The Tor Browser: layout/tables/SpanningCellSorter.h@deefc01c0e14

Integrate friendly tips from Tor colleagues to make (or not) 4.5 alpha 3;
This includes removal of overloaded (but unused) methods, and addition of
a overlooked call to DataStruct::SetData(nsISupports, uint32_t, bool.)

     1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

     2 // vim:cindent:ts=4:et:sw=4:

     3 /* This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #ifndef SpanningCellSorter_h

     8 #define SpanningCellSorter_h

    10 /*

    11  * Code to sort cells by their colspan, used by BasicTableLayoutStrategy.

    12  */

    14 #include "pldhash.h"

    15 #include "nsDebug.h"

    16 #include "StackArena.h"

    18 class nsIPresShell;

    20 /**

    21  * The SpanningCellSorter is responsible for accumulating lists of cells

    22  * with colspans so that those cells can later be enumerated, sorted

    23  * from lowest number of columns spanned to highest.  It does not use a

    24  * stable sort (in fact, it currently reverses).

    25  */

    26 class MOZ_STACK_CLASS SpanningCellSorter {

    27 public:

    28     SpanningCellSorter();

    29     ~SpanningCellSorter();

    31     struct Item {

    32         int32_t row, col;

    33         Item *next;

    34     };

    36     /**

    37      * Add a cell to the sorter.  Returns false on out of memory.

    38      * aColSpan is the number of columns spanned, and aRow/aCol are the

    39      * position of the cell in the table (for GetCellInfoAt).

    40      */

    41     bool AddCell(int32_t aColSpan, int32_t aRow, int32_t aCol);

    43     /**

    44      * Get the next *list* of cells.  Each list contains all the cells

    45      * for a colspan value, and the lists are given in order from lowest

    46      * to highest colspan.  The colspan value is filled in to *aColSpan.

    47      */

    48     Item* GetNext(int32_t *aColSpan);

    49 private:

    51     enum State { ADDING, ENUMERATING_ARRAY, ENUMERATING_HASH, DONE };

    52     State mState;

    54     // store small colspans in an array for fast sorting and

    55     // enumeration, and large colspans in a hash table

    57     enum { ARRAY_BASE = 2 };

    58     enum { ARRAY_SIZE = 8 };

    59     Item *mArray[ARRAY_SIZE];

    60     int32_t SpanToIndex(int32_t aSpan) { return aSpan - ARRAY_BASE; }

    61     int32_t IndexToSpan(int32_t aIndex) { return aIndex + ARRAY_BASE; }

    62     bool UseArrayForSpan(int32_t aSpan) {

    63         NS_ASSERTION(SpanToIndex(aSpan) >= 0, "cell without colspan");

    64         return SpanToIndex(aSpan) < ARRAY_SIZE;

    65     }

    67     PLDHashTable mHashTable;

    68     struct HashTableEntry : public PLDHashEntryHdr {

    69         int32_t mColSpan;

    70         Item *mItems;

    71     };

    73     static const PLDHashTableOps HashTableOps;

    75     static PLDHashNumber

    76         HashTableHashKey(PLDHashTable *table, const void *key);

    77     static bool

    78         HashTableMatchEntry(PLDHashTable *table, const PLDHashEntryHdr *hdr,

    79                             const void *key);

    81     static PLDHashOperator

    82         FillSortedArray(PLDHashTable *table, PLDHashEntryHdr *hdr,

    83                         uint32_t number, void *arg);

    85     static int SortArray(const void *a, const void *b, void *closure);

    87     /* state used only during enumeration */

    88     uint32_t mEnumerationIndex; // into mArray or mSortedHashTable

    89     HashTableEntry **mSortedHashTable;

    91     /*

    92      * operator new is forbidden since we use the pres shell's stack

    93      * memory, which much be pushed and popped at points matching a

    94      * push/pop on the C++ stack.

    95      */

    96     void* operator new(size_t sz) CPP_THROW_NEW { return nullptr; }

    97 };

    99 #endif

The Tor Browser / file revision

layout/tables/SpanningCellSorter.h@deefc01c0e14

layout/tables/SpanningCellSorter.h