Initial implementation with new config system.

1 files changed, 275 insertions, 237 deletions

diff --git a/module/hash.c b/module/hash.c
index 512a914..84d57a2 100644
--- a/module/hash.c
+++ b/module/hash.c
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2004, Stefan Walter
- * All rights reserved.
+ * Copyright (c) 2011, Collabora Ltd.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -52,11 +52,12 @@
  */
 
 #include <sys/types.h>
+
+#include <assert.h>
 #include <stdlib.h>
 #include <string.h>
-#include "hash.h"
 
-#define KEY_DATA(he)    ((he)->key)
+#include "hash.h"
 
 /*
  * The internal form of a hash table.
@@ -67,30 +68,14 @@
  * isn't too bad given that pools have a low allocation overhead.
  */
 
-typedef struct hsh_entry_t hsh_entry_t;
+typedef struct hash_entry hash_entry_t;
 
-struct hsh_entry_t
-{
-    hsh_entry_t* next;
-    unsigned int hash;
-    const void* key;
-    size_t klen;
-    const void* val;
-};
-
-/*
- * Data structure for iterating through a hash table.
- *
- * We keep a pointer to the next hash entry here to allow the current
- * hash entry to be freed or otherwise mangled between calls to
- * hsh_next().
- */
-struct hsh_index_t
+struct hash_entry
 {
-    hsh_t* ht;
-    hsh_entry_t* ths;
-    hsh_entry_t* next;
-    unsigned int index;
+	hash_entry_t* next;
+	unsigned int hash;
+	void* key;
+	void* val;
 };
 
 /*
@@ -100,15 +85,16 @@ struct hsh_index_t
  * The count of hash entries may be greater depending on the chosen
  * collision rate.
  */
-struct hsh_t
-{
-    hsh_entry_t** array;
-    hsh_index_t iterator;    /* For hsh_first(...) */
-    unsigned int count;
-    unsigned int max;
+struct hash {
+	hash_entry_t** array;
+	unsigned int count;
+	unsigned int max;
+	hash_hash_func hash_func;
+	hash_equal_func equal_func;
+	hash_destroy_func key_destroy_func;
+	hash_destroy_func value_destroy_func;
 };
 
-
 #define INITIAL_MAX 15 /* tunable == 2^n - 1 */
 #define int_malloc malloc
 #define int_calloc calloc
@@ -118,109 +104,121 @@ struct hsh_t
  * Hash creation functions.
  */
 
-static hsh_entry_t** alloc_array(hsh_t* ht, unsigned int max)
+static hash_entry_t**
+alloc_array(hash_t* ht, unsigned int max)
 {
-    return (hsh_entry_t**)int_calloc(sizeof(*(ht->array)), (max + 1));
+	return (hash_entry_t**)int_calloc (sizeof (*(ht->array)), (max + 1));
 }
 
-hsh_t* hsh_create()
+hash_t*
+hash_create (hash_hash_func hash_func,
+             hash_equal_func equal_func,
+             hash_destroy_func key_destroy_func,
+             hash_destroy_func value_destroy_func)
 {
-    hsh_t* ht = int_malloc(sizeof(hsh_t));
-    if(ht)
-    {
-        ht->count = 0;
-        ht->max = INITIAL_MAX;
-        ht->array = alloc_array(ht, ht->max);
-        if(!ht->array)
-        {
-            int_free(ht);
-            return NULL;
-        }
-    }
-    return ht;
+	hash_t* ht;
+
+	assert (hash_func);
+	assert (equal_func);
+
+	ht = int_malloc (sizeof (hash_t));
+	if (ht) {
+		ht->count = 0;
+		ht->max = INITIAL_MAX;
+		ht->hash_func = hash_func;
+		ht->equal_func = equal_func;
+		ht->key_destroy_func = key_destroy_func;
+		ht->value_destroy_func = value_destroy_func;
+		ht->array = alloc_array (ht, ht->max);
+		if (!ht->array) {
+			int_free (ht);
+			return NULL;
+		}
+	}
+	return ht;
 }
 
-void hsh_free(hsh_t* ht)
+void
+hash_free (hash_t* ht)
 {
-    hsh_index_t* hi;
+	hash_iter_t hi;
+
+	if (!ht)
+		return;
 
-    for(hi = hsh_first(ht); hi; hi = hsh_next(hi))
-        int_free(hi->ths);
+	hash_iterate (ht, &hi);
+	while (hash_next (&hi, NULL, NULL)) {
+		if (ht->key_destroy_func)
+			ht->key_destroy_func (hi.ths->key);
+		if (ht->value_destroy_func)
+			ht->value_destroy_func (hi.ths->val);
+	}
 
-    if(ht->array)
-        int_free(ht->array);
+	if (ht->array)
+		int_free (ht->array);
 
