Added khash

2 files changed, 940 insertions, 0 deletions

diff --git a/others/khash.h b/others/khash.h
new file mode 100644
index 00000000..61dabc4d
--- /dev/null
+++ b/others/khash.h
@@ -0,0 +1,595 @@
+/* The MIT License
+   Copyright (c) 2008, 2009, 2011 by Attractive Chaos <[email protected]>
+   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.
+*/
+
+/*
+  An example:
+#include "khash.h"
+KHASH_MAP_INIT_INT(32, char)
+int main() {
+    int ret, is_missing;
+    khiter_t k;
+    khash_t(32) *h = kh_init(32);
+    k = kh_put(32, h, 5, &ret);
+    kh_value(h, k) = 10;
+    k = kh_get(32, h, 10);
+    is_missing = (k == kh_end(h));
+    k = kh_get(32, h, 5);
+    kh_del(32, h, k);
+    for (k = kh_begin(h); k != kh_end(h); ++k)
+        if (kh_exist(h, k)) kh_value(h, k) = 1;
+    kh_destroy(32, h);
+    return 0;
+}
+*/
+
+/*
+  2013-05-02 (0.2.8):
+    * Use quadratic probing. When the capacity is power of 2, stepping function
+      i*(i+1)/2 guarantees to traverse each bucket. It is better than double
+      hashing on cache performance and is more robust than linear probing.
+      In theory, double hashing should be more robust than quadratic probing.
+      However, my implementation is probably not for large hash tables, because
+      the second hash function is closely tied to the first hash function,
+      which reduce the effectiveness of double hashing.
+    Reference: http://research.cs.vt.edu/AVresearch/hashing/quadratic.php
+  2011-12-29 (0.2.7):
+    * Minor code clean up; no actual effect.
+  2011-09-16 (0.2.6):
+    * The capacity is a power of 2. This seems to dramatically improve the
+      speed for simple keys. Thank Zilong Tan for the suggestion. Reference:
+       - http://code.google.com/p/ulib/
+       - http://nothings.org/computer/judy/
+    * Allow to optionally use linear probing which usually has better
+      performance for random input. Double hashing is still the default as it
+      is more robust to certain non-random input.
+    * Added Wang's integer hash function (not used by default). This hash
+      function is more robust to certain non-random input.
+  2011-02-14 (0.2.5):
+    * Allow to declare global functions.
+  2009-09-26 (0.2.4):
+    * Improve portability
+  2008-09-19 (0.2.3):
+    * Corrected the example
+    * Improved interfaces
+  2008-09-11 (0.2.2):
+    * Improved speed a little in kh_put()
+  2008-09-10 (0.2.1):
+    * Added kh_clear()
+    * Fixed a compiling error
+  2008-09-02 (0.2.0):
+    * Changed to token concatenation which increases flexibility.
+  2008-08-31 (0.1.2):
+    * Fixed a bug in kh_get(), which has not been tested previously.
+  2008-08-31 (0.1.1):
+    * Added destructor
+*/
+
+
+#ifndef __AC_KHASH_H
+#define __AC_KHASH_H
+
+/*!
+  @header
+  Generic hash table library.
+ */
+
+#define AC_VERSION_KHASH_H "0.2.8"
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+/* compiler specific configuration */
+
+#if UINT_MAX == 0xffffffffu
+typedef unsigned int khint32_t;
+#elif ULONG_MAX == 0xffffffffu
+typedef unsigned long khint32_t;
+#endif
+
+#if ULONG_MAX == ULLONG_MAX
+typedef unsigned long khint64_t;
+#else
+typedef unsigned long long khint64_t;
+#endif
+
+#ifndef kh_inline
+#ifdef _MSC_VER
+#define kh_inline __inline
+#else
+#define kh_inline inline
+#endif
+#endif /* kh_inline */
+
+#ifndef klib_unused
+#if (defined __clang__ && __clang_major__ >= 3) || (defined __GNUC__ && __GNUC__ >= 3)
+#define klib_unused __attribute__ ((__unused__))
+#else
+#define klib_unused
+#endif
+#endif /* klib_unused */
+
+typedef khint32_t khint_t;
+typedef khint_t khiter_t;
+
+#define __ac_isempty(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&2)
+#define __ac_isdel(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&1)
+#define __ac_iseither(flag, i) ((flag[i>>4]>>((i&0xfU)<<1))&3)
+#define __ac_set_isdel_false(flag, i) (flag[i>>4]&=~(1ul<<((i&0xfU)<<1)))
+#define __ac_set_isempty_false(flag, i) (flag[i>>4]&=~(2ul<<((i&0xfU)<<1)))
+#define __ac_set_isboth_false(flag, i) (flag[i>>4]&=~(3ul<<((i&0xfU)<<1)))
+#define __ac_set_isdel_true(flag, i) (flag[i>>4]|=1ul<<((i&0xfU)<<1))
+
+#define __ac_fsize(m) ((m) < 16? 1 : (m)>>4)
+
+#ifndef kroundup32
+#define kroundup32(x) (--(x), (x)|=(x)>>1, (x)|=(x)>>2, (x)|=(x)>>4, (x)|=(x)>>8, (x)|=(x)>>16, ++(x))
+#endif
+
+#ifndef kcalloc
+#define kcalloc(N,Z) calloc(N,Z)
+#endif
+#ifndef kmalloc
+#define kmalloc(Z) malloc(Z)
+#endif
+#ifndef krealloc
+#define krealloc(P,Z) realloc(P,Z)
+#endif
+#ifndef kfree
+#define kfree(P) free(P)
+#endif
+
+static const double __ac_HASH_UPPER = 0.77;
+
+#define __KHASH_TYPE(name, khkey_t, khval_t) \
+    typedef struct kh_##name##_s { \
+        khint_t n_buckets, size, n_occupied, upper_bound; \
+        khint32_t *flags; \
+        khkey_t *keys; \
+        khval_t *vals; \
+    } kh_##name##_t;
+
+#define __KHASH_PROTOTYPES(name, khkey_t, khval_t)                      \
+    extern kh_##name##_t *kh_init_##name(void);                         \
+    extern void kh_destroy_##name(kh_##name##_t *h);                    \
+    extern void kh_clear_##name(kh_##name##_t *h);                      \
+    extern khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key);  \
+    extern int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets); \
+    extern khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret); \
+    extern void kh_del_##name(kh_##name##_t *h, khint_t x);
+
+#define __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
+    SCOPE kh_##name##_t *kh_init_##name(void) {                         \
+        return (kh_##name##_t*)kcalloc(1, sizeof(kh_##name##_t));       \
+    }                                                                   \
+    SCOPE void kh_destroy_##name(kh_##name##_t *h)                      \
+    {                                                                   \
+        if (h) {                                                        \
+            kfree((void *)h->keys); kfree(h->flags);                    \
+            kfree((void *)h->vals);                                     \
+            kfree(h);                                                   \
+        }                                                               \
+    }                                                                   \
