Hash :
f0e693b1
Author :
Date :
2021-09-07T17:53:49
str: introduce `git_str` for internal, `git_buf` is external libgit2 has two distinct requirements that were previously solved by `git_buf`. We require: 1. A general purpose string class that provides a number of utility APIs for manipulating data (eg, concatenating, truncating, etc). 2. A structure that we can use to return strings to callers that they can take ownership of. By using a single class (`git_buf`) for both of these purposes, we have confused the API to the point that refactorings are difficult and reasoning about correctness is also difficult. Move the utility class `git_buf` to be called `git_str`: this represents its general purpose, as an internal string buffer class. The name also is an homage to Junio Hamano ("gitstr"). The public API remains `git_buf`, and has a much smaller footprint. It is generally only used as an "out" param with strict requirements that follow the documentation. (Exceptions exist for some legacy APIs to avoid breaking callers unnecessarily.) Utility functions exist to convert a user-specified `git_buf` to a `git_str` so that we can call internal functions, then converting it back again.
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#include "clar_libgit2.h"
#include "zstream.h"
static const char *data = "This is a test test test of This is a test";
#define INFLATE_EXTRA 2
static void assert_zlib_equal_(
const void *expected, size_t e_len,
const void *compressed, size_t c_len,
const char *msg, const char *file, const char *func, int line)
{
z_stream stream;
char *expanded = git__calloc(1, e_len + INFLATE_EXTRA);
cl_assert(expanded);
memset(&stream, 0, sizeof(stream));
stream.next_out = (Bytef *)expanded;
stream.avail_out = (uInt)(e_len + INFLATE_EXTRA);
stream.next_in = (Bytef *)compressed;
stream.avail_in = (uInt)c_len;
cl_assert(inflateInit(&stream) == Z_OK);
cl_assert(inflate(&stream, Z_FINISH));
inflateEnd(&stream);
clar__assert_equal(
file, func, line, msg, 1,
"%d", (int)stream.total_out, (int)e_len);
clar__assert_equal(
file, func, line, "Buffer len was not exact match", 1,
"%d", (int)stream.avail_out, (int)INFLATE_EXTRA);
clar__assert(
memcmp(expanded, expected, e_len) == 0,
file, func, line, "uncompressed data did not match", NULL, 1);
git__free(expanded);
}
#define assert_zlib_equal(E,EL,C,CL) \
assert_zlib_equal_(E, EL, C, CL, #EL " != " #CL, __FILE__, __func__, (int)__LINE__)
void test_core_zstream__basic(void)
{
git_zstream z = GIT_ZSTREAM_INIT;
char out[128];
size_t outlen = sizeof(out);
cl_git_pass(git_zstream_init(&z, GIT_ZSTREAM_DEFLATE));
cl_git_pass(git_zstream_set_input(&z, data, strlen(data) + 1));
cl_git_pass(git_zstream_get_output(out, &outlen, &z));
cl_assert(git_zstream_done(&z));
cl_assert(outlen > 0);
git_zstream_free(&z);
assert_zlib_equal(data, strlen(data) + 1, out, outlen);
}
void test_core_zstream__fails_on_trailing_garbage(void)
{
git_str deflated = GIT_STR_INIT, inflated = GIT_STR_INIT;
char i = 0;
/* compress a simple string */
git_zstream_deflatebuf(&deflated, "foobar!!", 8);
/* append some garbage */
for (i = 0; i < 10; i++) {
git_str_putc(&deflated, i);
}
cl_git_fail(git_zstream_inflatebuf(&inflated, deflated.ptr, deflated.size));
git_str_dispose(&deflated);
git_str_dispose(&inflated);
}
void test_core_zstream__buffer(void)
{
git_str out = GIT_STR_INIT;
cl_git_pass(git_zstream_deflatebuf(&out, data, strlen(data) + 1));
assert_zlib_equal(data, strlen(data) + 1, out.ptr, out.size);
git_str_dispose(&out);
}
#define BIG_STRING_PART "Big Data IS Big - Long Data IS Long - We need a buffer larger than 1024 x 1024 to make sure we trigger chunked compression - Big Big Data IS Bigger than Big - Long Long Data IS Longer than Long"
static void compress_and_decompress_input_various_ways(git_str *input)
{
git_str out1 = GIT_STR_INIT, out2 = GIT_STR_INIT;
git_str inflated = GIT_STR_INIT;
size_t i, fixed_size = max(input->size / 2, 256);
char *fixed = git__malloc(fixed_size);
cl_assert(fixed);
/* compress with deflatebuf */
cl_git_pass(git_zstream_deflatebuf(&out1, input->ptr, input->size));
assert_zlib_equal(input->ptr, input->size, out1.ptr, out1.size);
/* compress with various fixed size buffer (accumulating the output) */
for (i = 0; i < 3; ++i) {
git_zstream zs = GIT_ZSTREAM_INIT;
size_t use_fixed_size;
switch (i) {
case 0: use_fixed_size = 256; break;
case 1: use_fixed_size = fixed_size / 2; break;
case 2: use_fixed_size = fixed_size; break;
}
cl_assert(use_fixed_size <= fixed_size);
cl_git_pass(git_zstream_init(&zs, GIT_ZSTREAM_DEFLATE));
cl_git_pass(git_zstream_set_input(&zs, input->ptr, input->size));
while (!git_zstream_done(&zs)) {
size_t written = use_fixed_size;
cl_git_pass(git_zstream_get_output(fixed, &written, &zs));
cl_git_pass(git_str_put(&out2, fixed, written));
}
git_zstream_free(&zs);
assert_zlib_equal(input->ptr, input->size, out2.ptr, out2.size);
/* did both approaches give the same data? */
cl_assert_equal_sz(out1.size, out2.size);
cl_assert(!memcmp(out1.ptr, out2.ptr, out1.size));
git_str_dispose(&out2);
}
cl_git_pass(git_zstream_inflatebuf(&inflated, out1.ptr, out1.size));
cl_assert_equal_i(input->size, inflated.size);
cl_assert(memcmp(input->ptr, inflated.ptr, inflated.size) == 0);
git_str_dispose(&out1);
git_str_dispose(&inflated);
git__free(fixed);
}
void test_core_zstream__big_data(void)
{
git_str in = GIT_STR_INIT;
size_t scan, target;
for (target = 1024; target <= 1024 * 1024 * 4; target *= 8) {
/* make a big string that's easy to compress */
git_str_clear(&in);
while (in.size < target)
cl_git_pass(
git_str_put(&in, BIG_STRING_PART, strlen(BIG_STRING_PART)));
compress_and_decompress_input_various_ways(&in);
/* make a big string that's hard to compress */
srand(0xabad1dea);
for (scan = 0; scan < in.size; ++scan)
in.ptr[scan] = (char)rand();
compress_and_decompress_input_various_ways(&in);
}
git_str_dispose(&in);
}