Changeset 331 for EcnlProtoTool/trunk/onigmo-6.1.3/src/st.c

Timestamp:

Jan 21, 2018, 12:10:09 AM (6 years ago)

Author:

coas-nagasima

Message:

prototoolに関連するプロジェクトをnewlibからmuslを使うよう変更・更新
ntshellをnewlibの下位の実装から、muslのsyscallの実装に変更・更新
以下のOSSをアップデート
・mruby-1.3.0
・musl-1.1.18
・onigmo-6.1.3
・tcc-0.9.27
以下のOSSを追加
・openssl-1.1.0e
・curl-7.57.0
・zlib-1.2.11
以下のmrbgemsを追加
・iij/mruby-digest
・iij/mruby-env
・iij/mruby-errno
・iij/mruby-iijson
・iij/mruby-ipaddr
・iij/mruby-mock
・iij/mruby-require
・iij/mruby-tls-openssl

Location:

EcnlProtoTool/trunk/onigmo-6.1.3

Files:

• . (moved) (moved from EcnlProtoTool/trunk/onigmo-5.15.0 )
• src/st.c (modified) (1 diff)

EcnlProtoTool/trunk/onigmo-6.1.3/src/st.c

@@ -1 @@
-/* This is a public domain general purpose hash table package written by Peter Moore @ UCB. */
-
-/* static       char    sccsid[] = "@(#) st.c 5.1 89/12/14 Crucible"; */
+/* This is a public domain general purpose hash table package
+   originally written by Peter Moore @ UCB.
+
+   The hash table data structures were redesigned and the package was
+   rewritten by Vladimir Makarov <vmakarov@redhat.com>.  */
+
+/* The original package implemented classic bucket-based hash tables
+   with entries doubly linked for an access by their insertion order.
+   To decrease pointer chasing and as a consequence to improve a data
+   locality the current implementation is based on storing entries in
+   an array and using hash tables with open addressing.  The current
+   entries are more compact in comparison with the original ones and
+   this also improves the data locality.
+
+   The hash table has two arrays called *bins* and *entries*.
+
+     bins:
+    -------
+   |       |                  entries array:
+   |-------|            --------------------------------
+   | index |           |      | entry:  |        |      |
+   |-------|           |      |         |        |      |
+   | ...   |           | ...  | hash    |  ...   | ...  |
+   |-------|           |      | key     |        |      |
+   | empty |           |      | record  |        |      |
+   |-------|            --------------------------------
+   | ...   |                   ^                  ^
+   |-------|                   |_ entries start   |_ entries bound
+   |deleted|
+    -------
+
+   o The entry array contains table entries in the same order as they
+     were inserted.
+
+     When the first entry is deleted, a variable containing index of
+     the current first entry (*entries start*) is changed.  In all
+     other cases of the deletion, we just mark the entry as deleted by
+     using a reserved hash value.
+
+     Such organization of the entry storage makes operations of the
+     table shift and the entries traversal very fast.
+
+   o The bins provide access to the entries by their keys.  The
+     key hash is mapped to a bin containing *index* of the
+     corresponding entry in the entry array.
+
+     The bin array size is always power of two, it makes mapping very
+     fast by using the corresponding lower bits of the hash.
+     Generally it is not a good idea to ignore some part of the hash.
+     But alternative approach is worse.  For example, we could use a
+     modulo operation for mapping and a prime number for the size of
+     the bin array.  Unfortunately, the modulo operation for big
+     64-bit numbers are extremely slow (it takes more than 100 cycles
+     on modern Intel CPUs).
+
+     Still other bits of the hash value are used when the mapping
+     results in a collision.  In this case we use a secondary hash
+     value which is a result of a function of the collision bin
+     index and the original hash value.  The function choice
+     guarantees that we can traverse all bins and finally find the
+     corresponding bin as after several iterations the function
+     becomes a full cycle linear congruential generator because it
+     satisfies requirements of the Hull-Dobell theorem.
+
+     When an entry is removed from the table besides marking the
+     hash in the corresponding entry described above, we also mark
+     the bin by a special value in order to find entries which had
+     a collision with the removed entries.
+
+     There are two reserved values for the bins.  One denotes an
+     empty bin, another one denotes a bin for a deleted entry.
+
+   o The length of the bin array is at least two times more than the
+     entry array length.  This keeps the table load factor healthy.
+     The trigger of rebuilding the table is always a case when we can
+     not insert an entry anymore at the entries bound.  We could
+     change the entries bound too in case of deletion but than we need
+     a special code to count bins with corresponding deleted entries
+     and reset the bin values when there are too many bins
+     corresponding deleted entries
+
+     Table rebuilding is done by creation of a new entry array and
+     bins of an appropriate size.  We also try to reuse the arrays
+     in some cases by compacting the array and removing deleted
+     entries.
+
+   o To save memory very small tables have no allocated arrays
+     bins.  We use a linear search for an access by a key.
+
+   o To save more memory we use 8-, 16-, 32- and 64- bit indexes in
+     bins depending on the current hash table size.
+
+   This implementation speeds up the Ruby hash table benchmarks in
+   average by more 40% on Intel Haswell CPU.
+
+*/
+
+#ifdef RUBY
+#include "internal.h"
+#else
+#include "regint.h"
+#include "st.h"
+#endif
 
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-
-#ifdef _WIN32
-#include <malloc.h>
-#endif
-
-#include "regint.h"
-#include "st.h"
-
-typedef struct st_table_entry st_table_entry;
+#include <assert.h>
+
+#ifdef __GNUC__
+#define PREFETCH(addr, write_p) __builtin_prefetch(addr, write_p)
+#define EXPECT(expr, val) __builtin_expect(expr, val)
+#define ATTRIBUTE_UNUSED  __attribute__((unused))
+#else
+#define PREFETCH(addr, write_p)
+#define EXPECT(expr, val) (expr)
+#define ATTRIBUTE_UNUSED
+#endif
+
+#ifdef ST_DEBUG
+#define st_assert(cond) assert(cond)
+#else
+#define st_assert(cond) ((void)(0 && (cond)))
+#endif
+
+/* The type of hashes.  */
+typedef st_index_t st_hash_t;
 
 struct st_table_entry {
-    unsigned int hash;
+    st_hash_t hash;
     st_data_t key;
     st_data_t record;
-    st_table_entry *next;
 };
 
-#define ST_DEFAULT_MAX_DENSITY 5
-#define ST_DEFAULT_INIT_TABLE_SIZE 11
-
-    /*
-     * DEFAULT_MAX_DENSITY is the default for the largest we allow the
-     * average number of items per bin before increasing the number of
-     * bins
-     *
-     * DEFAULT_INIT_TABLE_SIZE is the default for the number of bins
-     * allocated initially
-     *
-     */
-
-static int numcmp(long, long);
-static int numhash(long);
-static struct st_hash_type type_numhash = {
-    numcmp,
-    numhash,
+#ifdef RUBY
+#define type_numhash st_hashtype_num
+const struct st_hash_type st_hashtype_num = {
+    st_numcmp,
+    st_numhash,
 };
 
 /* extern int strcmp(const char *, const char *); */
-static int strhash(const char *);
-static struct st_hash_type type_strhash = {
+static st_index_t strhash(st_data_t);
+static const struct st_hash_type type_strhash = {
     strcmp,
     strhash,
 };
 
