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, 31 insertions, 31 deletions

diff --git a/src/revparse.c b/src/revparse.c
index b4d5d4759..cf39936a5 100644
--- a/src/revparse.c
+++ b/src/revparse.c
@@ -7,7 +7,7 @@
 
 #include "common.h"
 
-#include "buffer.h"
+#include "str.h"
 #include "tree.h"
 #include "refdb.h"
 #include "regexp.h"
@@ -145,7 +145,7 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out,
 	size_t i, numentries, cur;
 	const git_reflog_entry *entry;
 	const char *msg;
-	git_buf buf = GIT_BUF_INIT;
+	git_str buf = GIT_STR_INIT;
 
 	cur = position;
 
@@ -179,16 +179,16 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out,
 		if (cur > 0)
 			continue;
 
-		if ((git_buf_put(&buf, msg+regexmatches[1].start, regexmatches[1].end - regexmatches[1].start)) < 0)
+		if ((git_str_put(&buf, msg+regexmatches[1].start, regexmatches[1].end - regexmatches[1].start)) < 0)
 			goto cleanup;
 
-		if ((error = git_reference_dwim(base_ref, repo, git_buf_cstr(&buf))) == 0)
+		if ((error = git_reference_dwim(base_ref, repo, git_str_cstr(&buf))) == 0)
 			goto cleanup;
 
 		if (error < 0 && error != GIT_ENOTFOUND)
 			goto cleanup;
 
-		error = maybe_abbrev(out, repo, git_buf_cstr(&buf));
+		error = maybe_abbrev(out, repo, git_str_cstr(&buf));
 
 		goto cleanup;
 	}
@@ -197,7 +197,7 @@ static int retrieve_previously_checked_out_branch_or_revision(git_object **out,
 
 cleanup:
 	git_reference_free(ref);
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 	git_regexp_dispose(&preg);
 	git_reflog_free(reflog);
 	return error;
@@ -314,12 +314,12 @@ static int handle_at_syntax(git_object **out, git_reference **ref, const char *s
 {
 	bool is_numeric;
 	int parsed = 0, error = -1;
-	git_buf identifier = GIT_BUF_INIT;
+	git_str identifier = GIT_STR_INIT;
 	git_time_t timestamp;
 
 	GIT_ASSERT(*out == NULL);
 
-	if (git_buf_put(&identifier, spec, identifier_len) < 0)
+	if (git_str_put(&identifier, spec, identifier_len) < 0)
 		return -1;
 
 	is_numeric = !try_parse_numeric(&parsed, curly_braces_content);
@@ -331,15 +331,15 @@ static int handle_at_syntax(git_object **out, git_reference **ref, const char *s
 
 	if (is_numeric) {
 		if (parsed < 0)
-			error = retrieve_previously_checked_out_branch_or_revision(out, ref, repo, git_buf_cstr(&identifier), -parsed);
+			error = retrieve_previously_checked_out_branch_or_revision(out, ref, repo, git_str_cstr(&identifier), -parsed);
 		else
-			error = retrieve_revobject_from_reflog(out, ref, repo, git_buf_cstr(&identifier), parsed);
+			error = retrieve_revobject_from_reflog(out, ref, repo, git_str_cstr(&identifier), parsed);
 
 		goto cleanup;
 	}
 
 	if (!strcmp(curly_braces_content, "u") || !strcmp(curly_braces_content, "upstream")) {
-		error = retrieve_remote_tracking_reference(ref, git_buf_cstr(&identifier), repo);
+		error = retrieve_remote_tracking_reference(ref, git_str_cstr(&identifier), repo);
 
 		goto cleanup;
 	}
@@ -347,10 +347,10 @@ static int handle_at_syntax(git_object **out, git_reference **ref, const char *s
 	if (git__date_parse(&timestamp, curly_braces_content) < 0)
 		goto cleanup;
 
-	error = retrieve_revobject_from_reflog(out, ref, repo, git_buf_cstr(&identifier), (size_t)timestamp);
+	error = retrieve_revobject_from_reflog(out, ref, repo, git_str_cstr(&identifier), (size_t)timestamp);
 
 cleanup:
-	git_buf_dispose(&identifier);
+	git_str_dispose(&identifier);
 	return error;
 }
 
@@ -520,9 +520,9 @@ static int handle_caret_curly_syntax(git_object **out, git_object *obj, const ch
 	return git_object_peel(out, obj, expected_type);
 }
 
-static int extract_curly_braces_content(git_buf *buf, const char *spec, size_t *pos)
+static int extract_curly_braces_content(git_str *buf, const char *spec, size_t *pos)
 {
-	git_buf_clear(buf);
+	git_str_clear(buf);
 
 	GIT_ASSERT_ARG(spec[*pos] == '^' || spec[*pos] == '@');
 
