Currently nsAtom::mString points to the interior of an nsStringBuffer. For
static atoms this requires the use of nsFakeStringBuffer, which is pretty
gross.
This patch changes things so that nsAtom::mString points to a static char
buffer for static atoms. This simplifies a number of things:
- nsFakeStringBuffer and CheckStaticAtomSizes are no longer needed.
- FakeBufferRefCountHelper is no longer needed.
- nsAtom's constructor for static atoms is simpler.
- RegisterStaticAtoms() is simpler.
On the flip-side, a couple of things get more complicated.
- nsAtom::ToString() treats static and dynamic atoms differently.
- nsAtom::GetStringBuffer() is now only valid for dynamic atoms. This
function is only used in two places, both involving DOMString, so those
locations are updated appropriately. This also requires updating some other
code assigning nsStrings to DOMStrings, because we can't assume that
nsStrings are shared.
On Linux64 this change reduces the size of the binary by 8752 B, and moves
81968 B from the .data to the .rodata section, where it can be shared between
processes.
(Path is actually r=froydnj.)
Bug 1400459 devirtualized nsIAtom so that it is no longer a subclass of
nsISupports. This means that nsAtom is now a better name for it than nsIAtom.
MozReview-Commit-ID: 91U22X2NydP
Inserting/removing things into a doubly-linked list is much faster than doing
the same with a hashtable. Selection ranges register themselves on their common
ancestor, but all we do with that in non-debug code is iterate all the ranges
registered. A doubly-linked list works fine for that.
This adds three words to every range for the LinkedListItem members, but that
should be OK.
Inserting/removing things into a doubly-linked list is much faster than doing
the same with a hashtable. Selection ranges register themselves on their common
ancestor, but all we do with that in non-debug code is iterate all the ranges
registered. A doubly-linked list works fine for that.
This adds three words to every range for the LinkedListItem members, but that
should be OK.
This is a purely non-functional plumbing change. Instead of passing a
SizeOfState and an nsStyleSizes a bunch of places, we pass an nsWindowSizes,
which contains both of them.
This is a necessary precursor for the next patch.
MozReview-Commit-ID: Ek03wDM50rB
This patch moves measurement of ComputedValues objects from Rust to C++.
Measurement now happens (a) via DOM elements and (b) remaining elements via
the frame tree. Likewise for the style structs hanging off ComputedValues
objects.
Here is an example of the output.
> ├──27,600,448 B (26.49%) -- active/window(https://en.wikipedia.org/wiki/Barack_Obama)
> │ ├──12,772,544 B (12.26%) -- layout
> │ │ ├───4,483,744 B (04.30%) -- frames
> │ │ │ ├──1,653,552 B (01.59%) ── nsInlineFrame
> │ │ │ ├──1,415,760 B (01.36%) ── nsTextFrame
> │ │ │ ├────431,376 B (00.41%) ── nsBlockFrame
> │ │ │ ├────340,560 B (00.33%) ── nsHTMLScrollFrame
> │ │ │ ├────302,544 B (00.29%) ── nsContinuingTextFrame
> │ │ │ ├────156,408 B (00.15%) ── nsBulletFrame
> │ │ │ ├─────73,024 B (00.07%) ── nsPlaceholderFrame
> │ │ │ ├─────27,656 B (00.03%) ── sundries
> │ │ │ ├─────23,520 B (00.02%) ── nsTableCellFrame
> │ │ │ ├─────16,704 B (00.02%) ── nsImageFrame
> │ │ │ ├─────15,488 B (00.01%) ── nsTableRowFrame
> │ │ │ ├─────13,776 B (00.01%) ── nsTableColFrame
> │ │ │ └─────13,376 B (00.01%) ── nsTableFrame
> │ │ ├───3,412,192 B (03.28%) -- servo-style-structs
> │ │ │ ├──1,288,224 B (01.24%) ── Display
> │ │ │ ├────742,400 B (00.71%) ── Position
> │ │ │ ├────308,736 B (00.30%) ── Font
> │ │ │ ├────226,512 B (00.22%) ── Background
> │ │ │ ├────218,304 B (00.21%) ── TextReset
> │ │ │ ├────214,896 B (00.21%) ── Text
> │ │ │ ├────130,560 B (00.13%) ── Border
> │ │ │ ├─────81,408 B (00.08%) ── UIReset
