[PATCH 1/8] odb: refactor parsing of alternates to be self-contained
From: Patrick Steinhardt <hidden>
Date: 2025-12-08 08:04:34
Subsystem:
the rest · Maintainer:
Linus Torvalds
Parsing of the alternates file and environment variable is currently
split up across multiple different functions and is entangled with
`link_alt_odb_entries()`, which is responsible for linking the parsed
object database sources. This results in two downsides:
- We have mutual recursion between parsing alternates and linking them
into the object database. This is because we also parse alternates
that the newly added sources may have.
- We mix up the actual logic to parse the data and to link them into
place.
Refactor the logic so that parsing of the alternates file is entirely
self-contained. Note that this doesn't yet fix the above two issues, but
it is a necessary step to get there.
Signed-off-by: Patrick Steinhardt <redacted>
---
odb.c | 70 ++++++++++++++++++++++++++++++++++++++-----------------------------
1 file changed, 40 insertions(+), 30 deletions(-)
diff --git a/odb.c b/odb.c
index dc8f292f3d..9785f62cb6 100644
--- a/odb.c
+++ b/odb.c@@ -216,39 +216,50 @@ static struct odb_source *link_alt_odb_entry(struct object_database *odb, return alternate; } -static const char *parse_alt_odb_entry(const char *string, - int sep, - struct strbuf *out) +static void parse_alternates(const char *string, + int sep, + struct strvec *out) { - const char *end; + struct strbuf buf = STRBUF_INIT; - strbuf_reset(out); + while (*string) { + const char *end; + + strbuf_reset(&buf); + + if (*string == '#') { + /* comment; consume up to next separator */ + end = strchrnul(string, sep); + } else if (*string == '"' && !unquote_c_style(&buf, string, &end)) { + /* + * quoted path; unquote_c_style has copied the + * data for us and set "end". Broken quoting (e.g., + * an entry that doesn't end with a quote) falls + * back to the unquoted case below. + */ + } else { + /* normal, unquoted path */ + end = strchrnul(string, sep); + strbuf_add(&buf, string, end - string); + } - if (*string == '#') { - /* comment; consume up to next separator */ - end = strchrnul(string, sep); - } else if (*string == '"' && !unquote_c_style(out, string, &end)) { - /* - * quoted path; unquote_c_style has copied the - * data for us and set "end". Broken quoting (e.g., - * an entry that doesn't end with a quote) falls - * back to the unquoted case below. - */ - } else { - /* normal, unquoted path */ - end = strchrnul(string, sep); - strbuf_add(out, string, end - string); + if (*end) + end++; + string = end; + + if (!buf.len) + continue; + + strvec_push(out, buf.buf); } - if (*end) - end++; - return end; + strbuf_release(&buf); } static void link_alt_odb_entries(struct object_database *odb, const char *alt, int sep, const char *relative_base, int depth) { - struct strbuf dir = STRBUF_INIT; + struct strvec alternates = STRVEC_INIT; if (!alt || !*alt) return;
@@ -259,13 +270,12 @@ static void link_alt_odb_entries(struct object_database *odb, const char *alt, return; } - while (*alt) { - alt = parse_alt_odb_entry(alt, sep, &dir); - if (!dir.len) - continue; - link_alt_odb_entry(odb, dir.buf, relative_base, depth); - } - strbuf_release(&dir); + parse_alternates(alt, sep, &alternates); + + for (size_t i = 0; i < alternates.nr; i++) + link_alt_odb_entry(odb, alternates.v[i], relative_base, depth); + + strvec_clear(&alternates); } static void read_info_alternates(struct object_database *odb,
--
2.52.0.270.g3f4935d65f.dirty