\n036\n037\n038\n039\n" \
"040\n041\n042\n043\n044\n045\n046\n047\n048\n049\n"
));
cl_git_pass(git_hashsig_create(&b, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
sim = git_hashsig_compare(a, b);
cl_assert_in_range(95, sim, 100); /* expect >95% similarity */
git_hashsig_free(a);
git_hashsig_free(b);
/* let's try comparing data to a superset of itself */
cl_git_pass(git_buf_sets(&buf, SIMILARITY_TEST_DATA_1));
cl_git_pass(git_hashsig_create(&a, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
cl_git_pass(git_buf_sets(&buf, SIMILARITY_TEST_DATA_1
"050\n051\n052\n053\n054\n055\n056\n057\n058\n059\n"));
cl_git_pass(git_hashsig_create(&b, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
sim = git_hashsig_compare(a, b);
/* 20% lines added ~= 10% lines changed */
cl_assert_in_range(85, sim, 95); /* expect similarity around 90% */
git_hashsig_free(a);
git_hashsig_free(b);
/* what if we keep about half the original data and add half new */
cl_git_pass(git_buf_sets(&buf, SIMILARITY_TEST_DATA_1));
cl_git_pass(git_hashsig_create(&a, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
cl_git_pass(git_buf_sets(&buf,
"000\n001\n002\n003\n004\n005\n006\n007\n008\n009\n" \
"010\n011\n012\n013\n014\n015\n016\n017\n018\n019\n" \
"020x\n021\n022\n023\n024\n" \
"x25\nx26\nx27\nx28\nx29\n" \
"x30\nx31\nx32\nx33\nx34\nx35\nx36\nx37\nx38\nx39\n" \
"x40\nx41\nx42\nx43\nx44\nx45\nx46\nx47\nx48\nx49\n"
));
cl_git_pass(git_hashsig_create(&b, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
sim = git_hashsig_compare(a, b);
/* 50% lines changed */
cl_assert_in_range(40, sim, 60); /* expect in the 40-60% similarity range */
git_hashsig_free(a);
git_hashsig_free(b);
/* lastly, let's check that we can hash file content as well */
cl_git_pass(git_buf_sets(&buf, SIMILARITY_TEST_DATA_1));
cl_git_pass(git_hashsig_create(&a, buf.ptr, buf.size, GIT_HASHSIG_NORMAL));
cl_git_pass(git_futils_mkdir("scratch", NULL, 0755, GIT_MKDIR_PATH));
cl_git_mkfile("scratch/testdata", SIMILARITY_TEST_DATA_1);
cl_git_pass(git_hashsig_create_fromfile(
&b, "scratch/testdata", GIT_HASHSIG_NORMAL));
cl_assert_equal_i(100, git_hashsig_compare(a, b));
git_hashsig_free(a);
git_hashsig_free(b);
git_buf_free(&buf);
git_futils_rmdir_r("scratch", NULL, GIT_RMDIR_REMOVE_FILES);
}