@@ -537,7 +537,7 @@ static int extract_curly_braces_content(git_buf *buf, const char *spec, size_t *
 		if (spec[*pos] == '\0')
 			return GIT_EINVALIDSPEC;
 
-		if (git_buf_putc(buf, spec[(*pos)++]) < 0)
+		if (git_str_putc(buf, spec[(*pos)++]) < 0)
 			return -1;
 	}
 
@@ -546,18 +546,18 @@ static int extract_curly_braces_content(git_buf *buf, const char *spec, size_t *
 	return 0;
 }
 
-static int extract_path(git_buf *buf, const char *spec, size_t *pos)
+static int extract_path(git_str *buf, const char *spec, size_t *pos)
 {
-	git_buf_clear(buf);
+	git_str_clear(buf);
 
 	GIT_ASSERT_ARG(spec[*pos] == ':');
 
 	(*pos)++;
 
-	if (git_buf_puts(buf, spec + *pos) < 0)
+	if (git_str_puts(buf, spec + *pos) < 0)
 		return -1;
 
-	*pos += git_buf_len(buf);
+	*pos += git_str_len(buf);
 
 	return 0;
 }
@@ -610,7 +610,7 @@ static int object_from_reference(git_object **object, git_reference *reference)
 static int ensure_base_rev_loaded(git_object **object, git_reference **reference, const char *spec, size_t identifier_len, git_repository *repo, bool allow_empty_identifier)
 {
 	int error;
-	git_buf identifier = GIT_BUF_INIT;
+	git_str identifier = GIT_STR_INIT;
 
 	if (*object != NULL)
 		return 0;
@@ -621,11 +621,11 @@ static int ensure_base_rev_loaded(git_object **object, git_reference **reference
 	if (!allow_empty_identifier && identifier_len == 0)
 		return GIT_EINVALIDSPEC;
 
-	if (git_buf_put(&identifier, spec, identifier_len) < 0)
+	if (git_str_put(&identifier, spec, identifier_len) < 0)
 		return -1;
 
-	error = revparse_lookup_object(object, reference, repo, git_buf_cstr(&identifier));
-	git_buf_dispose(&identifier);
+	error = revparse_lookup_object(object, reference, repo, git_str_cstr(&identifier));
+	git_str_dispose(&identifier);
 
 	return error;
 }
@@ -669,7 +669,7 @@ static int revparse(
 {
 	size_t pos = 0, identifier_len = 0;
 	int error = -1, n;
-	git_buf buf = GIT_BUF_INIT;
+	git_str buf = GIT_STR_INIT;
 
 	git_reference *reference = NULL;
 	git_object *base_rev = NULL;
@@ -698,7 +698,7 @@ static int revparse(
 				if ((error = extract_curly_braces_content(&buf, spec, &pos)) < 0)
 					goto cleanup;
 
-				if ((error = handle_caret_curly_syntax(&temp_object, base_rev, git_buf_cstr(&buf))) < 0)
+				if ((error = handle_caret_curly_syntax(&temp_object, base_rev, git_str_cstr(&buf))) < 0)
 					goto cleanup;
 
 				git_object_free(base_rev);
@@ -750,11 +750,11 @@ static int revparse(
 				if ((error = ensure_base_rev_loaded(&base_rev, &reference, spec, identifier_len, repo, true)) < 0)
 					goto cleanup;
 
-				if ((error = handle_colon_syntax(&temp_object, base_rev, git_buf_cstr(&buf))) < 0)
+				if ((error = handle_colon_syntax(&temp_object, base_rev, git_str_cstr(&buf))) < 0)
 					goto cleanup;
 			} else {
-				if (*git_buf_cstr(&buf) == '/') {
-					if ((error = handle_grep_syntax(&temp_object, repo, NULL, git_buf_cstr(&buf) + 1)) < 0)
+				if (*git_str_cstr(&buf) == '/') {
+					if ((error = handle_grep_syntax(&temp_object, repo, NULL, git_str_cstr(&buf) + 1)) < 0)
 						goto cleanup;
 				} else {
 
@@ -783,7 +783,7 @@ static int revparse(
 				if ((error = ensure_base_rev_is_not_known_yet(base_rev)) < 0)
 					goto cleanup;
 
-				if ((error = handle_at_syntax(&temp_object, &reference, spec, identifier_len, repo, git_buf_cstr(&buf))) < 0)
+				if ((error = handle_at_syntax(&temp_object, &reference, spec, identifier_len, repo, git_str_cstr(&buf))) < 0)
 					goto cleanup;
 
 				if (temp_object != NULL)
@@ -824,7 +824,7 @@ cleanup:
 		git_reference_free(reference);
 	}
 
-	git_buf_dispose(&buf);
+	git_str_dispose(&buf);
 	return error;
 }