-static void rehash(st_table *);
-
-#define alloc(type) (type*)xmalloc((unsigned)sizeof(type))
-#define Calloc(n,s) (char*)xcalloc((n),(s))
-
-#define EQUAL(table,x,y) ((x)==(y) || (*table->type->compare)((x),(y)) == 0)
-
-#define do_hash(key,table) (unsigned int)(*(table)->type->hash)((key))
-#define do_hash_bin(key,table) (do_hash(key, table)%(table)->num_bins)
-
-/*
- * MINSIZE is the minimum size of a dictionary.
- */
-
-#define MINSIZE 8
-
-/*
-Table of prime numbers 2^n+a, 2<=n<=30.
-*/
-static const long primes[] = {
-        8 + 3,
-        16 + 3,
-        32 + 5,
-        64 + 3,
-        128 + 3,
-        256 + 27,
-        512 + 9,
-        1024 + 9,
-        2048 + 5,
-        4096 + 3,
-        8192 + 27,
-        16384 + 43,
-        32768 + 3,
-        65536 + 45,
-        131072 + 29,
-        262144 + 3,
-        524288 + 21,
-        1048576 + 7,
-        2097152 + 17,
-        4194304 + 15,
-        8388608 + 9,
-        16777216 + 43,
-        33554432 + 35,
-        67108864 + 15,
-        134217728 + 29,
-        268435456 + 3,
-        536870912 + 11,
-        1073741824 + 85,
-        0
+static st_index_t strcasehash(st_data_t);
+static const struct st_hash_type type_strcasehash = {
+    st_locale_insensitive_strcasecmp,
+    strcasehash,
 };
-
+#endif /* RUBY */
+
+/* Value used to catch uninitialized entries/bins during debugging.
+   There is a possibility for a false alarm, but its probability is
+   extremely small.  */
+#define ST_INIT_VAL 0xafafafafafafafaf
+#define ST_INIT_VAL_BYTE 0xafa
+
+#ifdef RUBY
+#undef malloc
+#undef realloc
+#undef calloc
+#undef free
+#define malloc ruby_xmalloc
+#define calloc ruby_xcalloc
+#define realloc ruby_xrealloc
+#define free ruby_xfree
+#else /* RUBY */
+#define MEMCPY(p1,p2,type,n)  memcpy((p1), (p2), sizeof(type)*(n))
+#endif /* RUBY */
+
+#define EQUAL(tab,x,y) ((x) == (y) || (*(tab)->type->compare)((x),(y)) == 0)
+#define PTR_EQUAL(tab, ptr, hash_val, key_) \
+    ((ptr)->hash == (hash_val) && EQUAL((tab), (key_), (ptr)->key))
+
+/* Features of a table.  */
+struct st_features {
+    /* Power of 2 used for number of allocated entries.  */
+    unsigned char entry_power;
+    /* Power of 2 used for number of allocated bins.  Depending on the
+       table size, the number of bins is 2-4 times more than the
+       number of entries.  */
+    unsigned char bin_power;
+    /* Enumeration of sizes of bins (8-bit, 16-bit etc).  */
+    unsigned char size_ind;
+    /* Bins are packed in words of type st_index_t.  The following is
+       a size of bins counted by words.  */
+    st_index_t bins_words;
+};
+
+/* Features of all possible size tables.  */
+#if SIZEOF_ST_INDEX_T == 8
+#define MAX_POWER2 62
+static const struct st_features features[] = {
+    {0, 1, 0, 0x0},
+    {1, 2, 0, 0x1},
+    {2, 3, 0, 0x1},
+    {3, 4, 0, 0x2},
+    {4, 5, 0, 0x4},
+    {5, 6, 0, 0x8},
+    {6, 7, 0, 0x10},
+    {7, 8, 0, 0x20},
+    {8, 9, 1, 0x80},
+    {9, 10, 1, 0x100},
+    {10, 11, 1, 0x200},
+    {11, 12, 1, 0x400},
+    {12, 13, 1, 0x800},
+    {13, 14, 1, 0x1000},
+    {14, 15, 1, 0x2000},
+    {15, 16, 1, 0x4000},
+    {16, 17, 2, 0x10000},
+    {17, 18, 2, 0x20000},
+    {18, 19, 2, 0x40000},
+    {19, 20, 2, 0x80000},
+    {20, 21, 2, 0x100000},
+    {21, 22, 2, 0x200000},
+    {22, 23, 2, 0x400000},
+    {23, 24, 2, 0x800000},
+    {24, 25, 2, 0x1000000},
+    {25, 26, 2, 0x2000000},
+    {26, 27, 2, 0x4000000},
+    {27, 28, 2, 0x8000000},
+    {28, 29, 2, 0x10000000},
+    {29, 30, 2, 0x20000000},
+    {30, 31, 2, 0x40000000},
+    {31, 32, 2, 0x80000000},
+    {32, 33, 3, 0x200000000},
+    {33, 34, 3, 0x400000000},
+    {34, 35, 3, 0x800000000},
+    {35, 36, 3, 0x1000000000},
+    {36, 37, 3, 0x2000000000},
+    {37, 38, 3, 0x4000000000},
+    {38, 39, 3, 0x8000000000},
+    {39, 40, 3, 0x10000000000},
+    {40, 41, 3, 0x20000000000},
+    {41, 42, 3, 0x40000000000},
+    {42, 43, 3, 0x80000000000},
+    {43, 44, 3, 0x100000000000},
+    {44, 45, 3, 0x200000000000},
+    {45, 46, 3, 0x400000000000},
+    {46, 47, 3, 0x800000000000},
+    {47, 48, 3, 0x1000000000000},
+    {48, 49, 3, 0x2000000000000},
+    {49, 50, 3, 0x4000000000000},
+    {50, 51, 3, 0x8000000000000},
+    {51, 52, 3, 0x10000000000000},
+    {52, 53, 3, 0x20000000000000},
+    {53, 54, 3, 0x40000000000000},
+    {54, 55, 3, 0x80000000000000},
+    {55, 56, 3, 0x100000000000000},
+    {56, 57, 3, 0x200000000000000},
+    {57, 58, 3, 0x400000000000000},
+    {58, 59, 3, 0x800000000000000},
+    {59, 60, 3, 0x1000000000000000},
+    {60, 61, 3, 0x2000000000000000},
+    {61, 62, 3, 0x4000000000000000},
+    {62, 63, 3, 0x8000000000000000},
+};
+
+#else
+#define MAX_POWER2 30
+
+static const struct st_features features[] = {
+    {0, 1, 0, 0x1},
+    {1, 2, 0, 0x1},
+    {2, 3, 0, 0x2},
+    {3, 4, 0, 0x4},
+    {4, 5, 0, 0x8},
+    {5, 6, 0, 0x10},
+    {6, 7, 0, 0x20},
+    {7, 8, 0, 0x40},
+    {8, 9, 1, 0x100},
+    {9, 10, 1, 0x200},
+    {10, 11, 1, 0x400},
+    {11, 12, 1, 0x800},
+    {12, 13, 1, 0x1000},
+    {13, 14, 1, 0x2000},
+    {14, 15, 1, 0x4000},
+    {15, 16, 1, 0x8000},
+    {16, 17, 2, 0x20000},
+    {17, 18, 2, 0x40000},
+    {18, 19, 2, 0x80000},
+    {19, 20, 2, 0x100000},
+    {20, 21, 2, 0x200000},
+    {21, 22, 2, 0x400000},
+    {22, 23, 2, 0x800000},
+    {23, 24, 2, 0x1000000},
+    {24, 25, 2, 0x2000000},
+    {25, 26, 2, 0x4000000},
+    {26, 27, 2, 0x8000000},
+    {27, 28, 2, 0x10000000},
+    {28, 29, 2, 0x20000000},
+    {29, 30, 2, 0x40000000},
+    {30, 31, 2, 0x80000000},
+};
+
+#endif
+
+/* The reserved hash value and its substitution.  */
+#define RESERVED_HASH_VAL (~(st_hash_t) 0)
+#define RESERVED_HASH_SUBSTITUTION_VAL ((st_hash_t) 0)
+
+/* Return hash value of KEY for table TAB.  */
+static inline st_hash_t
+do_hash(st_data_t key, st_table *tab)
+{
+    st_hash_t hash = (st_hash_t)(tab->type->hash)(key);
+
+    /* RESERVED_HASH_VAL is used for a deleted entry.  Map it into
+       another value.  Such mapping should be extremely rare.  */
+    return hash == RESERVED_HASH_VAL ? RESERVED_HASH_SUBSTITUTION_VAL : hash;
+}
+
+/* Power of 2 defining the minimal number of allocated entries.  */
+#define MINIMAL_POWER2 2
+
+#if MINIMAL_POWER2 < 2
+#error "MINIMAL_POWER2 should be >= 2"
+#endif
+
+/* If the power2 of the allocated `entries` is less than the following
+   value, don't allocate bins and use a linear search.  */
+#define MAX_POWER2_FOR_TABLES_WITHOUT_BINS 4
+
+/* Return smallest n >= MINIMAL_POWER2 such 2^n > SIZE.  */
 static int
-new_size(size)
-    int size;
-{
-    int i;
-
-#if 0
-    for (i=3; i<31; i++) {
-        if ((1<<i) > size) return 1<<i;
-    }
+get_power2(st_index_t size)
+{
+    unsigned int n;
+
+    for (n = 0; size != 0; n++)
+        size >>= 1;
+    if (n <= MAX_POWER2)
+        return n < MINIMAL_POWER2 ? MINIMAL_POWER2 : n;
+#ifdef RUBY
+    /* Ran out of the table entries */
+    rb_raise(rb_eRuntimeError, "st_table too big");
+#endif
+    /* should raise exception */
     return -1;
-#else
-    int newsize;
-
-    for (i = 0, newsize = MINSIZE;
-         i < (int )(sizeof(primes)/sizeof(primes[0]));
-         i++, newsize <<= 1)
+}
+
+/* Return value of N-th bin in array BINS of table with bins size
+   index S.  */
+static inline st_index_t
+get_bin(st_index_t *bins, int s, st_index_t n)
+{
+  return (s == 0 ? ((unsigned char *) bins)[n]
+          : s == 1 ? ((unsigned short *) bins)[n]
+          : s == 2 ? ((unsigned int *) bins)[n]
+          : ((st_index_t *) bins)[n]);
+}
+
+/* Set up N-th bin in array BINS of table with bins size index S to
+   value V.  */
+static inline void
+set_bin(st_index_t *bins, int s, st_index_t n, st_index_t v)
+{
+    if (s == 0) ((unsigned char *) bins)[n] = (unsigned char) v;
+    else if (s == 1) ((unsigned short *) bins)[n] = (unsigned short) v;
+    else if (s == 2) ((unsigned int *) bins)[n] = (unsigned int) v;
+    else ((st_index_t *) bins)[n] = v;
+}
+
+/* These macros define reserved values for empty table bin and table
+   bin which contains a deleted entry.  We will never use such values
+   for an entry index in bins.  */
+#define EMPTY_BIN    0
+#define DELETED_BIN  1
+/* Base of a real entry index in the bins.  */
+#define ENTRY_BASE 2
+
+/* Mark I-th bin of table TAB as empty, in other words not
+   corresponding to any entry.  */
+#define MARK_BIN_EMPTY(tab, i) (set_bin((tab)->bins, get_size_ind(tab), i, EMPTY_BIN))
+
+/* Values used for not found entry and bin with given
+   characteristics.  */
+#define UNDEFINED_ENTRY_IND (~(st_index_t) 0)
+#define UNDEFINED_BIN_IND (~(st_index_t) 0)
+
+/* Mark I-th bin of table TAB as corresponding to a deleted table
+   entry.  Update number of entries in the table and number of bins
+   corresponding to deleted entries. */
+#define MARK_BIN_DELETED(tab, i)                                \
+    do {                                                        \
+        st_assert(i != UNDEFINED_BIN_IND);                      \
+        st_assert(! IND_EMPTY_OR_DELETED_BIN_P(tab, i));        \
+        set_bin((tab)->bins, get_size_ind(tab), i, DELETED_BIN); \
+    } while (0)
+
+/* Macros to check that value B is used empty bins and bins
+   corresponding deleted entries.  */
+#define EMPTY_BIN_P(b) ((b) == EMPTY_BIN)
+#define DELETED_BIN_P(b) ((b) == DELETED_BIN)
+#define EMPTY_OR_DELETED_BIN_P(b) ((b) <= DELETED_BIN)
+
+/* Macros to check empty bins and bins corresponding to deleted
+   entries.  Bins are given by their index I in table TAB.  */
+#define IND_EMPTY_BIN_P(tab, i) (EMPTY_BIN_P(get_bin((tab)->bins, get_size_ind(tab), i)))
+#define IND_DELETED_BIN_P(tab, i) (DELETED_BIN_P(get_bin((tab)->bins, get_size_ind(tab), i)))
+#define IND_EMPTY_OR_DELETED_BIN_P(tab, i) (EMPTY_OR_DELETED_BIN_P(get_bin((tab)->bins, get_size_ind(tab), i)))
+
+/* Macros for marking and checking deleted entries given by their
+   pointer E_PTR.  */
+#define MARK_ENTRY_DELETED(e_ptr) ((e_ptr)->hash = RESERVED_HASH_VAL)
+#define DELETED_ENTRY_P(e_ptr) ((e_ptr)->hash == RESERVED_HASH_VAL)
+
+/* Return bin size index of table TAB.  */
+static inline unsigned int
+get_size_ind(const st_table *tab)
+{
+    return tab->size_ind;
+}
+
+/* Return the number of allocated bins of table TAB.  */
+static inline st_index_t
+get_bins_num(const st_table *tab)
+{
+    return ((st_index_t) 1)<<tab->bin_power;
+}
+
+/* Return mask for a bin index in table TAB.  */
+static inline st_index_t
+bins_mask(const st_table *tab)
+{
+    return get_bins_num(tab) - 1;
+}
+
+/* Return the index of table TAB bin corresponding to
+   HASH_VALUE.  */
+static inline st_index_t
+hash_bin(st_hash_t hash_value, st_table *tab)
+{
+    return hash_value & bins_mask(tab);
+}
+
+/* Return the number of allocated entries of table TAB.  */
+static inline st_index_t
+get_allocated_entries(const st_table *tab)
+{
+    return ((st_index_t) 1)<<tab->entry_power;
+}
+
+/* Return size of the allocated bins of table TAB.  */
+static inline st_index_t
+bins_size(const st_table *tab)
+{
+    return features[tab->entry_power].bins_words * sizeof (st_index_t);
+}
+
+/* Mark all bins of table TAB as empty.  */
+static void
+initialize_bins(st_table *tab)
+{
+    memset(tab->bins, 0, bins_size(tab));
+}
+
+/* Make table TAB empty.  */
+static void
+make_tab_empty(st_table *tab)
+{
+    tab->num_entries = 0;
+    tab->entries_start = tab->entries_bound = 0;
+    if (tab->bins != NULL)
+        initialize_bins(tab);
+}
+
+#ifdef ST_DEBUG
+/* Check the table T consistency.  It can be extremely slow.  So use
+   it only for debugging.  */
+static void
+st_check(st_table *tab)
+{
+    st_index_t d, e, i, n, p;
+
+    for (p = get_allocated_entries(tab), i = 0; p > 1; i++, p>>=1)
+        ;
+    p = i;
+    assert(p >= MINIMAL_POWER2);
+    assert(tab->entries_bound <= get_allocated_entries(tab)
+           && tab->entries_start <= tab->entries_bound);
+    n = 0;
+    return;
+    if (tab->entries_bound != 0)
+        for (i = tab->entries_start; i < tab->entries_bound; i++) {
+            assert(tab->entries[i].hash != (st_hash_t) ST_INIT_VAL
+                   && tab->entries[i].key != ST_INIT_VAL
+                   && tab->entries[i].record != ST_INIT_VAL);
+            if (! DELETED_ENTRY_P(&tab->entries[i]))
+                n++;
+        }
+    assert(n == tab->num_entries);
+    if (tab->bins == NULL)
+        assert(p <= MAX_POWER2_FOR_TABLES_WITHOUT_BINS);
+    else {
+        assert(p > MAX_POWER2_FOR_TABLES_WITHOUT_BINS);
+        for (n = d = i = 0; i < get_bins_num(tab); i++) {
+            assert(get_bin(tab->bins, tab->size_ind, i) != ST_INIT_VAL);
+            if (IND_DELETED_BIN_P(tab, i)) {
+                d++;
+                continue;
+            }
+            else if (IND_EMPTY_BIN_P(tab, i))
+                continue;
+            n++;
+            e = get_bin(tab->bins, tab->size_ind, i) - ENTRY_BASE;
+            assert(tab->entries_start <= e && e < tab->entries_bound);
+            assert(! DELETED_ENTRY_P(&tab->entries[e]));
+            assert(tab->entries[e].hash != (st_hash_t) ST_INIT_VAL
+                   && tab->entries[e].key != ST_INIT_VAL
+                   && tab->entries[e].record != ST_INIT_VAL);
+        }
+        assert(n == tab->num_entries);
+        assert(n + d < get_bins_num(tab));
+    }
+}
+#endif
+
+#ifdef HASH_LOG
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+static struct {
+    int all, total, num, str, strcase;
+}  collision;
+
+/* Flag switching off output of package statistics at the end of
+   program.  */
+static int init_st = 0;
+
+/* Output overall number of table searches and collisions into a
+   temporary file.  */
+static void
+stat_col(void)
+{
+    char fname[10+sizeof(long)*3];
+    FILE *f;
+    if (!collision.total) return;
+    f = fopen((snprintf(fname, sizeof(fname), "/tmp/col%ld", (long)getpid()), fname), "w");
+    if (f == 0) return ;
+
+    fprintf(f, "collision: %d / %d (%6.2f)\n", collision.all, collision.total,
+            ((double)collision.all / (collision.total)) * 100);
+    fprintf(f, "num: %d, str: %d, strcase: %d\n", collision.num, collision.str, collision.strcase);
+    fclose(f);
+}
+#endif
+
+/* Create and return table with TYPE which can hold at least SIZE
+   entries.  The real number of entries which the table can hold is
+   the nearest power of two for SIZE.  */
+st_table *
+st_init_table_with_size(const struct st_hash_type *type, st_index_t size)
+{
+    st_table *tab;
+    int n;
+
+#ifdef HASH_LOG
+#if HASH_LOG+0 < 0
     {
-        if (newsize > size) return primes[i];
-    }
-    /* Ran out of polynomials */
-    return -1;                  /* should raise exception */
-#endif
-}
+        const char *e = getenv("ST_HASH_LOG");
+        if (!e || !*e) init_st = 1;
+    }
+#endif
+    if (init_st == 0) {
+        init_st = 1;
+        atexit(stat_col);
+    }
+#endif
+
+    n = get_power2(size);
+#ifndef RUBY
+    if (n < 0)
+        return NULL;
+#endif
+    tab = (st_table *) malloc(sizeof (st_table));
+    if (tab == NULL)
+        return NULL;
+    tab->type = type;
+    tab->entry_power = n;
+    tab->bin_power = features[n].bin_power;
+    tab->size_ind = features[n].size_ind;
+    if (n <= MAX_POWER2_FOR_TABLES_WITHOUT_BINS)
+        tab->bins = NULL;
+    else {
+        tab->bins = (st_index_t *) malloc(bins_size(tab));
+        if (tab->bins == NULL) {
+            free(tab);
+            return NULL;
+        }
+    }
+    tab->entries = (st_table_entry *) malloc(get_allocated_entries(tab)
+                                             * sizeof(st_table_entry));
+    if (tab->entries == NULL) {
+        st_free_table(tab);
+        return NULL;
+    }
+#ifdef ST_DEBUG
+    memset(tab->entries, ST_INIT_VAL_BYTE,
+           get_allocated_entries(tab) * sizeof(st_table_entry));
+    if (tab->bins != NULL)
+        memset(tab->bins, ST_INIT_VAL_BYTE, bins_size(tab));
+#endif
+    make_tab_empty(tab);
+    tab->rebuilds_num = 0;
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+    return tab;
+}
+
+#ifdef RUBY
+/* Create and return table with TYPE which can hold a minimal number
+   of entries (see comments for get_power2).  */
+st_table *
+st_init_table(const struct st_hash_type *type)
+{
+    return st_init_table_with_size(type, 0);
+}
+
+/* Create and return table which can hold a minimal number of
+   numbers.  */
+st_table *
+st_init_numtable(void)
+{
+    return st_init_table(&type_numhash);
+}
+
+/* Create and return table which can hold SIZE numbers.  */
+st_table *
+st_init_numtable_with_size(st_index_t size)
+{
+    return st_init_table_with_size(&type_numhash, size);
+}
+
+/* Create and return table which can hold a minimal number of
+   strings.  */
+st_table *
+st_init_strtable(void)
+{
+    return st_init_table(&type_strhash);
+}
+
+/* Create and return table which can hold SIZE strings.  */
+st_table *
+st_init_strtable_with_size(st_index_t size)
+{
+    return st_init_table_with_size(&type_strhash, size);
+}
+
+/* Create and return table which can hold a minimal number of strings
+   whose character case is ignored.  */
+st_table *
+st_init_strcasetable(void)
+{
+    return st_init_table(&type_strcasehash);
+}
+
+/* Create and return table which can hold SIZE strings whose character
+   case is ignored.  */
+st_table *
+st_init_strcasetable_with_size(st_index_t size)
+{
+    return st_init_table_with_size(&type_strcasehash, size);
+}
+
+/* Make table TAB empty.  */
+void
+st_clear(st_table *tab)
+{
+    make_tab_empty(tab);
+    tab->rebuilds_num++;
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+}
+#endif /* RUBY */
+
+/* Free table TAB space.  */
+void
+st_free_table(st_table *tab)
+{
+    if (tab->bins != NULL)
+        free(tab->bins);
+    free(tab->entries);
+    free(tab);
+}
+
+#ifdef RUBY
+/* Return byte size of memory allocted for table TAB.  */
+size_t
+st_memsize(const st_table *tab)
+{
+    return(sizeof(st_table)
+           + (tab->bins == NULL ? 0 : bins_size(tab))
+           + get_allocated_entries(tab) * sizeof(st_table_entry));
+}
+#endif /* RUBY */
+
+static st_index_t
+find_table_entry_ind(st_table *tab, st_hash_t hash_value, st_data_t key);
+
+static st_index_t
+find_table_bin_ind(st_table *tab, st_hash_t hash_value, st_data_t key);
+
+static st_index_t
+find_table_bin_ind_direct(st_table *table, st_hash_t hash_value, st_data_t key);
+
+static st_index_t
+find_table_bin_ptr_and_reserve(st_table *tab, st_hash_t *hash_value,
+                               st_data_t key, st_index_t *bin_ind);
 
