Alexandre Julliard : gdi32: Pre-allocate the points array in CreatePolyPolygonRgn.
Module: wine Branch: master Commit: 97f996744eafc4ad640ca3b9d97016625443c8cd URL: https://source.winehq.org/git/wine.git/?a=commit;h=97f996744eafc4ad640ca3b9d... Author: Alexandre Julliard <julliard(a)winehq.org> Date: Wed Apr 4 12:38:29 2018 +0200 gdi32: Pre-allocate the points array in CreatePolyPolygonRgn. Signed-off-by: Alexandre Julliard <julliard(a)winehq.org> --- dlls/gdi32/region.c | 127 ++++++++++++++++++---------------------------------- 1 file changed, 44 insertions(+), 83 deletions(-) diff --git a/dlls/gdi32/region.c b/dlls/gdi32/region.c index e9bed18..8e0f32d 100644 --- a/dlls/gdi32/region.c +++ b/dlls/gdi32/region.c @@ -94,6 +94,7 @@ SOFTWARE. * the y-x-banding that's so nice to have... */ +#include <assert.h> #include <stdarg.h> #include <stdlib.h> #include <string.h> @@ -172,48 +173,6 @@ static inline BOOL is_in_rect( const RECT *rect, int x, int y ) return (rect->right > x && rect->left <= x && rect->bottom > y && rect->top <= y); } -/* - * used to allocate buffers for points and link - * the buffers together - */ - -struct point_block -{ - int count, size; - struct point_block *next; - POINT pts[1]; /* Variable sized array - must be last. */ -}; - -static struct point_block *add_point( struct point_block *block, int x, int y ) -{ - if (block->count == block->size) - { - struct point_block *new; - int size = block->size * 2; - new = HeapAlloc( GetProcessHeap(), 0, FIELD_OFFSET( struct point_block, pts[size] ) ); - if (!new) return NULL; - block->next = new; - new->count = 0; - new->size = size; - new->next = NULL; - block = new; - } - block->pts[block->count].x = x; - block->pts[block->count].y = y; - block->count++; - return block; -} - -static void free_point_blocks( struct point_block *block ) -{ - while (block) - { - struct point_block *tmp = block->next; - HeapFree( GetProcessHeap(), 0, block ); - block = tmp; - } -} - /* * This file contains a few macros to help track @@ -452,6 +411,7 @@ static BOOL init_region( WINEREGION *pReg, INT n ) if (n > RGN_DEFAULT_RECTS) { + if (n > INT_MAX / sizeof(RECT)) return FALSE; if (!(pReg->rects = HeapAlloc( GetProcessHeap(), 0, n * sizeof( RECT ) ))) return FALSE; } @@ -2426,15 +2386,15 @@ static void REGION_InsertEdgeInET(EdgeTable *ET, EdgeTableEntry *ETE, * which an edge is initially entered. * */ -static void REGION_CreateEdgeTable(const INT *Count, INT nbpolygons, - const POINT *pts, EdgeTable *ET, - EdgeTableEntry *pETEs, ScanLineListBlock *pSLLBlock) +static unsigned int REGION_CreateEdgeTable(const INT *Count, INT nbpolygons, + const POINT *pts, EdgeTable *ET, + EdgeTableEntry *pETEs, ScanLineListBlock *pSLLBlock) { const POINT *top, *bottom; const POINT *PrevPt, *CurrPt, *EndPt; INT poly, count; int iSLLBlock = 0; - int dy; + unsigned int dy, total = 0; /* * initialize the Edge Table. @@ -2490,6 +2450,8 @@ static void REGION_CreateEdgeTable(const INT *Count, INT nbpolygons, */ dy = bottom->y - top->y; bres_init_polygon(dy, top->x, bottom->x, &pETEs->bres); + if (total + dy < total) return 0; /* overflow */ + total += dy; REGION_InsertEdgeInET(ET, pETEs, top->y, &pSLLBlock, &iSLLBlock); @@ -2504,6 +2466,7 @@ static void REGION_CreateEdgeTable(const INT *Count, INT nbpolygons, PrevPt = CurrPt; } } + return total; } /*********************************************************************** @@ -2622,40 +2585,34 @@ static void REGION_FreeStorage(ScanLineListBlock *pSLLBlock) * * Create an array of rectangles from a list of points. */ -static WINEREGION *REGION_PtsToRegion( struct point_block *FirstPtBlock ) +static WINEREGION *REGION_PtsToRegion( const POINT *pts, unsigned int size ) { - POINT *pts; - struct point_block *pb; - int i, size, cur_band = 0, prev_band = 0; + int cur_band = 0, prev_band = 0; RECT *extents; WINEREGION *reg; - for (pb = FirstPtBlock, size = 0; pb; pb = pb->next) size += pb->count; - if (!(reg = alloc_region( size ))) return NULL; + if (!