diff options
author | Peter Lieven <pl@kamp.de> | 2015-10-30 12:09:56 +0100 |
---|---|---|
committer | Gerd Hoffmann <kraxel@redhat.com> | 2015-11-05 09:08:29 +0100 |
commit | 5c10dbb7b577370e86ff459973b06d530c3777cf (patch) | |
tree | b357398dd2197ba03f51cd82b07380e1faf221c1 | |
parent | 79cf9fad341e6e7bd6b55395b71d5c5727d7f5b0 (diff) |
buffer: make the Buffer capacity increase in powers of two
This makes sure the number of reallocs is in O(log N).
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1446203414-4013-2-git-send-email-kraxel@redhat.com
[ rebased to util/buffer.c ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
-rw-r--r-- | util/buffer.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/util/buffer.c b/util/buffer.c index cedd055680..7ddd693fa8 100644 --- a/util/buffer.c +++ b/util/buffer.c @@ -20,10 +20,13 @@ #include "qemu/buffer.h" +#define BUFFER_MIN_INIT_SIZE 4096 + void buffer_reserve(Buffer *buffer, size_t len) { if ((buffer->capacity - buffer->offset) < len) { - buffer->capacity += (len + 1024); + buffer->capacity = pow2ceil(buffer->offset + len); + buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE); buffer->buffer = g_realloc(buffer->buffer, buffer->capacity); } } |