 #ifdef HASH_LOG
-static int collision = 0;
-static int init_st = 0;
-
 static void
-stat_col()
-{
-    FILE *f = fopen("/tmp/col", "w");
-    fprintf(f, "collision: %d\n", collision);
-    fclose(f);
-}
-#endif
-
-st_table*
-st_init_table_with_size(type, size)
-    struct st_hash_type *type;
-    int size;
-{
-    st_table *tbl;
-
-#ifdef HASH_LOG
-    if (init_st == 0) {
-        init_st = 1;
-        atexit(stat_col);
-    }
-#endif
-
-    size = new_size(size);      /* round up to prime number */
-
-    tbl = alloc(st_table);
-    tbl->type = type;
-    tbl->num_entries = 0;
-    tbl->num_bins = size;
-    tbl->bins = (st_table_entry **)Calloc(size, sizeof(st_table_entry*));
-
-    return tbl;
-}
-
-st_table*
-st_init_table(type)
-    struct st_hash_type *type;
-{
-    return st_init_table_with_size(type, 0);
-}
-
-st_table*
-st_init_numtable(void)
-{
-    return st_init_table(&type_numhash);
-}
-
-st_table*
-st_init_numtable_with_size(size)
-    int size;
-{
-    return st_init_table_with_size(&type_numhash, size);
-}
-
-st_table*
-st_init_strtable(void)
-{
-    return st_init_table(&type_strhash);
-}
-
-st_table*
-st_init_strtable_with_size(size)
-    int size;
-{
-    return st_init_table_with_size(&type_strhash, size);
-}
-
+count_collision(const struct st_hash_type *type)
+{
+    collision.all++;
+    if (type == &type_numhash) {
+        collision.num++;
+    }
+    else if (type == &type_strhash) {
+        collision.strcase++;
+    }
+    else if (type == &type_strcasehash) {
+        collision.str++;
+    }
+}
+
+#define COLLISION (collision_check ? count_collision(tab->type) : (void)0)
+#define FOUND_BIN (collision_check ? collision.total++ : (void)0)
+#define collision_check 0
+#else
+#define COLLISION
+#define FOUND_BIN
+#endif
+
+/* If the number of entries in the table is at least REBUILD_THRESHOLD
+   times less than the entry array length, decrease the table
+   size.  */
+#define REBUILD_THRESHOLD 4
+
+#if REBUILD_THRESHOLD < 2
+#error "REBUILD_THRESHOLD should be >= 2"
+#endif
+
+/* Rebuild table TAB.  Rebuilding removes all deleted bins and entries
+   and can change size of the table entries and bins arrays.
+   Rebuilding is implemented by creation of a new table or by
+   compaction of the existing one.  */
+static void
+rebuild_table(st_table *tab)
+{
+    st_index_t i, ni, bound;
+    unsigned int size_ind;
+    st_table *new_tab;
+    st_table_entry *entries, *new_entries;
+    st_table_entry *curr_entry_ptr;
+    st_index_t *bins;
+    st_index_t bin_ind;
+
+    st_assert(tab != NULL);
+    bound = tab->entries_bound;
+    entries = tab->entries;
+    if ((2 * tab->num_entries <= get_allocated_entries(tab)
+         && REBUILD_THRESHOLD * tab->num_entries > get_allocated_entries(tab))
+        || tab->num_entries < (1 << MINIMAL_POWER2)) {
+        /* Compaction: */
+        tab->num_entries = 0;
+        if (tab->bins != NULL)
+            initialize_bins(tab);
+        new_tab = tab;
+        new_entries = entries;
+    }
+    else {
+        new_tab = st_init_table_with_size(tab->type,
+                                          2 * tab->num_entries - 1);
+        new_entries = new_tab->entries;
+    }
+    ni = 0;
+    bins = new_tab->bins;
+    size_ind = get_size_ind(new_tab);
+    for (i = tab->entries_start; i < bound; i++) {
+        curr_entry_ptr = &entries[i];
+        PREFETCH(entries + i + 1, 0);
+        if (EXPECT(DELETED_ENTRY_P(curr_entry_ptr), 0))
+            continue;
+        if (&new_entries[ni] != curr_entry_ptr)
+            new_entries[ni] = *curr_entry_ptr;
+        if (EXPECT(bins != NULL, 1)) {
+            bin_ind = find_table_bin_ind_direct(new_tab, curr_entry_ptr->hash,
+                                                curr_entry_ptr->key);
+            st_assert(bin_ind != UNDEFINED_BIN_IND
+                      && (tab == new_tab || new_tab->rebuilds_num == 0)
+                      && IND_EMPTY_BIN_P(new_tab, bin_ind));
+            set_bin(bins, size_ind, bin_ind, ni + ENTRY_BASE);
+        }
+        new_tab->num_entries++;
+        ni++;
+    }
+    if (new_tab != tab) {
+        tab->entry_power = new_tab->entry_power;
+        tab->bin_power = new_tab->bin_power;
+        tab->size_ind = new_tab->size_ind;
+        st_assert (tab->num_entries == ni && new_tab->num_entries == ni);
+        if (tab->bins != NULL)
+            free(tab->bins);
+        tab->bins = new_tab->bins;
+        free(tab->entries);
+        tab->entries = new_tab->entries;
+        free(new_tab);
+    }
+    tab->entries_start = 0;
+    tab->entries_bound = tab->num_entries;
+    tab->rebuilds_num++;
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+}
+
+/* Return the next secondary hash index for table TAB using previous
+   index IND and PERTERB.  Finally modulo of the function becomes a
+   full *cycle linear congruential generator*, in other words it
+   guarantees traversing all table bins in extreme case.
+
+   According the Hull-Dobell theorem a generator
+   "Xnext = (a*Xprev + c) mod m" is a full cycle generator iff
+     o m and c are relatively prime
+     o a-1 is divisible by all prime factors of m
+     o a-1 is divisible by 4 if m is divisible by 4.
+
+   For our case a is 5, c is 1, and m is a power of two.  */
+static inline st_index_t
+secondary_hash(st_index_t ind, st_table *tab, st_index_t *perterb)
+{
+    *perterb >>= 11;
+    ind = (ind << 2) + ind + *perterb + 1;
+    return hash_bin(ind, tab);
+}
+
+/* Find an entry with HASH_VALUE and KEY in TABLE using a linear
+   search.  Return the index of the found entry in array `entries`.
+   If it is not found, return UNDEFINED_ENTRY_IND.  */
+static inline st_index_t
+find_entry(st_table *tab, st_hash_t hash_value, st_data_t key)
+{
+    st_index_t i, bound;
+    st_table_entry *entries;
+
+    bound = tab->entries_bound;
+    entries = tab->entries;
+    for (i = tab->entries_start; i < bound; i++) {
+        if (PTR_EQUAL(tab, &entries[i], hash_value, key))
+            return i;
+    }
+    return UNDEFINED_ENTRY_IND;
+}
+
+/* Use the quadratic probing.  The method has a better data locality
+   but more collisions than the current approach.  In average it
+   results in a bit slower search.  */
+/*#define QUADRATIC_PROBE*/
+
+/* Return index of entry with HASH_VALUE and KEY in table TAB.  If
+   there is no such entry, return UNDEFINED_ENTRY_IND.  */
+static st_index_t
+find_table_entry_ind(st_table *tab, st_hash_t hash_value, st_data_t key)
+{
+    st_index_t ind;
+#ifdef QUADRATIC_PROBE
+    st_index_t d;
+#else
+    st_index_t peterb;
+#endif
+    st_index_t bin;
+    st_table_entry *entries = tab->entries;
+
+    st_assert(tab != NULL && tab->bins != NULL);
+    ind = hash_bin(hash_value, tab);
+#ifdef QUADRATIC_PROBE
+    d = 1;
+#else
+    peterb = hash_value;
+#endif
+    FOUND_BIN;
+    for (;;) {
+        bin = get_bin(tab->bins, get_size_ind(tab), ind);
+        if (! EMPTY_OR_DELETED_BIN_P(bin)
+            && PTR_EQUAL(tab, &entries[bin - ENTRY_BASE], hash_value, key))
+            break;
+        else if (EMPTY_BIN_P(bin))
+            return UNDEFINED_ENTRY_IND;
+#ifdef QUADRATIC_PROBE
+        ind = hash_bin(ind + d, tab);
+        d++;
+#else
+        ind = secondary_hash(ind, tab, &peterb);
+#endif
+        COLLISION;
+    }
+    return bin;
+}
+
+/* Find and return index of table TAB bin corresponding to an entry
+   with HASH_VALUE and KEY.  If there is no such bin, return
+   UNDEFINED_BIN_IND.  */
+static st_index_t
+find_table_bin_ind(st_table *tab, st_hash_t hash_value, st_data_t key)
+{
+    st_index_t ind;
+#ifdef QUADRATIC_PROBE
+    st_index_t d;
+#else
+    st_index_t peterb;
+#endif
+    st_index_t bin;
+    st_table_entry *entries = tab->entries;
+
+    st_assert(tab != NULL && tab->bins != NULL);
+    ind = hash_bin(hash_value, tab);
+#ifdef QUADRATIC_PROBE
+    d = 1;
+#else
+    peterb = hash_value;
+#endif
+    FOUND_BIN;
+    for (;;) {
+        bin = get_bin(tab->bins, get_size_ind(tab), ind);
+        if (! EMPTY_OR_DELETED_BIN_P(bin)
+            && PTR_EQUAL(tab, &entries[bin - ENTRY_BASE], hash_value, key))
+            break;
+        else if (EMPTY_BIN_P(bin))
+            return UNDEFINED_BIN_IND;
+#ifdef QUADRATIC_PROBE
+        ind = hash_bin(ind + d, tab);
+        d++;
+#else
+        ind = secondary_hash(ind, tab, &peterb);
+#endif
+        COLLISION;
+    }
+    return ind;
+}
+
+/* Find and return index of table TAB bin corresponding to an entry
+   with HASH_VALUE and KEY.  The entry should be in the table
+   already.  */
+static st_index_t
+find_table_bin_ind_direct(st_table *tab, st_hash_t hash_value, st_data_t key)
+{
+    st_index_t ind;
+#ifdef QUADRATIC_PROBE
+    st_index_t d;
+#else
+    st_index_t peterb;
+#endif
+    st_index_t bin;
+    st_table_entry *entries = tab->entries;
+
+    st_assert(tab != NULL && tab->bins != NULL);
+    ind = hash_bin(hash_value, tab);
+#ifdef QUADRATIC_PROBE
+    d = 1;
+#else
+    peterb = hash_value;
+#endif
+    FOUND_BIN;
+    for (;;) {
+        bin = get_bin(tab->bins, get_size_ind(tab), ind);
+        if (EMPTY_OR_DELETED_BIN_P(bin))
+            return ind;
+        st_assert (! PTR_EQUAL(tab, &entries[bin - ENTRY_BASE], hash_value, key));
+#ifdef QUADRATIC_PROBE
+        ind = hash_bin(ind + d, tab);
+        d++;
+#else
+        ind = secondary_hash(ind, tab, &peterb);
+#endif
+        COLLISION;
+    }
+}
+
+/* Return index of table TAB bin for HASH_VALUE and KEY through
+   BIN_IND and the pointed value as the function result.  Reserve the
+   bin for inclusion of the corresponding entry into the table if it
+   is not there yet.  We always find such bin as bins array length is
+   bigger entries array.  Although we can reuse a deleted bin, the
+   result bin value is always empty if the table has no entry with
+   KEY.  Return the entries array index of the found entry or
+   UNDEFINED_ENTRY_IND if it is not found.  */
+static st_index_t
+find_table_bin_ptr_and_reserve(st_table *tab, st_hash_t *hash_value,
+                               st_data_t key, st_index_t *bin_ind) {
+    st_index_t ind;
+    st_hash_t curr_hash_value = *hash_value;
+#ifdef QUADRATIC_PROBE
+    st_index_t d;
+#else
+    st_index_t peterb;
+#endif
+    st_index_t entry_index;
+    st_index_t first_deleted_bin_ind;
+    st_table_entry *entries;
+
+    st_assert(tab != NULL && tab->bins != NULL
+              && tab->entries_bound <= get_allocated_entries(tab)
+              && tab->entries_start <= tab->entries_bound);
+    ind = hash_bin(curr_hash_value, tab);
+#ifdef QUADRATIC_PROBE
+    d = 1;
+#else