(reg = alloc_region( size / 2 ))) return NULL; extents = ®->extents; extents->left = LARGE_COORDINATE, extents->right = SMALL_COORDINATE; - for (pb = FirstPtBlock; pb; pb = pb->next) + /* the loop uses 2 points per iteration */ + for (; size > 0; pts += 2, size -= 2) { - /* the loop uses 2 points per iteration */ - i = pb->count / 2; - for (pts = pb->pts; i--; pts += 2) { - if (pts->x == pts[1].x) - continue; - - if (reg->numRects && pts[0].y != reg->rects[cur_band].top) - { - prev_band = REGION_Coalesce( reg, prev_band, cur_band ); - cur_band = reg->numRects; - } + if (pts[0].x == pts[1].x) + continue; - add_rect( reg, pts[0].x, pts[0].y, pts[1].x, pts[1].y + 1 ); - if (pts[0].x < extents->left) - extents->left = pts[0].x; - if (pts[1].x > extents->right) - extents->right = pts[1].x; + if (reg->numRects && pts[0].y != reg->rects[cur_band].top) + { + prev_band = REGION_Coalesce( reg, prev_band, cur_band ); + cur_band = reg->numRects; } + + add_rect( reg, pts[0].x, pts[0].y, pts[1].x, pts[1].y + 1 ); + if (pts[0].x < extents->left) + extents->left = pts[0].x; + if (pts[1].x > extents->right) + extents->right = pts[1].x; } if (reg->numRects) { @@ -2692,9 +2649,9 @@ HRGN WINAPI CreatePolyPolygonRgn(const POINT *Pts, const INT *Count, EdgeTableEntry *pETEs; /* EdgeTableEntries pool */ ScanLineListBlock SLLBlock; /* header for scanlinelist */ BOOL fixWAET = FALSE; - char first_blk_buf[FIELD_OFFSET( struct point_block, pts[NUMPTSTOBUFFER] )]; - struct point_block *first_block = (struct point_block *)first_blk_buf, *block; + POINT buffer[NUMPTSTOBUFFER], *points = buffer; struct edge_table_entry *active, *next; + unsigned int nb_points, pos = 0; INT poly, total; TRACE("%p, count %d, polygons %d, mode %d\n", Pts, *Count, nbpolygons, mode); @@ -2719,14 +2676,14 @@ HRGN WINAPI CreatePolyPolygonRgn(const POINT *Pts, const INT *Count, if (! (pETEs = HeapAlloc( GetProcessHeap(), 0, sizeof(EdgeTableEntry) * total ))) return 0; - REGION_CreateEdgeTable(Count, nbpolygons, Pts, &ET, pETEs, &SLLBlock); + if (!(nb_points = REGION_CreateEdgeTable(Count, nbpolygons, Pts, &ET, pETEs, &SLLBlock))) goto done; + if (nb_points > NUMPTSTOBUFFER) + { + if (nb_points > INT_MAX / sizeof(*points)) goto done; + if (!(points = HeapAlloc( GetProcessHeap(), 0, nb_points * sizeof(*points) ))) goto done; + } list_init( &AET ); pSLL = ET.scanlines.next; - block = first_block; - first_block->count = 0; - first_block->size = NUMPTSTOBUFFER; - first_block->next = NULL; - if (mode != WINDING) { /* * for each scanline @@ -2743,8 +2700,9 @@ HRGN WINAPI CreatePolyPolygonRgn(const POINT *Pts, const INT *Count, LIST_FOR_EACH_ENTRY_SAFE( active, next, &AET, struct edge_table_entry, entry ) { - block = add_point( block, active->bres.minor_axis, y ); - if (!block) goto done; + points[pos].x = active->bres.minor_axis; + points[pos].y = y; + pos++; if (active->ymax == y) /* leaving this edge */ list_remove( &active->entry ); @@ -2780,8 +2738,9 @@ HRGN WINAPI CreatePolyPolygonRgn(const POINT *Pts, const INT *Count, * are in the Winding active edge table. */ if (pWETE == &active->winding_entry) { - block = add_point( block, active->bres.minor_axis, y ); - if (!block) goto done; + points[pos].x = active->bres.minor_axis; + points[pos].y = y; + pos++; pWETE = list_next( &WETE, pWETE ); } if (active->ymax == y) /* leaving this edge */ @@ -2804,13 +2763,15 @@ HRGN WINAPI CreatePolyPolygonRgn(const POINT *Pts, const INT *Count, } } - if (!(obj = REGION_PtsToRegion( first_block ))) goto done; + assert( pos == nb_points ); + + if (!(obj = REGION_PtsToRegion( points, pos ))) goto done; if (!(hrgn = alloc_gdi_handle( obj, OBJ_REGION, ®ion_funcs ))) free_region( obj ); done: REGION_FreeStorage(SLLBlock.next); - free_point_blocks( first_block->next ); + if (points != buffer) HeapFree( GetProcessHeap(), 0, points ); HeapFree( GetProcessHeap(), 0, pETEs ); return hrgn; }
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Alexandre Julliard