-    int_free(ht);
+	int_free (ht);
 }
 
 /*
  * Hash iteration functions.
  */
-
-hsh_index_t* hsh_next(hsh_index_t* hi)
+int
+hash_next (hash_iter_t* hi, void **key, void **value)
 {
-    hi->ths = hi->next;
-    while(!hi->ths)
-    {
-        if(hi->index > hi->ht->max)
-            return NULL;
-
-        hi->ths = hi->ht->array[hi->index++];
-    }
-    hi->next = hi->ths->next;
-    return hi;
-}
-
-hsh_index_t* hsh_first(hsh_t* ht)
-{
-    hsh_index_t* hi = &ht->iterator;
-
-    hi->ht = ht;
-    hi->index = 0;
-    hi->ths = NULL;
-    hi->next = NULL;
-    return hsh_next(hi);
+	hi->ths = hi->next;
+	while (!hi->ths) {
+		if (hi->index > hi->ht->max)
+			return 0;
+		hi->ths = hi->ht->array[hi->index++];
+	}
+	hi->next = hi->ths->next;
+	if (key)
+		*key = hi->ths->key;
+	if (value)
+		*value = hi->ths->val;
+	return 1;
 }
 
-void* hsh_this(hsh_index_t* hi, const void** key, size_t* klen)
+void
+hash_iterate (hash_t* ht, hash_iter_t *hi)
 {
-    if(key)
-        *key = KEY_DATA(hi->ths);
-    if(klen)
-        *klen = hi->ths->klen;
-    return (void*)hi->ths->val;
+	hi->ht = ht;
+	hi->index = 0;
+	hi->ths = NULL;
+	hi->next = NULL;
 }
 
-
 /*
  * Expanding a hash table
  */
 
-static int expand_array(hsh_t* ht)
+static int
+expand_array (hash_t* ht)
 {
-    hsh_index_t* hi;
-    hsh_entry_t** new_array;
-    unsigned int new_max;
+	hash_iter_t hi;
+	hash_entry_t** new_array;
+	unsigned int new_max;
 
-    new_max = ht->max * 2 + 1;
-    new_array = alloc_array(ht, new_max);
+	new_max = ht->max * 2 + 1;
+	new_array = alloc_array (ht, new_max);
 
-    if(!new_array)
-        return 0;
+	if(!new_array)
+		return 0;
 
-    for(hi = hsh_first(ht); hi; hi = hsh_next(hi))
-    {
-        unsigned int i = hi->ths->hash & new_max;
-        hi->ths->next = new_array[i];
-        new_array[i] = hi->ths;
-    }
+	hash_iterate (ht, &hi);
+	while (hash_next (&hi, NULL, NULL)) {
+		unsigned int i = hi.ths->hash & new_max;
+		hi.ths->next = new_array[i];
+		new_array[i] = hi.ths;
+	}
 
-    if(ht->array)
-        free(ht->array);
+	if(ht->array)
+		int_free (ht->array);
 
-    ht->array = new_array;
-    ht->max = new_max;
-    return 1;
+	ht->array = new_array;
+	ht->max = new_max;
+	return 1;
 }
 
 /*
@@ -232,151 +230,96 @@ static int expand_array(hsh_t* ht)
  * that hash entries can be removed.
  */
 
