[PATCH 4/6] fast-import: avoid awkward use of `strbuf_attach()`
- From
- Martin Ågren <martin.agren@gmail.com>
- Date
- Apr 18, 2020, 20:18 UTC
- Message-ID
- <5db92b51c0363694c72b2de0c841449fa4e03f28.1587240635.git.martin.agren@gmail.com>
- In-Reply-To
- <cover.1587240635.git.martin.agren@gmail.com>
As explained in an earlier commit, per the documentation of `strbuf_attach()`, it is incorrect to pass in the same value for `alloc` as we do for `len`. But, and this was also explained earlier, doing so is still ok-ish because we'll end up allocating a large enough buffer under the hood.
But then one really has to wonder whether
strbuf_attach(&sb, buf, size, size);
is any better than
strbuf_reset(&sb); strbuf_add(&sb, buf, size); free(buf);
The latter is certainly a lot less subtle about what is going on, and if we're lucky, the strbuf's allocated buffer is large enough that we won't even need to allocate. So let's change to this more explicit form.
In short, this commit should not make things any worse.
Nearby commits are changing other callsites to pass in a larger 'alloc` parameter. Maybe that's safe here, too -- I admit I don't quite follow where this memory comes from. In the future, we could possibly switch back to `strbuf_attach()` here after looking into the allocations in more detail. The immediate reason for this commit is that we want to simplify the usage of `strbuf_attach()`, and we won't be able to pass in "size, size" any more.
Signed-off-by: Martin Ågren <martin.agren@gmail.com> --- fast-import.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fast-import.c b/fast-import.c index 202dda11a6..7fd501c5cf 100644 --- a/fast-import.c +++ b/fast-import.c @@ -2946,10 +2946,11 @@ static void cat_blob(struct object_entry *oe, struct object_id *oid) cat_blob_write("\n", 1); if (oe && oe->pack_id == pack_id) { last_blob.offset = oe->idx.offset; - strbuf_attach(&last_blob.data, buf, size, size); + strbuf_reset(&last_blob.data); + strbuf_add(&last_blob.data, buf, size); last_blob.depth = oe->depth; - } else - free(buf); + } + free(buf); } static void parse_get_mark(const char *p)
-- 2.26.1