+    SCOPE void kh_clear_##name(kh_##name##_t *h)                        \
+    {                                                                   \
+        if (h && h->flags) {                                            \
+            memset(h->flags, 0xaa, __ac_fsize(h->n_buckets) * sizeof(khint32_t)); \
+            h->size = h->n_occupied = 0;                                \
+        }                                                               \
+    }                                                                   \
+    SCOPE khint_t kh_get_##name(const kh_##name##_t *h, khkey_t key)    \
+    {                                                                   \
+        if (h->n_buckets) {                                             \
+            khint_t k, i, last, mask, step = 0; \
+            mask = h->n_buckets - 1;                                    \
+            k = __hash_func(key); i = k & mask;                         \
+            last = i; \
+            while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
+                i = (i + (++step)) & mask; \
+                if (i == last) return h->n_buckets;                     \
+            }                                                           \
+            return __ac_iseither(h->flags, i)? h->n_buckets : i;        \
+        } else return 0;                                                \
+    }                                                                   \
+    SCOPE int kh_resize_##name(kh_##name##_t *h, khint_t new_n_buckets) \
+    { /* This function uses 0.25*n_buckets bytes of working space instead of [sizeof(key_t+val_t)+.25]*n_buckets. */ \
+        khint32_t *new_flags = 0;                                       \
+        khint_t j = 1;                                                  \
+        {                                                               \
+            kroundup32(new_n_buckets);                                  \
+            if (new_n_buckets < 4) new_n_buckets = 4;                   \
+            if (h->size >= (khint_t)(new_n_buckets * __ac_HASH_UPPER + 0.5)) j = 0; /* requested size is too small */ \
+            else { /* hash table size to be changed (shrink or expand); rehash */ \
+                new_flags = (khint32_t*)kmalloc(__ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
+                if (!new_flags) return -1;                              \
+                memset(new_flags, 0xaa, __ac_fsize(new_n_buckets) * sizeof(khint32_t)); \
+                if (h->n_buckets < new_n_buckets) { /* expand */        \
+                    khkey_t *new_keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
+                    if (!new_keys) { kfree(new_flags); return -1; }     \
+                    h->keys = new_keys;                                 \
+                    if (kh_is_map) {                                    \
+                        khval_t *new_vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
+                        if (!new_vals) { kfree(new_flags); return -1; } \
+                        h->vals = new_vals;                             \
+                    }                                                   \
+                } /* otherwise shrink */                                \
+            }                                                           \
+        }                                                               \
+        if (j) { /* rehashing is needed */                              \
+            for (j = 0; j != h->n_buckets; ++j) {                       \
+                if (__ac_iseither(h->flags, j) == 0) {                  \
+                    khkey_t key = h->keys[j];                           \
+                    khval_t val;                                        \
+                    khint_t new_mask;                                   \
+                    new_mask = new_n_buckets - 1;                       \
+                    if (kh_is_map) val = h->vals[j];                    \
+                    __ac_set_isdel_true(h->flags, j);                   \
+                    while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \
+                        khint_t k, i, step = 0; \
+                        k = __hash_func(key);                           \
+                        i = k & new_mask;                               \
+                        while (!__ac_isempty(new_flags, i)) i = (i + (++step)) & new_mask; \
+                        __ac_set_isempty_false(new_flags, i);           \
+                        if (i < h->n_buckets && __ac_iseither(h->flags, i) == 0) { /* kick out the existing element */ \
+                            { khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
+                            if (kh_is_map) { khval_t tmp = h->vals[i]; h->vals[i] = val; val = tmp; } \
+                            __ac_set_isdel_true(h->flags, i); /* mark it as deleted in the old hash table */ \
+                        } else { /* write the element and jump out of the loop */ \
+                            h->keys[i] = key;                           \
+                            if (kh_is_map) h->vals[i] = val;            \
+                            break;                                      \
+                        }                                               \
+                    }                                                   \
+                }                                                       \
+            }                                                           \
+            if (h->n_buckets > new_n_buckets) { /* shrink the hash table */ \
+                h->keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
+                if (kh_is_map) h->vals = (khval_t*)krealloc((void *)h->vals, new_n_buckets * sizeof(khval_t)); \
+            }                                                           \
+            kfree(h->flags); /* free the working space */               \
+            h->flags = new_flags;                                       \
+            h->n_buckets = new_n_buckets;                               \
+            h->n_occupied = h->size;                                    \
