Currently, Chromium stores segmented data in a SharedBuffer and appends
to SkRWBuffer one segment at a time:
const char* segment = 0;
for (size_t length = data->getSomeData(segment, m_rwBuffer->size());
length; length = data->getSomeData(segment, m_rwBuffer->size())) {
m_rwBuffer->append(segment, length, remaining);
}
This can yield a bunch of just-above-4k allocations => wasted RAM due to
internal fragmentation.
Ideally, we'd want a SkRWBuffer::reserve(size_t bytes) API, but the
current internals don't support that trivially.
Alternatively, the caller can pass a reserve hint at append() time.
BUG=chromium:651698
R=scroggo@google.com,reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2385803002
Review-Url: https://codereview.chromium.org/2385803002
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