> │ │ │ ├─────61,440 B (00.06%) ── Padding
> │ │ │ ├─────38,176 B (00.04%) ── UserInterface
> │ │ │ ├─────29,232 B (00.03%) ── Margin
> │ │ │ ├─────21,824 B (00.02%) ── sundries
> │ │ │ ├─────20,080 B (00.02%) ── Color
> │ │ │ ├─────20,080 B (00.02%) ── Column
> │ │ │ └─────10,320 B (00.01%) ── Effects
> │ │ ├───2,227,680 B (02.14%) -- computed-values
> │ │ │ ├──1,182,928 B (01.14%) ── non-dom
> │ │ │ └──1,044,752 B (01.00%) ── dom
> │ │ ├───1,500,016 B (01.44%) ── text-runs
> │ │ ├─────492,640 B (00.47%) ── line-boxes
> │ │ ├─────326,688 B (00.31%) ── frame-properties
> │ │ ├─────301,760 B (00.29%) ── pres-shell
> │ │ ├──────27,648 B (00.03%) ── pres-contexts
> │ │ └─────────176 B (00.00%) ── style-sets
The 'servo-style-structs' and 'computed-values' sub-trees are new. (Prior to
this patch, ComputedValues under DOM elements were tallied under the the
'dom/element-nodes' sub-tree, and ComputedValues not under DOM element were
ignored.) 'servo-style-structs/sundries' aggregates all the style structs that
are smaller than 8 KiB.
Other notable things done by the patch are as follows.
- It significantly changes the signatures of the methods measuring nsINode and
its subclasses, in order to handle the tallying of style structs separately
from element-nodes. Likewise for nsIFrame.
- It renames the 'layout/style-structs' sub-tree as
'layout/gecko-style-structs', to clearly distinguish it from the new
'layout/servo-style-structs' sub-tree.
- It adds some FFI functions to access various Rust-side data structures from
C++ code.
- There is a nasty hack used twice to measure Arcs, by stepping backwards from
an interior pointer to a base pointer. It works, but I want to replace it
with something better eventually. The "XXX WARNING" comments have details.
- It makes DMD print a line to the console if it sees a pointer it doesn't
recognise. This is useful for detecting when we are measuring an interior
pointer instead of a base pointer, which is bad but easy to do when Arcs are
involved.
- It removes the Rust code for measuring CVs, because it's now all done on the
C++ side.
MozReview-Commit-ID: BKebACLKtCi
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.
Unfortunately, nsGenericHTMLElement::GetAssociatedEditor() cannot use concrete classes because it may return nsIEditor which is set via nsIDocShell.editor. The editor set to nsIDocShell may be implemented by JS since nsIEditor isn't marked as builtinclass.
MozReview-Commit-ID: 6GY9LOYp4hM
Currently, attribute and child arrays (implemented in dom/base/nsAttrAndChildArray.h) start out empty. When cloning, the array ends up being resized multiple times in order to add the attributes and children that are being cloned from the original node. This would be quicker if the array was initialized to the correct size in the first place so that resizes are not necessary.
However, preallocating space for children is only necessary when performing a deep clone. Therefore, an additional parameter is being added to the Clone, CopyInnerTo, and CloneDocHelper methods to indicate whether preallocation of children should happen. Attributes are copied either way, so that part of the array is preallocated in both cases.
MozReview-Commit-ID: 3iVezeAKXnI
We can remove unnecesasary SMILMappedAttribute and SMILAttrAnimationRuleProcessor since earlier patches in this serieas mean this code is no longer used.
MozReview-Commit-ID: 5Rl5WFW5zZ1
We can remove unnecesasary SMILMappedAttribute and SMILAttrAnimationRuleProcessor since earlier patches in this serieas mean this code is no longer used.
MozReview-Commit-ID: 5Rl5WFW5zZ1
This fits a bit better with the other stuff, and allows us to add our new NAC
bit with the other NAC related bits, which also happens to be a field that
Servo already has easy access to.