+    peterb = curr_hash_value;
+#endif
+    FOUND_BIN;
+    first_deleted_bin_ind = UNDEFINED_BIN_IND;
+    entries = tab->entries;
+    for (;;) {
+        entry_index = get_bin(tab->bins, get_size_ind(tab), ind);
+        if (EMPTY_BIN_P(entry_index)) {
+            tab->num_entries++;
+            entry_index = UNDEFINED_ENTRY_IND;
+            if (first_deleted_bin_ind != UNDEFINED_BIN_IND) {
+                /* We can reuse bin of a deleted entry.  */
+                ind = first_deleted_bin_ind;
+                MARK_BIN_EMPTY(tab, ind);
+            }
+            break;
+        } else if (! DELETED_BIN_P(entry_index)) {
+            if (PTR_EQUAL(tab, &entries[entry_index - ENTRY_BASE], curr_hash_value, key))
+                break;
+        } else if (first_deleted_bin_ind == UNDEFINED_BIN_IND)
+            first_deleted_bin_ind = ind;
+#ifdef QUADRATIC_PROBE
+        ind = hash_bin(ind + d, tab);
+        d++;
+#else
+        ind = secondary_hash(ind, tab, &peterb);
+#endif
+        COLLISION;
+    }
+    *bin_ind = ind;
+    return entry_index;
+}
+
+/* Find an entry with KEY in table TAB.  Return non-zero if we found
+   it.  Set up *RECORD to the found entry record.  */
+int
+st_lookup(st_table *tab, st_data_t key, st_data_t *value)
+{
+    st_index_t bin;
+    st_hash_t hash = do_hash(key, tab);
+
+    if (tab->bins == NULL) {
+        bin = find_entry(tab, hash, key);
+        if (bin == UNDEFINED_ENTRY_IND)
+            return 0;
+    } else {
+        bin = find_table_entry_ind(tab, hash, key);
+        if (bin == UNDEFINED_ENTRY_IND)
+            return 0;
+        bin -= ENTRY_BASE;
+    }
+    if (value != 0)
+        *value = tab->entries[bin].record;
+    return 1;
+}
+
+#ifdef RUBY
+/* Find an entry with KEY in table TAB.  Return non-zero if we found
+   it.  Set up *RESULT to the found table entry key.  */
+int
+st_get_key(st_table *tab, st_data_t key, st_data_t *result)
+{
+    st_index_t bin;
+    st_hash_t hash = do_hash(key, tab);
+
+    if (tab->bins == NULL) {
+        bin = find_entry(tab, hash, key);
+        if (bin == UNDEFINED_ENTRY_IND)
+            return 0;
+    } else {
+        bin = find_table_entry_ind(tab, hash, key);
+        if (bin == UNDEFINED_ENTRY_IND)
+            return 0;
+        bin -= ENTRY_BASE;
+    }
+    if (result != 0)
+        *result = tab->entries[bin].key;
+    return 1;
+}
+#endif /* RUBY */
+
+/* Check the table and rebuild it if it is necessary.  */
+static inline void
+rebuild_table_if_necessary (st_table *tab)
+{
+    st_index_t bound = tab->entries_bound;
+
+    if (bound == get_allocated_entries(tab))
+        rebuild_table(tab);
+    st_assert(tab->entries_bound < get_allocated_entries(tab));
+}
+
+/* Insert (KEY, VALUE) into table TAB and return zero.  If there is
+   already entry with KEY in the table, return nonzero and and update
+   the value of the found entry.  */
+int
+st_insert(st_table *tab, st_data_t key, st_data_t value)
+{
+    st_table_entry *entry;
+    st_index_t bin;
+    st_index_t ind;
+    st_hash_t hash_value;
+    st_index_t bin_ind;
+    int new_p;
+
+    rebuild_table_if_necessary(tab);
+    hash_value = do_hash(key, tab);
+    if (tab->bins == NULL) {
+        bin = find_entry(tab, hash_value, key);
+        new_p = bin == UNDEFINED_ENTRY_IND;
+        if (new_p)
+            tab->num_entries++;
+        bin_ind = UNDEFINED_BIN_IND;
+    } else {
+        bin = find_table_bin_ptr_and_reserve(tab, &hash_value,
+                                             key, &bin_ind);
+        new_p = bin == UNDEFINED_ENTRY_IND;
+        bin -= ENTRY_BASE;
+    }
+    if (new_p) {
+        st_assert(tab->entries_bound < get_allocated_entries(tab));
+        ind = tab->entries_bound++;
+        entry = &tab->entries[ind];
+        entry->hash = hash_value;
+        entry->key = key;
+        entry->record = value;
+        if (bin_ind != UNDEFINED_BIN_IND)
+            set_bin(tab->bins, get_size_ind(tab), bin_ind, ind + ENTRY_BASE);
+#ifdef ST_DEBUG
+        st_check(tab);
+#endif
+        return 0;
+    }
+    tab->entries[bin].record = value;
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+    return 1;
+}
+
+#ifdef RUBY
+/* Insert (KEY, VALUE, HASH) into table TAB.  The table should not have
+   entry with KEY before the insertion.  */
+static inline void
+st_add_direct_with_hash(st_table *tab,
+                        st_data_t key, st_data_t value, st_hash_t hash) {
+    st_table_entry *entry;
+    st_index_t ind;
+    st_index_t bin_ind;
+
+    rebuild_table_if_necessary(tab);
+    ind = tab->entries_bound++;
+    entry = &tab->entries[ind];
+    entry->hash = hash;
+    entry->key = key;
+    entry->record = value;
+    tab->num_entries++;
+    if (tab->bins != NULL) {
+        bin_ind = find_table_bin_ind_direct(tab, hash, key);
+        st_assert (bin_ind != UNDEFINED_BIN_IND);
+        set_bin(tab->bins, get_size_ind(tab), bin_ind, ind + ENTRY_BASE);
+    }
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+}
+
+/* Insert (KEY, VALUE) into table TAB.  The table should not have
+   entry with KEY before the insertion.  */
 void
-st_free_table(table)
-    st_table *table;
-{
-    register st_table_entry *ptr, *next;
-    int i;
-
-    for(i = 0; i < table->num_bins; i++) {
-        ptr = table->bins[i];
-        while (ptr != 0) {
-            next = ptr->next;
-            free(ptr);
-            ptr = next;
+st_add_direct(st_table *tab, st_data_t key, st_data_t value)
+{
+    st_hash_t hash_value;
+
+    hash_value = do_hash(key, tab);
+    st_add_direct_with_hash(tab, key, value, hash_value);
+}
+
+/* Insert (FUNC(KEY), VALUE) into table TAB and return zero.  If
+   there is already entry with KEY in the table, return nonzero and
+   and update the value of the found entry.  */
+int
+st_insert2(st_table *tab, st_data_t key, st_data_t value,
+           st_data_t (*func)(st_data_t)) {
+    st_table_entry *entry;
+    st_index_t bin;
+    st_index_t ind, check;
+    st_hash_t hash_value;
+    st_index_t bin_ind;
+    int new_p;
+
+    rebuild_table_if_necessary (tab);
+    hash_value = do_hash(key, tab);
+    if (tab->bins == NULL) {
+        bin = find_entry(tab, hash_value, key);
+        new_p = bin == UNDEFINED_ENTRY_IND;
+        bin_ind = UNDEFINED_BIN_IND;
+    } else {
+        bin = find_table_bin_ptr_and_reserve(tab, &hash_value,
+                                             key, &bin_ind);
+        new_p = bin == UNDEFINED_ENTRY_IND;
+        bin -= ENTRY_BASE;
+    }
+    if (new_p) {
+        st_assert(tab->entries_bound < get_allocated_entries(tab));
+        check = tab->rebuilds_num;
+        key = (*func)(key);
+        st_assert(check == tab->rebuilds_num
+                  && do_hash(key, tab) == hash_value);
+        ind = tab->entries_bound++;
+        entry = &tab->entries[ind];
+        entry->hash = hash_value;
+        entry->key = key;
+        entry->record = value;
+        if (bin_ind != UNDEFINED_BIN_IND)
+            set_bin(tab->bins, get_size_ind(tab), bin_ind, ind + ENTRY_BASE);
+#ifdef ST_DEBUG
+        st_check(tab);
+#endif
+        return 0;
+    }
+    tab->entries[bin].record = value;
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+    return 1;
+}
+
+/* Create and return a copy of table OLD_TAB.  */
+st_table *
+st_copy(st_table *old_tab)
+{
+    st_table *new_tab;
+
+    new_tab = (st_table *) malloc(sizeof(st_table));
+    if (new_tab == NULL)
+        return NULL;
+    *new_tab = *old_tab;
+    if (old_tab->bins == NULL)
+        new_tab->bins = NULL;
+    else {
+        new_tab->bins = (st_index_t *) malloc(bins_size(old_tab));
+        if (new_tab->bins == NULL) {
+            free(new_tab);
+            return NULL;
         }
     }
-    free(table->bins);
-    free(table);
-}
-
-#define PTR_NOT_EQUAL(table, ptr, hash_val, key) \
-((ptr) != 0 && (ptr->hash != (hash_val) || !EQUAL((table), (key), (ptr)->key)))
-
-#ifdef HASH_LOG
-#define COLLISION collision++
-#else
-#define COLLISION
-#endif
-
-#define FIND_ENTRY(table, ptr, hash_val, bin_pos) do {\
-    bin_pos = hash_val%(table)->num_bins;\
-    ptr = (table)->bins[bin_pos];\
-    if (PTR_NOT_EQUAL(table, ptr, hash_val, key)) {\
-        COLLISION;\
-        while (PTR_NOT_EQUAL(table, ptr->next, hash_val, key)) {\
-            ptr = ptr->next;\
-        }\
-        ptr = ptr->next;\
-    }\
-} while (0)
+    new_tab->entries = (st_table_entry *) malloc(get_allocated_entries(old_tab)
+                                                 * sizeof(st_table_entry));
+    if (new_tab->entries == NULL) {
+        st_free_table(new_tab);
+        return NULL;
+    }
+    MEMCPY(new_tab->entries, old_tab->entries, st_table_entry,
+           get_allocated_entries(old_tab));
+    if (old_tab->bins != NULL)
+        MEMCPY(new_tab->bins, old_tab->bins, char, bins_size(old_tab));
+#ifdef ST_DEBUG
+    st_check(new_tab);
+#endif
+    return new_tab;
+}
+#endif /* RUBY */
+
+/* Update the entries start of table TAB after removing an entry
+   with index N in the array entries.  */
+static inline void
+update_range_for_deleted(st_table *tab, st_index_t n)
+{
+    /* Do not update entries_bound here.  Otherwise, we can fill all
+       bins by deleted entry value before rebuilding the table.  */
+    if (tab->entries_start == n)
+        tab->entries_start = n + 1;
+}
+
+#ifdef RUBY
+/* Delete entry with KEY from table TAB, set up *VALUE (unless
+   VALUE is zero) from deleted table entry, and return non-zero.  If
+   there is no entry with KEY in the table, clear *VALUE (unless VALUE
+   is zero), and return zero.  */
+static int
+st_general_delete(st_table *tab, st_data_t *key, st_data_t *value)
+{
+    st_table_entry *entry;
+    st_index_t bin;
+    st_index_t bin_ind;
+    st_hash_t hash;
+
+    st_assert(tab != NULL);
+    hash = do_hash(*key, tab);
+    if (tab->bins == NULL) {
+        bin = find_entry(tab, hash, *key);
+        if (bin == UNDEFINED_ENTRY_IND) {
+            if (value != 0) *value = 0;
+            return 0;
+        }
+    } else {
+        bin_ind = find_table_bin_ind(tab, hash, *key);
+        if (bin_ind == UNDEFINED_BIN_IND) {
+            if (value != 0) *value = 0;
+            return 0;
+        }
+        bin = get_bin(tab->bins, get_size_ind(tab), bin_ind) - ENTRY_BASE;
+        MARK_BIN_DELETED(tab, bin_ind);
+    }
+    entry = &tab->entries[bin];
+    *key = entry->key;
+    if (value != 0) *value = entry->record;
+    MARK_ENTRY_DELETED(entry);
+    tab->num_entries--;
+    update_range_for_deleted(tab, bin);
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+    return 1;
+}
 
