str: introduce `git_str` for internal, `git_buf` is externalethomson/gitstr

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.

1 files changed, 17 insertions, 18 deletions

diff --git a/tests/core/zstream.c b/tests/core/zstream.c
index 3cbcea168..c22e81008 100644
--- a/tests/core/zstream.c
+++ b/tests/core/zstream.c
@@ -1,5 +1,4 @@
 #include "clar_libgit2.h"
-#include "buffer.h"
 #include "zstream.h"
 
 static const char *data = "This is a test test test of This is a test";
@@ -60,7 +59,7 @@ void test_core_zstream__basic(void)
 
 void test_core_zstream__fails_on_trailing_garbage(void)
 {
-	git_buf deflated = GIT_BUF_INIT, inflated = GIT_BUF_INIT;
+	git_str deflated = GIT_STR_INIT, inflated = GIT_STR_INIT;
 	char i = 0;
 
 	/* compress a simple string */
@@ -68,29 +67,29 @@ void test_core_zstream__fails_on_trailing_garbage(void)
 
 	/* append some garbage */
 	for (i = 0; i < 10; i++) {
-		git_buf_putc(&deflated, i);
+		git_str_putc(&deflated, i);
 	}
 
 	cl_git_fail(git_zstream_inflatebuf(&inflated, deflated.ptr, deflated.size));
 
-	git_buf_dispose(&deflated);
-	git_buf_dispose(&inflated);
+	git_str_dispose(&deflated);
+	git_str_dispose(&inflated);
 }
 
 void test_core_zstream__buffer(void)
 {
-	git_buf out = GIT_BUF_INIT;
+	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_buf_dispose(&out);
+	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_buf *input)
+static void compress_and_decompress_input_various_ways(git_str *input)
 {
-	git_buf out1 = GIT_BUF_INIT, out2 = GIT_BUF_INIT;
-	git_buf inflated = GIT_BUF_INIT;
+	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);
@@ -119,7 +118,7 @@ static void compress_and_decompress_input_various_ways(git_buf *input)
 		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_buf_put(&out2, fixed, written));
+			cl_git_pass(git_str_put(&out2, fixed, written));
 		}
 
 		git_zstream_free(&zs);
@@ -129,30 +128,30 @@ static void compress_and_decompress_input_various_ways(git_buf *input)
 		cl_assert_equal_sz(out1.size, out2.size);
 		cl_assert(!memcmp(out1.ptr, out2.ptr, out1.size));
 
-		git_buf_dispose(&out2);
+		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_buf_dispose(&out1);
-	git_buf_dispose(&inflated);
+	git_str_dispose(&out1);
+	git_str_dispose(&inflated);
 	git__free(fixed);
 }
 
 void test_core_zstream__big_data(void)
 {
-	git_buf in = GIT_BUF_INIT;
+	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_buf_clear(&in);
+		git_str_clear(&in);
 		while (in.size < target)
 			cl_git_pass(
-				git_buf_put(&in, BIG_STRING_PART, strlen(BIG_STRING_PART)));
+				git_str_put(&in, BIG_STRING_PART, strlen(BIG_STRING_PART)));
 
 		compress_and_decompress_input_various_ways(&in);
 
@@ -164,5 +163,5 @@ void test_core_zstream__big_data(void)
 		compress_and_decompress_input_various_ways(&in);
 	}
 
-	git_buf_dispose(&in);
+	git_str_dispose(&in);
 }