+            h->upper_bound = (khint_t)(h->n_buckets * __ac_HASH_UPPER + 0.5); \
+        }                                                               \
+        return 0;                                                       \
+    }                                                                   \
+    SCOPE khint_t kh_put_##name(kh_##name##_t *h, khkey_t key, int *ret) \
+    {                                                                   \
+        khint_t x;                                                      \
+        if (h->n_occupied >= h->upper_bound) { /* update the hash table */ \
+            if (h->n_buckets > (h->size<<1)) {                          \
+                if (kh_resize_##name(h, h->n_buckets - 1) < 0) { /* clear "deleted" elements */ \
+                    *ret = -1; return h->n_buckets;                     \
+                }                                                       \
+            } else if (kh_resize_##name(h, h->n_buckets + 1) < 0) { /* expand the hash table */ \
+                *ret = -1; return h->n_buckets;                         \
+            }                                                           \
+        } /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
+        {                                                               \
+            khint_t k, i, site, last, mask = h->n_buckets - 1, step = 0; \
+            x = site = h->n_buckets; k = __hash_func(key); i = k & mask; \
+            if (__ac_isempty(h->flags, i)) x = i; /* for speed up */    \
+            else {                                                      \
+                last = i; \
+                while (!__ac_isempty(h->flags, i) && (__ac_isdel(h->flags, i) || !__hash_equal(h->keys[i], key))) { \
+                    if (__ac_isdel(h->flags, i)) site = i;              \
+                    i = (i + (++step)) & mask; \
+                    if (i == last) { x = site; break; }                 \
+                }                                                       \
+                if (x == h->n_buckets) {                                \
+                    if (__ac_isempty(h->flags, i) && site != h->n_buckets) x = site; \
+                    else x = i;                                         \
+                }                                                       \
+            }                                                           \
+        }                                                               \
+        if (__ac_isempty(h->flags, x)) { /* not present at all */       \
+            h->keys[x] = key;                                           \
+            __ac_set_isboth_false(h->flags, x);                         \
+            ++h->size; ++h->n_occupied;                                 \
+            *ret = 1;                                                   \
+        } else if (__ac_isdel(h->flags, x)) { /* deleted */             \
+            h->keys[x] = key;                                           \
+            __ac_set_isboth_false(h->flags, x);                         \
+            ++h->size;                                                  \
+            *ret = 2;                                                   \
+        } else *ret = 0; /* Don't touch h->keys[x] if present and not deleted */ \
+        return x;                                                       \
+    }                                                                   \
+    SCOPE void kh_del_##name(kh_##name##_t *h, khint_t x)               \
+    {                                                                   \
+        if (x != h->n_buckets && !__ac_iseither(h->flags, x)) {         \
+            __ac_set_isdel_true(h->flags, x);                           \
+            --h->size;                                                  \
+        }                                                               \
+    }
+
+#define KHASH_DECLARE(name, khkey_t, khval_t)                           \
+    __KHASH_TYPE(name, khkey_t, khval_t)                                \
+    __KHASH_PROTOTYPES(name, khkey_t, khval_t)
+
+#define KHASH_INIT2(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
+    __KHASH_TYPE(name, khkey_t, khval_t)                                \
+    __KHASH_IMPL(name, SCOPE, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
+
+#define KHASH_INIT(name, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal) \
+    KHASH_INIT2(name, static kh_inline klib_unused, khkey_t, khval_t, kh_is_map, __hash_func, __hash_equal)
+
+/* --- BEGIN OF HASH FUNCTIONS --- */
+
+/*! @function
+  @abstract     Integer hash function
+  @param  key   The integer [khint32_t]
+  @return       The hash value [khint_t]
+ */
+#define kh_int_hash_func(key) (khint32_t)(key)
+/*! @function
+  @abstract     Integer comparison function
+ */
+#define kh_int_hash_equal(a, b) ((a) == (b))
+/*! @function
+  @abstract     64-bit integer hash function
+  @param  key   The integer [khint64_t]
+  @return       The hash value [khint_t]
+ */
+#define kh_int64_hash_func(key) (khint32_t)((key)>>33^(key)^(key)<<11)
+/*! @function
+  @abstract     64-bit integer comparison function
+ */
+#define kh_int64_hash_equal(a, b) ((a) == (b))
+/*! @function
+  @abstract     const char* hash function
+  @param  s     Pointer to a null terminated string
+  @return       The hash value
+ */
+static kh_inline khint_t __ac_X31_hash_string(const char *s)
+{
+    khint_t h = (khint_t)*s;
+    if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;
+    return h;
+}
+/*! @function
+  @abstract     Another interface to const char* hash function
+  @param  key   Pointer to a null terminated string [const char*]
+  @return       The hash value [khint_t]
+ */
+#define kh_str_hash_func(key) __ac_X31_hash_string(key)
+/*! @function
+  @abstract     Const char* comparison function
+ */
+#define kh_str_hash_equal(a, b) (strcmp(a, b) == 0)
+
+static kh_inline khint_t __ac_Wang_hash(khint_t key)
+{
+    key += ~(key << 15);
+    key ^=  (key >> 10);
+    key +=  (key << 3);
+    key ^=  (key >> 6);
+    key += ~(key << 11);
+    key ^=  (key >> 16);
+    return key;
+}
+#define kh_int_hash_func2(key) __ac_Wang_hash((khint_t)key)
+
+/* --- END OF HASH FUNCTIONS --- */
+
+/* Other convenient macros... */
+
+/*!