 int
-st_lookup(table, key, value)
-    st_table *table;
-    register st_data_t key;
-    st_data_t *value;
-{
-    unsigned int hash_val, bin_pos;
-    register st_table_entry *ptr;
-
-    hash_val = do_hash(key, table);
-    FIND_ENTRY(table, ptr, hash_val, bin_pos);
-
-    if (ptr == 0) {
-        return 0;
-    }
-    else {
-        if (value != 0)  *value = ptr->record;
-        return 1;
-    }
-}
-
-#define ADD_DIRECT(table, key, value, hash_val, bin_pos)\
-do {\
-    st_table_entry *entry;\
-    if (table->num_entries/(table->num_bins) > ST_DEFAULT_MAX_DENSITY) {\
-        rehash(table);\
-        bin_pos = hash_val % table->num_bins;\
-    }\
-    \
-    entry = alloc(st_table_entry);\
-    \
-    entry->hash = hash_val;\
-    entry->key = key;\
-    entry->record = value;\
-    entry->next = table->bins[bin_pos];\
-    table->bins[bin_pos] = entry;\
-    table->num_entries++;\
-} while (0)
-
+st_delete(st_table *tab, st_data_t *key, st_data_t *value)
+{
+    return st_general_delete(tab, key, value);
+}
+
+/* The function and other functions with suffix '_safe' or '_check'
+   are originated from the previous implementation of the hash tables.
+   It was necessary for correct deleting entries during traversing
+   tables.  The current implementation permits deletion during
+   traversing without a specific way to do this.  */
 int
-st_insert(table, key, value)
-    register st_table *table;
-    register st_data_t key;
-    st_data_t value;
-{
-    unsigned int hash_val, bin_pos;
-    register st_table_entry *ptr;
-
-    hash_val = do_hash(key, table);
-    FIND_ENTRY(table, ptr, hash_val, bin_pos);
-
-    if (ptr == 0) {
-        ADD_DIRECT(table, key, value, hash_val, bin_pos);
-        return 0;
-    }
-    else {
-        ptr->record = value;
-        return 1;
-    }
-}
-
-void
-st_add_direct(table, key, value)
-    st_table *table;
-    st_data_t key;
-    st_data_t value;
-{
-    unsigned int hash_val, bin_pos;
-
-    hash_val = do_hash(key, table);
-    bin_pos = hash_val % table->num_bins;
-    ADD_DIRECT(table, key, value, hash_val, bin_pos);
-}
-
-static void
-rehash(table)
-    register st_table *table;
-{
-    register st_table_entry *ptr, *next, **new_bins;
-    int i, old_num_bins = table->num_bins, new_num_bins;
-    unsigned int hash_val;
-
-    new_num_bins = new_size(old_num_bins+1);
-    new_bins = (st_table_entry**)Calloc(new_num_bins, sizeof(st_table_entry*));
-
-    for(i = 0; i < old_num_bins; i++) {
-        ptr = table->bins[i];
-        while (ptr != 0) {
-            next = ptr->next;
-            hash_val = ptr->hash % new_num_bins;
-            ptr->next = new_bins[hash_val];
-            new_bins[hash_val] = ptr;
-            ptr = next;
-        }
-    }
-    free(table->bins);
-    table->num_bins = new_num_bins;
-    table->bins = new_bins;
-}
-
-st_table*
-st_copy(old_table)
-    st_table *old_table;
-{
-    st_table *new_table;
-    st_table_entry *ptr, *entry;
-    int i, num_bins = old_table->num_bins;
-
-    new_table = alloc(st_table);
-    if (new_table == 0) {
-        return 0;
-    }
-
-    *new_table = *old_table;
-    new_table->bins = (st_table_entry**)
-        Calloc((unsigned)num_bins, sizeof(st_table_entry*));
-
-    if (new_table->bins == 0) {
-        free(new_table);
-        return 0;
-    }
-
-    for(i = 0; i < num_bins; i++) {
-        new_table->bins[i] = 0;
-        ptr = old_table->bins[i];
-        while (ptr != 0) {
-            entry = alloc(st_table_entry);
-            if (entry == 0) {
-                free(new_table->bins);
-                free(new_table);
-                return 0;
+st_delete_safe(st_table *tab, st_data_t *key, st_data_t *value,
+               st_data_t never ATTRIBUTE_UNUSED) {
+    return st_general_delete(tab, key, value);
+}
+
+/* If table TAB is empty, clear *VALUE (unless VALUE is zero), and
+   return zero.  Otherwise, remove the first entry in the table.
+   Return its key through KEY and its record through VALUE (unless
+   VALUE is zero).  */
+int
+st_shift(st_table *tab, st_data_t *key, st_data_t *value)
+{
+    st_index_t i, bound;
+    st_index_t bin;
+    st_table_entry *entries, *curr_entry_ptr;
+    st_index_t bin_ind;
+
+    entries = tab->entries;
+    bound = tab->entries_bound;
+    for (i = tab->entries_start; i < bound; i++) {
+        curr_entry_ptr = &entries[i];
+        if (! DELETED_ENTRY_P(curr_entry_ptr)) {
+            if (value != 0) *value = curr_entry_ptr->record;
+            *key = curr_entry_ptr->key;
+            if (tab->bins == NULL) {
+                bin = find_entry(tab, curr_entry_ptr->hash, curr_entry_ptr->key);
+                st_assert(bin != UNDEFINED_ENTRY_IND
+                          && &entries[bin] == curr_entry_ptr);
+            } else {
+                bin_ind = find_table_bin_ind(tab, curr_entry_ptr->hash,
+                                             curr_entry_ptr->key);
+                st_assert(bin_ind != UNDEFINED_BIN_IND
+                          && &entries[get_bin(tab->bins, get_size_ind(tab), bin_ind)
+                                      - ENTRY_BASE] == curr_entry_ptr);
+                MARK_BIN_DELETED(tab, bin_ind);
             }
-            *entry = *ptr;
-            entry->next = new_table->bins[i];
-            new_table->bins[i] = entry;
-            ptr = ptr->next;
-        }
-    }
-    return new_table;
-}
-
-int
-st_delete(table, key, value)
-    register st_table *table;
-    register st_data_t *key;
-    st_data_t *value;
-{
-    unsigned int hash_val;
-    st_table_entry *tmp;
-    register st_table_entry *ptr;
-
-    hash_val = do_hash_bin(*key, table);
-    ptr = table->bins[hash_val];
-
-    if (ptr == 0) {
-        if (value != 0) *value = 0;
-        return 0;
-    }
-
-    if (EQUAL(table, *key, ptr->key)) {
-        table->bins[hash_val] = ptr->next;
-        table->num_entries--;
-        if (value != 0) *value = ptr->record;
-        *key = ptr->key;
-        free(ptr);
-        return 1;
-    }
-
-    for(; ptr->next != 0; ptr = ptr->next) {
-        if (EQUAL(table, ptr->next->key, *key)) {
-            tmp = ptr->next;
-            ptr->next = ptr->next->next;
-            table->num_entries--;
-            if (value != 0) *value = tmp->record;
-            *key = tmp->key;
-            free(tmp);
+            MARK_ENTRY_DELETED(curr_entry_ptr);
+            tab->num_entries--;
+            update_range_for_deleted(tab, i);
+#ifdef ST_DEBUG
+            st_check(tab);
+#endif
             return 1;
         }
     }
-
+    st_assert(tab->num_entries == 0);
+    tab->entries_start = tab->entries_bound = 0;
+    if (value != 0) *value = 0;
     return 0;
 }
 
