… | |
… | |
993 | } |
993 | } |
994 | |
994 | |
995 | static signed char |
995 | static signed char |
996 | eio_dent_cmp (const eio_dirent *a, const eio_dirent *b) |
996 | eio_dent_cmp (const eio_dirent *a, const eio_dirent *b) |
997 | { |
997 | { |
998 | return b->score - a->score ? b->score - a->score /* works because our signed char is always 0..100 */ |
998 | return b->score - a->score ? b->score - a->score /* works because our signed char is always 0..100 */ |
999 | : a->inode < b->inode ? -1 : a->inode > b->inode ? 1 : 0; |
999 | : a->inode < b->inode ? -1 : a->inode > b->inode ? 1 : 0; |
1000 | } |
1000 | } |
1001 | |
1001 | |
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|
1002 | #define EIO_DENT_CMP(i,op,j) eio_dent_cmp (&i, &j) op 0 |
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1003 | |
1002 | #define EIO_QSORT_CUTOFF 20 /* quite high, but performs well on many filesystems */ |
1004 | #define EIO_QSORT_CUTOFF 30 /* quite high, but performs well on many filesystems */ |
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|
1005 | #define EIO_QSORT_SKIP 60 /* when to skip qsort completely */ |
1003 | |
1006 | |
1004 | static void |
1007 | static void |
1005 | eio_dent_sort (eio_dirent *dents, int size) |
1008 | eio_dent_sort (eio_dirent *dents, int size) |
1006 | { |
1009 | { |
1007 | /* should be good for 2**31 entries */ |
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|
1008 | struct rng { int l, r; } rng [32]; |
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|
1009 | int i, j; |
1010 | int i, j; |
1010 | |
1011 | |
1011 | i = 0; |
1012 | if (size <= 1) |
1012 | rng[0].l = 0; |
1013 | return; /* our insertion sort relies on size > 0 */ |
1013 | rng[0].r = size; |
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|
1014 | |
1014 | |
1015 | while (expect_true (i >= 0)) |
1015 | if (size > EIO_QSORT_SKIP) /* skip quicksort for small directories */ |
1016 | { |
1016 | { |
1017 | int L = rng [i].l; |
1017 | /* first, use quicksort */ |
1018 | int R = rng [i].r - 1; |
1018 | /* should be good for 2**31 entries */ |
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|
1019 | struct rng { int l, r; } rng [32]; |
1019 | |
1020 | |
1020 | if (expect_false (L + EIO_QSORT_CUTOFF < R)) |
1021 | i = 0; |
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|
1022 | rng[0].l = 0; |
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1023 | rng[0].r = size; |
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1024 | |
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|
1025 | while (expect_true (i >= 0)) |
1021 | { |
1026 | { |
1022 | eio_dirent piv = dents [L]; |
1027 | int L = rng [i].l; |
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|
1028 | int R = rng [i].r - 1; |
1023 | |
1029 | |
1024 | while (L < R) |
1030 | if (expect_false (L + EIO_QSORT_CUTOFF < R)) |
1025 | { |
1031 | { |
1026 | while (eio_dent_cmp (&dents [R], &piv) >= 0 && L < R) |
1032 | eio_dirent piv = dents [L]; |
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1033 | |
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|
1034 | while (L < R) |
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|
1035 | { |
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|
1036 | while (EIO_DENT_CMP (dents [R], >=, piv) && L < R) |
1027 | --R; |
1037 | --R; |
1028 | |
1038 | |
1029 | if (L < R) |
1039 | if (L < R) |
1030 | dents [L++] = dents [R]; |
1040 | dents [L++] = dents [R]; |
1031 | |
1041 | |
1032 | while (eio_dent_cmp (&dents [L], &piv) <= 0 && L < R) |
1042 | while (EIO_DENT_CMP (dents [L], <=, piv) && L < R) |
1033 | ++L; |
1043 | ++L; |
1034 | |
1044 | |
1035 | if (L < R) |
1045 | if (L < R) |
1036 | dents [R--] = dents [L]; |
1046 | dents [R--] = dents [L]; |
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|
1047 | } |
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1048 | |
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|
1049 | dents [L] = piv; |
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1050 | |
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1051 | ++i; |
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1052 | rng [i].l = L + 1; |
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|
1053 | rng [i].r = rng [i - 1].r; |
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|
1054 | rng [i - 1].r = L; |
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1055 | |
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1056 | if (rng [i].r - rng [i].l > rng [i - 1].r - rng [i - 1].l) |
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1057 | { |
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1058 | struct rng t; |
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1059 | |
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1060 | t = rng [i]; rng [i] = rng [i - 1]; rng [i - 1] = t; |
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1061 | } |
1037 | } |
1062 | } |
1038 | |
1063 | else |
1039 | dents [L] = piv; |
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1040 | |
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|
1041 | ++i; |
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1042 | rng [i].l = L + 1; |
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1043 | rng [i].r = rng [i - 1].r; |
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|
1044 | rng [i - 1].r = L; |
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1045 | |
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|
1046 | if (rng [i].r - rng [i].l > rng [i - 1].r - rng [i - 1].l) |
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1047 | { |
1064 | --i; |
1048 | struct rng t; |
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1049 | |
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|
1050 | t = rng [i]; rng [i] = rng [i - 1]; rng [i - 1] = t; |
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1051 | } |
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1052 | } |
1065 | } |
1053 | else |
1066 | } |
1054 | --i; |
1067 | |
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1068 | /* use an insertion sort after qsort, or for small arrays */ |
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1069 | /* first move the smallest element to the front, to act as a sentinel */ |
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|
1070 | { |
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1071 | int min = 0; |
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1072 | |
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1073 | for (i = size > EIO_QSORT_SKIP ? EIO_QSORT_CUTOFF : size; --i; ) |
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1074 | if (EIO_DENT_CMP (dents [i], <, dents [min])) |
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1075 | min = i; |
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1076 | |
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1077 | /* swap elements 0 and j (minimum) */ |
1055 | } |
1078 | { |
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1079 | eio_dirent tmp = dents [0]; dents [0] = dents [min]; dents [min] = tmp; |
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1080 | } |
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1081 | } |
1056 | |
1082 | |
1057 | /* use a simple insertion sort at the end */ |
1083 | /* then do standard insertion sort */ |
1058 | for (i = 1; i < size; ++i) |
1084 | for (i = 1; i < size; ++i) |
1059 | { |
1085 | { |
1060 | eio_dirent value = dents [i]; |
1086 | eio_dirent value = dents [i]; |
1061 | |
1087 | |
1062 | for (j = i - 1; j >= 0 && eio_dent_cmp (&dents [j], &value) > 0; --j) |
1088 | for (j = i - 1; EIO_DENT_CMP (dents [j], >, value); --j) |
1063 | dents [j + 1] = dents [j]; |
1089 | dents [j + 1] = dents [j]; |
1064 | |
1090 | |
1065 | dents [j + 1] = value; |
1091 | dents [j + 1] = value; |
1066 | } |
1092 | } |
1067 | } |
1093 | } |