+  @abstract Type of the hash table.
+  @param  name  Name of the hash table [symbol]
+ */
+#define khash_t(name) kh_##name##_t
+
+/*! @function
+  @abstract     Initiate a hash table.
+  @param  name  Name of the hash table [symbol]
+  @return       Pointer to the hash table [khash_t(name)*]
+ */
+#define kh_init(name) kh_init_##name()
+
+/*! @function
+  @abstract     Destroy a hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+ */
+#define kh_destroy(name, h) kh_destroy_##name(h)
+
+/*! @function
+  @abstract     Reset a hash table without deallocating memory.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+ */
+#define kh_clear(name, h) kh_clear_##name(h)
+
+/*! @function
+  @abstract     Resize a hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  s     New size [khint_t]
+ */
+#define kh_resize(name, h, s) kh_resize_##name(h, s)
+
+/*! @function
+  @abstract     Insert a key to the hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  k     Key [type of keys]
+  @param  r     Extra return code: -1 if the operation failed;
+                0 if the key is present in the hash table;
+                1 if the bucket is empty (never used); 2 if the element in
+                the bucket has been deleted [int*]
+  @return       Iterator to the inserted element [khint_t]
+ */
+#define kh_put(name, h, k, r) kh_put_##name(h, k, r)
+
+/*! @function
+  @abstract     Retrieve a key from the hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  k     Key [type of keys]
+  @return       Iterator to the found element, or kh_end(h) if the element is absent [khint_t]
+ */
+#define kh_get(name, h, k) kh_get_##name(h, k)
+
+/*! @function
+  @abstract     Remove a key from the hash table.
+  @param  name  Name of the hash table [symbol]
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  k     Iterator to the element to be deleted [khint_t]
+ */
+#define kh_del(name, h, k) kh_del_##name(h, k)
+
+/*! @function
+  @abstract     Test whether a bucket contains data.
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  x     Iterator to the bucket [khint_t]
+  @return       1 if containing data; 0 otherwise [int]
+ */
+#define kh_exist(h, x) (!__ac_iseither((h)->flags, (x)))
+
+/*! @function
+  @abstract     Get key given an iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  x     Iterator to the bucket [khint_t]
+  @return       Key [type of keys]
+ */
+#define kh_key(h, x) ((h)->keys[x])
+
+/*! @function
+  @abstract     Get value given an iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  x     Iterator to the bucket [khint_t]
+  @return       Value [type of values]
+  @discussion   For hash sets, calling this results in segfault.
