From 7cdca2e2337e82953495b907c60df3115a268428 Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Wed, 15 Jan 2020 14:56:26 +0100 Subject: [PATCH] qcow2: Use a GString in report_unsupported_feature() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This is a bit more efficient than having to allocate and free memory for each item. The default size (60) is enough for all the existing incompatible features or the "Unknown incompatible feature" message. Suggested-by: Philippe Mathieu-Daudé Signed-off-by: Alberto Garcia Reviewed-by: Alex Bennée Message-id: 20200115135626.19442-1-berto@igalia.com Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Stefano Garzarella Signed-off-by: Max Reitz --- block/qcow2.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index cef9d72b3a..e29fc07068 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -453,16 +453,15 @@ static void cleanup_unknown_header_ext(BlockDriverState *bs) static void report_unsupported_feature(Error **errp, Qcow2Feature *table, uint64_t mask) { - char *features = g_strdup(""); - char *old; + g_autoptr(GString) features = g_string_sized_new(60); while (table && table->name[0] != '\0') { if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { if (mask & (1ULL << table->bit)) { - old = features; - features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : "", - table->name); - g_free(old); + if (features->len > 0) { + g_string_append(features, ", "); + } + g_string_append_printf(features, "%.46s", table->name); mask &= ~(1ULL << table->bit); } } @@ -470,14 +469,14 @@ static void report_unsupported_feature(Error **errp, Qcow2Feature *table, } if (mask) { - old = features; - features = g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64, - old, *old ? ", " : "", mask); - g_free(old); + if (features->len > 0) { + g_string_append(features, ", "); + } + g_string_append_printf(features, + "Unknown incompatible feature: %" PRIx64, mask); } - error_setg(errp, "Unsupported qcow2 feature(s): %s", features); - g_free(features); + error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); } /* -- 2.30.2