Regardless of the size of an encoded image, SourceBuffer::Compact would
try to consolidate all of the chunks into a single chunk. If an image is
quite large, it can be actively harmful to do this, because we want a
very large contiguous chunk of memory for no real reason, and spend
extra time on the main thread doing the memcpy/consolidation.
Instead we now cap out the chunk size at 20MB. If we start allocating
chunks of this size, we will not perform compacting when we have
received all of the data. (Save for realloc'ing the last chunk since it
probably isn't full.)
On a related note, if we hit an out-of-memory condition in the middle of
appending data to the SourceBuffer, we would swallow the error. This is
because nsIInputStream::ReadSegments will succeed if any data was
written. This leaves the SourceBuffer out of sync. We now propogate this
error up properly to the higher levels.
fixup
When we need to recreate an animated image decoder because it was
discarded, the animation may have progressed beyond the first frame.
Given that later in the patch series we need FrameAnimator to be driving
the decoding more actively, it simplifies its role by making it assume
the initial state of the decoder matches its initial state. Passing in
the currently displayed frame allows the decoder to advance its frame
buffer (and potentially discard unnecessary frames), such that when the
animation actually wants to advance as it normally would, the decoder
state matches what it would have been if it had never been discarded.
Note that AnimationSurfaceProvider will override these methods to give a
proper implementation in a later patch in this series. For now, they are
mostly stubbed, using the default implementation from ISurfaceProvider.
They focus on the main operations we perform on an animation:
1) Progressing through the animation, e.g. advancing a frame. If we
don't decode the whole animation up front, we need to know at the
decoder level where we are in the display of the animation.
2) Restarting an animation from the beginning. This is a specialized
case of the above, where we want to skip explicitly advancing through
the remaining frames and instead restart at the beginning. The decoder
may have already discarded the earliest frames and must start redecoding
them.
3) Knowing whether or not the decoder is still active, e.g. can we be
missing frames.
If there is an active provider which has yet to produce a frame, any
calls to SurfaceCache::Lookup will return MatchType::PENDING. If
RasterImage::Lookup gets the above result while given FLAG_SYNC_DECODE,
it will attempt to start a new decoder. It is entirely possible that
when we try to insert the new provider into the SurfaceCache, it cannot
because the original provider finally did produce something. In that
case we should abandon attempting to redecode and retry our lookup.
This adds IsImageContainerAvailableAtSize and GetImageContainerAtSize to
the imgIContainer interface, as well as stubbing it for all of the
classes which implement it. The real implementations will follow for the
more complicated classes (RasterImage, VectorImage).
As part of the move, we add a IntSize parameter to
ImageResource::GetCurrentImage. This is because we don't have access to
the image's size (yet) from ImageResource, but additionally because we
will need this anyways when we support multiple image containers at
different sizes.
The only change to the moved implementation is that we no longer have
access to RasterImage::mHasSize and RasterImage::mSize. Thus we rely
upon imgIContainer::IsImageContainerAvailable to perform these checks.
This state will eventually be used by VectorImage when it supports image
containers. For now, it is harmless beyond using slightly more memory
for SVGs.
Most cases where the pointer is stored into an already-declared variable can
trivially be changed to MakeNotNull<T*>, as the NotNull raw pointer will end
up in a smart pointer.
In RAII cases, the target type can be specified (e.g.:
`MakeNotNull<RefPtr<imgFrame>>)`), in which case the variable type may just be
`auto`, similar to the common use of MakeUnique.
Except when the target type is a base pointer, in which case it must be
specified in the declaration.
MozReview-Commit-ID: BYaSsvMhiDi
--HG--
extra : rebase_source : 8fe6f2aeaff5f515b7af2276c439004fa3a1f3ab
Currently we only permit requests from HTTP channels to be retargeted to
the image IO thread. It was implemented this way originally in bug
867755 but it does not appear there was a specific reason for that.
The only kink in this is some browser chrome mochitests listen on debug
build only events to ensure certain chrome images are loaded and/or
drawn. As such, this patch ensures that those observer notifications
continue to be served, requiring a dispatch from the image IO thread to
the main thread.
Another issue to note is that SVGs must be processed on the main thread;
the underlying SVG document can only be accessed from it. We enforce
this by checking the content type. The possibility already exists that
an HTTP response could contain the wrong content type, and in that case,
we fail to decode the image, as there is no content sniffing support for
SVG. Thus there should be no additional risk taken by using the image IO
thread from other non-HTTP channels (if they don't specify the SVG
content type, it is not rendered today, and if they do, it will remain
on the main thread as it is today).
