Imported Upstream version 0.3
[pysam.git] / tabix / ksort.h
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+/* The MIT License
+
+   Copyright (c) 2008 Genome Research Ltd (GRL).
+
+   Permission is hereby granted, free of charge, to any person obtaining
+   a copy of this software and associated documentation files (the
+   "Software"), to deal in the Software without restriction, including
+   without limitation the rights to use, copy, modify, merge, publish,
+   distribute, sublicense, and/or sell copies of the Software, and to
+   permit persons to whom the Software is furnished to do so, subject to
+   the following conditions:
+
+   The above copyright notice and this permission notice shall be
+   included in all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+   BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+   ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+   CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+   SOFTWARE.
+*/
+
+/* Contact: Heng Li <lh3@sanger.ac.uk> */
+
+/*
+  2008-11-16 (0.1.4):
+
+    * Fixed a bug in introsort() that happens in rare cases.
+
+  2008-11-05 (0.1.3):
+
+    * Fixed a bug in introsort() for complex comparisons.
+
+       * Fixed a bug in mergesort(). The previous version is not stable.
+
+  2008-09-15 (0.1.2):
+
+       * Accelerated introsort. On my Mac (not on another Linux machine),
+         my implementation is as fast as std::sort on random input.
+
+       * Added combsort and in introsort, switch to combsort if the
+         recursion is too deep.
+
+  2008-09-13 (0.1.1):
+
+       * Added k-small algorithm
+
+  2008-09-05 (0.1.0):
+
+       * Initial version
+
+*/
+
+#ifndef AC_KSORT_H
+#define AC_KSORT_H
+
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct {
+       void *left, *right;
+       int depth;
+} ks_isort_stack_t;
+
+#define KSORT_SWAP(type_t, a, b) { register type_t t=(a); (a)=(b); (b)=t; }
+
+#define KSORT_INIT(name, type_t, __sort_lt)                                                            \
+       void ks_mergesort_##name(size_t n, type_t array[], type_t temp[])       \
+       {                                                                                                                                       \
+               type_t *a2[2], *a, *b;                                                                                  \
+               int curr, shift;                                                                                                \
+                                                                                                                                               \
+               a2[0] = array;                                                                                                  \
+               a2[1] = temp? temp : (type_t*)malloc(sizeof(type_t) * n);               \
+               for (curr = 0, shift = 0; (1ul<<shift) < n; ++shift) {                  \
+                       a = a2[curr]; b = a2[1-curr];                                                           \
+                       if (shift == 0) {                                                                                       \
+                               type_t *p = b, *i, *eb = a + n;                                                 \
+                               for (i = a; i < eb; i += 2) {                                                   \
+                                       if (i == eb - 1) *p++ = *i;                                                     \
+                                       else {                                                                                          \
+                                               if (__sort_lt(*(i+1), *i)) {                                    \
+                                                       *p++ = *(i+1); *p++ = *i;                                       \
+                                               } else {                                                                                \
+                                                       *p++ = *i; *p++ = *(i+1);                                       \
+                                               }                                                                                               \
+                                       }                                                                                                       \
+                               }                                                                                                               \
+                       } else {                                                                                                        \
+                               size_t i, step = 1ul<<shift;                                                    \
+                               for (i = 0; i < n; i += step<<1) {                                              \
+                                       type_t *p, *j, *k, *ea, *eb;                                            \
+                                       if (n < i + step) {                                                                     \
+                                               ea = a + n; eb = a;                                                             \
+                                       } else {                                                                                        \
+                                               ea = a + i + step;                                                              \
+                                               eb = a + (n < i + (step<<1)? n : i + (step<<1)); \
+                                       }                                                                                                       \
+                                       j = a + i; k = a + i + step; p = b + i;                         \
+                                       while (j < ea && k < eb) {                                                      \
+                                               if (__sort_lt(*k, *j)) *p++ = *k++;                             \
+                                               else *p++ = *j++;                                                               \
+                                       }                                                                                                       \
+                                       while (j < ea) *p++ = *j++;                                                     \
+                                       while (k < eb) *p++ = *k++;                                                     \
+                               }                                                                                                               \
+                       }                                                                                                                       \
+                       curr = 1 - curr;                                                                                        \
+               }                                                                                                                               \
+               if (curr == 1) {                                                                                                \
+                       type_t *p = a2[0], *i = a2[1], *eb = array + n;                         \
+                       for (; p < eb; ++i) *p++ = *i;                                                          \
+               }                                                                                                                               \
+               if (temp == 0) free(a2[1]);                                                                             \
+       }                                                                                                                                       \
+       void ks_heapadjust_##name(size_t i, size_t n, type_t l[])                       \
+       {                                                                                                                                       \
+               size_t k = i;                                                                                                   \