+ */
+#define kh_val(h, x) ((h)->vals[x])
+
+/*! @function
+  @abstract     Alias of kh_val()
+ */
+#define kh_value(h, x) ((h)->vals[x])
+
+/*! @function
+  @abstract     Get the start iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       The start iterator [khint_t]
+ */
+#define kh_begin(h) (khint_t)(0)
+
+/*! @function
+  @abstract     Get the end iterator
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       The end iterator [khint_t]
+ */
+#define kh_end(h) ((h)->n_buckets)
+
+/*! @function
+  @abstract     Get the number of elements in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       Number of elements in the hash table [khint_t]
+ */
+#define kh_size(h) ((h)->size)
+
+/*! @function
+  @abstract     Get the number of buckets in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @return       Number of buckets in the hash table [khint_t]
+ */
+#define kh_n_buckets(h) ((h)->n_buckets)
+
+/*! @function
+  @abstract     Iterate over the entries in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  kvar  Variable to which key will be assigned
+  @param  vvar  Variable to which value will be assigned
+  @param  code  Block of code to execute
+ */
+#define kh_foreach(h, kvar, vvar, code) { khint_t __i;      \
+    for (__i = kh_begin(h); __i != kh_end(h); ++__i) {      \
+        if (!kh_exist(h,__i)) continue;                     \
+        (kvar) = kh_key(h,__i);                             \
+        (vvar) = kh_val(h,__i);                             \
+        code;                                               \
+    } }
+
+/*! @function
+  @abstract     Iterate over the values in the hash table
+  @param  h     Pointer to the hash table [khash_t(name)*]
+  @param  vvar  Variable to which value will be assigned
+  @param  code  Block of code to execute
+ */
+#define kh_foreach_value(h, vvar, code) { khint_t __i;      \
+    for (__i = kh_begin(h); __i != kh_end(h); ++__i) {      \
+        if (!kh_exist(h,__i)) continue;                     \
+        (vvar) = kh_val(h,__i);                             \
+        code;                                               \
+    } }
+
+/* More convenient interfaces */
+
+/*! @function
+  @abstract     Instantiate a hash set containing integer keys
+  @param  name  Name of the hash table [symbol]
+ */
+#define KHASH_SET_INIT_INT(name)                                        \
+    KHASH_INIT(name, khint32_t, char, 0, kh_int_hash_func, kh_int_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing integer keys
+  @param  name  Name of the hash table [symbol]
+  @param  khval_t  Type of values [type]
+ */
+#define KHASH_MAP_INIT_INT(name, khval_t)                               \
+    KHASH_INIT(name, khint32_t, khval_t, 1, kh_int_hash_func, kh_int_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash set containing 64-bit integer keys
+  @param  name  Name of the hash table [symbol]
+ */
+#define KHASH_SET_INIT_INT64(name)                                      \
+    KHASH_INIT(name, khint64_t, char, 0, kh_int64_hash_func, kh_int64_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing 64-bit integer keys
+  @param  name  Name of the hash table [symbol]
+  @param  khval_t  Type of values [type]
+ */
+#define KHASH_MAP_INIT_INT64(name, khval_t)                             \
+    KHASH_INIT(name, khint64_t, khval_t, 1, kh_int64_hash_func, kh_int64_hash_equal)
+
+typedef const char *kh_cstr_t;
+/*! @function
+  @abstract     Instantiate a hash map containing const char* keys
+  @param  name  Name of the hash table [symbol]
+ */
+#define KHASH_SET_INIT_STR(name)                                        \
+    KHASH_INIT(name, kh_cstr_t, char, 0, kh_str_hash_func, kh_str_hash_equal)
+
+/*! @function
+  @abstract     Instantiate a hash map containing const char* keys
+  @param  name  Name of the hash table [symbol]
+  @param  khval_t  Type of values [type]
+ */
+#define KHASH_MAP_INIT_STR(name, khval_t)                               \
+    KHASH_INIT(name, kh_cstr_t, khval_t, 1, kh_str_hash_func, kh_str_hash_equal)
+
+#endif /* __AC_KHASH_H */
diff --git a/others/khashl.h b/others/khashl.h
new file mode 100644
index 00000000..3542ba98
--- /dev/null
+++ b/others/khashl.h
@@ -0,0 +1,345 @@
+/* The MIT License
+   Copyright (c) 2019 by Attractive Chaos <[email protected]>
+   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.
+*/
+
+#ifndef __AC_KHASHL_H
+#define __AC_KHASHL_H
+
+#define AC_VERSION_KHASHL_H "0.1"
+
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+
+/************************************
+ * Compiler specific configurations *
+ ************************************/
+
