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revert reverse order of blocks associated with the image

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take alignment into account when calculating lines_per_block
This commit is contained in:
Alexander 2017-09-23 06:07:47 +03:00
parent 385963928f
commit 9db1b760e5
1 changed files with 7 additions and 8 deletions
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15
libImaging/Storage.c
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@ -398,7 +398,7 @@ ImagingAllocateArray(Imaging im, int dirty, int block_size)
}
aligned_linesize = (im->linesize + arena->alignment - 1) & -arena->alignment;
lines_per_block = block_size / aligned_linesize;
lines_per_block = (block_size - (arena->alignment - 1)) / aligned_linesize;
if (lines_per_block == 0)
lines_per_block = 1;
blocks_count = (im->ysize + lines_per_block - 1) / lines_per_block;
@ -413,23 +413,22 @@ ImagingAllocateArray(Imaging im, int dirty, int block_size)
/* Allocate image as an array of lines */
line_in_block = 0;
/* Return blocks in reverse order to reduce reallocations */
current_block = blocks_count - 1;
current_block = 0;
for (y = 0; y < im->ysize; y++) {
if (line_in_block == 0) {
int block_size;
int required;
int lines_remained = lines_per_block;
if (lines_remained > im->ysize - y) {
lines_remained = im->ysize - y;
}
block_size = lines_remained * aligned_linesize + arena->alignment - 1;
block = memory_get_block(arena, block_size, dirty);
required = lines_remained * aligned_linesize + arena->alignment - 1;
block = memory_get_block(arena, required, dirty);
if ( ! block.ptr) {
ImagingDestroyArray(im);
return (Imaging) ImagingError_MemoryError();
}
im->blocks[current_block] = block;
/* This is copied from libc _int_memalign */
/* Bulletproof code from libc _int_memalign */
aligned_ptr = (char *)(
((unsigned long) (block.ptr + arena->alignment - 1)) &
-((signed long) arena->alignment));
@ -441,7 +440,7 @@ ImagingAllocateArray(Imaging im, int dirty, int block_size)
if (line_in_block >= lines_per_block) {
/* Reset counter and start new block */
line_in_block = 0;
current_block -= 1;
current_block += 1;
}
}