Upstream version 2.08rc7

1 files changed, 233 insertions, 0 deletions

diff --git a/hashtbl.c b/hashtbl.c
new file mode 100644
index 0000000..348bc40
--- /dev/null
+++ b/hashtbl.c
@@ -0,0 +1,233 @@
+/* ----------------------------------------------------------------------- *
+ *
+ *   Copyright 1996-2009 The NASM Authors - All Rights Reserved
+ *   See the file AUTHORS included with the NASM distribution for
+ *   the specific copyright holders.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following
+ *   conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * hashtbl.c
+ *
+ * Efficient dictionary hash table class.
+ */
+
+#include "compiler.h"
+
+#include <inttypes.h>
+#include <string.h>
+#include "nasm.h"
+#include "hashtbl.h"
+
+#define HASH_MAX_LOAD   2 /* Higher = more memory-efficient, slower */
+
+#define hash_calc(key)          crc64(CRC64_INIT, (key))
+#define hash_calci(key)         crc64i(CRC64_INIT, (key))
+#define hash_max_load(size)     ((size) * (HASH_MAX_LOAD - 1) / HASH_MAX_LOAD)
+#define hash_expand(size)       ((size) << 1)
+#define hash_mask(size)         ((size) - 1)
+#define hash_pos(hash, mask)    ((hash) & (mask))
+#define hash_inc(hash, mask)    ((((hash) >> 32) & (mask)) | 1) /* always odd */
+#define hash_pos_next(pos, inc, mask) (((pos) + (inc)) & (mask))
+
+static struct hash_tbl_node *alloc_table(size_t newsize)
+{
+    size_t bytes = newsize * sizeof(struct hash_tbl_node);
+    return nasm_zalloc(bytes);
+}
+
+void hash_init(struct hash_table *head, size_t size)
+{
+    nasm_assert(is_power2(size));
+    head->table    = alloc_table(size);
+    head->load     = 0;
+    head->size     = size;
+    head->max_load = hash_max_load(size);
+}
+
+/*
+ * Find an entry in a hash table.
+ *
+ * On failure, if "insert" is non-NULL, store data in that structure
+ * which can be used to insert that node using hash_add().
+ *
+ * WARNING: this data is only valid until the very next call of
+ * hash_add(); it cannot be "saved" to a later date.
+ *
+ * On success, return a pointer to the "data" element of the hash
+ * structure.
+ */
+void **hash_find(struct hash_table *head, const char *key,
+                 struct hash_insert *insert)
+{
+    struct hash_tbl_node *np;
+    struct hash_tbl_node *tbl = head->table;
+    uint64_t hash = hash_calc(key);
+    size_t mask = hash_mask(head->size);
+    size_t pos = hash_pos(hash, mask);
+    size_t inc = hash_inc(hash, mask);
+
+    while ((np = &tbl[pos])->key) {
+        if (hash == np->hash && !strcmp(key, np->key))
+            return &np->data;
+        pos = hash_pos_next(pos, inc, mask);
+    }
+
+    /* Not found.  Store info for insert if requested. */
+    if (insert) {
+        insert->head  = head;
+        insert->hash  = hash;
+        insert->where = np;
+    }
+    return NULL;
+}
+
+/*
+ * Same as hash_find, but for case-insensitive hashing.
+ */
+void **hash_findi(struct hash_table *head, const char *key,
+                  struct hash_insert *insert)
+{
+    struct hash_tbl_node *np;
+    struct hash_tbl_node *tbl = head->table;
+    uint64_t hash = hash_calci(key);
+    size_t mask = hash_mask(head->size);
+    size_t pos = hash_pos(hash, mask);
+    size_t inc = hash_inc(hash, mask);
+
+    while ((np = &tbl[pos])->key) {
+        if (hash == np->hash && !nasm_stricmp(key, np->key))
+            return &np->data;
+        pos = hash_pos_next(pos, inc, mask);
+    }
+
+    /* Not found.  Store info for insert if requested. */
+    if (insert) {
+        insert->head  = head;
+        insert->hash  = hash;
+        insert->where = np;
+    }
+    return NULL;
+}
+
+/*
+ * Insert node.  Return a pointer to the "data" element of the newly
+ * created hash node.
+ */
+void **hash_add(struct hash_insert *insert, const char *key, void *data)
+{
+    struct hash_table *head  = insert->head;
+    struct hash_tbl_node *np = insert->where;
+
+    /*
+     * Insert node.  We can always do this, even if we need to
+     * rebalance immediately after.
+     */
+    np->hash = insert->hash;
+    np->key  = key;
+    np->data = data;
+
+    if (++head->load > head->max_load) {
+        /* Need to expand the table */
+        size_t newsize                  = hash_expand(head->size);
+        struct hash_tbl_node *newtbl    = alloc_table(newsize);
+        size_t mask                     = hash_mask(newsize);
+
+        if (head->table) {
+            struct hash_tbl_node *op, *xp;
+            size_t i;
+
+            /* Rebalance all the entries */
+            for (i = 0, op = head->table; i < head->size; i++, op++) {
+                if (op->key) {
+                    size_t pos = hash_pos(op->hash, mask);
+                    size_t inc = hash_inc(op->hash, mask);
+
+                    while ((xp = &newtbl[pos])->key)
+                        pos = hash_pos_next(pos, inc, mask);
+
+                    *xp = *op;
+                    if (op == np)
+                        np = xp;
+                }
+            }
+            nasm_free(head->table);
+        }
+
+        head->table    = newtbl;
+        head->size     = newsize;
+        head->max_load = hash_max_load(newsize);
+    }
+
+    return &np->data;
+}
+
+/*
+ * Iterate over all members of a hash set.  For the first call,
+ * iterator should be initialized to NULL.  Returns the data pointer,
+ * or NULL on failure.
+ */
+void *hash_iterate(const struct hash_table *head,
+                   struct hash_tbl_node **iterator,
+                   const char **key)
+{
+    struct hash_tbl_node *np = *iterator;
+    struct hash_tbl_node *ep = head->table + head->size;
+
+    if (!np) {
+        np = head->table;
+        if (!np)
+            return NULL;        /* Uninitialized table */
+    }
+
+    while (np < ep) {
+        if (np->key) {
+            *iterator = np + 1;
+            if (key)
+                *key = np->key;
+            return np->data;
+        }
+        np++;
+    }
+
+    *iterator = NULL;
+    if (key)
+        *key = NULL;
+    return NULL;
+}
+
+/*
+ * Free the hash itself.  Doesn't free the data elements; use
+ * hash_iterate() to do that first, if needed.
+ */
+void hash_free(struct hash_table *head)
+{
+    void *p = head->table;
+    head->table = NULL;
+    nasm_free(p);
+}