+               type_t tmp = l[i];                                                                                              \
+               while ((k = (k << 1) + 1) < n) {                                                                \
+                       if (k != n - 1 && __sort_lt(l[k], l[k+1])) ++k;                         \
+                       if (__sort_lt(l[k], tmp)) break;                                                        \
+                       l[i] = l[k]; i = k;                                                                                     \
+               }                                                                                                                               \
+               l[i] = tmp;                                                                                                             \
+       }                                                                                                                                       \
+       void ks_heapmake_##name(size_t lsize, type_t l[])                                       \
+       {                                                                                                                                       \
+               size_t i;                                                                                                               \
+               for (i = (lsize >> 1) - 1; i != (size_t)(-1); --i)                              \
+                       ks_heapadjust_##name(i, lsize, l);                                                      \
+       }                                                                                                                                       \
+       void ks_heapsort_##name(size_t lsize, type_t l[])                                       \
+       {                                                                                                                                       \
+               size_t i;                                                                                                               \
+               for (i = lsize - 1; i > 0; --i) {                                                               \
+                       type_t tmp;                                                                                                     \
+                       tmp = *l; *l = l[i]; l[i] = tmp; ks_heapadjust_##name(0, i, l); \
+               }                                                                                                                               \
+       }                                                                                                                                       \
+       inline void __ks_insertsort_##name(type_t *s, type_t *t)                        \
+       {                                                                                                                                       \
+               type_t *i, *j, swap_tmp;                                                                                \
+               for (i = s + 1; i < t; ++i)                                                                             \
+                       for (j = i; j > s && __sort_lt(*j, *(j-1)); --j) {                      \
+                               swap_tmp = *j; *j = *(j-1); *(j-1) = swap_tmp;                  \
+                       }                                                                                                                       \
+       }                                                                                                                                       \
+       void ks_combsort_##name(size_t n, type_t a[])                                           \
+       {                                                                                                                                       \
+               const double shrink_factor = 1.2473309501039786540366528676643; \
+               int do_swap;                                                                                                    \
+               size_t gap = n;                                                                                                 \
+               type_t tmp, *i, *j;                                                                                             \
+               do {                                                                                                                    \
+                       if (gap > 2) {                                                                                          \
+                               gap = (size_t)(gap / shrink_factor);                                    \
+                               if (gap == 9 || gap == 10) gap = 11;                                    \
+                       }                                                                                                                       \
+                       do_swap = 0;                                                                                            \
+                       for (i = a; i < a + n - gap; ++i) {                                                     \
+                               j = i + gap;                                                                                    \
+                               if (__sort_lt(*j, *i)) {                                                                \
+                                       tmp = *i; *i = *j; *j = tmp;                                            \
+                                       do_swap = 1;                                                                            \
+                               }                                                                                                               \
+                       }                                                                                                                       \
+               } while (do_swap || gap > 2);                                                                   \
+               if (gap != 1) __ks_insertsort_##name(a, a + n);                                 \
+       }                                                                                                                                       \
+       void ks_introsort_##name(size_t n, type_t a[])                                          \
+       {                                                                                                                                       \
+               int d;                                                                                                                  \
+               ks_isort_stack_t *top, *stack;                                                                  \
+               type_t rp, swap_tmp;                                                                                    \
+               type_t *s, *t, *i, *j, *k;                                                                              \
+                                                                                                                                               \
+               if (n < 1) return;                                                                                              \
+               else if (n == 2) {                                                                                              \
+                       if (__sort_lt(a[1], a[0])) { swap_tmp = a[0]; a[0] = a[1]; a[1] = swap_tmp; } \
+                       return;                                                                                                         \
+               }                                                                                                                               \
+               for (d = 2; 1ul<<d < n; ++d);                                                                   \
+               stack = (ks_isort_stack_t*)malloc(sizeof(ks_isort_stack_t) * ((sizeof(size_t)*d)+2)); \
+               top = stack; s = a; t = a + (n-1); d <<= 1;                                             \
+               while (1) {                                                                                                             \