We also ignore data URIs. The specification requires that we process
these images sychronously. See bug 1325080 for details.
When SurfaceCache::Lookup is called to access surface data, it indicates
that the caller will not accept substitutes as in the case of
SurfaceCache::LookupBestMatch. As such, we need to be careful not to
remove those surfaces from our cache when pruning (in part 8b). This is
the marker used to track that, at some point, there was a caller which
got this surface that would accept no other (e.g. factor of 2 mode must
make an accept for this particular surface).
All the SizeOf{In,Ex}cludingThis() functions take a MallocSizeOf function
which measures memory blocks. This patch introduces a new type, SizeOfState,
which includes a MallocSizeOf function *and* a table of already-measured
pointers, called SeenPtrs. This gives us a general mechanism to measure
graph-like data structures, by recording which nodes have already been
measured. (This approach is used in a number of existing reporters, but not in
a uniform fashion.)
The patch also converts the window memory reporting to use SizeOfState in a lot
of places, all the way through to the measurement of Elements. This is a
precursor for bug 1383977 which will measure Stylo elements, which involve
Arcs.
The patch also converts the existing mAlreadyMeasuredOrphanTrees table in the
OrphanReporter to use the new mechanism.
--HG--
extra : rebase_source : 2c23285f8b6c3b667560a9d14014efc4633aed51
We currently use RasterImage::IsUnlocked for two different purposes:
1) to determine that we can't throw away the decoded image in WillDrawOpaqueNow
2) to determine when to send the unlockeddraw notification
For 1) what we want to check is mLockCount == 0.
For 2) what we actually want to check is mAnimationConsumers == 0. This is because images that are in the visible list in background tabs will have mLockCount == 0 but mAnimationConsumers > 0 and if we are drawing an image we need to make sure it will be animated (mAnimationConsumers == 0 stops the animation). This is what VectorImage already does.
This patch enables startupRecorder.js to collect data on
loaded and shown raster and SVG images on startup via events
from native code. It also adds a test that uses this data
to find images that are unnecessarily loaded.
I've not fixed any of the affected images yet, there's a
fairly comprehensive whitelist that I want to gradually
decrease by opening bugs in the respective components.
MozReview-Commit-ID: 9KqQvKLtZhu
--HG--
extra : rebase_source : 5f75fcd1152f569a5b48e21d4e4821a24f768ecd
This patch enables startupRecorder.js to collect data on
loaded and shown raster and SVG images on startup via events
from native code. It also adds a test that uses this data
to find images that are unnecessarily loaded.
I've not fixed any of the affected images yet, there's a
fairly comprehensive whitelist that I want to gradually
decrease by opening bugs in the respective components.
MozReview-Commit-ID: 9KqQvKLtZhu
--HG--
extra : rebase_source : 856f06320c78ed88c4578fce985b2a526566e825
This patch makes the following changes to the macros.
- Removes PROFILER_LABEL_FUNC. It's only suitable for use in functions outside
classes, due to PROFILER_FUNCTION_NAME not getting class names, and it was
mostly misused.
- Removes PROFILER_FUNCTION_NAME. It's no longer used, and __func__ is
universally available now anyway.
- Combines the first two string literal arguments of PROFILER_LABEL and
PROFILER_LABEL_DYNAMIC into a single argument. There was no good reason for
them to be separate, and it forced a '::' in the label, which isn't always
appropriate. Also, the meaning of the "name_space" argument was interpreted
in an interesting variety of ways.
- Adds an "AUTO_" prefix to PROFILER_LABEL and PROFILER_LABEL_DYNAMIC, to make
it clearer they construct RAII objects rather than just being function calls.
(I myself have screwed up the scoping because of this in the past.)
- Fills in the 'js::ProfileEntry::Category::' qualifier within the macro, so
the caller doesn't need to. This makes a *lot* more of the uses fit onto a
single line.
The patch also makes the following changes to the macro uses (beyond those
required by the changes described above).
- Fixes a bunch of labels that had gotten out of sync with the name of the
class and/or function that encloses them.
- Removes a useless PROFILER_LABEL use within a trivial scope in
EventStateManager::DispatchMouseOrPointerEvent(). It clearly wasn't serving
any useful purpose. It also serves as extra evidence that the AUTO_ prefix is
a good idea.
- Tweaks DecodePool::SyncRunIf{Preferred,Possible} so that the labelling is
done within them, instead of at their callsites, because that's a more
standard way of doing things.
--HG--
extra : rebase_source : 318d1bc6fc1425a94aacbf489dd46e4f83211de4