+/* See comments for function st_delete_safe.  */
+void
+st_cleanup_safe(st_table *tab ATTRIBUTE_UNUSED,
+                st_data_t never ATTRIBUTE_UNUSED) {
+}
+
+/* Find entry with KEY in table TAB, call FUNC with the key and the
+   value of the found entry, and non-zero as the 3rd argument.  If the
+   entry is not found, call FUNC with KEY, and 2 zero arguments.  If
+   the call returns ST_CONTINUE, the table will have an entry with key
+   and value returned by FUNC through the 1st and 2nd parameters.  If
+   the call of FUNC returns ST_DELETE, the table will not have entry
+   with KEY.  The function returns flag of that the entry with KEY was
+   in the table before the call.  */
 int
-st_delete_safe(table, key, value, never)
-    register st_table *table;
-    register st_data_t *key;
-    st_data_t *value;
-    st_data_t never;
-{
-    unsigned int hash_val;
-    register st_table_entry *ptr;
-
-    hash_val = do_hash_bin(*key, table);
-    ptr = table->bins[hash_val];
-
-    if (ptr == 0) {
-        if (value != 0) *value = 0;
-        return 0;
-    }
-
-    for(; ptr != 0; ptr = ptr->next) {
-        if ((ptr->key != never) && EQUAL(table, ptr->key, *key)) {
-            table->num_entries--;
-            *key = ptr->key;
-            if (value != 0) *value = ptr->record;
-            ptr->key = ptr->record = never;
-            return 1;
+st_update(st_table *tab, st_data_t key,
+          st_update_callback_func *func, st_data_t arg) {
+    st_table_entry *entry = NULL; /* to avoid uninitialized value warning */
+    st_index_t bin = 0; /* Ditto */
+    st_table_entry *entries;
+    st_index_t bin_ind;
+    st_data_t value = 0, old_key;
+    st_index_t check;
+    int retval, existing;
+    st_hash_t hash = do_hash(key, tab);
+
+    entries = tab->entries;
+    if (tab->bins == NULL) {
+        bin = find_entry(tab, hash, key);
+        existing = bin != UNDEFINED_ENTRY_IND;
+        entry = &entries[bin];
+        bin_ind = UNDEFINED_BIN_IND;
+    } else {
+        bin_ind = find_table_bin_ind(tab, hash, key);
+        existing = bin_ind != UNDEFINED_BIN_IND;
+        if (existing) {
+            bin = get_bin(tab->bins, get_size_ind(tab), bin_ind) - ENTRY_BASE;
+            entry = &entries[bin];
         }
     }
-
+    if (existing) {
+        key = entry->key;
+        value = entry->record;
+    }
+    old_key = key;
+    check = tab->rebuilds_num;
+    retval = (*func)(&key, &value, arg, existing);
+    st_assert(check == tab->rebuilds_num);
+    switch (retval) {
+    case ST_CONTINUE:
+        if (! existing) {
+            st_add_direct_with_hash(tab, key, value, hash);
+            break;
+        }
+        if (old_key != key) {
+            entry->key = key;
+        }
+        entry->record = value;
+        break;
+    case ST_DELETE:
+        if (existing) {
+            if (bin_ind != UNDEFINED_BIN_IND)
+                MARK_BIN_DELETED(tab, bin_ind);
+            MARK_ENTRY_DELETED(entry);
+            tab->num_entries--;
+            update_range_for_deleted(tab, bin);
+#ifdef ST_DEBUG
+            st_check(tab);
+#endif
+        }
+        break;
+    }
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
+    return existing;
+}
+#endif /* RUBY */
+
+/* Traverse all entries in table TAB calling FUNC with current entry
+   key and value and zero.  If the call returns ST_STOP, stop
+   traversing.  If the call returns ST_DELETE, delete the current
+   entry from the table.  In case of ST_CHECK or ST_CONTINUE, continue
+   traversing.  The function returns zero unless an error is found.
+   CHECK_P is flag of st_foreach_check call.  The behavior is a bit
+   different for ST_CHECK and when the current element is removed
+   during traversing.  */
+static inline int
+st_general_foreach(st_table *tab, int (*func)(ANYARGS), st_data_t arg,
+                   int check_p) {
+    st_index_t bin;
+    st_index_t bin_ind;
+    st_table_entry *entries, *curr_entry_ptr;
+    enum st_retval retval;
+    st_index_t i, rebuilds_num;
+    st_hash_t hash;
+    st_data_t key;
+    int error_p, packed_p = tab->bins == NULL;
+
+    st_assert(tab->entries_start <= tab->entries_bound);
+    entries = tab->entries;
+    /* The bound can change inside the loop even without rebuilding
+       the table, e.g. by an entry inesrtion.  */
+    for (i = tab->entries_start; i < tab->entries_bound; i++) {
+        curr_entry_ptr = &entries[i];
+        if (EXPECT(DELETED_ENTRY_P(curr_entry_ptr), 0))
+            continue;
+        key = curr_entry_ptr->key;
+        rebuilds_num = tab->rebuilds_num;
+        hash = curr_entry_ptr->hash;
+        retval = (*func)(key, curr_entry_ptr->record, arg, 0);
+        if (rebuilds_num != tab->rebuilds_num) {
+            entries = tab->entries;
+            packed_p = tab->bins == NULL;
+            if (packed_p) {
+                i = find_entry(tab, hash, key);
+                error_p = i == UNDEFINED_ENTRY_IND;
+            } else {
+                i = find_table_entry_ind(tab, hash, key);
+                error_p = i == UNDEFINED_ENTRY_IND;
+                i -= ENTRY_BASE;
+            }
+            if (error_p && check_p) {
+                /* call func with error notice */
+                retval = (*func)(0, 0, arg, 1);
+#ifdef ST_DEBUG
+                st_check(tab);
+#endif
+                return 1;
+            }
+            curr_entry_ptr = &entries[i];
+        }
+        switch (retval) {
+        case ST_CONTINUE:
+            break;
+        case ST_CHECK:
+            if (check_p)
+                break;
+        case ST_STOP:
+#ifdef ST_DEBUG
+            st_check(tab);
+#endif
+            return 0;
+        case ST_DELETE:
+            if (packed_p) {
+                bin = find_entry(tab, hash, curr_entry_ptr->key);
+                if (bin == UNDEFINED_ENTRY_IND)
+                    break;
+            } else {
+                bin_ind = find_table_bin_ind(tab, hash, curr_entry_ptr->key);
+                if (bin_ind == UNDEFINED_BIN_IND)
+                    break;
+                bin = get_bin(tab->bins, get_size_ind(tab), bin_ind) - ENTRY_BASE;
+                MARK_BIN_DELETED(tab, bin_ind);
+            }
+            st_assert(&entries[bin] == curr_entry_ptr);
+            MARK_ENTRY_DELETED(curr_entry_ptr);
+            tab->num_entries--;
+            update_range_for_deleted(tab, bin);
+#ifdef ST_DEBUG
+            st_check(tab);
+#endif
+            break;
+        }
+    }
+#ifdef ST_DEBUG
+    st_check(tab);
+#endif
     return 0;
 }
 