+#if UINT_MAX == 0xffffffffu
+typedef unsigned int khint32_t;
+#elif ULONG_MAX == 0xffffffffu
+typedef unsigned long khint32_t;
+#endif
+
+#if ULONG_MAX == ULLONG_MAX
+typedef unsigned long khint64_t;
+#else
+typedef unsigned long long khint64_t;
+#endif
+
+#ifndef kh_inline
+#ifdef _MSC_VER
+#define kh_inline __inline
+#else
+#define kh_inline inline
+#endif
+#endif /* kh_inline */
+
+#ifndef klib_unused
+#if (defined __clang__ && __clang_major__ >= 3) || (defined __GNUC__ && __GNUC__ >= 3)
+#define klib_unused __attribute__ ((__unused__))
+#else
+#define klib_unused
+#endif
+#endif /* klib_unused */
+
+#define KH_LOCAL static kh_inline klib_unused
+
+typedef khint32_t khint_t;
+
+/******************
+ * malloc aliases *
+ ******************/
+
+#ifndef kcalloc
+#define kcalloc(N,Z) calloc(N,Z)
+#endif
+#ifndef kmalloc
+#define kmalloc(Z) malloc(Z)
+#endif
+#ifndef krealloc
+#define krealloc(P,Z) realloc(P,Z)
+#endif
+#ifndef kfree
+#define kfree(P) free(P)
+#endif
+
+/****************************
+ * Simple private functions *
+ ****************************/
+
+#define __kh_used(flag, i)       (flag[i>>5] >> (i&0x1fU) & 1U)
+#define __kh_set_used(flag, i)   (flag[i>>5] |= 1U<<(i&0x1fU))
+#define __kh_set_unused(flag, i) (flag[i>>5] &= ~(1U<<(i&0x1fU)))
+
+#define __kh_fsize(m) ((m) < 32? 1 : (m)>>5)
+
+static kh_inline khint_t __kh_h2b(khint_t hash, khint_t bits) { return hash * 2654435769U >> (32 - bits); }
+
+/*******************
+ * Hash table base *
+ *******************/
+
+#define __KHASHL_TYPE(HType, khkey_t) \
+    typedef struct { \
+        khint_t bits, count; \
+        khint32_t *used; \
+        khkey_t *keys; \
+    } HType;
+
+#define __KHASHL_PROTOTYPES(HType, prefix, khkey_t) \
+    extern HType *prefix##_init(void); \
+    extern void prefix##_destroy(HType *h); \
+    extern void prefix##_clear(HType *h); \
+    extern khint_t prefix##_getp(const HType *h, const khkey_t *key); \
+    extern int prefix##_resize(HType *h, khint_t new_n_buckets); \
+    extern khint_t prefix##_putp(HType *h, const khkey_t *key, int *absent); \
+    extern void prefix##_del(HType *h, khint_t k);
+
+#define __KHASHL_IMPL_BASIC(SCOPE, HType, prefix) \
+    SCOPE HType *prefix##_init(void) { \
+        return (HType*)kcalloc(1, sizeof(HType)); \
+    } \
+    SCOPE void prefix##_destroy(HType *h) { \
+        if (!h) return; \
+        kfree((void *)h->keys); kfree(h->used); \
+        kfree(h); \
+    } \
+    SCOPE void prefix##_clear(HType *h) { \
+        if (h && h->used) { \
+            uint32_t n_buckets = 1U << h->bits; \
+            memset(h->used, 0, __kh_fsize(n_buckets) * sizeof(khint32_t)); \
+            h->count = 0; \
+        } \
+    }
+
+#define __KHASHL_IMPL_GET(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    SCOPE khint_t prefix##_getp(const HType *h, const khkey_t *key) { \
+        khint_t i, last, n_buckets, mask; \
+        if (h->keys == 0) return 0; \
+        n_buckets = 1U << h->bits; \
+        mask = n_buckets - 1U; \
+        i = last = __kh_h2b(__hash_fn(*key), h->bits); \
+        while (__kh_used(h->used, i) && !__hash_eq(h->keys[i], *key)) { \
+            i = (i + 1U) & mask; \
+            if (i == last) return n_buckets; \
+        } \
+        return !__kh_used(h->used, i)? n_buckets : i; \
+    } \
+    SCOPE khint_t prefix##_get(const HType *h, khkey_t key) { return prefix##_getp(h, &key); }
+
+#define __KHASHL_IMPL_RESIZE(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    SCOPE int prefix##_resize(HType *h, khint_t new_n_buckets) { \
+        khint32_t *new_used = 0; \
+        khint_t j = 0, x = new_n_buckets, n_buckets, new_bits, new_mask; \
+        while ((x >>= 1) != 0) ++j; \
+        if (new_n_buckets & (new_n_buckets - 1)) ++j; \
+        new_bits = j > 2? j : 2; \
+        new_n_buckets = 1U << new_bits; \
+        if (h->count > (new_n_buckets>>1) + (new_n_buckets>>2)) return 0; /* requested size is too small */ \
+        new_used = (khint32_t*)kmalloc(__kh_fsize(new_n_buckets) * sizeof(khint32_t)); \
+        memset(new_used, 0, __kh_fsize(new_n_buckets) * sizeof(khint32_t)); \
+        if (!new_used) return -1; /* not enough memory */ \
+        n_buckets = h->keys? 1U<<h->bits : 0U; \
+        if (n_buckets < new_n_buckets) { /* expand */ \
+            khkey_t *new_keys = (khkey_t*)krealloc((void*)h->keys, new_n_buckets * sizeof(khkey_t)); \
+            if (!new_keys) { kfree(new_used); return -1; } \
+            h->keys = new_keys; \
+        } /* otherwise shrink */ \
+        new_mask = new_n_buckets - 1; \
+        for (j = 0; j != n_buckets; ++j) { \
+            khkey_t key; \