-static hsh_entry_t** find_entry(hsh_t* ht, const void* key, size_t klen, const void* val)
+static hash_entry_t**
+find_entry (hash_t* ht, const void* key, void* val)
 {
-    hsh_entry_t** hep;
-    hsh_entry_t* he;
-    const unsigned char* p;
-    unsigned int hash;
-    size_t i;
-
-    /*
-     * This is the popular `times 33' hash algorithm which is used by
-     * perl and also appears in Berkeley DB. This is one of the best
-     * known hash functions for strings because it is both computed
-     * very fast and distributes very well.
-     *
-     * The originator may be Dan Bernstein but the code in Berkeley DB
-     * cites Chris Torek as the source. The best citation I have found
-     * is "Chris Torek, Hash function for text in C, Usenet message
-     * <27038@mimsy.umd.edu> in comp.lang.c , October, 1990." in Rich
-     * Salz's USENIX 1992 paper about INN which can be found at
-     * <http://citeseer.nj.nec.com/salz92internetnews.html>.
-     *
-     * The magic of number 33, i.e. why it works better than many other
-     * constants, prime or not, has never been adequately explained by
-     * anyone. So I try an explanation: if one experimentally tests all
-     * multipliers between 1 and 256 (as I did while writing a low-level
-     * data structure library some time ago) one detects that even
-     * numbers are not useable at all. The remaining 128 odd numbers
-     * (except for the number 1) work more or less all equally well.
-     * They all distribute in an acceptable way and this way fill a hash
-     * table with an average percent of approx. 86%.
-     *
-     * If one compares the chi^2 values of the variants (see
-     * Bob Jenkins ``Hashing Frequently Asked Questions'' at
-     * http://burtleburtle.net/bob/hash/hashfaq.html for a description
-     * of chi^2), the number 33 not even has the best value. But the
-     * number 33 and a few other equally good numbers like 17, 31, 63,
-     * 127 and 129 have nevertheless a great advantage to the remaining
-     * numbers in the large set of possible multipliers: their multiply
-     * operation can be replaced by a faster operation based on just one
-     * shift plus either a single addition or subtraction operation. And
-     * because a hash function has to both distribute good _and_ has to
-     * be very fast to compute, those few numbers should be preferred.
-     *
-     *                        -- Ralf S. Engelschall <rse@engelschall.com>
-     */
-    hash = 0;
-
-    if(klen == HSH_KEY_STRING)
-    {
-        for(p = key; *p; p++)
-            hash = hash * 33 + *p;
-
-        klen = p - (const unsigned char *)key;
-    }
-    else
-    {
-        for(p = key, i = klen; i; i--, p++)
-            hash = hash * 33 + *p;
-    }
-
-    /* scan linked list */
-    for(hep = &ht->array[hash & ht->max], he = *hep;
-            he; hep = &he->next, he = *hep)
-    {
-     if(he->hash == hash &&
-        he->klen == klen &&
-        memcmp(KEY_DATA(he), key, klen) == 0)
-         break;
-    }
-
-    if(he || !val)
-        return hep;
-
-    /* add a new entry for non-NULL val */
-    he = int_malloc(sizeof(*he));
-
-    if(he)
-    {
-        /* Key points to external data */
-        he->key = key;
-        he->klen = klen;
-
-        he->next = NULL;
-        he->hash = hash;
-        he->val    = val;
-
-        *hep = he;
-        ht->count++;
-    }
-
-    return hep;
-}
+	hash_entry_t** hep;
+	hash_entry_t* he;
+	unsigned int hash;
+
+	/* Perform the hashing */
+	hash = ht->hash_func (key);
+
+	/* scan linked list */
+	for (hep = &ht->array[hash & ht->max], he = *hep;
+	     he; hep = &he->next, he = *hep) {
+		if(he->hash == hash && ht->equal_func (he->key, key))
+			break;
+	}
 
-void* hsh_get(hsh_t* ht, const void *key, size_t klen)
-{
-        hsh_entry_t** he = find_entry(ht, key, klen, NULL);
+	if(he || !val)
+		return hep;
+
+	/* add a new entry for non-NULL val */
+	he = int_malloc (sizeof (*he));
+
+	if(he) {
+		he->key = (void*)key;
+		he->next = NULL;
+		he->hash = hash;
+		he->val = val;
 
-        if(he && *he)
-            return (void*)((*he)->val);
-        else
-            return NULL;
+		*hep = he;
+		ht->count++;
+	}
+
+	return hep;
 }
 
-int hsh_set(hsh_t* ht, const void* key, size_t klen, void* val)
+void*
+hash_get (hash_t* ht, const void *key)
 {
-    hsh_entry_t** hep = find_entry(ht, key, klen, val);
-
-    if(hep && *hep)
-    {
-        /* replace entry */
-        (*hep)->val = val;
+	hash_entry_t** he = find_entry (ht, key, NULL);
+	if (he && *he)
+		return (void*)((*he)->val);
+	else
+		return NULL;
+}
 
-        /* check that the collision rate isn't too high */
-        if(ht->count > ht->max)
-        {
-            if(!expand_array(ht))
-                return 0;
-        }
+int
+hash_set (hash_t* ht, void* key, void* val)
+{
+	hash_entry_t** hep = find_entry (ht, key, val);
+	if(hep && *hep) {
+		/* replace entry */
+		(*hep)->val = val;
+
+		/* check that the collision rate isn't too high */
+		if (ht->count > ht->max) {
+			if (!expand_array (ht))
+				return 0;
+		}
 
-        return 1;
-    }
+		return 1;
+	}
 
-    return 0;
+	return 0;
 }
 
-void* hsh_rem(hsh_t* ht, const void* key, size_t klen)
+int
+hash_remove (hash_t* ht, const void* key)
 {
-    hsh_entry_t** hep = find_entry(ht, key, klen, NULL);
-    void* val = NULL;
-
-    if(hep && *hep)
-    {
-        hsh_entry_t* old = *hep;
-        *hep = (*hep)->next;
-        --ht->count;
-        val = (void*)old->val;
-        free(old);
-    }
-
-    return val;
+	hash_entry_t** hep = find_entry (ht, key, NULL);
+
+	if (hep && *hep) {
+		hash_entry_t* old = *hep;
+		*hep = (*hep)->next;
+		--ht->count;
+		if (ht->key_destroy_func)
+			ht->key_destroy_func (old->key);
+		if (ht->value_destroy_func)
+			ht->value_destroy_func (old->val);
+		free (old);
+		return 1;
+	}
+
+	return 0;
 }
 