-static int
-#if defined(__GNUC__)
-delete_never(st_data_t key __attribute__ ((unused)), st_data_t value,
-             st_data_t never)
-#else
-delete_never(key, value, never)
-    st_data_t key, value, never;
-#endif
-{
-    if (value == never) return ST_DELETE;
-    return ST_CONTINUE;
-}
-
-void
-st_cleanup_safe(table, never)
-    st_table *table;
-    st_data_t never;
-{
-    int num_entries = table->num_entries;
-
-    st_foreach(table, delete_never, never);
-    table->num_entries = num_entries;
-}
-
 int
-st_foreach(table, func, arg)
-    st_table *table;
-    int (*func)();
-    st_data_t arg;
-{
-    st_table_entry *ptr, *last, *tmp;
-    enum st_retval retval;
-    int i;
-
-    for(i = 0; i < table->num_bins; i++) {
-        last = 0;
-        for(ptr = table->bins[i]; ptr != 0;) {
-            retval = (*func)(ptr->key, ptr->record, arg);
-            switch (retval) {
-            case ST_CHECK:      /* check if hash is modified during iteration */
-                tmp = 0;
-                if (i < table->num_bins) {
-                    for (tmp = table->bins[i]; tmp; tmp=tmp->next) {
-                        if (tmp == ptr) break;
-                    }
-                }
-                if (!tmp) {
-                    /* call func with error notice */
-                    return 1;
-                }
-                /* fall through */
-            case ST_CONTINUE:
-                last = ptr;
-                ptr = ptr->next;
-                break;
-            case ST_STOP:
-                return 0;
-            case ST_DELETE:
-                tmp = ptr;
-                if (last == 0) {
-                    table->bins[i] = ptr->next;
-                }
-                else {
-                    last->next = ptr->next;
-                }
-                ptr = ptr->next;
-                free(tmp);
-                table->num_entries--;
+st_foreach(st_table *tab, int (*func)(ANYARGS), st_data_t arg)
+{
+  return st_general_foreach(tab, func, arg, FALSE);
+}
+
+#ifdef RUBY
+/* See comments for function st_delete_safe.  */
+int
+st_foreach_check(st_table *tab, int (*func)(ANYARGS), st_data_t arg,
+                 st_data_t never ATTRIBUTE_UNUSED) {
+  return st_general_foreach(tab, func, arg, TRUE);
+}
+
+/* Set up array KEYS by at most SIZE keys of head table TAB entries.
+   Return the number of keys set up in array KEYS.  */
+static inline st_index_t
+st_general_keys(st_table *tab, st_data_t *keys, st_index_t size)
+{
+    st_index_t i, bound;
+    st_data_t key, *keys_start, *keys_end;
+    st_table_entry *curr_entry_ptr, *entries = tab->entries;
+
+    bound = tab->entries_bound;
+    keys_start = keys;
+    keys_end = keys + size;
+    for (i = tab->entries_start; i < bound; i++) {
+        if (keys == keys_end)
+            break;
+        curr_entry_ptr = &entries[i];
+        key = curr_entry_ptr->key;
+        if (! DELETED_ENTRY_P(curr_entry_ptr))
+            *keys++ = key;
+    }
+
+    return keys - keys_start;
+}
+
+st_index_t
+st_keys(st_table *tab, st_data_t *keys, st_index_t size)
+{
+    return st_general_keys(tab, keys, size);
+}
+
+/* See comments for function st_delete_safe.  */
+st_index_t
+st_keys_check(st_table *tab, st_data_t *keys, st_index_t size,
+              st_data_t never ATTRIBUTE_UNUSED) {
+    return st_general_keys(tab, keys, size);
+}
+
+/* Set up array VALUES by at most SIZE values of head table TAB
+   entries.  Return the number of values set up in array VALUES.  */
+static inline st_index_t
+st_general_values(st_table *tab, st_data_t *values, st_index_t size)
+{
+    st_index_t i, bound;
+    st_data_t *values_start, *values_end;
+    st_table_entry *curr_entry_ptr, *entries = tab->entries;
+
+    values_start = values;
+    values_end = values + size;
+    bound = tab->entries_bound;
+    st_assert(bound != 0);
+    for (i = tab->entries_start; i < bound; i++) {
+        if (values == values_end)
+            break;
+        curr_entry_ptr = &entries[i];
+        if (! DELETED_ENTRY_P(curr_entry_ptr))
+            *values++ = curr_entry_ptr->record;
+    }
+
+    return values - values_start;
+}
+
+st_index_t
+st_values(st_table *tab, st_data_t *values, st_index_t size)
+{
+    return st_general_values(tab, values, size);
+}
+
+/* See comments for function st_delete_safe.  */
+st_index_t
+st_values_check(st_table *tab, st_data_t *values, st_index_t size,
+                st_data_t never ATTRIBUTE_UNUSED) {
+    return st_general_values(tab, values, size);
+}
+#endif /* RUBY */
+
+#ifdef RUBY
+#define FNV1_32A_INIT 0x811c9dc5
+
+/*
+ * 32 bit magic FNV-1a prime
+ */
+#define FNV_32_PRIME 0x01000193
+
+#ifndef UNALIGNED_WORD_ACCESS
+# if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
+     defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD64) || \
+     defined(__powerpc64__) || \
+     defined(__mc68020__)
+#   define UNALIGNED_WORD_ACCESS 1
+# endif
+#endif
+#ifndef UNALIGNED_WORD_ACCESS
+# define UNALIGNED_WORD_ACCESS 0
+#endif
+
+/* This hash function is quite simplified MurmurHash3
+ * Simplification is legal, cause most of magic still happens in finalizator.
+ * And finalizator is almost the same as in MurmurHash3 */
+#define BIG_CONSTANT(x,y) ((st_index_t)(x)<<32|(st_index_t)(y))
+#define ROTL(x,n) ((x)<<(n)|(x)>>(SIZEOF_ST_INDEX_T*CHAR_BIT-(n)))
+
+#if ST_INDEX_BITS <= 32
+#define C1 (st_index_t)0xcc9e2d51
+#define C2 (st_index_t)0x1b873593
+#else
+#define C1 BIG_CONSTANT(0x87c37b91,0x114253d5);
+#define C2 BIG_CONSTANT(0x4cf5ad43,0x2745937f);
+#endif
+static inline st_index_t
+murmur_step(st_index_t h, st_index_t k)
+{
+#if ST_INDEX_BITS <= 32
+#define r1 (17)
+#define r2 (11)
+#else
+#define r1 (33)
+#define r2 (24)
+#endif
+    k *= C1;
+    h ^= ROTL(k, r1);
+    h *= C2;
+    h = ROTL(h, r2);
+    return h;
+}
+#undef r1
+#undef r2
+
+static inline st_index_t
+murmur_finish(st_index_t h)
+{
+#if ST_INDEX_BITS <= 32
+#define r1 (16)
+#define r2 (13)
+#define r3 (16)
+    const st_index_t c1 = 0x85ebca6b;
+    const st_index_t c2 = 0xc2b2ae35;
+#else
+/* values are taken from Mix13 on http://zimbry.blogspot.ru/2011/09/better-bit-mixing-improving-on.html */
+#define r1 (30)
+#define r2 (27)
+#define r3 (31)
+    const st_index_t c1 = BIG_CONSTANT(0xbf58476d,0x1ce4e5b9);
+    const st_index_t c2 = BIG_CONSTANT(0x94d049bb,0x133111eb);
+#endif
+#if ST_INDEX_BITS > 64
+    h ^= h >> 64;
+    h *= c2;
+    h ^= h >> 65;
+#endif
+    h ^= h >> r1;
+    h *= c1;
+    h ^= h >> r2;
+    h *= c2;
+    h ^= h >> r3;
+    return h;
+}
+#undef r1
+#undef r2
+#undef r3
+
+st_index_t
+st_hash(const void *ptr, size_t len, st_index_t h)
+{
+    const char *data = ptr;
+    st_index_t t = 0;
+    size_t l = len;
+
+#define data_at(n) (st_index_t)((unsigned char)data[(n)])
+#define UNALIGNED_ADD_4 UNALIGNED_ADD(2); UNALIGNED_ADD(1); UNALIGNED_ADD(0)
+#if SIZEOF_ST_INDEX_T > 4
+#define UNALIGNED_ADD_8 UNALIGNED_ADD(6); UNALIGNED_ADD(5); UNALIGNED_ADD(4); UNALIGNED_ADD(3); UNALIGNED_ADD_4
+#if SIZEOF_ST_INDEX_T > 8
+#define UNALIGNED_ADD_16 UNALIGNED_ADD(14); UNALIGNED_ADD(13); UNALIGNED_ADD(12); UNALIGNED_ADD(11); \
+    UNALIGNED_ADD(10); UNALIGNED_ADD(9); UNALIGNED_ADD(8); UNALIGNED_ADD(7); UNALIGNED_ADD_8
+#define UNALIGNED_ADD_ALL UNALIGNED_ADD_16
+#endif
+#define UNALIGNED_ADD_ALL UNALIGNED_ADD_8
+#else
+#define UNALIGNED_ADD_ALL UNALIGNED_ADD_4
+#endif
+#undef SKIP_TAIL
+    if (len >= sizeof(st_index_t)) {
+#if !UNALIGNED_WORD_ACCESS
+        int align = (int)((st_data_t)data % sizeof(st_index_t));
+        if (align) {
+            st_index_t d = 0;
+            int sl, sr, pack;
+
+            switch (align) {
+#ifdef WORDS_BIGENDIAN
+# define UNALIGNED_ADD(n) case SIZEOF_ST_INDEX_T - (n) - 1: \
+                t |= data_at(n) << CHAR_BIT*(SIZEOF_ST_INDEX_T - (n) - 2)
+#else
+# define UNALIGNED_ADD(n) case SIZEOF_ST_INDEX_T - (n) - 1:     \
+                t |= data_at(n) << CHAR_BIT*(n)
+#endif
+                UNALIGNED_ADD_ALL;
+#undef UNALIGNED_ADD
             }
+
+#ifdef WORDS_BIGENDIAN
+            t >>= (CHAR_BIT * align) - CHAR_BIT;
+#else
+            t <<= (CHAR_BIT * align);
+#endif
+
+            data += sizeof(st_index_t)-align;
+            len -= sizeof(st_index_t)-align;
+
+            sl = CHAR_BIT * (SIZEOF_ST_INDEX_T-align);
+            sr = CHAR_BIT * align;
+
+            while (len >= sizeof(st_index_t)) {
+                d = *(st_index_t *)data;
+#ifdef WORDS_BIGENDIAN
+                t = (t << sr) | (d >> sl);
+#else
+                t = (t >> sr) | (d << sl);
+#endif
+                h = murmur_step(h, t);
+                t = d;
+                data += sizeof(st_index_t);
+                len -= sizeof(st_index_t);
+            }
+
+            pack = len < (size_t)align ? (int)len : align;
+            d = 0;
+            switch (pack) {
+#ifdef WORDS_BIGENDIAN
+# define UNALIGNED_ADD(n) case (n) + 1: \
+                d |= data_at(n) << CHAR_BIT*(SIZEOF_ST_INDEX_T - (n) - 1)
+#else
+# define UNALIGNED_ADD(n) case (n) + 1: \
+                d |= data_at(n) << CHAR_BIT*(n)
+#endif
+                UNALIGNED_ADD_ALL;
+#undef UNALIGNED_ADD
+            }
+#ifdef WORDS_BIGENDIAN
+            t = (t << sr) | (d >> sl);
+#else
+            t = (t >> sr) | (d << sl);
+#endif
+
+            if (len < (size_t)align) goto skip_tail;
+# define SKIP_TAIL 1
+            h = murmur_step(h, t);
+            data += pack;
+            len -= pack;
         }
+        else
+#endif
+        {
+            do {
+                h = murmur_step(h, *(st_index_t *)data);
+                data += sizeof(st_index_t);
+                len -= sizeof(st_index_t);
+            } while (len >= sizeof(st_index_t));
+        }
+    }
+
+    t = 0;
+    switch (len) {
+#if UNALIGNED_WORD_ACCESS && SIZEOF_ST_INDEX_T <= 8 && CHAR_BIT == 8
+    /* in this case byteorder doesn't really matter */
+#if SIZEOF_ST_INDEX_T > 4
+        case 7: t |= data_at(6) << 48;
+        case 6: t |= data_at(5) << 40;
+        case 5: t |= data_at(4) << 32;
+        case 4:
+            t |= (st_index_t)*(uint32_t*)data;
+            goto skip_tail;
+# define SKIP_TAIL 1
+#endif
+        case 3: t |= data_at(2) << 16;
+        case 2: t |= data_at(1) << 8;
+        case 1: t |= data_at(0);
+#else
+#ifdef WORDS_BIGENDIAN
+# define UNALIGNED_ADD(n) case (n) + 1: \
+        t |= data_at(n) << CHAR_BIT*(SIZEOF_ST_INDEX_T - (n) - 1)
+#else
+# define UNALIGNED_ADD(n) case (n) + 1: \
+        t |= data_at(n) << CHAR_BIT*(n)
+#endif
+        UNALIGNED_ADD_ALL;
+#undef UNALIGNED_ADD
+#endif
+#ifdef SKIP_TAIL
+      skip_tail:
+#endif
+        h ^= t; h -= ROTL(t, 7);
+        h *= C2;
+    }
+    h ^= l;
+
+    return murmur_finish(h);
+}
+
+st_index_t
+st_hash_uint32(st_index_t h, uint32_t i)
+{
+    return murmur_step(h, i);
+}
+
+st_index_t
+st_hash_uint(st_index_t h, st_index_t i)
+{
+    i += h;
+/* no matter if it is BigEndian or LittleEndian,
+ * we hash just integers */
+#if SIZEOF_ST_INDEX_T*CHAR_BIT > 8*8
+    h = murmur_step(h, i >> 8*8);
+#endif
+    h = murmur_step(h, i);
+    return h;
+}
+
+st_index_t
+st_hash_end(st_index_t h)
+{
+    h = murmur_finish(h);
+    return h;
+}
+
+#undef st_hash_start
+st_index_t
+st_hash_start(st_index_t h)
+{
+    return h;
+}
+
+static st_index_t
+strhash(st_data_t arg)
+{
+    register const char *string = (const char *)arg;
+    return st_hash(string, strlen(string), FNV1_32A_INIT);
+}
+
+int
+st_locale_insensitive_strcasecmp(const char *s1, const char *s2)
+{
+    unsigned int c1, c2;
+
+    while (1) {
+        c1 = (unsigned char)*s1++;
+        c2 = (unsigned char)*s2++;
+        if (c1 == '\0' || c2 == '\0') {
+            if (c1 != '\0') return 1;
+            if (c2 != '\0') return -1;
+            return 0;
+        }
+        if ((unsigned int)(c1 - 'A') <= ('Z' - 'A')) c1 += 'a' - 'A';
+        if ((unsigned int)(c2 - 'A') <= ('Z' - 'A')) c2 += 'a' - 'A';
+        if (c1 != c2) {
+            if (c1 > c2)
+                return 1;
+            else
+                return -1;
+        }
+    }
+}
+
+int
+st_locale_insensitive_strncasecmp(const char *s1, const char *s2, size_t n)
+{
+    unsigned int c1, c2;
+
+    while (n--) {
+        c1 = (unsigned char)*s1++;
+        c2 = (unsigned char)*s2++;
+        if (c1 == '\0' || c2 == '\0') {
+            if (c1 != '\0') return 1;
+            if (c2 != '\0') return -1;
+            return 0;
+        }
+        if ((unsigned int)(c1 - 'A') <= ('Z' - 'A')) c1 += 'a' - 'A';
+        if ((unsigned int)(c2 - 'A') <= ('Z' - 'A')) c2 += 'a' - 'A';
+        if (c1 != c2) {
+            if (c1 > c2)
+                return 1;
+            else
+                return -1;
+        }
     }
     return 0;
 }
 
