Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-12-07 05:15:09 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Bug 696233. Switch the nth-index cache to having a single hashtable per selector type (from end vs from start and of-type vs not-of-type). Gives somewhat better cache locality on some workloads and makes entry addition much cheaper because we no longer need to initialize all the new memory when the hashtable store is resized; we just initialize the parts of it we need as we need them. r=smaug

Browse Source
This commit is contained in:
Boris Zbarsky 2011-10-26 15:34:20 -04:00
parent 63d3c04397
commit 1c68a1582a
2 changed files with 40 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
layout/style/nsNthIndexCache.cpp
View File

@ -56,7 +56,10 @@ nsNthIndexCache::~nsNthIndexCache()
void
nsNthIndexCache::Reset()
{
mCache.clear();
mCaches[0][0].clear();
mCaches[0][1].clear();
mCaches[1][0].clear();
mCaches[1][1].clear();
}
inline bool
@ -73,12 +76,13 @@ nsNthIndexCache::IndexDeterminedFromPreviousSibling(nsIContent* aSibling,
Element* aChild,
bool aIsOfType,
bool aIsFromEnd,
const Cache& aCache,
PRInt32& aResult)
{
if (SiblingMatchesElement(aSibling, aChild, aIsOfType)) {
Cache::Ptr siblingEntry = mCache.lookup(aSibling);
Cache::Ptr siblingEntry = aCache.lookup(aSibling);
if (siblingEntry) {
PRInt32 siblingIndex = siblingEntry->value.mNthIndices[aIsOfType][aIsFromEnd];
PRInt32 siblingIndex = siblingEntry->value;
NS_ASSERTION(siblingIndex != 0,
"How can a non-anonymous node have an anonymous sibling?");
if (siblingIndex > 0) {
@ -110,19 +114,22 @@ nsNthIndexCache::GetNthIndex(Element* aChild, bool aIsOfType,
return 0;
}
if (!mCache.initialized() && !mCache.init()) {
Cache &cache = mCaches[aIsOfType][aIsFromEnd];
if (!cache.initialized() && !cache.init()) {
// Give up and just don't match.
return 0;
}
Cache::AddPtr entry = mCache.lookupForAdd(aChild);
if (!entry && !mCache.add(entry, aChild)) {
Cache::AddPtr entry = cache.lookupForAdd(aChild);
// Default the value to -2 when adding
if (!entry && !cache.add(entry, aChild, -2)) {
// No good; don't match.
return 0;
}
PRInt32 &slot = entry->value.mNthIndices[aIsOfType][aIsFromEnd];
PRInt32 &slot = entry->value;
if (slot != -2 && (slot != -1 || aCheckEdgeOnly)) {
return slot;
}
@ -157,7 +164,7 @@ nsNthIndexCache::GetNthIndex(Element* aChild, bool aIsOfType,
cur;
cur = cur->GetPreviousSibling()) {
if (IndexDeterminedFromPreviousSibling(cur, aChild, aIsOfType,
aIsFromEnd, result)) {
aIsFromEnd, cache, result)) {
slot = result;
return result;
}

53
layout/style/nsNthIndexCache.h
View File

@ -80,6 +80,23 @@ private:
inline bool SiblingMatchesElement(nsIContent* aSibling, Element* aElement,
bool aIsOfType);
// This node's index for this cache.
// If -2, needs to be computed.
// If -1, needs to be computed but known not to be 1.
// If 0, the node is not at any index in its parent.
typedef PRInt32 CacheEntry;
class SystemAllocPolicy {
public:
void *malloc_(size_t bytes) { return ::malloc(bytes); }
void *realloc_(void *p, size_t bytes) { return ::realloc(p, bytes); }
void free_(void *p) { ::free(p); }
void reportAllocOverflow() const {}
};
typedef js::HashMap<nsIContent*, CacheEntry, js::DefaultHasher<nsIContent*>,
SystemAllocPolicy> Cache;
/**
* Returns true if aResult has been set to the correct value for aChild and
* no more work needs to be done. Returns false otherwise.
@ -95,37 +112,15 @@ private:
Element* aChild,
bool aIsOfType,
bool aIsFromEnd,
const Cache& aCache,
PRInt32& aResult);
struct CacheEntry {
CacheEntry() {
mNthIndices[0][0] = -2;
mNthIndices[0][1] = -2;
mNthIndices[1][0] = -2;
mNthIndices[1][1] = -2;
}
// This node's index for :nth-child(), :nth-last-child(),
// :nth-of-type(), :nth-last-of-type(). If -2, needs to be computed.
// If -1, needs to be computed but known not to be 1.
// If 0, the node is not at any index in its parent.
// The first subscript is 0 for -child and 1 for -of-type, the second
// subscript is 0 for nth- and 1 for nth-last-.
PRInt32 mNthIndices[2][2];
};
class SystemAllocPolicy {
public:
void *malloc_(size_t bytes) { return ::malloc(bytes); }
void *realloc_(void *p, size_t bytes) { return ::realloc(p, bytes); }
void free_(void *p) { ::free(p); }
void reportAllocOverflow() const {}
};
typedef js::HashMap<nsIContent*, CacheEntry, js::DefaultHasher<nsIContent*>,
SystemAllocPolicy> Cache;
Cache mCache;
// Caches of indices for :nth-child(), :nth-last-child(),
// :nth-of-type(), :nth-last-of-type(), keyed by Element*.
//
// The first subscript is 0 for -child and 1 for -of-type, the second
// subscript is 0 for nth- and 1 for nth-last-.
Cache mCaches[2][2];
};
#endif /* nsContentIndexCache_h__ */