+            if (!__kh_used(h->used, j)) continue; \
+            key = h->keys[j]; \
+            __kh_set_unused(h->used, j); \
+            while (1) { /* kick-out process; sort of like in Cuckoo hashing */ \
+                khint_t i; \
+                i = __kh_h2b(__hash_fn(key), new_bits); \
+                while (__kh_used(new_used, i)) i = (i + 1) & new_mask; \
+                __kh_set_used(new_used, i); \
+                if (i < n_buckets && __kh_used(h->used, i)) { /* kick out the existing element */ \
+                    { khkey_t tmp = h->keys[i]; h->keys[i] = key; key = tmp; } \
+                    __kh_set_unused(h->used, i); /* mark it as deleted in the old hash table */ \
+                } else { /* write the element and jump out of the loop */ \
+                    h->keys[i] = key; \
+                    break; \
+                } \
+            } \
+        } \
+        if (n_buckets > new_n_buckets) /* shrink the hash table */ \
+            h->keys = (khkey_t*)krealloc((void *)h->keys, new_n_buckets * sizeof(khkey_t)); \
+        kfree(h->used); /* free the working space */ \
+        h->used = new_used, h->bits = new_bits; \
+        return 0; \
+    }
+
+#define __KHASHL_IMPL_PUT(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    SCOPE khint_t prefix##_putp(HType *h, const khkey_t *key, int *absent) { \
+        khint_t n_buckets, i, last, mask; \
+        n_buckets = h->keys? 1U<<h->bits : 0U; \
+        *absent = -1; \
+        if (h->count >= (n_buckets>>1) + (n_buckets>>2)) { /* rehashing */ \
+            if (prefix##_resize(h, n_buckets + 1U) < 0) \
+                return n_buckets; \
+            n_buckets = 1U<<h->bits; \
+        } /* TODO: to implement automatically shrinking; resize() already support shrinking */ \
+        mask = n_buckets - 1; \
+        i = last = __kh_h2b(__hash_fn(*key), h->bits); \
+        while (__kh_used(h->used, i) && !__hash_eq(h->keys[i], *key)) { \
+            i = (i + 1U) & mask; \
+            if (i == last) break; \
+        } \
+        if (!__kh_used(h->used, i)) { /* not present at all */ \
+            h->keys[i] = *key; \
+            __kh_set_used(h->used, i); \
+            ++h->count; \
+            *absent = 1; \
+        } else *absent = 0; /* Don't touch h->keys[i] if present */ \
+        return i; \
+    } \
+    SCOPE khint_t prefix##_put(HType *h, khkey_t key, int *absent) { return prefix##_putp(h, &key, absent); }
+
+#define __KHASHL_IMPL_DEL(SCOPE, HType, prefix, khkey_t, __hash_fn) \
+    SCOPE int prefix##_del(HType *h, khint_t i) { \
+        khint_t j = i, k, mask, n_buckets; \
+        if (h->keys == 0) return 0; \
+        n_buckets = 1U<<h->bits; \
+        mask = n_buckets - 1U; \
+        while (1) { \
+            j = (j + 1U) & mask; \
+            if (j == i || !__kh_used(h->used, j)) break; /* j==i only when the table is completely full */ \
+            k = __kh_h2b(__hash_fn(h->keys[j]), h->bits); \
+            if ((j > i && (k <= i || k > j)) || (j < i && (k <= i && k > j))) \
+                h->keys[i] = h->keys[j], i = j; \
+        } \
+        __kh_set_unused(h->used, i); \
+        --h->count; \
+        return 1; \
+    }
+
+#define KHASHL_DECLARE(HType, prefix, khkey_t) \
+    __KHASHL_TYPE(HType, khkey_t) \
+    __KHASHL_PROTOTYPES(HType, prefix, khkey_t)
+
+#define KHASHL_INIT(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    __KHASHL_TYPE(HType, khkey_t) \
+    __KHASHL_IMPL_BASIC(SCOPE, HType, prefix) \
+    __KHASHL_IMPL_GET(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    __KHASHL_IMPL_RESIZE(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    __KHASHL_IMPL_PUT(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    __KHASHL_IMPL_DEL(SCOPE, HType, prefix, khkey_t, __hash_fn)
+
+/*****************************
+ * More convenient interface *
+ *****************************/
+
+#define __kh_packed __attribute__ ((__packed__))
+#define __kh_cached_hash(x) ((x).hash)
+
+#define KHASHL_SET_INIT(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    typedef struct { khkey_t key; } __kh_packed HType##_s_bucket_t; \
+    static kh_inline khint_t prefix##_s_hash(HType##_s_bucket_t x) { return __hash_fn(x.key); } \
+    static kh_inline int prefix##_s_eq(HType##_s_bucket_t x, HType##_s_bucket_t y) { return __hash_eq(x.key, y.key); } \
+    KHASHL_INIT(KH_LOCAL, HType, prefix##_s, HType##_s_bucket_t, prefix##_s_hash, prefix##_s_eq) \
+    SCOPE HType *prefix##_init(void) { return prefix##_s_init(); } \
+    SCOPE void prefix##_destroy(HType *h) { prefix##_s_destroy(h); } \