-static int
-strhash(string)
-    register const char *string;
-{
-    register int c;
-
-#ifdef HASH_ELFHASH
-    register unsigned int h = 0, g;
-
-    while ((c = *string++) != '\0') {
-        h = ( h << 4 ) + c;
-        if ( g = h & 0xF0000000 )
-            h ^= g >> 24;
-        h &= ~g;
-    }
-    return h;
-#elif HASH_PERL
-    register int val = 0;
-
-    while ((c = *string++) != '\0') {
-        val += c;
-        val += (val << 10);
-        val ^= (val >> 6);
-    }
-    val += (val << 3);
-    val ^= (val >> 11);
-
-    return val + (val << 15);
-#else
-    register int val = 0;
-
-    while ((c = *string++) != '\0') {
-        val = val*997 + c;
-    }
-
-    return val + (val>>5);
-#endif
-}
-
-static int
-numcmp(x, y)
-    long x, y;
+static st_index_t
+strcasehash(st_data_t arg)
+{
+    register const char *string = (const char *)arg;
+    register st_index_t hval = FNV1_32A_INIT;
+
+    /*
+     * FNV-1a hash each octet in the buffer
+     */
+    while (*string) {
+        unsigned int c = (unsigned char)*string++;
+        if ((unsigned int)(c - 'A') <= ('Z' - 'A')) c += 'a' - 'A';
+        hval ^= c;
+
+        /* multiply by the 32 bit FNV magic prime mod 2^32 */
+        hval *= FNV_32_PRIME;
+    }
+    return hval;
+}
+
+int
+st_numcmp(st_data_t x, st_data_t y)
 {
     return x != y;
 }
 
-static int
-numhash(n)
-    long n;
-{
-    return n;
-}
+st_index_t
+st_numhash(st_data_t n)
+{
+    enum {s1 = 11, s2 = 3};
+    return (st_index_t)((n>>s1|(n<<s2)) ^ (n>>s2));
+}
+#endif /* RUBY */