+                       if (s < t) {                                                                                            \
+                               if (--d == 0) {                                                                                 \
+                                       ks_combsort_##name(t - s + 1, s);                                       \
+                                       t = s;                                                                                          \
+                                       continue;                                                                                       \
+                               }                                                                                                               \
+                               i = s; j = t; k = i + ((j-i)>>1) + 1;                                   \
+                               if (__sort_lt(*k, *i)) {                                                                \
+                                       if (__sort_lt(*k, *j)) k = j;                                           \
+                               } else k = __sort_lt(*j, *i)? i : j;                                    \
+                               rp = *k;                                                                                                \
+                               if (k != t) { swap_tmp = *k; *k = *t; *t = swap_tmp; }  \
+                               for (;;) {                                                                                              \
+                                       do ++i; while (__sort_lt(*i, rp));                                      \
+                                       do --j; while (i <= j && __sort_lt(rp, *j));            \
+                                       if (j <= i) break;                                                                      \
+                                       swap_tmp = *i; *i = *j; *j = swap_tmp;                          \
+                               }                                                                                                               \
+                               swap_tmp = *i; *i = *t; *t = swap_tmp;                                  \
+                               if (i-s > t-i) {                                                                                \
+                                       if (i-s > 16) { top->left = s; top->right = i-1; top->depth = d; ++top; } \
+                                       s = t-i > 16? i+1 : t;                                                          \
+                               } else {                                                                                                \
+                                       if (t-i > 16) { top->left = i+1; top->right = t; top->depth = d; ++top; } \
+                                       t = i-s > 16? i-1 : s;                                                          \
+                               }                                                                                                               \
+                       } else {                                                                                                        \
+                               if (top == stack) {                                                                             \
+                                       free(stack);                                                                            \
+                                       __ks_insertsort_##name(a, a+n);                                         \
+                                       return;                                                                                         \
+                               } else { --top; s = (type_t*)top->left; t = (type_t*)top->right; d = top->depth; } \
+                       }                                                                                                                       \
+               }                                                                                                                               \
+       }                                                                                                                                       \
+       /* This function is adapted from: http://ndevilla.free.fr/median/ */ \
+       /* 0 <= kk < n */                                                                                                       \
+       type_t ks_ksmall_##name(size_t n, type_t arr[], size_t kk)                      \
+       {                                                                                                                                       \
+               type_t *low, *high, *k, *ll, *hh, *mid;                                                 \
+               low = arr; high = arr + n - 1; k = arr + kk;                                    \
+               for (;;) {                                                                                                              \
+                       if (high <= low) return *k;                                                                     \
+                       if (high == low + 1) {                                                                          \
+                               if (__sort_lt(*high, *low)) KSORT_SWAP(type_t, *low, *high); \
+                               return *k;                                                                                              \
+                       }                                                                                                                       \
+                       mid = low + (high - low) / 2;                                                           \
+                       if (__sort_lt(*high, *mid)) KSORT_SWAP(type_t, *mid, *high); \
+                       if (__sort_lt(*high, *low)) KSORT_SWAP(type_t, *low, *high); \
+                       if (__sort_lt(*low, *mid)) KSORT_SWAP(type_t, *mid, *low);      \
+                       KSORT_SWAP(type_t, *mid, *(low+1));                                                     \
+                       ll = low + 1; hh = high;                                                                        \
+                       for (;;) {                                                                                                      \
+                               do ++ll; while (__sort_lt(*ll, *low));                                  \
+                               do --hh; while (__sort_lt(*low, *hh));                                  \
+                               if (hh < ll) break;                                                                             \
+                               KSORT_SWAP(type_t, *ll, *hh);                                                   \
+                       }                                                                                                                       \
+                       KSORT_SWAP(type_t, *low, *hh);                                                          \
+                       if (hh <= k) low = ll;                                                                          \
+                       if (hh >= k) high = hh - 1;                                                                     \
+               }                                                                                                                               \
+       }
+
+#define ks_mergesort(name, n, a, t) ks_mergesort_##name(n, a, t)
+#define ks_introsort(name, n, a) ks_introsort_##name(n, a)
+#define ks_combsort(name, n, a) ks_combsort_##name(n, a)
+#define ks_heapsort(name, n, a) ks_heapsort_##name(n, a)
+#define ks_heapmake(name, n, a) ks_heapmake_##name(n, a)
+#define ks_heapadjust(name, i, n, a) ks_heapadjust_##name(i, n, a)
+#define ks_ksmall(name, n, a, k) ks_ksmall_##name(n, a, k)
+
+#define ks_lt_generic(a, b) ((a) < (b))
+#define ks_lt_str(a, b) (strcmp((a), (b)) < 0)
+
+typedef const char *ksstr_t;
+
+#define KSORT_INIT_GENERIC(type_t) KSORT_INIT(type_t, type_t, ks_lt_generic)
+#define KSORT_INIT_STR KSORT_INIT(str, ksstr_t, ks_lt_str)
+
+#endif