+    SCOPE khint_t prefix##_get(const HType *h, khkey_t key) { HType##_s_bucket_t t; t.key = key; return prefix##_s_getp(h, &t); } \
+    SCOPE int prefix##_del(HType *h, khint_t k) { return prefix##_s_del(h, k); } \
+    SCOPE khint_t prefix##_put(HType *h, khkey_t key, int *absent) { HType##_s_bucket_t t; t.key = key; return prefix##_s_putp(h, &t, absent); }
+
+#define KHASHL_MAP_INIT(SCOPE, HType, prefix, khkey_t, kh_val_t, __hash_fn, __hash_eq) \
+    typedef struct { khkey_t key; kh_val_t val; } __kh_packed HType##_m_bucket_t; \
+    static kh_inline khint_t prefix##_m_hash(HType##_m_bucket_t x) { return __hash_fn(x.key); } \
+    static kh_inline int prefix##_m_eq(HType##_m_bucket_t x, HType##_m_bucket_t y) { return __hash_eq(x.key, y.key); } \
+    KHASHL_INIT(KH_LOCAL, HType, prefix##_m, HType##_m_bucket_t, prefix##_m_hash, prefix##_m_eq) \
+    SCOPE HType *prefix##_init(void) { return prefix##_m_init(); } \
+    SCOPE void prefix##_destroy(HType *h) { prefix##_m_destroy(h); } \
+    SCOPE khint_t prefix##_get(const HType *h, khkey_t key) { HType##_m_bucket_t t; t.key = key; return prefix##_m_getp(h, &t); } \
+    SCOPE int prefix##_del(HType *h, khint_t k) { return prefix##_m_del(h, k); } \
+    SCOPE khint_t prefix##_put(HType *h, khkey_t key, int *absent) { HType##_m_bucket_t t; t.key = key; return prefix##_m_putp(h, &t, absent); }
+
+#define KHASHL_CSET_INIT(SCOPE, HType, prefix, khkey_t, __hash_fn, __hash_eq) \
+    typedef struct { khkey_t key; khint_t hash; } __kh_packed HType##_cs_bucket_t; \
+    static kh_inline int prefix##_cs_eq(HType##_cs_bucket_t x, HType##_cs_bucket_t y) { return x.hash == y.hash && __hash_eq(x.key, y.key); } \
+    KHASHL_INIT(KH_LOCAL, HType, prefix##_cs, HType##_cs_bucket_t, __kh_cached_hash, prefix##_cs_eq) \
+    SCOPE HType *prefix##_init(void) { return prefix##_cs_init(); } \
+    SCOPE void prefix##_destroy(HType *h) { prefix##_cs_destroy(h); } \
+    SCOPE khint_t prefix##_get(const HType *h, khkey_t key) { HType##_cs_bucket_t t; t.key = key; t.hash = __hash_fn(key); return prefix##_cs_getp(h, &t); } \
+    SCOPE int prefix##_del(HType *h, khint_t k) { return prefix##_cs_del(h, k); } \
+    SCOPE khint_t prefix##_put(HType *h, khkey_t key, int *absent) { HType##_cs_bucket_t t; t.key = key, t.hash = __hash_fn(key); return prefix##_cs_putp(h, &t, absent); }
+
+#define KHASHL_CMAP_INIT(SCOPE, HType, prefix, khkey_t, kh_val_t, __hash_fn, __hash_eq) \
+    typedef struct { khkey_t key; kh_val_t val; khint_t hash; } __kh_packed HType##_cm_bucket_t; \
+    static kh_inline int prefix##_cm_eq(HType##_cm_bucket_t x, HType##_cm_bucket_t y) { return x.hash == y.hash && __hash_eq(x.key, y.key); } \
+    KHASHL_INIT(KH_LOCAL, HType, prefix##_cm, HType##_cm_bucket_t, __kh_cached_hash, prefix##_cm_eq) \
+    SCOPE HType *prefix##_init(void) { return prefix##_cm_init(); } \
+    SCOPE void prefix##_destroy(HType *h) { prefix##_cm_destroy(h); } \
+    SCOPE khint_t prefix##_get(const HType *h, khkey_t key) { HType##_cm_bucket_t t; t.key = key; t.hash = __hash_fn(key); return prefix##_cm_getp(h, &t); } \
+    SCOPE int prefix##_del(HType *h, khint_t k) { return prefix##_cm_del(h, k); } \
+    SCOPE khint_t prefix##_put(HType *h, khkey_t key, int *absent) { HType##_cm_bucket_t t; t.key = key, t.hash = __hash_fn(key); return prefix##_cm_putp(h, &t, absent); }
+
+/**************************
+ * Public macro functions *
+ **************************/
+
+#define kh_bucket(h, x) ((h)->keys[x])
+#define kh_size(h) ((h)->count)
+#define kh_capacity(h) ((h)->keys? 1U<<(h)->bits : 0U)
+#define kh_end(h) kh_capacity(h)
+
+#define kh_key(h, x) ((h)->keys[x].key)
+#define kh_val(h, x) ((h)->keys[x].val)
+
+/**************************************
+ * Common hash and equality functions *
+ **************************************/
+
+#define kh_eq_generic(a, b) ((a) == (b))
+#define kh_eq_str(a, b) (strcmp((a), (b)) == 0)
+#define kh_hash_dummy(x) ((khint_t)(x))
+
+static kh_inline khint_t kh_hash_uint32(khint_t key) {
+    key += ~(key << 15);
+    key ^=  (key >> 10);
+    key +=  (key << 3);
+    key ^=  (key >> 6);
+    key += ~(key << 11);
+    key ^=  (key >> 16);
+    return key;
+}
+
+static kh_inline khint_t kh_hash_uint64(khint64_t key) {
+    key = ~key + (key << 21);
+    key = key ^ key >> 24;
+    key = (key + (key << 3)) + (key << 8);
+    key = key ^ key >> 14;
+    key = (key + (key << 2)) + (key << 4);
+    key = key ^ key >> 28;
+    key = key + (key << 31);
+    return (khint_t)key;
+}
+
+static kh_inline khint_t kh_hash_str(const char *s) {
+    khint_t h = (khint_t)*s;
+    if (h) for (++s ; *s; ++s) h = (h << 5) - h + (khint_t)*s;
+    return h;
+}
+
+#endif /* __AC_KHASHL_H */