-void hsh_clear(hsh_t* ht)
+void
+hash_clear (hash_t* ht)
 {
-	hsh_entry_t *he, *next;
+	hash_entry_t *he, *next;
 	int i;
 
 	/* Free all entries in the array */
@@ -384,17 +327,112 @@ void hsh_clear(hsh_t* ht)
 		he = ht->array[i];
 		while (he) {
 			next = he->next;
+			if (ht->key_destroy_func)
+				ht->key_destroy_func (he->key);
+			if (ht->value_destroy_func)
+				ht->value_destroy_func (he->val);
 			free (he);
 			he = next;
 		}
 	}
 
-	memset (ht->array, 0, ht->max * sizeof (hsh_entry_t*));
+	memset (ht->array, 0, ht->max * sizeof (hash_entry_t*));
 	ht->count = 0;
 }
 
-unsigned int hsh_count(hsh_t* ht)
+unsigned int
+hash_count (hash_t* ht)
+{
+	return ht->count;
+}
+
+unsigned int
+hash_string_hash (const void *string)
+{
+	unsigned int hash;
+	const unsigned char *p;
+
+	assert (string);
+
+	/*
+	 * This is the popular `times 33' hash algorithm which is used by
+	 * perl and also appears in Berkeley DB. This is one of the best
+	 * known hash functions for strings because it is both computed
+	 * very fast and distributes very well.
+	 *
+	 * The originator may be Dan Bernstein but the code in Berkeley DB
+	 * cites Chris Torek as the source. The best citation I have found
+	 * is "Chris Torek, Hash function for text in C, Usenet message
+	 * <27038@mimsy.umd.edu> in comp.lang.c , October, 1990." in Rich
+	 * Salz's USENIX 1992 paper about INN which can be found at
+	 * <http://citeseer.nj.nec.com/salz92internetnews.html>.
+	 *
+	 * The magic of number 33, i.e. why it works better than many other
+	 * constants, prime or not, has never been adequately explained by
+	 * anyone. So I try an explanation: if one experimentally tests all
+	 * multipliers between 1 and 256 (as I did while writing a low-level
+	 * data structure library some time ago) one detects that even
+	 * numbers are not useable at all. The remaining 128 odd numbers
+	 * (except for the number 1) work more or less all equally well.
+	 * They all distribute in an acceptable way and this way fill a hash
+	 * table with an average percent of approx. 86%.
+	 *
+	 * If one compares the chi^2 values of the variants (see
+	 * Bob Jenkins ``Hashing Frequently Asked Questions'' at
+	 * http://burtleburtle.net/bob/hash/hashfaq.html for a description
+	 * of chi^2), the number 33 not even has the best value. But the
+	 * number 33 and a few other equally good numbers like 17, 31, 63,
+	 * 127 and 129 have nevertheless a great advantage to the remaining
+	 * numbers in the large set of possible multipliers: their multiply
+	 * operation can be replaced by a faster operation based on just one
+	 * shift plus either a single addition or subtraction operation. And
+	 * because a hash function has to both distribute good _and_ has to
+	 * be very fast to compute, those few numbers should be preferred.
+	 *
+	 *                        -- Ralf S. Engelschall <rse@engelschall.com>
+	 */
+
+	hash = 0;
+
+	for(p = string; *p; p++)
+		hash = hash * 33 + *p;
+
+	return hash;
+}
+
+int
+hash_string_equal (const void *string_one, const void *string_two)
+{
+	assert (string_one);
+	assert (string_two);
+
+	return strcmp (string_one, string_two) == 0;
+}
+
+unsigned int
+hash_ulongptr_hash (const void *to_ulong)
+{
+	assert (to_ulong);
+	return (unsigned int)*((unsigned long*)to_ulong);
+}
+
+int
+hash_ulongptr_equal (const void *ulong_one, const void *ulong_two)
+{
+	assert (ulong_one);
+	assert (ulong_two);
+	return *((unsigned long*)ulong_one) == *((unsigned long*)ulong_two);
+}
+
+unsigned int
+hash_direct_hash (const void *ptr)
+{
+	return (unsigned int)ptr;
+}
+
+int
+hash_direct_equal (const void *ptr_one, const void *ptr_two)
 {
-    return ht->count;
+	return ptr_one == ptr_two;
 }