firefox-main/layout/tables/SpanningCellSorter.cpp (file symbol)

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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* Code to sort cells by their colspan, used by BasicTableLayoutStrategy.
*/
#include "SpanningCellSorter.h"
#include "nsTArray.h"
using namespace mozilla;
// #define DEBUG_SPANNING_CELL_SORTER
SpanningCellSorter::SpanningCellSorter() = default;
SpanningCellSorter::~SpanningCellSorter() = default;
bool SpanningCellSorter::AddCell(int32_t aColSpan, int32_t aRow, int32_t aCol) {
NS_ASSERTION(mState == ADDING, "cannot call AddCell after GetNext");
NS_ASSERTION(aColSpan >= ARRAY_BASE, "cannot add cells with colspan<2");
Item* i = (Item*)mozilla::AutoStackArena::Allocate(sizeof(Item));
NS_ENSURE_TRUE(i != nullptr, false);
i->row = aRow;
i->col = aCol;
if (UseArrayForSpan(aColSpan)) {
int32_t index = SpanToIndex(aColSpan);
i->next = mArray[index];
mArray[index] = i;
} else {
Item*& entryItems = mHashTable.LookupOrInsert(aColSpan, nullptr);
i->next = entryItems;
entryItems = i;
}
return true;
}
SpanningCellSorter::Item* SpanningCellSorter::GetNext(int32_t* aColSpan) {
NS_ASSERTION(mState != DONE, "done enumerating, stop calling");
// Our comparator needs the SpanningCellSorter private HashTableEntry
class HashTableEntryComparator {
public:
bool Equals(HashTableEntry* left, HashTableEntry* right) const {
return left->GetKey() == right->GetKey();
}
bool LessThan(HashTableEntry* left, HashTableEntry* right) const {
return left->GetKey() < right->GetKey();
}
};
switch (mState) {
case ADDING:
/* prepare to enumerate the array */
mState = ENUMERATING_ARRAY;
mEnumerationIndex = 0;
[[fallthrough]];
case ENUMERATING_ARRAY:
while (mEnumerationIndex < ARRAY_SIZE && !mArray[mEnumerationIndex]) {
++mEnumerationIndex;
}
if (mEnumerationIndex < ARRAY_SIZE) {
Item* result = mArray[mEnumerationIndex];
*aColSpan = IndexToSpan(mEnumerationIndex);
NS_ASSERTION(result, "logic error");
#ifdef DEBUG_SPANNING_CELL_SORTER
printf(
"SpanningCellSorter[%p]:"
" returning list for colspan=%d from array\n",
static_cast<void*>(this), *aColSpan);
#endif
++mEnumerationIndex;
return result;
}
/* prepare to enumerate the hash */
mState = ENUMERATING_HASH;
mEnumerationIndex = 0;
if (!mHashTable.IsEmpty()) {
// This clear is a no-op if the array is empty and it makes us
// resilient against re-entrance.
mSortedHashTable.ClearAndRetainStorage();
mSortedHashTable.SetCapacity(mHashTable.Count());
for (HashTableEntry& entry : mHashTable) {
mSortedHashTable.AppendElement(&entry);
}
mSortedHashTable.Sort(HashTableEntryComparator());
}
[[fallthrough]];
case ENUMERATING_HASH:
if (mEnumerationIndex < mSortedHashTable.Length()) {
Item* result = mSortedHashTable[mEnumerationIndex]->GetData();
*aColSpan = mSortedHashTable[mEnumerationIndex]->GetKey();
NS_ASSERTION(result, "holes in hash table");
#ifdef DEBUG_SPANNING_CELL_SORTER
printf(
"SpanningCellSorter[%p]:"
" returning list for colspan=%d from hash\n",
static_cast<void*>(this), *aColSpan);
#endif
++mEnumerationIndex;
return result;
}
mState = DONE;
[[fallthrough]];
case DONE:;
}
return nullptr;
}